文章快速检索     高级检索
  热带亚热带植物学报  2019, Vol. 27 Issue (2): 196-202  DOI: 10.11926/jtsb.3958
0

引用本文  

李薇, 梅文莉, 董文化, 等. 国产绿奇楠沉香的化学成分研究[J]. 热带亚热带植物学报, 2019, 27(2): 196-202. DOI: 10.11926/jtsb.3958.
LI Wei, MEI Wen-li, DONG Wen-hua, et al. Study on Chemical Constituents of Chinese Agarwood 'Qi-Nan'[J]. Journal of Tropical and Subtropical Botany, 2019, 27(2): 196-202. DOI: 10.11926/jtsb.3958.

基金项目

海南自然科学基金创新研究团队项目(2017CXTD020);中国热带农业科学院院级创新团队南药产业技术创新团队(17CXTD-15);现代农业产业技术体系建设专项(CARS-21)资助

通信作者

戴好富.E-mail:daihaofu@itbb.org.cn

作者简介

李薇(1988~), 女, 助理研究员, 从事天然产物化学研究。E-mail:liwei@itbb.org.cn

文章历史

收稿日期:2018-06-11
接受日期:2018-07-13
国产绿奇楠沉香的化学成分研究
李薇 , 梅文莉 , 董文化 , 蔡彩虹 , 盖翠娟 , 戴好富     
中国热带农业科学院热带生物技术研究所, 农业部热带作物生物学与遗传资源利用重点实验室, 海南省沉香工程技术研究中心, 海南省黎药资源天然产物研究与利用重点实验室, 海口 571101
摘要:为了解国产绿‘奇楠’沉香的化学成分,采用色谱和波谱方法从其乙醚和乙醇提取物中分离鉴定了7个化合物,分别鉴定为顺式-7-羟基菖蒲烯(1),(5R,6R,7S,8R)-2-(苯乙基)-6,7,8-三羟基-5,6,7,8-四氢-5-[2-(2-苯乙基)色酮基-6-氧代]色酮(2),1-羟基-1,5-二苯基戊-3-酮(3),丁香树脂酚葡萄糖苷(4),(3β)-齐墩果-12-烯-3,23-二醇(5),β-谷甾醇(6)和棕榈酸-α-单甘油酯(7)。化合物13~57均为首次从沉香中分离得到,其中化合物1表现出非常甜的芳香气味。乙酰胆碱酯酶体外抑制活性测试结果表明,50 μmol L-1的化合物1对乙酰胆碱酯酶抑制率为(49.9±1.4)%。
关键词奇楠    沉香    化学成分    乙酰胆碱酯酶    抑制活性    
Study on Chemical Constituents of Chinese Agarwood 'Qi-Nan'
LI Wei , MEI Wen-li , DONG Wen-hua , CAI Cai-hong , GAI Cui-juan , DAI Hao-fu     
Key Laboratory of Biology and Genetic Resources of Tropical Crops, Ministry of Agriculture, Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Hainan engineering research center of agarwood, Haikou Key Laboratory for Research and Development of Tropical Natural Products, Haikou 571101, China
Foundation item: This work was supported by Innovative Research Team Grant of the Natural Science Foundation of Hainan Province (Grant No. 2017CXTD020), Central Public-interest Scientific Institution Basal Research Fund for Innovative Research Team Program of CATAS (Grant No. 17CXTD-15), and the Special Project for China Agriculture Research System (Grant No. CARS-21)
Abstract: To understand the chemical constituents of Chinese agarwood "Qi-Nan", seven compounds were isolated by various column chromatographic methods. On the basis of spectral data, they were identified as cis-7-hydroxycalamenene (1), (5R, 6R, 7S, 8R)-2-(phenylethyl)-6, 7, 8-trihydroxy-5, 6, 7, 8-tetrahydro-5-[2-(2-phenylethyl) chromonyl-6-oxy]chromone (2), 1-hydroxy-1, 5-diphenylpentan-3-one (3), syringaresinol-glycoside (4), (3β)- olean-12-ene-3, 23-diol (5), β-sitosterol (6) and hexadecanoic acid, 2, 3-dihydroxypropyl ester (7). Compounds 1, 3-5, and 7 were isolated from agarwood for the first time, and compound 1 showed a very sweet aromatic odor. Compound 1 showed acetylcholinesterase (AChE) inhibitory activity with the inhibition rate of (49.9±1.4)% at the concentration of 50 μmol L-1.
Key words: 'Qi-Nan'    Chinese agarwood    Chemical constituent    Acetylcholinesterase (AChE)    Inhibitory activity    

