【作者】 李瑞娟；

【导师】 娄红祥； Kuo-Hsiung Lee；

【作者基本信息】 山东大学 ， 天然药物化学， 2014， 博士

【摘要】 苔藓植物在分类学上介于藻类和蕨类之间,从形态学上可以分为苔纲(Hepaticae)、藓纲(Musci)和角苔纲(Anthocerotae)三类。苔类植物在全球约有6000余种,我国约有880余种。近年来,对苔类植物的化学成分研究较多,因为这类植物的细胞中含有独特的油体,其中富含脂溶性萜类和芳香类化合物,而藓纲和角苔纲植物细胞中不含油体。苔类植物中很多次生代谢产物具有良好的生物活性。近年来,从苔类植物中分离得到大量结构新颖而且活性显著的倍半萜、二萜和双联苄类化合物,其中许多化合物具有很好的生物学活性,可以作为药物研发的先导化合物。双联苄类化合物是苔类植物中的特征性成分,具有多种显著生物活性。以活性显著地双联苄类化合物为目标进行全合成,并且进一步对其结构进行修饰衍生化,对于发现和研制新型药物具有重要意义。本文对采自中国的六种苔类植物,包括采自广西的全缘广萼苔(Chandonanthus birmensis)、斯氏合叶苔(Scapania stephanii)和鳞叶拟大萼苔(Cephaloziella kiaeri),采自云南的齿叶耳叶苔(Frullania serrata),以及采自贵州的尖瓣光萼苔(东亚亚种)(Porella acutifolia subsp. tosana)和短齿羽苔(Plagiochila vexans)的化学成分研究进行了系统的阐述,共从中分离鉴定了61个化合物。综合采用核磁共振、质谱、X射线单晶衍射法、CD激子手性法以及含时密度泛函理论CD计算等方法确定了这些化合物的结构,包括39个二萜、10个倍半萜、2个三萜、6个甾体和4个单联苄,其中新化合物28个,包括25个新的二萜和3个新的倍半萜。对分离得到的化合物进行了初步的生物活性研究,发现西松烷型二萜具有较弱的肿瘤细胞生长抑制活性以及克罗烷型二萜对植物根部生长具有显著的抑制作用。对全缘广萼苔、斯氏合叶苔和鳞叶拟大萼苔的化学成分研究尚属首次。从全缘广萼苔中分离并鉴定了7个化合物,包括6个西松烷型二萜,chandonanones B (1). C (2). E (3)、F (4)、chandonanthone (5)和isochandonanthone(6),以及1个朵拉比烷型二萜2,10,14-triacetoxy-7,8,18,19-diepoxydolabell-3(E)-ene(7)。其中西松烷型二萜1-4为新化合物。生物活性实验表明,西松烷型二萜对鼠嗜铬细胞瘤PCl2细胞株、人肺癌NCI-H292细胞株以及人肺癌NCI-H1299细胞株具有较弱的肿瘤细胞生长抑制活性,其IC50范围为19.5-48.7μM。从斯氏合叶苔中分离并鉴定了12个顺式克罗烷型二萜,包括stephanialides A-E (8-12)、scaparvins A-C (13-15)、parvitexins B (16)和C (17)、3-chloro-4-hydroxy-parvitexin A (18)以及scapanialide B (19)。其中8-12为新化合物。测定了化合物10、12-14、16和17对拟南芥(Arabidopsis thaliana)、家独行菜(Lepidium sativum)和大白菜(Brassica pekinensis)种子根部生长的化感活性。所测化合物对三种植物种子的根部生长均具有显著的抑制作用,其IC50范围为3.5-30.7μg/mL。从鳞叶拟大萼苔中分离纯化并鉴定了21个化合物,这些化合物包括：18个克罗烷型二萜：cephaloziellins A-P (20-35)、amphiacrolide F (36)和cephaloziellin Q(37)；2个愈创木烷型倍半萜：4β,6β-dihydroxy-1α,5β(H)-guai-9-ene (38)和teucladiol(39)；以及1个香木兰烷型倍半萜：ent-3β-hydroxyspathulenol (40)。其中克罗烷型二萜20-35均为新化合物。从齿叶耳叶苔中分离纯化并鉴定了6个化合物,这些化合物包括2个杜松烷型倍半萜[frullanic acid (41)和frullanic acid methyl ester (42)]和4个单联苄[brittonin B (43)、3,3’-dimethoxy-4,5-methylene-dioxybibenzyl (44)、3,4,5,3’,4’-penla-methoxy-bibenzyl (45)和(±)-3-(4’-methoxy-benzyl)-5,6-dimethoxyphtbalide (46)]。其中41和42为新化合物。从尖瓣光萼苔(东亚亚种)中分离纯化并鉴定了7个化合物,这些化合物包括1个愈创木烷型倍半萜[guaian-3-en-2α,14-6a,12-diolide (47)]和6个甾体[(20R)-6-hydroxystigmasta-4,22-dien-3-one (48)、(20R)-3-hydroxystigmasta-5,22-dien-7-one (49)、7-oxositosterol (50)、(24S)-ethyl-5,22-cholestadien-3(51). ergosterol peroxide (52)和β-sitosterol (53)]。其中化合物47为新化合物。从短齿羽苔中分离纯化得到8个化合物,这些化合物包括：3个香木兰烷型的倍半萜：aromadendrane-4α,10α-diol (54)、aromadendrane-4β,10β-diol (55)和aromadendrane-4α,10β-diol (56);1个开环香木兰烷型的倍半萜：ent-2,3-secoalloaromadendra-4(14),10(15)-diene-2,3-diol (57);2个壳梭胞烷型二萜：fusicoauritone (58)和anadensin (59);2个三萜：betulinic acid (60)和oleanolic acid(61)。本文以具有显著肿瘤化学预防活性的双联苄化合物plagiochin G为目标,进行了化学全合成,并且制备了4个酯化衍生物。首次发现Plagiochin G及衍生物等大环双联苄类化合物具有比较显著的肿瘤化学预防活性。更多还原

