常燕玲, 梁曉琴, 黃 艷, 潘立衛(wèi), 侯 萍, 任晨陽(yáng), 李 俊

( 廣西師范大學(xué) 化學(xué)與藥學(xué)學(xué)院, 省部共建藥用資源化學(xué)與藥物分子工程國(guó)家重點(diǎn)實(shí)驗(yàn)室, 廣西 桂林 541004 )

香茶菜屬(Isodon)為唇形科(Lamiaceae)植物,曾用過(guò)Rabdosia、Plectranthus、Amethystanthus和Isodon等屬名,1985年將該屬名正式定為Isodon。該屬植物全球有150余種,我國(guó)有90種、21個(gè)變種,遍布全國(guó)各地,但以西南諸省種類最多,其中廣西分布有13種(中國(guó)科學(xué)院中國(guó)植物志編輯委員會(huì),2004;覃海寧和劉演,2010)。香茶菜屬植物是我國(guó)民間廣泛使用的民間中藥,供藥用的約有30種,被制成了清熱解毒、抗菌消炎、保肝、抗肝炎、抗癌和治療腸胃炎的藥品(Olveira et al., 2007;Park, 2011;項(xiàng)昭保和金永生,2022)。香茶菜屬中含有大量的二萜、三萜、甾醇、黃酮、木脂素、多酚等化合物,特別是結(jié)構(gòu)類型多樣的二萜化合物(孫漢董等,2001;Olveira et al., 2007;Park, 2011;Liu et al., 2017; 張義等,2019)。周重陽(yáng)(1988)研究表明,二萜化合物香茶菜甲素對(duì)革蘭氏陰性菌和部分陽(yáng)性菌都有抑制作用且對(duì)福氏痢疾桿菌的作用又優(yōu)于黃連素。藍(lán)萼香茶菜中分離得到的貝殼杉烷型二萜冬凌草甲素能抑制多種癌細(xì)胞的增殖(丁蘭等,2008;李翔等,2009)。

大萼香茶菜(Isodonmacrocalyx)系唇形科香茶菜屬植物,主要分布于江西、福建、湖南、廣東、廣西和臺(tái)灣等省(區(qū))。民間用其全草治療急性黃疽型肝炎和急性膽囊炎(呂惠珍,1999)。大萼香茶菜總二萜對(duì)二甲苯引起的血管通透性增加有明顯的抑制作用(陳澍禾等,1988)。迄今為止,僅從大萼香茶菜中分離得到大萼香茶菜甲素、乙素和丙素等少數(shù)的化合物(王先榮等,1984;程培元等,1984)。為了更加深入了解大萼香茶菜的物質(zhì)基礎(chǔ),本文對(duì)其地上部分的化學(xué)成分進(jìn)行分離和結(jié)構(gòu)鑒定。

1 材料、儀器與方法

1.1 實(shí)驗(yàn)藥材

實(shí)驗(yàn)藥材于2019年8月12日采自海南陵水縣佳西,經(jīng)云南中醫(yī)藥大學(xué)中藥學(xué)院李國(guó)棟教授鑒定為大萼香茶菜(Isodonmacrocalyx),植物標(biāo)本(ZFC201903015e) 存放于廣西師范大學(xué)化學(xué)與藥學(xué)學(xué)院國(guó)家重點(diǎn)實(shí)驗(yàn)室天然產(chǎn)物研究室。

1.2 實(shí)驗(yàn)儀器

Agilent 6545 Q-TOF LC-MS 高分辨質(zhì)譜儀(美國(guó)Agilent公司);Bruker AVANCE 400/500 MHz 核磁共振儀(Bruker BioSpin AGFacilities 公司);LC3000半制備高效液相色譜儀(北京創(chuàng)新通恒科技有限公司);LC1260半制備高效液相色譜儀(美國(guó)Agilent公司);柱層析硅膠粉 (200～400目) 和薄層色譜硅膠板(G254) 購(gòu)自青島海洋化工廠;ODS填料、Sephadex LH-20填料和MCI填料 (Merck, Germany) 均購(gòu)自北京綠百草科技有限公司。5%硫酸乙醇顯色劑自配,其原材料購(gòu)自西隴化工有限公司;甲醇、乙醇、丙酮、乙酸乙酯、三氯甲烷、二氯甲烷等分析純化學(xué)試劑均購(gòu)自西隴化工有限公司。

