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Sesquiterpene from Myanmar Medicinal Plant (Curcuma comosa)

By Khun Nay Win Tun, Nanik Siti Aminah, Alfinda Novi Kristanti, Hnin Thanda Aung and Yoshiaki Takaya

Submitted: June 7th 2020Reviewed: August 28th 2020Published: October 13th 2020

DOI: 10.5772/intechopen.93794

Downloaded: 24

Abstract

Curcuma comosa (Zingiberaceae) is widely grown in tropical and subtropical areas of Asia, like Thailand, Indonesia, Malaysia, and Myanmar. In Myanmar, the rhizome of Curcuma comosa is called Sa-nwin-ga, and local people had used it as a traditional medicine for stomach ache, diabetes mellitus, and hypertension. This species produces secondary metabolites of phenolic and nonphenolic groups. Phenolic groups like diarylheptanoids and flavonoids. While nonphenolics are terpenoids, especially sesqui- and monoterpenes. In this chapter, the group of sesquiterpene compounds from Curcuma comosa starts from the isolation technique, followed by the elucidation of the molecular structure, and their activity tests have been discussed.

Keywords

  • Curcuma comosa
  • Myanmar
  • sesquiterpenes
  • Zingiberaceae
  • Sa-nwin-ga

1. Introduction

Terpenes are formally derived from the carbon backbone of isoprene and based on the polymers of the active building blocks head-to-tail and tail-to-tail. Virtually all parts of the plant, especially flowers, leaves, fruits, and roots, contain different quantities of terpenes and terpenoids which are separated by means of methods such as distillation, extraction and other techniques. More than 30,000 terpenes and terpenoids are known to date. Their role in nature is still unknown and undergoes further research. Essential oils play an important role in defense and signaling as a product of plant secondary metabolism. Today, herbs and spices have an important role to play in disease prevention. In vitro trials have shown that terpenes can inhibit or sometimes induce pathways that regulating cell division, cell proliferation and detoxification [1]. Curcuma comosa (Zingiberaceae), widely grown in tropical and subtropical area of Asia, like Thailand, Indonesia, Malaysia, and Taunggyi (Shan State of Myanmar). It is popularly known for its beneficial effect in human health, being traditionally used in folk medicine in Asian countries, including Myanmar, Malaysia, Indonesia, and Thailand. In Taunggyi, the rhizome of Curcuma comosa is called Sa-nwin-ga and local people had used as a traditional medicine for stomach ache, diabetes mellitus and hypertension. In Thailand, the rhizome of Curcuma comosa is called Waamchak mod luuk and had been used for the treatment of reproductive disorders in women, and for relief of unpleasant menopausal symptoms among postmenopausal women. Phytochemical investigations of this plant led to the isolation of several compounds. Two major groups of structures reported constituents include sesquiterpenes and diarylheptanoids [2, 3].

2. Classification of terpenes

Terpenes are typically classified according to the number of biogenetically derived isoprene units (Figure 1). (i) Hemiterpenes: They are made up of C5 unit or 1 residues of isoprene. (ii) Monoterpenes: They are made up of C10 unit or 2 residues of isoprene. (iii) Sesquiterpenes: They are made up of C15 unit or 3 residues of isoprene. (iv) Diterpenes: They are made up of C20unit or 4 residues of isoprene. (v) Sesterterpenes: They are made up of C25 unit or 5 residues of isoprene. (vi) Triterpenes: They are made up of C30 unit or 6 residues of isoprene. (vii) Tetraterpenes: They are made up of C40 unit or 8 residues of isoprene [4, 5].

Figure 1.

Classification of terpenes [4].

2.1 Sesquiterpenes

Sesquiterpenes can be classified into five sub-groups (Figure 2): (i) germacrane-type sesquiterpenes, (ii) guaiane-type sesquiterpenes, (iii) bisaborane-type sesquiterpenes, (iv) carabrane-type sesquiterpenes, and (v) eudesmane-type sesquiterpenes [6].

Figure 2.

Sesquiterpenes (1-48) from Curcuma comosa [6, 18, 19, 20].

3. Sample collection and preparation

Plant material may be obtained from fresh or dried plant parts such as leaves, barks, stem barks, roots, rhizomes, fruits, and flowers. The plant materials were dried at room temperature. These were cut into small pieces. The air-dried samples were kept in a covered glass container to protect them from humidity and light prior to extraction.

3.1 Extraction

Plant materials are an immensely complicated system containing a broad range of natural compounds. The most relevant techniques can effortlessly be used for especially selective and reliable extraction of specific components found in complex matrices. These techniques comprise maceration, percolation, decoction, reflux extraction, soxhlet extraction, pressurized liquid extraction, ultrasonic extraction, (sonication), microwave-assisted extraction (MAE), accelerated solvent extraction (ASE), supercritical fluid extraction (SFE), pulsed electric field extraction, enzyme assisted extraction, hydro distillation, and steam distillation. The point of the method for extraction is to optimize the number of goal compounds and to realize most biological activity [7, 8].

3.2 Examination of the crude extract

Analytical TLC was used to examine the composition of the unrefined extracts. The visualizations were assisted either by the UV detection of the TLC or by anisaldehyde dipping, accompanied by warming at 100°C. The TLC has been changed more than once by altering solvent processes to achieve the best separation [9].

3.3 Fractionation

Fractionation is the method of classification by physical or chemical characteristics of a specific sample of an analyte or group of analytes. Raw extracts can contain thousands of compounds in a complicated mix. It would not be possible to produce a single compound from crude extract with a single separation procedure. It is therefore also important to divide the crude extract into different fractions that contain a similar group of polarities or molecular compounds [10].

3.4 Isolation and purification

Solvent extraction and partition accompanied by column chromatography (CC), vacuum-liquid chromatography (VLC), thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and gas chromatography–mass spectrometry (GCMS) are the prevalent separation techniques for sesquiterpenes. Resembling extraction, the most significant factor to be considered before choosing an isolation protocol is the nature of the goal compound(s) present in the crude extracts or fractions. Chromatography is a technique that allows qualitative and quantitative analysis to separate, identify and purify the mixture of a compound. Chromatography is based on the concept under which the mixed molecules deposited on or in the solid and fluid stationary phases are separated with the aid of a mobile phase. The stationary phase normally employed is silica gel with the mobile the solvent(s) of choice to fractionate or extract bioactive compounds [11, 12, 13].

3.5 Structure elucidation

A mixture of physical (melting point, CD and alpha-D) and spectroscopic (UV, IR, 1D-, 2D- NMR, and HR-MS) techniques have typically used to characterize the structures of the isolated pure sesquiterpenes. UV–Vis spectroscopy is widely used in analytical chemistry for the measurement of various analyze, such as strongly multiple bonds or aromatic conjugation within molecules, bioprocess, and fermentation of food production. Fourier-transform infrared (FTIR) spectroscopy is an effective method to classify the functional groups found in the sesquiterpenes compound. Nuclear magnetic resonance (NMR) may be the capable spectroscopy that gives complete data on atomic structure and is well appropriate for the identification of simple molecules. NMR spectroscopy is primarily partitioned into one dimensional (1D-NMR) and two-dimensional techniques (2D-NMR). The 1H-NMR and 13C-NMR one-dimension techniques provide information about the numbers and types of protons and carbon atoms in the sesquiterpenes compound. There are five 2D-NMR techniques commonly used to determine the sesquiterpenes structure, double quantum filtered correlated spectroscopy (DQF-COSY), nuclear Overhauser enhancement spectroscopy (NOESY), heteronuclear multiple-bond correlation (HMBC), heteronuclear single-quantum correlation spectroscopy (HSQC)/heteronuclear multiple-quantum coherence (HMQC), rotating frame Overhauser enhancement spectroscopy (ROESY), and total correlation spectroscopy (TOCSY) [13, 14, 15, 16].

4. Sesquiterpenes from C. comosa

Xu et al., isolated six new sesquiterpenes (1-6) from the EtOAc soluble portion of the methanol rhizomes extract of C. comosa by using silica gel column chromatography, octa decyl silica (ODS) column chromatography, and high-performance-liquid-chromatography (HPLC) [17]. Qu et al., also isolated 26 known compounds (7-32) from the EtOAc soluble layer of the methanol rhizomes extract of C. comosa by using silica gel column chromatography, octa decyl silica (ODS) column chromatography, and high-performance-liquid-chromatography (HPLC) [18]. Khine isolated 25 sesquiterpenes (7, 15, 24-28, and 30-47) from the hexane extract and n-butanol fraction of C. comosa by using different chromatographic techniques [6]. In our previous work, 3 known sesquiterpenes (25, 36, and 48) were isolated from the MeOH soluble fraction of C. comosa by using vacuum-liquid chromatography and successive repeated column chromatography [19]. The physical and spectroscopic data of the isolated compounds are depicted in Table 1.