‘奇楠’又名伽楠、伽羅、琪南、伽沉等,英文名有Kanankoh、Kyara、Chi-Nan、Qi-Nan等,因其神秘优雅的香味被认为是具有最上等品质和最珍贵价值的沉香,且在市场上价格也最为昂贵[1-2]。‘奇楠’在物理特征方面主要基于其芳香气味和外观差别而与普通沉香相区别[3-4],并根据其外表和断面的颜色可分为绿奇、紫奇、黑奇和黄奇等[2, 5]。据记载奇楠外表油润光滑,油性重,以指甲刻之,如锥画沙,油随即溢出,用刀刮削,能捻捏成丸、成饼,能散发耐久的幽香,味微苦麻辣,嚼之粘牙, 燃之出油,而普通沉香质坚,雕剔之,如刀刮竹[5]。在化学特征方面,根据本研究组前期对‘奇楠’沉香化学成分的分析和分离研究,发现‘奇楠’沉香中有较多母核无取代的2-(2-苯乙基)色酮类化合物,而这种类型的2-(2-苯乙基)色酮在普通沉香中几乎没有过报道[6-7]。同时,在前期研究中我们还发现,‘奇楠’沉香中有两个含量非常大的2-(2-苯乙基)色酮类成分,即2-(2-苯乙基)色酮和2-[2-(4-甲氧基苯)乙基]色酮,其二者相对含量之和分别占到了研究的4种‘奇楠’沉香(海南产的白奇、紫奇、绿奇和越南产的绿奇)乙醚提取物的66.47%、82.09%、84.71%和71.98%,因此,也可以将上述两个2-(2-苯乙基)色酮在乙醚提取物中的相对含量之和作为区分‘奇楠’沉香与普通沉香的一项重要指标[8]。本研究采用的沉香样品为产自于我国广东省的绿‘奇楠’沉香,其基源植物白木香[Aquilaria sinensis (Lour.) Gilg]是我国特有树种,主要分布在广东、广西、福建、海南和台湾等地[9]

本研究组在前期研究中,已从国产绿‘奇楠’沉香中分离鉴定出一系列新的2-(2-苯乙基)色酮和倍半萜类化合物[6, 10-13],为了进一步完善对‘奇楠’沉香的化学成分研究,本次从国产绿‘奇楠’沉香乙醚和乙醇提取物中共分离鉴定出7个化合物,其中化合物13~57均为首次从沉香中分离得到的化合物,且本研究还发现化合物1在体外对乙酰胆碱酯酶有一定的抑制作用。本文报道了化合物1~7的分离方法、结构鉴定和乙酰胆碱酯酶抑制活性测试结果。

1 材料和方法 1.1 材料

绿‘奇楠’沉香,表面可观测到浅褐色细密树脂条带均匀分布其上(图 1),质地较普通沉香更软,不点燃即可闻到有明显的沁人心脾的香气,被称为金丝软绿奇,于2011年8月由沉香收藏家张晓武先生及官茂有先生惠赠,由中国热带农业科学院热带生物技术研究所戴好富研究员与中国医学科学院药用植物研究所海南分所郑希龙博士共同鉴定其源植物为白木香[Aquilaria sinensis (Lour.) Gilg],凭证标本(QN 20110830)存放于中国热带农业科学院热带生物技术研究所。

图 1 绿奇楠沉香样品(编号: QN 20110830) Fig. 1 Chinese agarwood "Qi-Nan" (No. QN 20110830)
1.2 仪器和试剂

Buker amazon SL质谱仪;Bruker AV-500型超导核磁仪,TMS为内标;XY-JH-21BC超净工作台(上海昕仪仪器仪表有限公司);Multiskan FC酶标仪(塞默飞世尔上海仪器有限公司);旋转蒸发仪(德国海道夫公司);Delta 320-S pH计(梅特勒-托利多仪器上海有限公司);柱色谱硅胶(200~300目,60~80目)和薄层层析硅胶板G (青岛海洋化工厂), Sephadex LH-20和RP-18填料柱(Merck公司),提取和分离所用试剂均为重蒸工业试剂。S-硫代乙酰胆碱,5, 5ʹ-二硫-双-2-硝基苯甲酸(DTNB, Ellman试剂),乙酰胆碱酯酶,他克林均购自Sigma Chemical。

1.3 提取和分离

绿奇楠沉香(干重180.2 g)粉碎后,以乙醚超声提取4次,每次超声0.5 h,静置5 h。合并滤液, 减压浓缩得油状乙醚提取物19.3 g,得率为10.7%。将乙醚提取物留样20.0 mg,取5.0 mg用作GC-MS分析后,再以硅胶柱色谱分离,以石油醚-乙酸乙酯梯度(体积比1:0~0:1)洗脱,得到11个流分(D1~ D11)。乙醚提取后,剩余滤渣用乙醇加热回流提取3次,减压浓缩,得到乙醇提取物15.8 g,以减压硅胶柱(C:M=1:0~0:1)色谱分离,得到11个流分(E1~E11)。