1.3 實(shí)驗(yàn)方法

取風(fēng)干的大萼香茶菜地上部分20.0 kg,粉碎,用75%乙醇提取,收集提取液濃縮。得浸膏4.0 kg,將浸膏分散于水中,依次用PE、EtOAc和BuOH萃取,余下的為水部分,萃取液濃縮后得浸膏。對(duì)EtOAc部分經(jīng)硅膠柱層析,用CH2Cl2-EtOAc (100∶0、90∶10、80∶20、50∶50、0∶100)為洗脫劑梯度洗脫,共得到5個(gè)部分Fr.A～Fr.E。Fr.A (80.2 g)經(jīng)硅膠柱層析,用PE-EtOAc (100∶0→50∶50) 進(jìn)行梯度洗脫,得5個(gè)組分Fr.A.1～Fr.A.5。Fr.A.2 (20.4 g) 經(jīng)硅膠柱層析,用PE-EtOAc (98∶2→50∶50) 進(jìn)行梯度洗脫,得5個(gè)亞組分Fr.A.2.1～Fr.A.2.5。Fr.A.2.1反復(fù)硅膠柱層析,用PE-EtOAc (98∶2→60∶40) 進(jìn)行梯度洗脫,得化合物1(15.6 mg);Fr.A.2.2經(jīng)硅膠層析,用EtOAc-PE (1%、2%、3%、4%、5%) 進(jìn)行梯度洗脫,得化合物7(7.1 mg);Fr.A.2.3經(jīng)Sephadex LH-20層析,用 PE∶CHCl3∶MeOH(1∶2∶1)洗脫純化,得化合物2(12.4 mg)和3(10.5 mg)。Fr.A.3 (25.3 g) 經(jīng)硅膠柱層析,用PE-acetone (98∶2→10∶90) 進(jìn)行梯度洗脫,得4個(gè)亞組分Fr.A.3.1～Fr.A.3.4。Fr.A.3.2經(jīng)Sephadex LH-20層析,用 PE∶CHCl3∶MeOH(1∶2∶1)洗脫純化,得化合物4(6.8 mg)和5(6.7 mg);Fr.A.3.3經(jīng)硅膠層析,用EtOAc-PE (1%、2%、3%、4%、5%) 梯度洗脫,得化合物6(5.6 mg)和11(7.7 mg)。Fr.A.4 (18.5 g) 經(jīng)C18層析,用H2O∶MeOH (70∶30→0∶100) 進(jìn)行梯度洗脫,得4個(gè)亞組分Fr.A.4.1～Fr.A.4.4。Fr.A.4.2 (15.3 g) 經(jīng)RP-C18半制備高效液相色譜層析,用流動(dòng)相H2O∶MeOH (70∶30→50∶50)梯度洗脫,得化合物8(5.8 mg)和12(12.5 mg);Fr.A.4.3經(jīng)Sephadex LH-20 層析,用MeOH洗脫,得化合物9(29.3 mg)、10(6.0 mg)和13(7.8 mg)。

2 化合物結(jié)構(gòu)鑒定

首先對(duì)大萼香茶菜地上部分用75%乙醇提取物進(jìn)行EtOAc萃取,然后經(jīng)硅膠、ODS、Sephadex LH-20、反相半制備高效液相等色譜分離純化,得到13個(gè)二萜,最后利用1H NMR、13C NMR和HR-ESI-MS等波譜手段,以及結(jié)合參考文獻(xiàn),確定了這些二萜的結(jié)構(gòu)。這些二萜包括松香烷型(2、6、7)、桃柘烷型(1、3-5)、貝葉烷型(8、9)和貝殼杉烷(10、12、13),得到的二萜均為首次從該植物中分離得到。化合物結(jié)構(gòu)見(jiàn)圖1。