CompoundPhysical and spectral data
(+)-Comosol (1) [17]A colorless oil; αD23+34.7° (c = 0.2, CHCl3); IR (cm−1): 3420, 2936, 1655, 1541, 754. 1H NMR (600 MHz, CDCl3) δΗ: 0.80, 1.79 (each 3H, s H3-14, 13), 1.16, 1.99 (1H each, both m, H2-10), 1.59, 1.82 (1H each, both m, H2-3), 1.73 (1H, br d, J = ca. 12 Hz, H-6), [1.88 (1H, dd, J = 13.0, 11.7 Hz), 2.53 (1H, br d, J = ca. 13 Hz), H2-7], [1.94 (1H, dd like, J = 13.7 Hz), 2.67 (1H, br d, J = ca. 14 Hz), H2-9], 2.10, 2.32 (1H each, both m, H2-4), 3.39 (1H, dd, J = 11.6, 4.1 Hz, H-2), 4.16 (2H, s, H2-12), 4.57, 4.82 (1H each, both br s, H2-15). 13C NMR (150 MHz, CDCl3) δC: 40.5 (C-1), 79.1 (C-2), 31.4 (C-3), 34.1 (C-4), 148.8 (C-5), 48.1 (C-6), 28.1 (C-7), 136.5 (C-8), 25.0 (C-9), 38.3 (C-10), 125.4 (C-11), 63.4 (C-12), 16.4 (C-13), 9.8 (C-14), 107.0 (C15). EI-MS m/z: 236 [M+] (6), 218 [M -H2O]+ (100). HR-EI-MS m/z: 236.1771 (Calcd for C15H24O2: 236.1776).
(−)-Comosol (2) [17]A colorless oil; αD22−34.7° (c = 0.2, CHCl3); IR (cm−1): 3420, 2936, 1655, 1541, 754. 1H NMR (600 MHz, CDCl3) δH: 0.80, 1.79 (3H each, both s, H3-14, 13), 1.16, 1.99 (1H each, both m, H2-10), 1.59, 1.82 (1H each, both m, H2-3), 1.73 (1H, br d, J = ca. 12 Hz, H-6), [1.88 (1H, dd, J = 13.0, 11.7 Hz), 2.53 (1H, br d, J = ca. 13 Hz), H2-7], [1.94 (1H, dd like, J = 13.7 Hz), 2.67 (1H, br d, J = ca. 14 Hz), H2-9], 2.10, 2.32 (1H each, both m, H2-4), 3.39 (1H, dd, J = 11.6, 4.1 Hz, H-2), 4.16 (2H, s, H2-12), 4.57, 4.82 (1H each, both br s, H2-15). 13C NMR (150 MHz, CDCl3) δC: 40.5 (C-1), 79.1 (C-2), 31.4 (C-3), 34.1 (C-4), 148.8 (C-5), 48.1 (C-6), 28.1 (C-7), 136.5 (C-8), 25.0 (C-9), 38.3 (C-10), 125.4 (C-11), 63.4 (C-12), 16.4 (C-13), 9.8 (C-14), 107.0 (C-15). EI-MS m/z: 236 [M+] (6), 218 [M - H2O]+ (100). HR-EI-MS m/z: 236.1771 (Calcd for C15H24O2: 236.1776).
Comosone I (3) [17]A colorless oil; αD25+15.4° (c = 0.80, MeOH). UV λmax (MeOH) nm (log ε): 221 (3.78). IR (cm−1): 3420, 2936, 1655, 1541, 754. 1H NMR (600 MHz, CDCl3) δH: 1.22, 1.74 (1H each, both m, H2-2), 1.34, 1.65, 1.92, 1.92 (3H each, all s, H3-14, 15, 12, 13), 1.92 (2H, m, H2-3), 1.96 (1H, m, H-1), 2.35 (1H, dd, J = 18.3, 1.6 Hz, H-9b), 2.50 (1H, d, J = 18.3 Hz, H-9a), 3.74, 5.33 (1H each, both br s, H-6, 5). 13C NMR (150 MHz, CDCl3) δC: 43.9 (C-1), 23.5 (C-2), 29.6 (C-3), 134.8 (C-4), 121.6 (C-5), 36.0 (C-6), 134.3 (C-7), 203.4 (C-8), 51.5 (C-9), 72.9 (C-10), 141.6 (C-11), 22.4 (C-12) 22.5 (C-13), 27.6 (C-14), 23.7 (C-15). EI-MS m/z: 234 (M+) (28), 216 (M - H2O)+ (30), 43 (M - 191) (100). HR-EI-MS m/z: 234.1616 (Calcd for C15H22O2: 234.1620).
Comosone II (4) [17]A colorless oil; αD27+10.1° (c = 0.70, MeOH). UV λmax (MeOH) nm (log ε): 237 (3.77). IR (cm−1): 1665, 1651, 1515, 1439, 1379, 754. 1H NMR (600 MHz, CDCl3) δH: 1.58, 1.87, 1.93, 2.06 (3H each, all s, H3-15, 13, 14, 12), 1.82 (2H, m, H2-3), 1.83, 2.20 (1H each, both m, H2-2), 2.75 (1H, m, H-1), 3.76 (1H, br s, H-6), 4.92 (1H, br s, H-5), 5.90 (1H, s, H-9). 13C NMR (150 MHz, CDCl3) δC: 38.3 (C-1), 25.3 (C-2), 26.0 (C-3), 135.1 (C-4), 122.0 (C-5), 39.8 (C-6), 1333.5 (C-7), 191.8 (C-8), 130.8 (C-9), 158.6 (C-10), 141.8 (C-11), 23.0 (C-12), 21.9 (C-13), 20.8 (C-14), 23.5 (C-15). EI-MS m/z: 216 (M+) (100). HR-EI-MS m/z: 216.1509 (Calcd for C15H20O: 216.1514).
Comosone III (5) [17]A colorless oil; αD24+23.9° (c = 0.5, MeOH). IR (cm−1): 1713, 1092. 1H NMR (600 MHz, CDCl3) δH: 0.79 (1H, ddd, J = 8.1, 5.4, 5.4 Hz, H-1), 1.13 (1H, t like, J = ca. 5 Hz, H-5), 1.18, 1.21, 1.39, 2.17 (3H each, all s, H3-12, 14, 13, 15), 1.64, 1.76 (1H each, both m, H2-2), 2.56 (2H, t, J = 7.6 Hz, H2-3), 2.68, 2.77 (1H each, both d, J = 19.9 Hz, H2-9), 3.43 (3H, s, OCH3-6), 3.88 (1H, d, J = 4.1 Hz, H-6). 13C NMR (150 MHz, CDCl3) δC: 25.9 (C-1), 23.09 (C-2), 43.3 (C-3), 208.0 (C-4), 30.4 (C-5), 79.3 (C-6), 69.9 (C-7), 204.9 (C-8), 47.2 (C-9), 18.8 (C-10), 62.6 (C-11), 19.4 (C-12), 20.8 (C-13), 19.3 (C-14), 30.0 (C-15), 57.7 (C-16). EI-MS m/z: 280 [M+] (2), 265[M - Me]+ (3), 139 [M - 141]+ (100). HR-EI-MS m/z: 280.1676 (Calcd for C16H24O4: 280.1674).
Dimethoxycurcumenone (6) [17]A colorless oil; αD25−10.1° (c = 1.4, MeOH). UV λmax (MeOH) nm (log ε): 255 (3.59). IR (cm−1): 1682, 1601, 1458, 1375, 1055, 853. 1H NMR (600 MHz, CDCl3) δH: 0.47, 0.66 (1H each, both m, H-1, 5), 1.13, 1.23, 1.79, 2.10 (3H each, all s, H3-14, 15, 13, 12), 1.34, 1.65 (2H each, both m, H2-2, 3), 2.51, 2.56 (1H each, both d, J = 15.6 Hz, H2-9), 2.83 (2H, br s, H2-6), 3.15, 3.15 (3H each, both s, OCH3-4). 13C NMR (150 MHz, CDCl3) δC: 24.7 (C-1), 23.9 (C-2), 36.7(C-3), 101.3 (C-4), 24.1 (C-5), 28.0 (C-6), 128.2 (C-7), 201.7 (C-8), 49.0 (C-9), 20.0 (C-10), 147.0 (C-11), 23.4 (C-12), 23.4 (C-13), 19.1 (C-14), 20.9 (C-15), 48.0 (C-16), 48.0 (C-17). EI-MS m/z: 280 [M+] (3), 85 [M – 195]+ (100). HR-EI-MS m/z: 280.2046 (Calcd for C17H28O3: 280.2038).