D2 (与E1合并后1.7 g)以甲醇溶解,不溶解部分(400.0 mg)反复柱层析(P:E=20:1)得到化合物6 (1.0 mg)。甲醇溶解部分经Sephadex LH-20柱色谱分离,甲醇洗脱得到D2-1和D2-2。D2-2 (400.0 mg)以硅胶柱色谱分离,石油醚-乙酸乙酯梯度(80:1μ→10:1,V/V, 下同)洗脱,得到化合物1 (1.3 mg)。D3 (3.8 g)以Sephadex LH-20柱色谱分离,甲醇洗脱得到D3-1 (2.3 g)和D3-2 (1.5 g)。D3-1 (2.3 g)以反相ODS柱色谱分离,甲醇-水梯度(40:60~ 100:0)洗脱得到10个流分(D3-1-1~D3-1-10)。D3- 1-5 (43.0 mg)以Sephadex LH-20柱色谱分离,甲醇洗脱后得到D3-1-5-1和D3-1-5-2;D3-1-5-2 (7.9 mg)以硅胶柱色谱分离,石油醚-氯仿(3:7)洗脱得到化合物3 (5.8 mg)。D6 (1.6 g)以甲醇溶解,不溶部分(32.0 mg)以硅胶柱色谱分离,氯仿-甲醇(100:1)洗脱得到化合物7 (11.1 mg)。D-8 (1.7 g)以反相ODS柱色谱分离,甲醇-水梯度(30:70~100:0)洗脱得到D-8-1~D-8-4,D-8-4以葡聚糖凝胶色谱分离,甲醇洗脱得到化合物5 (4.7 mg)。D11 (1.2 g)以反相ODS柱色谱分离,甲醇-水梯度(3:7μ®1:0)洗脱,得到D11-1~D11-70, D11-(62+63) (30.0 mg)以硅胶柱色谱分离,氯仿-甲醇(25:1)洗脱得到化合物2 (5.0 mg)。E8 (2.6 g)经ODS(甲醇-水=5:5~1:0)梯度洗脱,得到E8-1~E8-4。E8-4 (44.1 mg)经Sephadex LH-20 (甲醇)再经硅胶柱(C:M=20:1)色谱分离,得到化合物4 (1.7 mg)。化合物结构见图 2

图 2 化合物1~7的结构 Fig. 2 Structures of compounds 1-7
1.4 乙酰胆碱酯酶抑制活性的测试方法

化合物的乙酰胆碱酯酶抑制活性测定参照Ellman法[14]并略有改进。化合物溶解于DMSO中, 含有磷酸缓冲液(pH=8.0)、测试化合物(50 μmol L–1)和乙酰胆碱酯酶(0.02 U mL-1)的最终反应体系(200 μL), 先在30℃孵育20 min,于405 nm紫外光下测两次背景值, 加入20 μL的DTNB (2.48 mg mL-1)和20 μL的硫代乙酰胆碱(1.81 mg mL-1)开始反应,将反应体系于405 nm紫外波长下监测1 h。他克林用作阳性对照,反应终浓度为0.08 μg mL-1;DMSO用作阴性对照,反应终浓度为0.1%。每个样品重复3次实验。选择阴性对照组吸光值平均约为1时的样品吸光值,计算化合物吸光值平均值(化合物测定值μ-背景值),化合物的抑制率(%)=(ES)/E×100, 式中, E为阴性对照组的平均吸光值;S为化合物组的平均吸光值。

2 结果和分析 2.1 结构鉴定

顺式-7-羟基菖蒲烯 (cis-7-hydroxycalamenene, 1)  芳香味无色油状;遇体积分数5%的硫酸显蓝色。分子式C15H22O。ESI-MS m/z: 241.1 (100) [M + Na]+1H NMR (CDCl3, 500 MHz): δ 6.88 (1H, s, H-5), 6.64 (1H, s, H-8), 2.80 (1H, m, H-1), 2.54 (1H, m, H-4), 2.20 (1H, m, H-12), 2.16 (3H, s, H-15), 1.77 (1H, m, H-2a), 1.68 (2H, m, H-3), 1.63 (1H, m, H-2b), 1.21 (3H, d, J = 7.1 Hz, H-11), 1.02 (3H, d, J = 6.9 Hz, H-14), 0.75 (3H, d, J = 6.8 Hz, H-13);13C NMR (CDCl3, 125 MHz): δ 32.2 (C-1), 29.0 (C-2), 19.3 (C-3), 43.5 (C-4), 131.1 (C-5), 121.1 (C-6), 151.6 (C-7), 114.0 (C-8), 139.0 (C-9), 135.4 (C-10), 23.6 (C-11), 31.1 (C-12), 17.4 (C-13), 21.5 (C-14), 15.5 (C-15)。以上数据与文献[15]一致,确定化合物1为顺式-7-羟基菖蒲烯。