化合物1白色固體。HR-ESI-MSm/z: 303.232 9 [M + H]+(calcd for C20H31O2, 303.232 4)。1H NMR (400 MHz, CD3COCD3)δH6.93 (d,J= 8.6 Hz, 1H), 6.60 (d,J= 8.6 Hz, 1H), 1.33 (d,J= 1.3 Hz, 3H), 1.30 (d,J= 1.3 Hz, 3H), 1.15 (s, 3H), 1.03 (s, 3H)。13C NMR (100 MHz, CD3COCD3)δC154.3 (C-13), 142.5 (C-8), 133.8 (C-9), 131.3 (C-14), 123.7 (C-11), 115.1 (C-12), 64.5 (C-19), 51.7 (C-5), 40.7 (C-1), 40.7 (C-6), 39.4 (C-10), 38.3 (C-4), 36.0 (C-3), 30.1 (C-7), 28.2 (C-15), 27.6 (C-18), 26.5 (C-20), 20.5 (C-17), 20.3 (C-16), 20.0 (C-2)。以上數(shù)據(jù)與文獻(xiàn)(Kalule &Li,2005)比對(duì)基本一致,故鑒定化合物1為19-羥基陶塔酚。

化合物2HR-ESI-MSm/z: 303.232 0 [M + H]+(calcd for C20H31O2, 303.232 4)。1H NMR (400 MHz, CDCl3)δH6.99 (d,J= 8.6 Hz, 1H), 6.52 (d,J= 8.6 Hz, 1H), 3.86 (d,J= 11.0 Hz, 1H), 3.55 (d,J= 11.0 Hz, 1H), 2.94 (dd,J= 17.1, 6.0 Hz, 1H), 1.87 (dd,J= 13.7, 1.2 Hz, 1H), 1.35 (d,J= 2.8 Hz, 3H), 1.33 (d,J= 2.8 Hz, 3H), 1.17 (s, 3H), 1.05 (s, 3H)。13C NMR (100 MHz, CDCl3)δC152.2 (C-14), 142.9 (C-8), 133.8 (C-9), 131.1(C-13), 123.4 (C-12), 114.6 (C-11), 65.5 (C-19), 50.6 (C-5), 39.8 (C-6), 38.7 (C-4), 37.8 (C-10), 35.2 (C-3), 29.4 (C-7), 27.3 (C-15), 26.8 (C-18), 26.1 (C-20), 20.4(C-16, 17), 19.6 (C-1), 19.3(C-2)。以上數(shù)據(jù)與文獻(xiàn)(Qin et al., 2007)比對(duì)基本一致,故鑒定化合物2為macrophynin E。

化合物3HR-ESI-MSm/z: 317.211 4 [M + H]+(calcd for C20H29O3, 317.211 7)。1H NMR (500 MHz, CD3OD)δH6.92 (1H, d,J= 8.6 Hz, H-12), 6.52 (1H, d,J= 8.6 Hz, H-13), 2.92 (1H, dd,J= 16.8, 4.6 Hz, H-7), 2.55～2.65 (1H, m, H-7), 1.89～1.95 (1H, m, H-2, 9), 1.56 (1H, d,J= 14.2 Hz, H-2), 1.44 (1H, d,J= 12.4 Hz, H-5), 1.32 (3H, d,J= 7.0 Hz, H-17), 1.31 (3H, d,J= 7.0 Hz, H-16), 1.28 (3H, s, H-19), 1.12 (3H, s, H-20)。13C NMR (125 MHz, CD3OD)δC181.7 (C-19), 154.8 (C-11), 140.9 (C-9), 134.5 (C-8), 131.8 (C-14), 124.9 (C-12), 115.3 (C-13), 53.4 (C-5), 44.7 (C-4), 41.7 (C-3), 39.5 (C-10), 38.7 (C-1), 31.2 (C-7), 29.2 (C-18), 27.4 (C-15), 22.6 (C-6), 21.3 (C-2), 20.7 (C-17), 20.5 (C-16), 14.4 (C-20)。以上數(shù)據(jù)與文獻(xiàn)(Devkota et al., 2011)比對(duì)基本一致,故鑒定化合物3為inumakoic acid。