Zederone (7) [20, 21]Colorless plates; melting point: 153 ∼ 154°C; αD20+220° (c = 0.10, CHCl3). UV λmax (MeOH) nm (log ε): 232 (5010), 285 (2450). IR (cm−1) 1662. 1H NMR (400 MHz, CDCl3) δH: 1.56 (3H, br.s, H3-15), 1.30 (3H, s, H3-14), 2.07 (3H, s, H3-13), 7.04 (1H, br.s, H-12), 3.66, 3.70 (2H, m, H2-9), 3.77 (1H, s, H-5), 1.24, 2.27 (2H, m, H2-3), 2.24, 2.46 (2H, m, H2-2), 5.46 (1H, d, J = 11.8 Hz, H-1). 13C NMR (100 MHz, CDCl3) δC: 131.2 (C-1), 24.7 (C-2), 38.0 (C-3), 64.0 (C-4), 66.6 (C-5), 192.2 (C-6), 123.2 (C-7), 157.2 (C-8), 41.9 (C-9), 131.1 (C-10), 122.2 (C-11), 138.1 (C-12), 10.3 (C-13), 15.2 (C-14), 15.8 (C-15). MS m/z: 246 (M+, 18%), 188 (15), 175 (100), 161, 119 (50), 43 (27). HR-TOF-MS m/z: 247.0889 (C15H18O3).
Zederone epoxide (8) [22]White amorphous powder;αD25+38.3° (c = 0.3, MeOH). 1H NMR (500 MHz, CDCl3) δH: 7.08 (1H, br. s, H-12), 3.78 (1H, s, H-5), 3.68 (1H, d, J = 17.0 Hz, H-9a), 2.93 (1H, br. d, J = 10.0 Hz, H-1), 2.82 (d, J = 17.0 Hz, H-9b); 2.41 (1H, br. d, J = 11.0 Hz, H-3a), 2.21 (1H, br d, J = 14.0 Hz, H-2a), 2.16 (3H, s, H3-13), 1.52 (1H, m, H-2b), 1.47 (1H, m, H-3b), 1.32 (3H, s, H3-14), 1.15 (3H, s, H3-15). 13C NMR (125 MHz, CDCl3): 189.8 (C-6), 156.1 (C-8), 138.4 (C-12), 123.4 (C-11), 122.6 (C-7), 69.0 (C-1), 63.6 (C-4), 63.2 (C-5), 57.9 (C-10), 39.5 (C-9), 36.1 (C-3), 23.8 (C-2), 16.8 (C-14), 15.3 (C-15), 10.5 (C-13). EI-MS: 262 (18.2, Mþ), 43 (100,C3H7+).
Furanodienone (9) [23, 24]Colorless prisms; melting point 87 ∼ 88°C. UV λmax (EtOH) nm (ε): 241 (9150), 269 (6800). IR (cm−1) 1664, 1608, 1231, 1013, 755. 1H NMR (400 MHz, CDCl3) δH: 5.15 (1H, dd, J = 11.4, 4.1 Hz, H-1), 2.16 (1H, td, J = 12.4, 3.5 Hz, H-2α), 2.30 (1H, td, J = 12.4, 4.1 Hz, H-2β), 1.85 (1H, td, J = 11.4, 4.1 Hz, H-3α), 2.44 (1H, ddd, J = 11.4, 6.9, 3.4 Hz, H-3β), 5.78 (1H, br s, H-5), 3.66 (1H, br d, J = 14.5 Hz, H-9α), 3.70 (1H, br d, J = 14.5 Hz, H-9β), 7.05 (1H, br s, H-12), 2.11 (3H, s, H3-13), 1.97 (3H, s, H3-14), 1.28 (3H, s, H3-15). 13C NMR (100 MHz, CDCl3) δC: 130.5 (C-1), 26.4 (C-2), 40.6 (C-3), 145.8 (C-4), 132.4 (C-5), 190.0 (C-6), 123.9 (C-7), 156.5 (C-8), 41.7 (C-9), 135.4 (C-10), 122.0 (C-11), 138.0 (C-12), 9.5 (C-13), 18.9 (C-14), 15.7 (C-15). MS m/z: 230 (M+, 47%), 150 (50), 122 (100), 94 (26), 81 (48).
Isofuranodienone (10) [24, 25]Needles; melting point: 70-71°C; .αD±0°145º (c = 10.0). UV λmax (EtOH) nm (ε): 223 (4.17), 248 (3.95). IR (KBr) cm−1: 1667. 1H NMR (CDCl3, 400 MHz), δH: 5.25 (1H, br t, J = 8.6 Hz, H-1), 1.78 (1H, m, H-2α), 2.09 (1H, m, H-2β), 2.20 (1H, m, H-3α), 2.25 (1H, m, H-3β), 5.84 (1H, br s, H-5), 3.03 (1H, d, J = 14.5 Hz, H-9α), 3.57 (1H, d, J = 14.5 Hz, H-9β), 7.05 (3H, br s, H-12), 2.16 (3H, br s, H3-13), 1.73 (3H, s, H3-14), 1.63 (3H, s, H3-15). 13C NMR (CDCl3, 100 MHz), δC: 123.9 (C-1), 26.1 (C-2), 36.3 (C-3), 141.1 (C-4), 129.0 (C-5), 193.8 (C-6), 123.9 (C-7), 161.5 (C-8), 32.8 (C-9), 134.0 (C-10), 122.1 (C-11), 138.4 (C-12), 9.5 (C-13), 22.6 (C-14), 19.1 (C-15). MS m/z: 230 [M+], 122 (100%).
1(10)Z,4Z-furanodiene-6-one (11)No data
Glechomanolide (12)No data
Dehydrocurdione (13) [26, 27]Colorless needles; melting point 40-42°C.αD23+145° (c = 1.1, MeOH): θ303+13,671. UV λmax (EtOH) nm (ε): 207 (1.16). IR (CHCl3) cm−1: 1742, 2934, 1680, 1453, 1375. 1H NMR (400 MHz, CDCl3) δH: 5.13 (1H, t, J = 8.24 Hz, H-1), 2.10 (2H, m, H2-2), 2.0 (2H, m, H2-3), 2.38 (1H, m, H-4), 3.21/3.29 (each 1H, dd, J = 16.48 Hz, H2-6), 3.06/3.23 (each 1H, dd, J = 11.44 Hz, H2-9), 1.76 (3H, s, H3-12), 1.73 (3H, s, H3-13), 1.01 (3H, d, J = 6.88 Hz, H3-14), 1.3 (3H, s, H3-15). 13C NMR (100 MHz, CDCl3) δC: 133.0 (C-1), 26.4(C-2), 34.2(C-3), 46.4(C-4), 211.1(C-5), 43.4(C-6), 129.3(C-7), 207.2(C-8), 57.0(C-9), 129.9(C-10), 137.0(C-11), 21.0(C-12), 22.1(C-13), 18.4(C-14), 16.3(C-15). MS m/z: 234 (M+) (C15H22O2).
Neocurdione (14) [27]Colorless needles; melting point 45-47°C (hexane). .αD23−190° (c = 2.1, CHCl3): CD (c = 0.022, MeOH): θ301−29,230. UV λmax (EtOH) nm (ε): 203 (3.73). IR (KBr) cm−1: 1696, 1682, 1395, 1282. 1H NMR (CDCl3): 0.92 (3H, d, J = 6.6 Hz, H3-14), 0.98 (3H, d, J = 6.8 Hz, H3-12 or −13), 1.03 (3H, d, J = 6.8 Hz, H3-13 or −12), 1.67 (3H, s, H3-15), 5.18 (1H, br t, J = 7.0 Hz, H-1). 13C NMR (CDCl3) δC: 131.1 (C-1), 25.5 (C-2), 32.8 (C-3), 45.8 (C-4), 210.2 (C-5), 42.4 (C-6), 52.6 (C-7), 212.5 (C-8), 55.3 (C-9), 129.1 (C-10), 30.9 (C-11), 20.2 (C-12), 21.1 (C-13), 18.2 (C-14), 18.2 (C-15). MS m/z: 236.1763 [M +] (Calcd for C15H24O2 236.1777).
Curdione (15) [23, 27, 28]Colorless prisms; melting point 53-54°C (MeOH).αD23+214° (c = 1.6, MeOH). CD (c = 0.0033, CHCl3) θ309+26,655. IR (KBr) cm−1: 1690, 1460, 1420, 1170, 1060. 1H NMR (CDCl3, 400 MHz), δ: 5.14 (1H, br s, H-1), 2.08-2.13 (2H, m, H2-2), 1.56 (1H, m, H-3α), 2.08-2.13 (1H, m, H-3β), 2.30 (1H, br s, H-4), 2.37 (1H, dd, J = 16.4, 1.5 Hz, H-6α), 2.65 (1H, m, H-6β), 2.88 (1H, ddd, J = 16.4, 8.5, 7.8 Hz, H-7), 2.91 (1H, d, J = 10.7 Hz, H-9α), 3.04 (1H, d, J = 10.7 Hz, H-9β), 1.85 (1H, m, H-11), 0.85 (3H, d, J = 6.5 Hz, H3-12), 0.92 (3H, d, J = 6.5 Hz, H3-13), 0.95 (3H, d, J = 6.9 Hz, H3-14), 1.62 (3H, s, H3-15).13C NMR (CDCl3, 100 MHz) δC: 131.5 (C-1), 26.3 (C-2), 34.0 (C-3), 46.7 (C-4), 214.6 (C-5), 44.2 (C-6), 53.5 (C-7), 211.1 (C-8), 55.8 (C-9), 129.2 (C-10), 29.9 (C-11), 21.1 (C-12), 19.8 (C-13), 18.5 (C-14), 16.5 (C-15). EI-MS m/z (rel. Int.): 236 (2), 208 (1), 180 (33), 167 (28), 109 (52), 95 (23), 83 (13), 69 (100), 55 (76). MS m/z 236[M+] C15H24O2.