(5R, 6R, 7S, 8R)-2-(苯乙基)-6, 7, 8-三羟基-5, 6, 7, 8-四氢-5-[2-(2-苯乙基)色酮基-6-氧代]色酮(AH14) [(5R, 6R, 7S, 8R)-2-(phenylethyl)-6, 7, 8-trihydroxy-5, 6, 7, 8-tetrahydro-5-[2-(2-phenylethyl)chromonyl-6-oxy] chromone, 2]  白色粉末;遇碘显黄色,遇体积分数5%的硫酸显浅红色。分子式C34H30O8。ESI-MS m/z: 589.4 (100) [M + Na]+1H NMR (CDCl3, 500 MHz) δH: Unit A: 7.29 (2H, m, H-2″, H-6″), 6.96 (2H, d, J = 7.0 Hz, H-3″, H-5″), 7.20 (1H, m, H-4″), 6.11 (1H, s, H-3), 5.35(1H, dd, J = 7.4, 1.3 Hz, H-5), 4.86 (1H, dd, J = 7.5, 1.3 Hz, H-8), 4.10 (1H, dd, J = 10.2, 7.4 Hz, H-6), 3.91 (1H, dd, J = 10.2, 7.5 Hz, H-7), 2.68 (4H, m, H-7″, H-8″), Unit B: 7.20 (5H, m, H-2‴~6‴), 7.93 (1H, d, J = 1.8 Hz, H-5′), 7.42 (1H, d, J = 9.2 Hz, H-8′), 7.32 (1H, dd, J = 9.2, 1.8 Hz, H-7′), 6.15 (1H, s, H-3′), 3.05 (2H, m, H-7‴), 2.94 (2H, m, H-8‴); 13C NMR (CDCl3, 125 MHz) δC: Unit A: 169.4 (C-2), 113.8 (C-3), 180.6 (C-4), 78.4 (C-5), 72.5 (C-6), 74.0 (C-7), 69.9 (C-8), 157.9 (C-9), 121.1 (C-10), 139.2 (C-1″), 128.8 (C-2″, C-6″), 128.2 (C-3″, C-5″), 126.8 (C-4″), 32.6 (C-7″), 35.4 (C-8″), Unit B: 168.8 (C-2′), 109.7 (C-3′), 178.0 (C-4′), 109.6 (C-5′), 156.5 (C-6′), 124.7 (C-7′), 119.7 (C-8′), 152.1 (C-9′), 124.4 (C-10′), 139.8 (C-1‴), 128.8 (C-2‴, C-6‴), 128.4 (C-3‴, C-5‴), 126.8 (C-4‴), 33.1 (C-7‴), 36.2 (C-8‴)。上述数据与文献[16]报道的AH14的数据一致,确定化合物2为(5R, 6R, 7S, 8R)-2-(苯乙基)-6, 7, 8-三羟基-5, 6, 7, 8-四氢-5-[2-(2-苯乙基)色酮基-6-氧代]色酮。

1-羟基-1, 5二苯基戊-3-酮 (1-hydroxy-1, 5-di- phenylpentan-3-one, 3)  无色油状;遇体积分数5%的硫酸浅黄色。分子式C17H18O2。ESI-MS m/z: 277.1 (100) [M + Na]+1H NMR (CDCl3, 500 MHz): δ 7.35 (4H, m, H-2″, H-6″, H-3' , H-5' ), 7.29 (3H, m, H-2' , H-4' , H-6' ), 7.21 (1H, m, H-4″), 7.17 (2H, m, H-3″, H-5″), 5.15 (1H, dd, J = 3.0, 9.3 Hz, H-1), 2.91 (2H, t, J = 7.6 Hz, H-5), 2.85 (1H, dd, J = 9.3, 17.3 Hz, H-2a), 2.78 (2H, m, H-4), 2.74 (1H, dd, J = 3.0, 17.3 Hz, H-2b); 13C NMR (CDCl3, 125 MHz): δ 70.1 (C-1), 51.4 (C-2), 210.4 (C-3), 45.2 (C-4), 29.6 (C-5), 140.8 (C-1' ), 128.4 (C-2' , C-6' ), 125.7 (C-3' , C-5' ), 127.8 (C-4' ), 142.8 (C-1" ), 128.7 (C-2″, C-3″, C-5″, C-6″), 126.4 (C-4″)。以上数据与文献[17]一致,确定化合物3为1-羟基-1, 5-二苯基戊-3-酮。

丁香树脂酚葡萄糖苷 (syringaresinol-glyco- side, 4)  淡黄色粉末(MeOD); ESI-MS m/z: 603 [M + Na]+, C28H36O13; 1H NMR (MeOD, 500 MHz): δ 6.71 (2H, s, H-2″, H-6″), 6.65 (2H, s, H-2′, H-6′), 4.90 (1H, d, J = 7.5 Hz, G-H-1), 4.76 (1H, d, J = 4.0 Hz, H-6), 4.71 (1H, d, J = 4.3 Hz, H-2), 3.85 (6H, s, 3″, 5″-OCH3), 3.83 (6H, s, 3′, 5′-OCH3); 13C NMR (MeOD, 125 MHz): δ 154.7 (C-3″, C-5″), 149.7 (C-3', C-5'), 139.8 (C-4″), 136.5 (C-4′), 135.8 (C-1″), 133.4 (C-1′), 105.6 (G-C-1), 105.2 (C-2″, C-6″), 104.8 (C-2′, C-6′), 87.8 (C-2), 87.5 (C-6), 78.6 (G-C-5), 78.1 (G-C-3), 75.9 (G-C-2), 73.2 (C-4), 73.2 (C-8), 71.6 (G-C-4), 62.9 (G-C-6), 57.4 (2×OCH3), 57.1 (2× OCH3), 56.1 (C-1), 55.8 (C-5)。以上数据与文献[18-19]对照,鉴定该化合物为丁香树脂酚葡萄糖苷。