化合物4HR-ESI-MSm/z: 333.206 8 [M + H]+(calcd for C20H29O4, 333.206 6)。1H NMR (500 MHz, CD3COCD3)δH6.98 (1H, d,J= 8.6 Hz, H-12), 6.71 (1H, d,J= 8.6 Hz,), 5.62(1H, s, H-11), 3.64 (1H, m, H-5), 1.39 (d,J= 7.0 Hz, 3H, H-16), 1.35 (3H, d,J= 7.0 Hz, H-17), 1.28 (3H, s, H-18), 1.05 (3H, s, H-20)。13C NMR (125 MHz, CD3COCD3)δC179.1 (C-19), 154.9 (C-13), 140.7 (C-9), 136.0 (C-8), 133.5 (C-14), 124.5 (C-11), 117.2 (C-12), 65.4 (C-7), 45.6 (C-5), 43.7 (C-4), 40.6(C-1), 39.3 (C-10), 38.4 (C-3), 32.3 (C-6), 28.8 (C-18), 28.4 (C-15), 22.8 (C-20), 21.0(C-2), 20.9 (C-17)。以上數(shù)據(jù)與文獻(xiàn)(Sato et al., 2008)比對(duì)基本一致,故鑒定化合物4為inumakiol D。

化合物5HR-ESI-MSm/z: 317.211 1 [M + H]+(calcd for C20H29O3, 317.211 7)。1H NMR (400 MHz, CDCl3)δH7.02 (1H, d,J= 8.3 Hz, H-11), 6.56 (1H, d,J= 8.3 Hz, H-12), 3.34 (1H, d,J= 6.1 Hz, H-15), 3.01 (1H, d,J= 16.6 Hz, H-7), 2.72 (1H, t,J= 14.2 Hz, H-7), 2.27 (2H, t,J= 14.3 Hz, H-1, 6), 2.05 (1H,d,J= 4.7 Hz, H-3), 1.65 (1H, m, H-5), 1.53 (1H, dd,J= 11.7, 5.4 Hz, H-2), 1.36 (9H, m, H-16, 17, 18), 1.18 (3H, s, H-20)。13C NMR (100 MHz, CDCl3)δC184.4 (C-18), 152.2 (C-13), 141.0 (C-9), 134.4 (C-8), 131.1 (C-14), 124.2 (C-11), 114.7 (C-12), 52.2 (C-5), 43.9 (C-1), 40.2 (C-10), 38.6 (C-4), 37.3 (C-3), 30.1 (C-7), 28.7 (C-15), 27.4 (C-19), 23.3 (C-20), 21.2 (C-17), 20.5 (C-16), 20.4(C-6), 20.2 (C-2)。以上數(shù)據(jù)與文獻(xiàn)(李雯等,2014)比對(duì)基本一致,故鑒定化合物5為4β-carboxy-19-nortotarol。

化合物6HR-ESI-MSm/z: 317.212 3 [M + H]+(calcd for C20H29O3, 317.211 7)。1H NMR (400 MHz, CD3COCD3)δH6.79 (1H, s, H-14), 6.73 (1H, s, H-14), 3.22 (1H, m, H-15), 2.74～2.82 (1H, m, H-7), 2.62～2.72 (1H, m, H-7), 1.28 (3H, s, H-20), 1.19 (3H, d,J= 4.0 Hz, H-16), 1.17 (3H, d,J= 7.0 Hz, H-17), 1.10 (3H, s, H-18)。13C NMR (100 MHz, CD3COCD3)δC178.9 (C-19), 153.2 (C-12), 147.0 (C-9), 132.9 (C-8), 127.2 (C-14), 126.7 (C-13), 112.3 (C-11), 53.5 (C-5), 44.2 (C-4), 40.4 (C-6), 39.0 (C-10), 38.4 (C-1), 32.0 (C-3), 29.0 (C-15), 27.4 (C-18), 23.6 (C-24), 23.0 (C-7), 22.9 (C-16), 22.2 (C-17), 20.8 (C-2)。以上數(shù)據(jù)與文獻(xiàn)(Qin et al., 2007)比對(duì)基本一致,故鑒定化合物6為(-)-lambertic acid。