7α-hydroxyneocurdione (16)No data
7β-hydroxycurdione (17)No data
Germacrone-1(10),4-diepoxide (18) [6]White powder; melting point 84-86°C.αD= +71.17° (c = 0.14, MeOH). UV (MeOH) λmax nm (log ε): 256 (4.22), 315 (2.30). IR (KBr) cm−1. 1678, 1645. 1H NMR (400 MHz, CDCl3) δH: 1.143 (3H, s, H3-14), 1.26-1.32 (1H, m, H-3b), 1.444 (3H, s, H3-15), 1.45-1.50 (1H, m, H-2b), 1.794 (3H, s, H3-12), 1.862 (3H, s,H3-13), 2.02-2.08 (1H, m, H-2a), 2.19-2.24 (1H, m, H-3a), 2.260 (1H, dd, J = 14.2/10.8 Hz, H-6b), 2.644 (1H, d, J = 10.8 Hz, H-9b), 2.652 (1H, dd, J = 10.9/2.2 Hz H-5), 2.855 (1H, dd, J = 14.2/2.2 Hz, H-6a), 2.918 (1H, d, J = 10.8 Hz, H-1), 3.007 (1H, J = 10.8 Hz, H-9a). EI-MS m/z: 124.9 (100), 122 (80). 13C NMR (500 MHz, CDCl3) δC: 61.3 (C-1), 22.8 (C-2), 35.7 (C-3), 60.1 (C-4), 64.0 (C-5), 29.2 (C-6), 134.3 (C-7), 207.2 (C-8), 54.5 (C-9), 58.4 (C-10), 137.8 (C-11), 22.9 (C-12), 20.8 (C-13), 15.5 (C-14), 17.3 (C-15). HR-ESI-MS: C15H22O3Na[M + Na]+ calcd. 273.14611 found 273.14575.
Germacrone (19) [20, 27]Colorless prisms; melting point: 53-54°C (MeOH). IR (cm−1): 1679, 1665, 1445, 1294, 1135. 1H NMR (400 MHz, CDCl3) δH: 1.62 (3H, s, H3-15), 1.43 (3H, s, H3-14), 1.76 (3H, s, H3-13), 1.73 (1H, s, H-12), 3.42, 2.95 (2H, dd, J = 11, 3.68 Hz, H2-9), 2.86 (2H, m, H2-6), 4.71 (1H, d, J = 11 Hz, H-5), 2.15 (2H, m, H2-3), 2.08, 2.35 (2H, m, H2-2), 4.94 (1H, d, J = 11.8 Hz, H-1). 13C NMR (100 MHz, CDCl3) δC: 132.8 (C-1), 24.0 (C-2), 38.1 (C-3), 126.0 (C-4), 125.4 (C-5), 29.3 (C-6), 129.0 (C-7), 208.0 (C-8), 56.0 (C-9), 135.1 (C-10), 137.0 (C-11), 20.0 (C-12), 22.4 (C-13), 15.6 (C-14), 16.8 (C-15). MS m/z: 218 (M +) (C15H22O).
13-hydroxygermacrone (20) [29]Colorless oil (CHCl3); IR (KBr) cm−1: 3452, 1679. 1H NMR (400 MHz, CDCl3) δH: 4.95 (1H, br. d, J = 10.8 Hz, H-1), 4.63 (1H, dd, J = 10.0, 3.2 Hz, H-5), 4.25 (1H, d, J = 12.4 Hz, H-13a), 4.13 (1H, d, J = 12.4 Hz, H-13b), 3.40 (1H, d, J = 10.4 Hz, H-9a), 2.95 (1H, d, J = 10.4 Hz, H-9b), 2.92 (2H, overapped, H2-6), 2.33 (1H, m, H-2a), 2.14 (1H, m, H-3a), 2.04 (1H, m, H-3b), 1.89 (1H, m, H-2b), 1.78 (3H, s, H3-12), 1.59 (3H, s, H3-15), 1.40 (3H, s, H3- 14). 13C NMR (100 MHz, CDCl3) δC: 133.08 (C-1), 24.03 (C-2), 38.02 (C-3), 135.70 (C-4), 124.94 (C-5), 28.55 (C-6), 131.43 (C-7), 207.32 (C-8), 55.48 (C-9), 126.20 (C-10), 139.80 (C-11), 17.73 (C-12), 62.65 (C13), 15.56 (C-14), 16.60 (C-15). EI-MS m/z: 234.
Curzerenone (21) [30, 31]Yellowish oil. 1H-NMR (400 MHz, CDCl3) δ: 7.07 (1H, brs, H-11), 5.81 (1H, brs, H-5), 5.18 (1H, t, J = 7.5 Hz, H-1), 3.72 (2H, AB-system, J = 15 Hz, H-9a, 9b), 2.20 (3H, d, J = 1.5 Hz, H3-13), 1.76 (3H, d, J = 1.5 Hz, H3-14), 1.31 (3H, s, H3-15), 1.60–2.48 (4H, m, H2-2 and H2-3). 13C-NMR (100 MHz, CDCl3) δ: 130.5 (C-1), 26.4 (C-2), 41.6 (C-3), 145.7 (C-4), 132.4 (C-5), 189.7 (C-6), 122.2 (C-7), 156.5 (C-8), 40.6 (C-9), 135.4 (C-10), 138.1 (C-11), 123.7 (C-12), 9.5 (C-13), 18.9 (C-14), 15.7 (C-15). ESI-MS m/z: 231 [M + H]+ (C15H18O2, M = 230).
Curcolonol (22) [32]Colorless prisms (acetone); melting point 183-184°C;αD25= 0° (c = 2.0, EtOH). IR (cm−1): 3420, 2934, 2872, 1723, 1653, 1562, 1426, 1381, 1275, 1126, 1067, 1040, 922, 742. 1H NMR (500 MHz, Acetone-d6) δH: 3.69 (1H, m, H-1), 1.73 (1H, m, H-2 eq), 1.63 (1H, m, H-2ax), 1.58 (2H, m, H2-3), 2.61 (1H, s, H-5), 3.03 (d, J = 17 Hz, H-9 eq), 2.84 (d, J = 17 Hz, H-9ax), 7.29 (1H, br s, H-11), 2.14 (3H, d, J = 1.3 Hz, H3-13), 1.40 (3H, s, H3-14), 0.97 (3H, s, H3-15). 13C NMR (50 MHz, Acetone-d6) δC: 77.9 (C-1), 28.8 (C-2), 39.3 (C-3), 71.5 (C-4), 62.8 (C-5), 198.4 (C-6), 119.8 (C-7), 167.6 (C-8), 40.3 (C-9), 45.4 (C-10), 140.6 (C-11), 119.6 (C-12), 9.1 (C-13), 25.0 (C-14), 15.0 (C-15). EIMS m/z (rel int) 264 [m] + (13, 249 (29), 246 (15), 231 (5), 228 (5), 213 (12), 163 (100), 135 (35), 122 (37), 107 (31), 94 (14); HR-EI-MS m/z: 264.1354 (calcd for C15H20O4, 264.1362).
Alismol (23) [33, 34]Colorless oil; (+)-alismol:αD25= +38.8° (c = 0.80, CHCl3,), (−)-alismol:αD25= −38.6° (c = 0.80, CHCl3). 1H NMR (600 MHz, CDCl3) δH: 0.99 (3H, d, J = 6.9 Hz), 1.00 (3H, d, J = 6.9 Hz), 1.25 (3H, s), 1.72 -1.80 (2H, m), 1.92 (1H, m), 1.99-2.08 (1H, m), 2.02-2.09 (1H, m), 2.19-2.25 (1H, m), 2.25-2.28 (1H, m), 2.03 (2H, m), 2.51 (1H, m), 4.71 (1H, s), 4.77 (1H, s), 5.55 (1H, s). 13C NMR (400 MHz, CDC13) δC: 47.3 (C-1), 24.7 (C-2), 40.2 (C-3), 80.7 (C-4), 55.0 (C-5), 121.3 (C-6), 149.8 (C-7), 30.0 (C-8), 37.1 (C-9), 153.9 (C-10), 37.4 (C-11), 21.5, 21.3 (C-12 and C-13), 24.1 (C-14), 106.5 (C-15). MS: m/z %: 220 [M+](6), 205 (12), 202 (10), 187 (16), 177 (18), 162 (53), 159 (52), 149 (18), 147 (37), 145 (16), 134 (25), 131 (23), 119 (100), 117 (30), 107 (39), 105 (47), 93 (48), 91 (76), 85 (9), 81 (15), 79 (36), 77 (28), 71 (15), 69 (14), 67 (16), 55 (25),53 (16), 43 (87), 41 (38).