(3β)-齐墩果-12-烯-3, 23-二醇 [(3β)-olean-12-ene-3, 23-diol, 5]  白色无定型固体;遇体积分数5%的硫酸显紫色。分子式C30H50O2。ESI-MS m/z: 465 (100) [M + Na]+1H NMR (CDCl3, 500 MHz): δ 5.18 (1H, t, J = 4.8 Hz, H-12), 3.68 (1H, d, J = 9.8 Hz, H-23a), 3.52 (1H, t, J = 7.6 Hz, H-3), 3.42 (1H, d, J = 9.8 Hz, H-23b), 2.24 (1H, m, H-18), 2.01 (1H, m, H-15a), 1.93 (2H, m, H-11), 1.78 (1H, m, H-16a), 1.73 (1H, m, H-1a), 1.70 (2H, m, H-2), 1.62 (1H, m, H-9), 1.60 (1H, m, H-7a), 1.52 (1H, m, H-6a), 1.50 (1H, m, H-22a), 1.42 (1H, m, H-6b), 1.40 (1H, m, H-21a), 1.37 (1H, m, H-7b), 1.25 (H, m, H-22b), 1.14 (3H, s, H-27), 1.08 (1H, m, H-21b), 1.03 (1H, m, H-19b), 1.02 (2H, m, H-1b, H-16b), 1.00 (3H, s, H-25), 0.98 (3H, s, H-26), 0.92 (3H, s, H-24), 0.88 (6H, s, H-29, H-30), 0.86 (1H, m, H-5), 0.84 (3H, s, H-28), 0.79 (1H, s, H-15b); 13C NMR (CDCl3, 125 MHz):δ 37.8 (C-1), 27.4 (C-2), 77.4 (C-3), 41.5 (C-4), 49.1 (C-5), 18.0 (C-6), 32.4 (C-7), 38.9 (C-8), 47.3 (C-9), 36.6 (C-10), 23.1 (C-11), 121.8 (C-12), 143.8 (C-13), 41.3 (C-14), 25.7 (C-15), 23.1 (C-16), 46.2 (C-17), 41.1 (C-18), 45.8 (C-19), 30.4 (C-20), 33.6 (C-21), 32.1 (C-22), 70.2 (C-23), 11.2 (C-24), 15.3 (C-25), 16.5 (C-26), 25.5 (C-27), 25.5 (C-28), 32.7 (C-29), 23.1 (C-30)。以上数据与文献[20]一致,确定化合物5为(3β)-齐墩果-12-烯-3, 23-二醇。

β-谷甾醇 (β-sitosterol, 6)  白色粉末,遇体积分数5%的硫酸显紫色。分子式为C29H50O。ESI- MS m/z: 414 [M]+1H NMR (CDCl3, 500 MHz): δ 5.36 (1H, br s, H-6), 3.51 (1H, m, H-3), 1.01 (3H, s, H-19), 0.92 (3H, d, J = 6.4 Hz, H-21), 0.84 (3H, d, J = 7.8 Hz, H-29), 0.84 (3H, d, J = 6.8 Hz, H-26), 0.80 (3H, d, J = 6.9 Hz, H-27), 0.69 (3H, s, H-18); 13C NMR (CDCl3, 125 MHz): δ 37.4 (C-1), 31.8 (C-2), 72.0 (C-3), 42.4 (C-4), 140.9 (C-5), 121.9 (C-6), 32.0 (C-7), 31.8 (C-8), 50.3 (C-9), 36.6 (C-10), 21.2 (C-11), 39.8 (C-12), 42.4 (C-13), 56.9 (C-14), 24.4 (C-15), 28.4 (C-16), 56.2 (C-17), 12.1 (C-18), 19.5 (C-19), 36.3 (C-20), 18.9 (C-21), 34.1 (C-22), 26.2 (C-23), 46.0 (C-24), 29.3 (C-25), 20.0 (C-26), 19.2 (C-27), 23.2 (C-28), 12.0 (C-29)。以上数据与文献[21]报道的一致,确定化合物6β-谷甾醇。

棕榈酸-α-单甘油酯 (hexadecanoic acid, 2, 3- dihydroxypropyl ester, 7)  白色粉末,遇体积分数5%的硫酸显浅黄色。分子式为C19H38O4。ESI-MS m/z: 329.3 (10) [M-H]-1H NMR (CDCl3, 500 MHz): δ 4.13 (1H, dd, J = 4.6, 11.4 Hz), 4.06 (1H, dd, J = 6.2, 11.6 Hz), 3.83 (1H, dt, J = 5.4, 10.7 Hz), 3.57 (1H, dd, J = 5.0, 11.4 Hz), 3.53 (1H, dd, J = 5.8, 11.4 Hz), 2.33 (2H, d, J = 7.6 Hz), 1.59 (2H, dd, J = 7.0, 14.4 Hz), 1.26 (24H, m), 0.86 (3H, t, J = 6.9 Hz, H-16); 13C NMR (CDCl3, 125 MHz): δ 173.9 (C-1), 69.2 (C-1' ), 64.6 (C-2' ), 62.3 (C-3' ), 33.3 (C-2), 31.2 (C-14), 28.4~28.9 (C-4-14), 24.2 (C-3), 21.9 (C-15), 13.0 (C-16)。以上数据与文献[22]一致,确定化合物7为棕榈酸-α-单甘油酯。