化合物7白色粉末。HR-ESI-MSm/z: 321.243 5 [M + H]+(calcd for C20H33O3, 321.243 0)。1H NMR (400 MHz, CD3OD)δH1.11 (1H, m, H-1), 1.53 (1H, m, H-1), 5.71 (1H, s, H-3), 1.36 (1H, m, H-6), 1.10 (1H, m, H-6), 2.43 (1H, m, H-7), 1.75 (1H, m, H-7), 1.38 (1H, m, H-8), 1.77 (1H, m, H-10), 1.54 (1H, m, H-11), 1.30 (1H, m, H-11), 1.11 (1H, m, H-12), 1.72(1H, m, H-12), 1.93 (1H, m, H-14), 1.54(1H, m, H-14), 3.23 (1H, dd,J= 9.2, 2.6 Hz, H-15), 3.71 (1H, dd,J= 11.2, 2.6 Hz, H-16), 3.45 (1H, dd,J= 11.2, 9.2 Hz, H-16), 1.95 (3H, m, H-17), 1.19 (3H, m, H-18), 0.95 (3H, m, H-19), 0.90 (3H, m, H-)。13C NMR (100 MHz, CD3OD)δC35.5 (C-1), 203.5 (C-2), 125.8 (C-3), 176.6 (C-4), 37.9 (C-5), 36.6 (C-6), 35.3 (C-7), 42.7 (C-8), 37.9 (C-9), 54.4 (C-10), 26.7 (C-11), 30.1 (C-12), 41.7 (C-13), 37.3(C-14), 82.5 (C-15), 63.5 (C-16), 19.1 (C-17), 19.3 (C-18), 19.9 (C-19),12.5 (C-20)。以上數(shù)據(jù)與文獻(xiàn)(Abdel-Kader et al., 1994)比對(duì)基本一致,故鑒定化合物7為2-oxo-5-fagonene。

化合物8HR-ESI-MSm/z: 393.228 0 [M + H]+(calcd for C22H33O6, 393.227 7)。1H NMR (500 MHz, CDCl3)δH5.20 (1H, t,J= 5.0 Hz, H-11), 5.11 (1H, s, H-17), 5.09 (1H, s, H-17), 4.48 (1H, s, H-15), 4.23 (1H, d,J= 8.7 Hz, H-20), 4.06 (1H, d,J= 8.7 Hz, H-20), 3.93 (1H, d,J= 6.2 Hz, H-6), 2.70 (1H, dd,J= 8.5, 4.7 Hz, H-13), 2.11～2.21 (2H, m, H-12, 14), 2.05 (3H, s, CH3C=O), 1.77 (1H, dd,J= 15.7, 5.6 Hz, H-12), 1.63 (1H, m, H-14), 1.44 (1H, dd,J= 7.5, 1.1 Hz, H-5), 1.17 (d,J= 10.9 Hz, 1H), 1.09 (3H, s, H-18), 1.02 (3H, s, H-19)。13C NMR (125 MHz, CDCl3)δC170.0 (-C=O), 159.2 (C-16), 108.6 (C-17), 97.2 (C-7), 74.2 (C-15) 74.1 (C-6), 69.1 (C-20), 68.5 (C-11), 56.0 (C-5), 50.7 (C-8), 45.8 (C-9), 41.4 (C-12), 41.1 (C-3), 36.4 (C-10), 35.6 (C-13), 33.9 (C-18), 33.6 (C-4), 31.0 (C-1), 26.1 (C-14), 22.5 (C-19), 22.2 (C-MeCO-), 18.6 (C-2)。以上數(shù)據(jù)與文獻(xiàn)(王智民等,1996)比對(duì)基本一致,故鑒定化合物8為isodoterniofiln B。

