【作者】 张凤；

【导师】 陈万生； 岳建民；

【作者基本信息】 第二军医大学 ， 生药学， 2011， 博士

【摘要】 在过去25年上市的药物中,直接或者间接地来自天然产物的药物约占40%,这表明天然产物(植物,动物,以及微生物等生物体内的次生代谢产物)在现代药物研究中具有重要意义。作为天然产物中最为重要的一部分,植物药也是现代药物发现的重要源泉。本文涉及的五种药用植物或其同属植物,均有研究报道一些结构复杂多样、且具有重要生物活性的化合物。因此对其开展深入的系统化学研究,有望发现结构新颖的化合物,为进一步活性筛选奠定物质基础。本文对五种药用植物独一味Lamiophlomis rotata (Benth.) Kudo,滇红椿Toona ciliata Roem. var. yunnanensis (C. DC.) C. Y. Wu,毛麻楝Chukrasia tabularis var. velutina,溪桫Chisocheton paniculatus (Roxb.) Hiern和山椤Aglaia roxburghiana Miq.进行了系统的化学成分研究和生物活性测试,运用波谱学技术和化学反应沟通等手段鉴定了146个化合物,包括黄酮类10个,环烯醚萜类21个,苯乙醇苷类8个,糖类11个,柠檬苦素类39个,三萜类18个,二萜类11个,倍半萜类11个等;其中新化合物24个。并对部分化合物进行了抗炎和抗菌活性筛选。从唇形科独一味属植物独一味中分离获得59个化合物,包括黄酮类10个(1-10),环烯醚萜类21个(11-31),苯乙醇苷类8个(32-39),糖类共11个(40-50),以及其他类化合物9个( 51-59 )。其中包括新的环烯醚萜类4个: 6′-O-syringyl-deoxysesamoside(11)、7-dehydroxy-zaluzioside(12)、barlerin-6′′-hydroxy- 2′′,6′′-dimethylocta-2′′,7′′-dienate ester(13)和6β-n-butoxy-7,8-dehydropenstemonoside(14),以及新的C13-降异戊二烯糖类衍生物1个,5β,6α-dihydroxy-3β-(β-D- glucoyranosyloxy)-7-megastigmen-9-one ( 44 )。新化合物6β-n-butoxy-7,8- dehydropenstemonoside(14)和已知化合物apigenin-7-O-(6″-O-β-D-apiofuranosyl)-β-D- glucopyranoside(3)、8-epi-7-deoxyloganin(21)、7,8-dehydropenstemonoside(26)及β-D-glucopyranoside-(2→1)-β-D-glucopyranoside(49)对于LPS引起的核转录因子NF-κB激活有明显的抑制作用,且在检测的浓度范围内呈浓度依赖。研究表明独一味中的黄酮类及苯乙醇苷类成分均为活性成分,目前从独一味分离得到的常见及含量较大的黄酮类化合物有3种,分别为芹菜素-7-O-β-D-吡喃葡萄糖苷,木犀草素-7-O-β-D-吡喃葡萄糖苷和木犀草素-7-O-(6″-O-β-D-呋喃芹菜糖)-β-D-吡喃葡萄糖苷;苯乙醇苷类成分有2种,分别为毛蕊花糖苷和连翘酯苷。本试验采用HPLC法测定了6个产地独一味全草中上述5种化合物的含量,以其含量为指标,考察不同产地独一味的品质差异。这也是首次测量黄酮类和苯乙醇苷类成分含量的报道。从楝科香椿属植物滇红椿中分离获得29个化合物,包括柠檬苦素类9个(60-62,67-72),二萜类11个(63-66,73-79),倍半萜类5个(80-84),以及其他类化合物4个(85-88)。其中柠檬苦素toonaciliatins N-P(60-62)和二萜toonacilidins A-D(63-66)为新化合物。Toonaciliatin N(60)是一个具有1,11-氧桥-3-酮基结构的柠檬苦素类化合物,在氘带极性溶液(CD3OD)中容易通过形成烯醇式的过渡态,与溶液发生质子交换作用,该过程具有可逆性。化合物toonacilidin A(63)和eudesm-4(15)-ene-1β,6α-diol(83)对幽门螺旋杆菌菌株Helicobacter pylori-SS1显示较为温和的抗菌活性。将分离得到的柠檬苦素类化合物与红椿及其变种中分离到的柠檬苦素类化合物对比,发现滇红椿中共分离的到9个柠檬苦素类化合物,主要骨架结构与红椿中分离到的柠檬苦素类化合物更加接近;并且根据已有研究提出的共存于同一植物的共同前体解释,成功产生了滇红椿中9个柠檬苦素可能的转化过程的生物图。从楝科麻楝属植物毛麻楝中分离获得30个化合物(89-118),除去xyloccensin K(118)外,余下均为phragmalin型柠檬苦素类化合物,包括1,8,9-原酸酯类型6个(89-93,99),8,9,11-原酸酯类型5个(109-113),8,9,30-原酸酯类型2个(114、115);C-15位引入多碳单元并与C-16形成缩酮的衍生物13个(95-97,101-108,116-117);C-8/C-9成五元环碳酸酯的衍生物2个(94,100);以及其它氧化类型的化合物1个(98)。其中velutinasins A-I(89-97)9个为新化合物。新化合物velutinasins A-D(89-92)为一类具有δ-内酯环和1,8,9-原酸酯结构的phragmalin类柠檬苦素,并且在C-15位引入多碳单元形成较稳定的烯醇式结构。这种结构比较罕见,属于自然界第二次发现该种类型的化合物。其中velutinasin A(89)为C-16位和C-17位形成δ-内酯环;velutinasins B-D(90-92)为C-16位和C-30位形成δ-内酯环。并利用圆二色谱激子手性法对该类化合物进行了绝对构型的确定。从楝科溪桫属植物溪桫中分离获得16个化合物,其中包括2个新的apotirucallane型三萜(119、120),4个已知apotirucallane型三萜(121、125-127),4个已知tirucallane型三萜(122-124、128),以及4个已知倍半萜(129-132)和2个已知甾体化合物(133、134)。化合物ghisiamol G(119)的结构通过波谱学方法和化学沟通共同确定,ghisiamol G(119)和ghisiamol H(120)是首次在该属植物中分离获得的具有五元内酯环的apotirucallane型三萜。从楝科米仔兰属植物山椤中分离获得12个化合物,其中包括1个新的tirucallane型三萜(135),6个已知apotirucallane型三萜(136-141),1个已知甾体(142),以及2个已知楝酰胺类(143、144)和2个已知倍半萜化合物(145、146)。柠檬苦素类化学成分是楝科植物的主要活性成分和最为特征的次生代谢产物,从多种楝科植物中,报道了数目众多的骨架新颖、结构复杂多变的柠檬苦素类成分,并显示出昆虫拒食、抗真菌、抗细菌、抗病毒、抗疟疾及抗癌等多方面的活性。人们使用的药物绝大多数具有手性,被称为手性药物。手性药物的“镜像”称为它的对映体,两者之间在生物活性方面往往存在差别,有的甚至作用相反。由于柠檬苦素类化合物结构内有多个手性中心,确定该类天然产物的绝对构型对了解其化学及生物行为非常重要。因此论文就近几年来用于测定柠檬苦素类天然产物绝对构型的几种方法进行综述。更多还原