2.2 乙酰胆碱酯酶抑制活性

参照Ellman法[14]并略有改进后,对国产绿奇楠沉香中化合物1~7的乙酰胆碱酯酶抑制活性进行测定,结果表明,50 μmol L–1的化合物1具有一定的乙酰胆碱酯酶抑制活性,其抑制率为(49.9± 1.4)%,化合物2~7的抑制率均小于10.0%。

3 讨论

本研究组前期报道了国产‘绿奇楠’沉香的化学成分主要是倍半萜和2-(2-苯乙基)色酮类化合物[6, 10-13],本研究从国产‘绿奇楠’沉香的乙醚和乙醇提取物中共分离鉴定出7个化合物,其中有1个倍半萜类化合物顺式-7-羟基菖蒲烯(1), 1个2-(2-苯乙基)色酮聚合物(5R, 6R, 7S, 8R)-2-(苯乙基)-6, 7, 8-三羟基-5, 6, 7, 8-四氢-5-[2-(2-苯乙基)色酮基-6-氧代]色酮(2), 1个酚类化合物1-羟基-1, 5-二苯基戊-3-酮(3), 1个木脂素苷丁香树脂酚葡萄糖苷(4), 1个三萜类化合物(3β)-齐墩果-12-烯-3, 23-二醇 (5), 1个甾体类化合物β-谷甾醇(6)和1个脂肪酸类化合物棕榈酸-α-单甘油酯(7),其中,化合物13~57均为首次从沉香中分离得到。

本研究组前期报道‘绿奇楠’沉香中具有乙酰胆碱酯酶抑制活性的艾里莫酚烷型倍半萜,而本研究分离出1个杜松烷型倍半萜:顺式-7-羟基菖蒲烯(1),也显示出较好的抑制活性,且表现出非常甜的芳香气味。值得一提的是,从沉香分离鉴定出的300余个化学成分中,仅有3个杜松烷型倍半萜[7],且均不是从国产沉香中得到的,而倍半萜类化合物是沉香的两大类主要成分之一,基于此,沉香中杜松烷型倍半萜还是有较大分离潜力的。在本研究中, 我们还得到了(5R, 6R, 7S, 8R)-2-(苯乙基)-6, 7, 8-三羟基-5, 6, 7, 8-四氢-5-[2-(2-苯乙基)色酮基-6-氧代]色酮(2),这是目前从‘奇楠’沉香中分离鉴定出的唯一1个2-(2-苯乙基)色酮聚合物[3-4, 7, 23-26],而目前报道沉香中的2-(2-苯乙基)色酮聚合物约有40个[16, 27-33], 由此推断,从‘奇楠’沉香继续分离出2-(2-苯乙基)色酮聚合物的可能性是较大的。1-羟基-1, 5-二苯基戊-3-酮(3)在结构上与沉香特征性沉香分2-(2-苯乙基)色酮类具有相关性,且据报道,此类化合物主要分布在瑞香科植物中[34],本次也是首次从沉香树脂中得到此类成分。此外,木脂素类化合物在未结香的白木部分大量分布[35-36],而本研究首次在结香后的沉香树脂中发现了1个木脂素苷丁香树脂酚葡萄糖苷(4);同时,三萜和甾体类化合物在白木香的树干、叶子、果实等部位均有分布,且β-谷甾醇(6)也从白木香分离得到[35-36]。本研究分离得到的化合物3~7并不属于沉香的两类特征性成分倍半萜和2-(2-苯乙基)色酮,同时结合前人对未结香的白木部分的研究,不难推断,这些成分很可能是残存的白木部分的成分,也即虽然‘奇楠’沉香是品质非常高的沉香,但其还是残存白木部分的化学成分,这为后续高品质‘奇楠’沉香的深入研究提供了一些参考。综上,本研究果进一步揭示了国产‘绿奇楠’沉香的化学成分和生物活性,为高品质‘奇楠’沉香的后续研究和开发利用提供了一定的研究基础。