化合物9HR-ESI-MSm/z: 391.212 5 [M + H]+(calcd for C22H31O6, 391.212 1)。1H NMR (400 MHz, CDCl3)δH5.99 (1H, s, H-17), 5.46 (1H, m, H-11), 5.31 (1H, s, H-17), 4.17(1H, d, J = 9.3 Hz, H-20), 4.09 (1H, d, J = 9.2 Hz, H-20), 3.88 (1H, d,J= 6.8 Hz, H-5), 2.10 (s, 3H), 1.15 (s, 3H), 1.13 (s, 3H)。13C NMR (100 MHz, CDCl3)δC208.2 (C-15), 169.8 (C=O), 151.8 (C-16), 118.6 (C-17), 95.1 (C-7), 74.9 (C-6), 69.2 (C-11), 68.2 (C-20), 58.8 (C-9), 58.6 (C-8), 53.9 (C-5), 41.6 (C-3), 38.1 (C-12), 37.3 (C-10), 34.3 (C-1), 33.8 (C-18), 33.8 (C-4), 31.5 (C-13), 26.5 (C-14), 22.8 (C-19), 22.0 (C-MeCO-), 18.6 (C-2)。以上數(shù)據(jù)與文獻(xiàn)(魏志雄等,2012)比對(duì)基本一致,故鑒定化合物9為長(zhǎng)管貝殼杉素E。

化合物10白色針狀晶體。HR-ESI-MSm/z: 349.201 9 [M + H]+(calcd for C20H29O5, 349.201 5)。1H NMR (400 MHz, CDCl3)δH6.62 (d,J= 10.8 Hz, 1H), 6.19 (s, 1H), 6.14 (s, 1H), 5.52 (s, 1H), 4.96 (s, 1H), 4.79 (s, 1H), 4.08 (d,J= 9.9 Hz, 1H), 3.77 (ddd,J= 17.5, 10.3, 3.9 Hz, 2H), 3.03 (d,J= 9.6 Hz, 1H), 1.55～1.69 (m, 3H), 1.37～1.46 (m, 3H), 1.28～1.35 (m, 2H), 1.23 (d,J= 6.7 Hz, 1H), 1.07 (s, 6H), 0.89～0.98 (m, 1H)。13C NMR (100 MHz, CDCl3)δC207.5 (C-15), 151.4 (C-16), 120.9 (C-17), 97.4 (C-7), 74.2 (C-6), 72.8 (C-14), 66.9 (C-20), 62.2 (C-8), 59.4 (C-9), 53.0 (C-5), 42.9 (C-13), 41.3 (C-3), 36.4 (C-10), 33.7 (C-18), 33.4 (C-4), 31.1 (C-1), 29.7 (C-12), 22.5 (C-19), 18.7 (C-11), 16.7 (C-2)。以上數(shù)據(jù)與文獻(xiàn)(納智等,2002)比對(duì)基本一致,故鑒定化合物10為長(zhǎng)管香茶菜素A。

化合物11HR-ESI-MSm/z: 391.212 4 [M + H]+(calcd for C22H31O6, 391.212 1)。1H NMR (500 MHz, CDCl3)δH6.01 (s, 1H), 5.50 (s, 1H), 4.87 (t,J= 14.8 Hz, 1H), 4.76 (d,J= 7.9 Hz, 1H), 4.43 (t,J= 12.3 Hz, 1H), 2.02 (s, 3H), 1.01 (s, 3H), 0.86 (s, 3H)。13C NMR (125 MHz, CDCl3)δC201.9 (C-15), 170.6 (C-7), 170.5 (C=O), 150.4 (C-16), 119.1 (C-17), 76.6 (C-1), 68.4 (C-20), 59.9 (C-6), 58.1 (C-8), 53.2 (C-5), 43.9 (C-10), 42.1 (C-9), 39.7 (C-3), 35.0 (C-13), 34.0 (C-4), 33.5 (C-18), 29.9 (C-12), 28.8 (C-14), 24.1 (C-72), 23.9 (C-19), 21.6 (C-CH3CO-), 17.6 (C-11)。以上數(shù)據(jù)與文獻(xiàn)(納智等,2002)比對(duì)基本一致,故鑒定化合物11為牛尾草素H。