Alismoxide(24) [33, 35]Colorless crystals, mp 138–141°C;αD20= +9.3 (c 0.9 CHCl3,). 1H NMR (400 MHz, CDCl3) δH: 5.44 (1H, br d, J = 3.0 Hz, H-6), 0.98, 1.0 (3H each, d, J = 6.9 Hz, H3-12, −13), 1.25, 128 (3H each, s, H3-14, −15). 13C NMR (100 MHz, CDCl3): δC: 50.5 (C-1), 21.4 (C-2), 40.3 (C-3), 80.0 (C-4), 50.1 (C-5), 121.3 (C-6), 149.4(C-7), 25.0 (C-8), 42.5 (C-9), 75.2 (C-10), 37.2 (C-11), 21.1 (C-12), 21.2 (C-13), 22.4 (C-14), 21.3 (C-15). MS: m/z (%): 220 (M+ -H2O)(7), 205 (9), 202 (4), 187 (9), 177 (12), 162 (66), 159 (28), 149 (20), 147 (38), 134 (34), 121 (23), 119 (53), 107 (34), 105 (24), 93 (42), 91 (30), 85 (12), 81 (14), 79 (28), 77 (16), 71 (12), 69 (12), 55 (20), 43 (100), 41 (24).
Zedoarondiol (25) [27]Colorless needles; melting point 134°C (CHCl3);αD23= −44° (c = 1.0, MeOH). CD (c = 0.03, MeOH): θ321− 6468. UV (MeOH) λmax nm (log ε): 258 (3.86). IR (cm−1): 3420, 1662, 1604. 1H NMR (CDCl3) δH: 1.18 (3H, s, H3-14 or −15), 1.20 (3H, s, H3-15 or −14), 1.84 (3H, s, H3-12, or −13), 1.94 (3H, s, H3-13 or −12), 2.60 (1H, d, J = 13.0 Hz, H-9β), 2.98 (1H, d, J = 13.0 Hz, H-9α). 13C NMR (CDCl3) δC: 55.9 (C-1), 22.9 (C-2), 28.5 (C-3), 79.9 (C-4), 52.0 (C-5), 39.7 (C-6), 134.6 (C-7), 202.9 (C-8), 59.8 (C-9), 72.7 (C-10), 142.1 (C-11), 21.9 (C-12), 22.2 (C-13), 22.7 (C-14), 20.6 (C-15). MS m/z: 252 (M+) (C15H24O3).
isozedoarondiol (26) [27]Colorless needles; melting point 150-156°C.αD23= −147.2° (c = 0.8, MeOH). CD (c = 0.003, MeOH): θ313−6323. UV (MeOH) λmax nm (log ε): 258 (3.86). IR (cm−1): 3420, 1662, 1604. 1H NMR (CDCl3) δH: 1.23 (3H, s, H3-14), 1.42 (3H, s, H3-15), 1.86 (3H, s, H3-12 or −13), 2.03 (3H, s, H3-13 or −12), 2.42 (H, d, J = 16.0 Hz, H-9β), 3.21(H, d, J = 16.0 Hz, H-9α). 53.4 (C-1), 25.2 (C-2), 27.4 (C-3), 82.4 (C-4), 51.7 (C-5), 37.0 (C-6), 134.0 (C-7), 203.0 (C-8), 50.2 (C-9), 73.2 (C-10), 143.7 (C-11), 22.1 (C-12), 22.8 (C-13), 25.0 (C-14), 32.2 (C-15). MS: Anal. Calcd for C15H24O3: C, 71.39; H, 9.59. Found: C, 71.65: H, 9.52.
Procurcumenol (27) [26, 36]Viscous oil;αD24= +218.5° (c = 0.15, MeOH). UV (MeOH) λmax nm (log ε):248 (3.90), 275 (3.75). IR (cm−1): 3430, 1646. 1H NMR (500 MHz, CDCl3) δH: 1.24 (3H, s, H3-14), 1.75 (3H, s, H3-13), 1.78 (3H, s, H3-12), 1.88 (3H, s, H3-15), 2.18 (1H, dd, J = 16.0, 13.0 Hz, H-6α), 2.38 (1H, ddd, J = 10.5, 10.0 Hz, H-1), 2.61 (1H, br d, J = 16.0 Hz, H-6β), 5.88 (1H, br s, H-9). 13C NMR (100 MHz, CDCl3) δC: 50.5 (C-1), 26.9(C-2), 39.9 (C-3), 80.3 (C-4), 53.9 (C-5), 28.6 (C-6), 136.9 (C-7), 199.2(C-8), 129.2 (C-9), 155.1(C-10), 136.3 (C-11), 21.3 (C-12), 22.4(C-13), 23.4 (C-14), 24.3 (C-15). ESI-MS m/z: 235 [M + H]+. C15H20O2. GC MS: RT 29.36 min, 234(M+, 6.08), 158(35), 121(84), 105(100), 93(60), 43(79).
Isoprocurcumenol (28) [26]Colorless oil; UV (MeOH) λmax nm (log ε): 205 (1.83). IR (CHCl3) cm−1: 3450, 1674, 1610. 1H NMR (400 MHz, CDCl3) δH: 3.22 (1H, q, J = 14.68 Hz, H-1), 1.21 (2H, m, H2-2), 1.39 (2H, m, H2-3), 1.40 (1H, m, H-5), 2.81 (2H, d, J = 14.2 Hz, H2-6), 2.16 (2H, s, H2-9), 1.92 (3H, s, H3-12), 1.82 (3H, s, H3-13), 1.24 (3H, s, H3-14), 4.90 (2H, br S, H2-15). 13C NMR (100 MHz, CDCl3) δC: 51.2 (C-1), 24.7(C-2), 28.2 (C-3), 77.4 (C-4), 58.9 (C-5), 39.8 (C-6), 134.5 (C-7), 203.0 (C-8), 53.8 (C-9), 141.3 (C-10), 143.9 (C-11), 21.9 (C-12), 22.8 (C-13), 24.4 (C-14), 111.6 (C-15). C15H20O2. GC mS: RT 29.36 min, 234 (M+, 6.08), 158(35), 121(84), 105(100), 93(60), 43(79).
Aerugidiol (29)No data
Zedoalactone B (30) [37]Oil; αD+177.7° (c = 0.4, MeOH). UV (MeOH) λmax nm (log ε): 273 (4.33). IR (KBr) cm−1: 3400, 2970, 2940, 2880, 1740, 1660, 1630. 1H NMR (500 MHz, pyridine-d5) δH: 2.06 (1H, ddd, J = 8.0, 11.5, 13.1 Hz, H-2α), 3.10 (1H, ddd, J = 2.0, 9.0, 13.1 Hz, H-2β), 2.15 (1H, ddd, J = 2.0, 8.0, 11.5 Hz, H-3α), 2.41 (1H, ddd, J = 9.0, 11.5, 11.5 Hz, H-3β), 3.35 (1H, dd, J = 3.0, 12.8 Hz, H-5), 3.21 (1H, ddd, J = 1.5, 12.8, 17.4 Hz, H-6α), 3.08 (1H, ddd, J = 1.5, 3.0, 17.4 Hz, H-6β), 6.09 (1H, s, H-9), 1.71 (3H, d, J = 1.5, H3-13), 1.75 (3H, br s, H3-14), 1.90 (3H, s, H3-15), 7.12 (s, 1-OH), 6.22 (s, 4-OH), 6.02 (s, 10-OH). 13C NMR (125 MHz, pyridine-d5) δH: 75.1 (C-1), 35.7(C-2), 41.5(C-3), 79.5(C-4), 50.3 (C-5), 22.0 (C-6), 151.2 (C-7), 148.5 (C-8), 118.8 (C-9), 82.7 (C-10), 125.8 (C-11), 170.2 (C-12), 8.4 (C-13), 23.7(C-14), 26.1 (C-15). EIMS m/z: [M]+ absent, 262 [M – H2O]+ (13), 244 [M – 2H2O]+ (33), 226 [M – 3H2O]+ (100), 211 [ M – 3H2O – CH3]+ (66). HR-MS, found: [M-H2O]+, 262.1195. C15H18O4 requires [M – H2O]+, 262.1205.
Curcumenone (31) [26]Colorless oil. IR (CHCl3) cm−1: 1679, 1715. UV (MeOH) λmax nm (log ε): 205(1.28). 1H NMR (400 MHz, CDCl3) δH: 0.43 (1H, dt, J = 4.56, 7.32 Hz, H-1), 1.64 (2H, q, J = 7.32 Hz, H2-2), 2.47 (2H, t, J = 7.36 Hz, H2-3), 0.67 (1H, q, J = 4.56 Hz, H-5), 2.8 (2H, m, H2-6), 2.52 (2H, d, J = 15.6 Hz, H2-9), 2.07 (3H, s, H3-12), 1.77 (3H, s, H3-13), 2.12 (3H, s, H3-14), 1.10 (3H, s, H3-15). 13C NMR (100 MHz, CDCl3) δC: 24.1 (C-1), 23.4(C-2), 44.0(C-3), 209.0(C-4), 24.2(C-5), 28.0(C-6), 128.1(C-7), 201.9(C-8), 49.0(C-9), 20.2(C-10), 147.6(C-11), 23.5(C-12), 23.5(C-13), 30.1(C-14), 19.1(C-15). C15H22O2. GC MS: RT 28.9, 234(M+, 13.5), 176(78), 163(29), 161(48), 149 (43), 133(37), 107(32), 91(29), 68(91), 67(75), 43(100).