参考文献
[1]
BARDEN A, AWANG ANAK N, MULLIKEN T A, et al. Heart of the Matter:Agarwood Use and Trade and CITES Implementation for Aquilaria malaccensis[M]. Cambridge: TRAFFIC International, 2000: 1-51.
[2]
YAMAGATA E, YONEDA K. Pharmacognostical studies on the crude drug of agarwood (Ⅵ):On "Kanankoh"[J]. Nat Med, 1987, 41(2): 142-146.
[3]
NAKANISHI T, INADA A, NISHI M, et al. A new and a known derivatives of 2-(2-phenylethyl) chromone from a kind of agarwood ("Kanankoh, " in Japanese) originating from Aquilaria agallocha[J]. J Nat Prod, 1986, 49(6): 1106-1108. DOI:10.1021/np50048a024
[4]
ISHIHARA M, TSUNEYA T, UNEYAMA K. Fragrant sesquiterpenes from agarwood[J]. Phytochemistry, 1993, 33(5): 1147-1155. DOI:10.1016/0031-9422(93)85039-T
[5]
XIE Z W. Discussion on Varieties of Chinese Medicinal Herb, Vol. 2[M]. Shanghai: Shanghai Science and Technology Press, 1984.
谢宗万. 中药材品种论述, 中册[M]. 上海: 上海科学技术出版社, 1984.
[6]
YANG D L, MEI W L, ZENG Y B, et al. 2-(2-Phenylethyl)chromone derivatives in Chinese agarwood "Qi-Nan" from Aquilaria sinensis[J]. Planta Med, 2013, 79(14): 1329-1334. DOI:10.1055/s-0033-1350647
[7]
DAI H F. Research Progress of Agarwood[M]. Beijing: Science Press, 2017.
戴好富. 沉香的现代研究[M]. 北京: 科学出版社, 2017.
[8]
YANG D L, MEI W L, YANG J L, et al. GC-MS analysis of the fragrant sesquiterpenes and 2-(2-phenylethyl) chromone derivatives in four types of agarwood "Qi-Nan"[J]. Chin J Trop Crops, 2014, 35(6): 1235-1243.
杨德兰, 梅文莉, 杨锦玲, 等. GC-MS分析4种奇楠沉香中致香的倍半萜和2-(2-苯乙基)色酮类成分[J]. 热带作物学报, 2014, 35(6): 1235-1243. DOI:10.3969/j.issn.1000-2561.2014.06.033
[9]
FU L G. Red Book of Chinese Plant:Rare and Endangered Plants[M]. Beijing: Science Press, 1992: 670.
傅立国. 中国植物红皮书——稀有濒危植物[M]. 北京: 科学出版社, 1992: 670.
[10]
YANG D L, WANG H, GUO Z K, et al. A new 2-(2-phenylethyl) chromone derivative in Chinese agarwood 'Qi-Nan' from Aquilaria sinensis[J]. J Asian Nat Prod Res, 2014, 16(7): 770-776. DOI:10.1080/10286020.2014.896342
[11]
YANG D L, WANG H, GUO Z K, et al. Fragrant agarofuran and eremophilane sesquiterpenes in agarwood 'Qi-Nan' from Aquilaria sinensis[J]. Phytochem Lett, 2014, 8: 121-125. DOI:10.1016/j.phytol.2014.03.003
[12]
YANG D L, LI W, DONG W H, et al. Five new 5, 11-epoxyguaiane sesquiterpenes in agarwood "Qi-Nan" from Aquilaria sinensis[J]. Fitoterapia, 2016, 112: 191-196. DOI:10.1016/j.fitote.2016.05.014
[13]
SHAO H, MEI W L, KONG F D, et al. A new 2-(2-phenylethyl) chromone glycoside in Chinese agarwood "Qi-Nan" from Aquilaria sinensis[J]. J Asian Nat Prod Res, 2017, 19(1): 42-46. DOI:10.1080/10286020.2016.1187602
[14]
ELLMAN G L, COURTNEY K D, ANDRES V Jr, et al. A new and rapid colorimetric determination of acetylcholinesterase activity[J]. Biochem Pharmacol, 1961, 7(2): 91-95. DOI:10.1016/0006-2952(61)90145-9
[15]
DAVILA-HUERTA G, HAMADA H, DAVIS G D, et al. Cadinane-type sesquiterpenes induced in Gossypium cotyledons by bacterial inoculation[J]. Phytochemistry, 1995, 39(3): 531-536. DOI:10.1016/0031-9422(94)00958-V
[16]
IWAGOE K, KAKAE T, KONISHI T, et al. Studies on the agalwood (Jinko):ⅤⅢ. Structures of bi-phenylethylchromone derivatives[J]. Chem Pharm Bull, 1989, 37(1): 124-128. DOI:10.1248/cpb.37.124
[17]
NIWA M, JIANG P F, HIRATA Y. Constituents of Wikstroemia sikokiana:Ⅱ. Absolute configurations of 1, 5-diphenylpentane-1, 3-diols[J]. Chem Pharm Bull, 1987, 35(1): 108-111. DOI:10.1248/cpb.35.108
[18]
KOBAYASHI H, KARASAWA H, MIYASE T, et al. Studies on the constituents of Cistanchis herba:Ⅴ. Isolation and structures of two new phenylpropanoid glycosides, cistanosides E and F[J]. Chem Pharm Bull, 1985, 32: 1452-1457.
[19]
SONG Z H, MO S H, CHEN Y, et al. Studies on chemical constituents of Cistanche tubulosa (Schenk) R. Wight[J]. China J Chin Mat Med, 2000, 25(12): 728-730.