【Abstract】 Bryophytes are taxonomically placed between the algae and the pteridophytes. Morphologically, they are divided into three classes, liverworts (Hepaticae), mosses (Musci) and hornworts (Anthocerotae). There are more than6000liverworts in the world, about880species of which have been found in China. Among the bryophytes, liverworts have been phytochemically investigated in the most detail, because they possess appealing cellular oil bodies, which are characteristic, membrane-bound cell organelles consisting of ethereal terpenoids and aromatic compounds, while the other two phyla do not. Many of the isolated compounds from liverworts exhibit interesting biological activities. Lots of different types of compounds are isolated from liverworts in the past decades. Now liverworts have been well known as a good source of biologically active comounds.Bisbibenzyls, a class of characteristic compounents isolated from liverworts, become to be a synthsis targeting recently because of their wide range of biological significance. So, total syntheses and preparation of bisbibenzyls with excellent biological activities is a good way to develop novel drugs.In this research, the liverworts Chandonanthus birmensis, Scapania stephanii and Cephaloziella kiaeri collected from Guangxi Zhuang Autonomous Region, and Frullania serrata collected from Yunnan Province, as well as Porella acutifolia subsp. tosana and Plagiochila vexans collected from Guizhou Province, were phytochemically investigated. A total of61compounds, including39diterpenoids,10sesquiterpenoids,2triterpenoids,6steriods, and4bibenzyls, were isolated and identified on the basis of NMR, MS, single crystal X-ray diffraction analysis, CD exciton chirality method and time-dependent density functional theory (TDDFT) CD calculations.28of them were new compounds, containing25new diterpenoids and3new sesquiterpenoids. Cembrane-type diterpenoids isolated from the liverwort C. birmensis exhibited weak cytotoxic activity. cis-Clerodane-type diterpenoids isolated from S. stephanii showed significant plant growth inhibitory activity. This work represents the first phytochemical investigations on the plants of C. birmensis, S. stephanii and C.kiaeri.Separation of the liverwort C. birmensis afforded seven diterpenoids, including six cembrane-type diterpenoids, named chandonanones B (1), C (2), E (3) and F (4), chandonanthone (5), and isochandonanthone (6), and one dolabellane-type diterpenoid2,10,14-triacetoxy-7,8,18,19-diepoxydolabell-3(E)-ene (7). The cytotoxicities of compounds1-7were tested against the human lung carcinoma cell lines NCI-H292and NCI-H1299and rat pheochromocytoma cell line PC12using the MTT method with IC50values ranging from19.5to48.7μM.From the liverwort S. stephanii, twelve c/s-clerodane-type diterpenoids, including stephanialides A-E (8-12), scaparvins A-C (13-15), parvitexins B (16) and C (17),3-chloro-4-hydroxy-parvitexin A (18), as well as scapanialide B (19), were isolated. The plant growth inhibitory activities of six compounds (10,12-14,16and17) were tested with models of the seeds of A. thaliana (Thale cress, Brassicaceae), L. sativum (garden cress, Brassicaceae) and B. pekinensis (Chinese cabbage, Brassicaceae). All six compounds could significantly inhibit root elongation of seeds of these three species with IC50values ranging from3.5to30.7μg/mL.Twenty one compounds, including eighteen c/s-clerodane diterpenoids, named cephaloziellins A-P (20-35), amphiacrolide F (36) and cephaloziellin Q (37), as well as three sesquiterpenes, named4β,6β-dihydroxy-1α,5β(H)-guai-9-ene (38), teucladiol (39) and ent-3β-hydroxyspathulenol (40), were isolated from the liverwort C. kiaeri. Sixteen cis-clerodane diterpenoids (20-35) were new compounds.Two new cadiane-type sesquiterpenes, named frullanic acid (41) and frullanic acid methyl ester (42), and four known bibenzyls, named brittonin B (43),3,3’-dimethoxy-4,5-methylene-dioxybibenzyl (44),3,4,5,3’,4’-penla-methoxy-bibenzyl (45), and (±)-3-(4’-methoxy-benzyl)-5,6-dimethoxyphtbalide (46), were isolated from the liverwort F. serrata.One new sesquiterpenoid, named guaian-3-en-2a,14-6α,12-diolide (47) and six known steriods,(20R)-6-hydroxystigmasta-4,22-dien-3-one (48),(20R)-3-hydroxystigmasta-5,22-dien-7-one (49),7-oxositosterol (50),(24S)-ethyl-5,22-cholestadien-3(51), ergosterol peroxide (52), and β-sitosterol (53), were isolated from the liverwort P. acutifolia subsp. tosana.From the liverwort P. vexans, three known aromandane-type sesquiterpenes, named aromadendrane-4α,10α-diol (54), aromadendrane-4β,10β-diol (55), and aromadendrane-4a,10β-diol (56), one known seco-aromandane-type sesquiterpene ent-2,3-secoalloaromadendra-4(14),10(15)-diene-2,3-diol (57), two known fusicoccane-type diterpenoids, named fusicoauritone (58) and anadensin (59), as well as two known triterpenoids, named betulinic acid (60) and oleanolic acid (61), were isolated.Plagiochin G with excenlent cancer chemopreventive activity have been synthsised. Four of its ester derivatives have been prepared. All of them showed good cancer chemopreventive activity.更多还原