Curcumadione (32) [38]Colorless oil; αD+63.3° (c = 0.15, MeOH). UV λmax (EtOH) nm (ε): 207 (1.16). 1H NMR (400 MHz, CDCl3) δH: 1.07 (3H, d, J = 6.8 Hz, H3-15), 1.80, 1.99 (3H each, s, H3-12, −13), 2.14 (3H, s, H3-14), 5.52 (1H, t, J = 6.6 Hz, H-5). 13C NMR (100 MHz, CDCl3) δC: 140.0 (C-1), 27.8(C-2), 42.6(C-3), 208.1(C-4), 121.1(C-5), 30.2(C-6), 134.7(C-7), 205.1(C-8), 48.6(C-9), 35.0(C-10), 143.7(C-11), 19.1(C-12), 22.6(C-13), 22.2(C-14), 19.1(C-15). MS m/z: 234.1625 (M+) (calcd for C15H22O2: 234.1620).
(1S, 10S), (4S, 5S)-Germacrone-1(10), 4(5)-diepoxide (33) [6]1H NMR (500 MHz, CDCl3) δH: 2.92 (1H, d, J = 10.8 Hz, H-1), 2.06, 1.46 (m, H2-2), 2.21, 1.28 (2H, m, H2-3), 2.65 (1H, dd, J = 10.9, 2.2 Hz, H-5), 2.86 (dd, J = 14.2, 2.2 Hz, H-6a), 2.26 (dd, J = 14.2, 10.8 Hz, H-6b), 3.01 (d, J = 10.8 Hz, H-9a), 2.64 (d, J = 10.8 Hz, H-9b), 1.79 (s, H3-12), 1.86 (s, H3-13), 1.14 (s, H3-14), 1.44 (s, H3-15). 13C NMR (500 MHz, CDCl3) δC: 61.3 (C-1), 22.8 (C-2), 35.7 (C-3), 60.1 (C-4), 64.0 (C-5), 29.2 (C-6), 134.3 (C-7), 207.2 (C-8), 54.5 (C-9), 58.4 (C-10), 137.8 (C-11), 22.9 (C-12), 20.8 (C-13), 15.5 (C-14), 17.3 (C-15).
3,6,10-trimethyl-7,8,11,11-atetrahydrocyclodeca[b]furan-2,5(4H,6H)-dione (34) [6]αD+35.2° (c = 0.15, MeOH). 1H NMR (500 MHz, CDCl3) δH: 4.92 (1H, br s, H-1), 2.06, 2.20 (2H, m, H2-2), 1.72, 2.04 (2H, m, H2-3), 2.44 (1H, m, H-4), 3.36 (2H, m, H2-6), 4.92 (1H, br s, H-8), 2.04, 2.94 (m, H2-9), 1.85 (3H, s, H3-13), 1.09 (3H, d, J = 6.7 Hz, H3-14), 1.82 (3H, s, H3-15). 13C NMR (500 MHz, CDCl3) δC: 133.4 (C-1), 27.3 (C-2), 35.9 (C-3), 48.0 (C-4), 208.2 (C-5), 41.6 (C-6), 155.2 (C-7), 79.7 (C-8), 46.1 (C-9), 128.9 (C-10), 128.9 (C-11), 173.5 (C-12), 9.2 (C-13), 18.6 (C-14), 16.0 (C-15).
11a-hydroxy-3,6,10-trimethyl-7,8,11,11a-tetrahydrocyclodeca[b]furan-2,5(4H,6H)-dione-methane (35) [6]1H NMR (500 MHz, CDCl3) δH: 4.88 (1H, d, J = 10.7 Hz, H-1), 2.00, 2.20 (2H, m, H2-2), 1.65, 2.10 (2H, m, H2-3), 2.45 1H, (m, H-4), 3.58 (d, J = 15.4 Hz, H-6a), 3.30 (d, J = 15.7 Hz, H-6b), 2.93 (1H, d, J = 13.4 Hz, H-9a), 2.31 (1H, d, J = 13.4 Hz, H-9b), 1.86 (3H, s, H3-13), 1.06 (3H, d, J = 6.8 Hz, H3-14), 1.93 (3H, s, H3-15). 13C NMR (500 MHz, CDCl3) δC: 133.8 (C-1), 27.2 (C-2), 36.0 (C-3), 47.8 (C-4), 209.6 (C-5), 40.2 (C-6), 154.6 (C-7), 106.9 (C-8), 49.7 (C-9), 130.5 (C-10), 129.9 (C-11), 172.3 (C-12), 9.2 (C-13), 18.4 (C-14), 16.5 (C-15). HR-ESI-MS: 287.12547[M + Na]+, calcd. For C15H20O4Na 287.1253802.
Curcumenol (36) [19]Colorless crystals; melting point: 98-100°C. IR (cm−1): 3371, 3321, 1695, 1658, 1274. 1H NMR (600 MHz, CDCl3) δH: 1.95 (1H, m, H-1), 1.96 2H, (m, H2-2), 1.90 (2H, m, H2-3), 1.93 (1H, m, H-4), 2.11, 2.66 (each, 1H, d, J = 16.9 Hz, H2-6), 5.77 (1H, s, H-9), 1.60 (3H, s, H3-12), 1.82 (3H, s, H3-13), 1.03 (3H, d, J = 6.4 Hz, H-14), 1.67 (3H, s, H-15).13C NMR (151 MHz, CDCl3) δC: 51.3 (C-1), 27.6 (C-2), 31.2 (C-3), 40.4 (C-4), 85.7 (C-5), 37.3 (C-6), 137.4 (C-7), 101.5 (C-8), 125.6 (C-9), 139.2 (C-10), 122.2 (C-11), 22.3 (C-12), 18.9 (C-13), 11.8 (C-14), 20.9 (C-15).
Isocurcumenol (37) [6]13C NMR (400 MHz, CDCl3) δC: 53.0 (C-1), 28.6 (C-2), 31.0 (C-3), 41.9 (C-4), 87.4 (C-5), 39.2 (C-6), 134.1 (C-7), 104.0 (C-8),36.4 (C-9), 145.4 (C-10), 127.2 (C-11), 22.8 (C-12), 19.2 (C-13), 12.7 (C-14), 112.5 (C-15).
1,4-dihydroxy-1,4-dimethyl-7-(1-methylethylidene)octahydroazulen-6(1H)-one-methane (38) [6]1H NMR (400 MHz, CDCl3) δH: 1.16 (s), 1.26 (s), 1.81 (s), 1.89 (s), 1.50-1.80 (m), 2.51 (d, J = 11.7), 2.83 (d, J = 15.6), 2.92 (d, J 11.7). 13C NMR (400 MHz, CDCl3) δC: 54.7 (C-1), 21.4 (C-2), 28.0 (C-3), 80.4 (C-4), 50.1 (C-5), 39.9 (C-6), 135.8 (C-7), 205.6 (C-8), 57.3 (C-9), 71.5 (C-10), 140.0 (C-11), 22.0 (C-12), 22.9 (C-13), 22.0 (C-14), 30.0 (C-15).
Zedoalactone A (39) [6]1H NMR (500 MHz, CDCl3) δH: 2.71 (1H, m, H-1), 1.85 (1H, m, H-2a), 1.49 (1H, m, H-2b), 1.80 (2H, m, H2-3), 2.00 (1H, ddd, J = 13.3, 6.6, 3.7 Hz, H-5), 2.71 (1H, m, H-6a), 1.85 (1H, m, H-6b), 4.92 (1H, ddq, J = 6.9, 2.6, 2.0 Hz, H-8), 2.33 (1H, dd, 16.0, 6.9 Hz, H-9a), 2.09 (1H, ddd, J = 16.0, 2.6, 0.7 Hz, H-9b), 1.83 (3H, d, J = 2.0 Hz, H3-13), 1.34 (3H, s, H3-14), 1.24 (3H, s, H3-15). 13C NMR (500 MHz, CDCl3) δC: 51.5 (C-1), 24.5 (C-2), 37.1 (C-3), 816 (C-4), 50.8 (C-5), 24.9 (C-6), 161.4 (C-7), 80.8 (C-8), 35.7 (C-9), 73.5 (C-10), 122.5 (C-11), 175.5 (C-12), 8.0 (C-13), 25.0 (C-14), 31.8 (C-15).
5,8-dihydroxy-3,5,8-trimethyl-4a,5,6,7,7a,8,9,9a-octahydroazuleno[6,5-b]furan-2(4H)-one (40) [6]1H NMR (500 MHz, CDCl3) δH: 1.97 (1H, m, H-1), 1.82 (m, H-2a), 1.70 (m, H-2b), 1.70 (2H, m, H2-3), 1.58 (1H, ddd, J = 13.0, 9.0, 2.8 Hz, H-5), 2.30 (1H, dd, J = 15.7, 2.8 Hz, H-6a), 2.06 (1H, dd, J = 14.7 13.3 Hz, H-6b), 5.13 (1H, d, J = 11.2 Hz, H-8), 2.31 (1H, dd, 14.7, 2.7 Hz, H-9a), 1.76 (1H, dd, J = 14.7, 11.3 Hz, H-9b), 1.81 (3H, dd, J = 1.7, 1.7 Hz, H3-13), 1.28 (3H, s, H3-14), 1.25 (3H, s, H3-15). 13C NMR (500 MHz, CDCl3) δC: 53.2 (C-1), 23.5 (C-2), 41.2 (C-3), 80.4 (C-4), 48.1 (C-5), 29.8 (C-6), 162.4 (C-7), 79.0 (C-8), 46.3 (C-9), 72.6 (C-10), 122.2 (C-11), 174.2 (C-12), 8.7 (C-13), 23.5 (C-14), 24.0 (C-15).