宋志宏, 莫少红, 陈燕, 等. 管花肉苁蓉化学成分的研究[J]. 中国中药杂志, 2000, 25(12): 728-730. DOI:10.3321/j.issn:1001-5302.2000.12.009
[20]
WANG K W, SUN H X, WU B, et al. Two novel olean triterpenoids from Celastrus hypoleucus[J]. Helv Chim Acta, 2005, 88(5): 990-995. DOI:10.1002/hlca.200590094
[21]
CUI Y L, MU Q, HU C Q. Studies on the chemical constituents of Caragana rosea[J]. Chin Pharm J, 2004, 39(3): 173-175.
崔益冷, 穆青, 胡昌奇. 红花锦鸡儿化学成分的研究[J]. 中国药学杂志, 2004, 39(3): 173-175. DOI:10.3321/j.issn:1001-2494.2004.03.005
[22]
LU L M, SONG S J, WU Y, et al. Study on the chemical constituents of the ovum oil of Rana temporaria chensinensis David (Ⅱ)[J]. J Shenyang Pharm Univ, 2002, 19(1): 25-26.
卢立明, 宋少江, 武勇, 等. 哈士蟆卵油化学成分研究(Ⅱ)[J]. 沈阳药科大学学报, 2002, 19(1): 25-26. DOI:10.3969/j.issn.1006-2858.2002.01.007
[23]
ISHIHARA M, TSUNEYA T, SHIGA M, et al. Three sesquiterpenes from agarwood[J]. Phytochemistry, 1991, 30(2): 563-566. DOI:10.1016/0031-9422(91)83727-3
[24]
ISHIHARA M, TSUNEYA T, UNEYAMA K. Guaiane sesquiterpenes from agarwood[J]. Phytochemistry, 1991, 30(10): 3343-3347. DOI:10.1016/0031-9422(91)83206-Z
[25]
HASHIMOTO K, NAKAHARA S, INOUE T, et al. A new chromone from agarwood and pyrolysis products of chromone derivatives[J]. Chem Pharm Bull, 1985, 33(11): 5088-5091. DOI:10.1248/cpb.33.5088
[26]
UEDA J Y, IMAMURA L, TEZUKA Y, et al. New sesquiterpene from Vietnamese agarwood and its induction effect on brain-derived neurotrophic factor mRNA expression in vitro[J]. Bioorg Med Chem, 2006, 14(10): 3571-3574. DOI:10.1016/j.bmc.2006.01.023
[27]
YANG Y, CHEN H Q, KONG F D, et al. Dimeric sesquiterpenoid- 4H-chromone derivatives from agarwood of Aquilaria crassna and their cytotoxicity[J]. Phytochemistry, 2018, 145: 207-213. DOI:10.1016/j.phytochem.2017.08.007
[28]
YANG Y, MEI W L, KONG F D, et al. Four new bi-2-(2-phenylethyl) chromone derivatives of agarwood from Aquilaria crassna[J]. Fitoterapia, 2017, 119: 20-25. DOI:10.1016/j.fitote.2017.03.008
[29]
XIANG P, MEI W L, CHEN H Q, et al. Four new biphenylethyl- chromones from artificial agarwood[J]. Fitoterapia, 2017, 120: 61-66. DOI:10.1016/j.fitote.2017.05.012
[30]
HUO H X, ZHU Z X, SONG Y L, et al. Anti-inflammatory dimeric 2-(2-phenylethyl)chromones from the resinous wood of Aquilaria sinensis[J]. J Nat Prod, 2018, 81(3): 543-553. DOI:10.1021/acs.jnatprod.7b00919
[31]
IWAGOE K, KONISHI T, KIYOSAWA S, et al. The structures of AH10 and AH11, nobel bi-phenylethylchromones from agalwood[J]. Chem Pharm Bull, 1986, 34(11): 4889-4891. DOI:10.1248/cpb.34.4889
[32]
IWAGOE K, KODAMA S, KONISHI T, et al. The structures of AH15 and AH18, new bi- and tri-phenylethylchromones from agalwood[J]. Chem Pharm Bull, 1987, 35(11): 4680-4682. DOI:10.1248/cpb.35.4680
[33]
KONISHI T, IWAGOE K, KIYOSAWA S, et al. Tri-2-(2-phenylethyl) chromones from agalwood[J]. Phytochemistry, 1989, 28(12): 3548-3550. DOI:10.1016/0031-9422(89)80391-7
[34]
PENG Y J, HUANG C S, LIU H X, et al. Recent advances in the structure and biological activity of 1, 5-dihpenylpentadions[J]. Nat Prod Res Dev, 2009, 21(6): 1069-1075, 1079.
彭艳君, 黄初升, 刘红星, 等. 1, 5-二芳基戊烷类化合物生物活性与结构关系的研究进展[J]. 天然产物研究与开发, 2009, 21(6): 1069-1075, 1079. DOI:10.3969/j.issn.1001-6880.2009.06.041
[35]
LI W, CAI C H, DONG W H, et al. 2-(2-Phenylethyl)chromone derivatives from Chinese agarwood induced by artificial holing[J]. Fitoterapia, 2014, 98: 117-123. DOI:10.1016/j.fitote.2014.07.011
[36]
LI W, MEI W L, ZUO W J, et al. Advances in chemical constituents and biological activities from Aquilaria sinensis[J]. J Trop Subtrop Bot, 2014, 22(2): 201-212.
李薇, 梅文莉, 左文健, 等. 白木香的化学成分与生物活性研究进展[J]. 热带亚热带植物学报, 2014, 22(2): 201-212. DOI:10.3969/j.issn.1005-3395.2014.02.015