化合物12HR-ESI-MSm/z: 351.217 6 [M + H]+(calcd for C20H31O5, 351.217 1)。1H NMR (400 MHz, CDCl3)δH4.74 (1H, s, H-14), 4.12 (1H, d,J= 9.9 Hz, H-20), 3.76 (2H, m, H-6, 20), 2.40 (dt,J= 13.6, 4.7 Hz, 1H), 1.33 (3H, d,J= 7.5 Hz, H-17), 1.11 (3H, s, H-18), 1.10 (3H, s, H-19)。13C NMR (100 MHz, CDCl3)δC209.0 (C-15), 97.3 (C-7), 74.8 (C-6), 74.7 (C-14), 67.3 (C-20), 62.9 (C-8), 58.6 (C-9), 52.6 (C-6), 50.9 (C-16), 42.0 (C-13), 41.5 (C-3), 36.4 (C-10), 33.7 (C-4), 33.7 (C-18), 31.7 (C-1), 30.0 (C-12), 22.8 (C-19), 18.8 (C-11), 18.2 (C-17), 16.7 (C-2)。以上數(shù)據(jù)與文獻(xiàn)(Takeda et al., 1988)比對(duì)基本一致,故鑒定化合物12為 16S-dihydrolongikaurin A。

化合物13無(wú)色晶體。HR-ESI-MSm/z: 321.243 6 [M + H]+(calcd for C20H33O3, 321.243 0)。1H NMR (400 MHz, CD3OD)δH2.02 (1H, m, H-1), 1.43 (1H, m, H-1), 2.49 (1H, m, H-2), 1.47 (1H, m, H-5), 1.52 (2H, m, H-6), 1.65 (2H, m, H-7), 1.16 (1H, m, H-9), 1.61 (2H, m, H-11), 1.54 (1H, m, H-12), 1.66 (1H, m, H-12), 2.06 (1H, m, H-13), 1.68 (1H, m, H-14), 1.89 (1H, m, H-14), 1.68 (1H, m, H-15), 1.89 (1H, m, H-15), 3.71 (1H, d,J= 11.4 Hz, H-17), 3.61 (1H, d,J= 11.4, Hz, H-17), 1.07 (3H, s, H-18), 1.03 (3H, s, H-19), 1.10 (3H, s, H-20)。13C NMR (100 MHz, CD3OD)δC40.4 (C-1), 35.0(C-2), 220.0 (C-3), 48.2 (C-4), 55.4 (C-5), 22.6 (C-6), 42.2 (C-7), 45.5 (C-8), 56.8 (C-9), 39.6 (C-10), 19.8 (C-11), 27.1 (C-12), 46.2 (C-13), 37.9 (C-14), 53.4 (C-15), 82.2 (C-16), 66.8 (C-17), 27.7 (C-18), 21.4 (C-19), 18.4 (C-20)。以上數(shù)據(jù)與文獻(xiàn)(王環(huán)等,2004)比對(duì)基本一致,故鑒定化合物13為ent-3S,16S,17-trihydroxy-kauran-2-one。

3 討論與結(jié)論

本研究對(duì)大萼香茶菜地上部分的乙酸乙酯部位化學(xué)成分進(jìn)行分離,得到13個(gè)二萜類化合物,表明大萼香茶菜中含有豐富的二萜類化合物。這些二萜化合物都是首次從該植物分離得到,它們包括松香烷型、桃柘烷型、貝葉烷型和貝殼杉烷型。文獻(xiàn)報(bào)道,二萜類化合物有抗菌消炎和抗癌等藥理活性,如19-羥基陶塔酚(Reynolds et al., 2006) 、macrophynin E(李雯等,2013)、(-)-lambertic acid(Thao et al., 2019)、長(zhǎng)管貝殼杉素E(Cheng et al., 2015; Ferrucci et al., 2016)和長(zhǎng)管香茶菜素A(Zou et al., 2013; Liao et al., 2014; Yuan et al., 2017)對(duì)肝癌細(xì)胞、卵巢癌細(xì)胞和食管癌細(xì)胞等具有良好的細(xì)胞毒性。同時(shí),inumakiol D(Sato et al., 2008)對(duì)口腔病原微生物具有抗菌活性,lambertic acid(王亞丹等,2013) 對(duì)柯薩奇B3病毒具有抗病毒活性。大萼香茶菜中含有豐富的且活性良好的二萜類化合物,預(yù)示該藥材的民間藥用療效或與這些二萜類化合物的活性有關(guān)。