5,8-dihydroxy-3,5,8-trimethyl-4a,5,6,7,7a,8,9,9a-octahydroazuleno[6,5-b]-furan-2(4H)-one (41) [6]1H NMR (500 MHz, CDCl3) δH: 2.86 (1H, dddd, J = 12.3, 7.9, 5.1, 1.4 Hz, H-1), 1.81 (m, H-2a), 1.34 (m, H-2b), 1.72 (2H, m, H2-3), 2.23 (1H, m, H-5), 2.72 (1H, m, H-6a), 2.23 (1H, m H-6b), 5.28 (1H, dqd, 11.7, 1.8, 1.7 Hz, H-8), 2.28 (1H, ddd, J = 13.7, 3.4, 1.7 Hz, H-9a), 1.68 (1H, dd, 13.7, 11.7 Hz, H-9b), 1.79 (3H, dd, 1.8, 1.4 Hz, H3-13), 1.40 (3H, s, H3-14), 1.32 (3H, s, H3-15). 13C NMR (500 MHz, C5D5N) δC: 53.1 (C-1), 24.9 (C-2), 37.8 (C-3), 80.7 (C-4), 48.4 (C-5), 24.9 (C-6), 165.4 (C-7), 79.8 (C-8), 41.2 (C-9), 71.2 (C-10), 121.3 (C-11), 174.9 (C-12), 8.8 (C-13), 25.8 (C-14), 32.4 (C-15).
Zedoarolide B (42) [6]1H NMR (400 MHz, C5D5N) δH: 3.38 (1H, ddd, 3.7, 7.6, 7.6 Hz, H-1), 1.98 (1H, m, H-2a), 1,79 (1H, m, H-2b), 2.08 (1H, m, H-3a), 1.97 (1H, m, H-3b), 2.64 (1H, ddd, J = 3.7, 3.7, 12.8 Hz, H-5), 2.82 (1H, dd, J = 3.7, 12.8 Hz, H-6a), 2.43 (1H, dd, J = 12.8, 12.8 Hz, H-6b), 2.86 (1H, Abq, J = 15.5 Hz, H-9a), 2.80 (1H, Abq, J = 15.5 Hz, H-9b), 1.81 (3H, s, H-13), 1.44 (3H, s, H-14), 1.58 (3H, s, H-15). 13C NMR (400 MHz, C5D5N) δC: 53.1 (C-1), 25.3 (C-2), 38.2 (C-3), 80.7 (C-4), 52.4 (C-5), 24.6 (C-6), 161.5 (C-7), 106.9 (C-8), 44.0 (C-9), 72.1 (C-10), 122.7 (C-11), 173.7 (C-12), 8.0 (C-13), 25.6 (C-14), 32.5 (C-15).
4a,8,9,9a-Tetrahydroxy-3,5,8-trimethyl-4a,5,6,7,7a,8,9,9a-octahydroazuleno[6,5-b]-furan-2(4H)-one (43) [6]1H NMR (400 MHz, C5D5N) δH: 3.74 (1H, dd, J = 5.0, 3.8 Hz, H-1), 1.77 (2H, m, H2-2), 2.36 (1H, dddd, J = 11.4, 11.4, 10.7, 6.8 Hz, H-3a), 1.43 (1H, m, H-3a), 2.05 (1H, qd, J = 7.3, 6.8 Hz, H-4), 3.28 (1H, d, J = 15.6 Hz, H-6a), 2.87 (1H, dq, J = 15.6, 1.7, H-6b), 3.99 (1H, s, H-9), 1.87 (3H, d, J = 1.7 Hz, H3-13), 0.71 (3H, d, J = 7.3 Hz, H3-14), 1.47 (3H, s, H3-15). 13C NMR (400 MHz, C5D5N) δC: 43.3 (C-1), 25.0 (C-2), 33.2 (C-3), 42.9 (C-4), 92.2 (C-5), 32.2 (C-6), 158.8 (C-7), 108.6 (C-8), 81.1 (C-9), 82.0 (C-10), 126.9 (C-11), 172.4 (C-12), 8.7 (C-13), 14.2 (C-14), 19.7 (C-15). MS: m/z 303.12047, [M – H2O + Na]+. HR-MS 303.12047 C15H22O6.
7-(1-hydroxy-1-methylethyl)-1,4-dimethyl-1,2,3,3a,4,5,8,8a-octahydroazulene-1,4-diol (44) [6]1H NMR (400 MHz, C5D5N) δH: 3.48 (m, H-1), 1.96 (1H, m, H-2a),
1.78 (1H, m, H-2b), 2.02 (1H, m, H-3a), 1.85 (1H, m, H-3b), 2.41 (dd, J = 12.8, 4.9 Hz, H-5), 2.52 (1H, d, J = 13.9 Hz, H-6a), 2.15 (1H, dd, J = 13.9, 12.8 Hz, H-6b), 6.16 (1H, br dd, J = 8.4, 5.2 Hz, H-8), 2.78 (91H, J = 14.2, 5.2 Hz, H-9a), 2.27 (1H, dd, J = 14.2, 8.4 Hz, H-9b), 1.57 (3H, s, H3-12), 1.57 (3H, s, H3-13), 1.62 (3H, s, H3-14), 1.36 (3H, s, H3-15). 13C NMR (400 MHz, C5D5N) δC: 54.2 (C-1), 25.5 (C-2), 37.5 (C-3), 80.9 (C-4), 49.4 (C-5), 26.2 (C-6), 150.9 (C-7), 118.8 (C-8), 35.4 (C-9), 70.6 (C-10), 72.7 (C-11), 29.2 (C-12), 29.4 (C-13), 26.3 (C-14), 31.6 (C-15).
Gajutsulactone B (45) [6]1H NMR (300 MHz, CDCl3) δH: 2.88 (ddd, 6.4, 6.4, 9.8 Hz, H-1), 2.06 (1H, m, H-2a), 1.86 (1H, m, H-2b), 1.90 (m, H-3), 2.30 (m, H-5), 2.50 (d, H-6a), 2.24 (d, H-6b), 5.01 (br s, H-9a), 4.84 (br s, H-9b), 2.18 (3H, s, H-12), 1.86 (3H, s, H-13), 1.78 (3H, s, H-14), 1.22 (3H, s, H-15). 13C NMR (300 MHz, CDCl3) δC: 42.4 (C-1), 26.2 (C-2), 38.0 (C-3), 85.3 (C-4), 45.7 (C-5), 25.7 (C-6), 120.4 (C-7), 167.5 (C-8), 111.9 (C-9), 145.2 (C-10), 151.8 (C-11), 23.3 (C-12), 23.5 (C-13), 25.2 (C-14), 19.9 (C-15).
Bisacumol (46) [6]13C NMR (300 MHz, CDCl3) δC: 144.2 (C-1), 127.2 (C-2), 129.3 (C-3), 135.7 (C-4), 129.3 (C-5), 127.2 (C-6), 36.1 (C-7), 46.1 (C-8), 67.1 (C-9), 128.6 (C-10), 135.0 (C-11), 18.4 (C-12), 26.0 (C-13), 23.3 (C-14), 21.3 (C-15).
7-isopropenyl-1,4a-dimethyldecahydronaphthalene-1,4-diol (47) [6]1H NMR (500 MHz, CDCl3) δH: 3.27 (1H, dd, 12.7, 4.2 Hz, H-1), 1.87 (1H, m, H-2a), 1.62 (1H, m, H-2b), 1.72 (1H, m, H-3a), 1.5 (1H, ddd, J = 14.1, 14.1, 4.5 Hz, H-3b), 1.07 (1H, dd, 12.4, 2.6 Hz, H-5), 1.68 (1H, m, H-6a), 1.94 (1H, m, H-6b), 1.62 (1H, m, H-8a), 1.45 (1H, m, H-8b), 1.87 (1H, m, H-9a), 1.11 (1H, dd, J = 13.2, 3.7 Hz, H-9b),1.76 (3H, s, H3-12), 4.74 1H, (H-13, Z), 4.71 (1H, H-13, E), 1.16 (3H, s, H3-14), 1.05 (3H, s, H3-15). 13C NMR (500 MHz, CDCl3) δC: 79.7 (C-1), 26.8 (C-2), 39.4 (C-3), 71.4 (C-4), 50.4 (C-5), 25.6 (C-6), 46.1 (C-7), 26.4 (C-8), 39.3 (C-9), 38.9 (C-10), 150.5 (C-11), 20.7 (C-12), 108.6 (C-13), 30.0 (C-14), 12.6 (C-15).
(1S,4S,5S,10R)-isozedoarondiol (48) [19]Yellow oil. IR (cm−1): 3394, 1701, 1665, 1612. 1H NMR (600 MHz, CDCl3) δH: 2.79 (1H, m, H-1), 1.63 (2H, m, H2-2), 1.73 (2H, m, H2-3), 2.02(1H, d, J = 12.9 Hz, H-5), 2.52, 1.91 (each, 1H, d, J = 13.9 Hz, H2-6), 2.30 (1H, dd, J = 16.1, 1.2 hz, H-9a), 3.34 (d, J = 16.1 Hz, H-9b), 1.97 (3H, s, H3-12), 1.88 (3H, s, H3-13), 1.39 (3H, d, J = 6.4 Hz, H-14), 1.19 (3H, s, H-15).13C NMR (151 MHz, methanol-d4) δC: 51.2 (C-1), 24.6 (C-2), 36.0 (C-3), 81.7 (C-4), 52.6 (C-5), 27.0 (C-6), 134.0 (C-7), 204.7 (C-8), 49.9 (C-9), 72.5 (C-10), 143.0 (C-11), 20.9 (C-12), 21.8 (C-13), 23.4 (C-14), 31.3 (C-15).

Table 1.

Physical and spectral data of sesquiterpenes.

5. Biological activities

Several studies have reported that Curcuma comosa have been successfully used for various diseases Table 2.

Sample/extractBiological activityReferences
Hexand and DCMNematocidal[39]
EtOAcCholeretic[40]
Crude proteinAntioxidant[41]
EtOHAntibacterial[42]
Hexane and EtOHAnti-inflammatory[43]
Hexane, EtOAc, and n-butanolAntifungal[6]
Zedoarondiol (25)Cytotoxic[19]
(1S, 10S), (4S, 5S)-Germacrone-1(10), 4(5)-diepoxide (33)Cellular viability[6]
Curcumenol (36)Cytotoxic[19]
(1S,4S,5S,10R)-isozedoarondiol (48)Cytotoxic[19]

Table 2.

Biological activities of extracts and compounds from Curcuma comosa.

6. Conclusion

Work on natural products has recently experienced rapid expansion due to improvement in isolation techniques and the design of synthesis methods and also for the identification of a wide range of biological properties of these compounds. In this chapter, the extraction, isolation, and spectroscopic data of sesquiterpenes from Curcuma comosa have been discussed.

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Khun Nay Win Tun, Nanik Siti Aminah, Alfinda Novi Kristanti, Hnin Thanda Aung and Yoshiaki Takaya (October 13th 2020). Sesquiterpene from Myanmar Medicinal Plant (<em>Curcuma comosa</em>) [Online First], IntechOpen, DOI: 10.5772/intechopen.93794. Available from:

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