【Abstract】 A great number of drugs (ca. 40% of drugs marketed) are directly or indirectly derived from natural products in the last 25 years), indicating that natural products, including secondary metabolite of plant, animal and microorganism, have played a significant role in modern drug researches. As a consequence, medical plants are the rich and vital source for modern drugs. Previous reaserches have reported the isolation of some complex compounds with diverse biological activities from the five medical plants studied in this thesis. Thus, it is meaningful to isolate and identify new compounds by profound chemical studies of these medical plants, which will lay the foundation for further biological activity screening.Five medicinal plants, Lamiophlomis rotata (Benth.) Kudo, Toona ciliata Roem. var. yunnanensis (C. DC.) C. Y. Wu, Chukrasia tabularis var. velutina, Chisocheton paniculatus (Roxb.) Hiern, and Aglaia roxburghiana Miq. have been chemically investigated and their bioactivities have been evaluated. A total of 146 compounds were obtained, which including ten flavonoids, twenty-one iridoids, eight phenylethanoid glucosides, eleven derivatized carbohydrates, thirty-nine limonoids, eighteen triterpenoids, eleven diterpenoids, eleven sesquiterpenoids, and so on. Twenty-four compounds were isolated as new compounds. Some compounds were found active in the tested pharmacological model.Fifty-nine compounds, including ten flavonoids (1-10), twenty-one iridoids (11-31), nine phenylethanoid glucosides (32-39), eleven derivatized carbohydrates (40-50), and nine compounds in other types (51-59) were isolated from L. rotata of the Lamiophlomis genus (Lamiacea). Four iridoids and one derivatized carbohydrate (C13-norisoprenoid derivative) were isolated as new compounds, viz. 6′-O-syringyl-deoxysesamoside (11), 7-dehydroxy-zaluzioside (12), barlerin-6′′-hydroxy-2′′,6′′-dimethylocta-2′′,7′′-dienate ester (13), 6β-n-butoxy-7,8-dehydropenstemonoside (14) and 5β,6α-dihydroxy-3β-(β-D- glucoyranosyloxy)-7-megastigmen-9-one (44). All compounds were screened by luciferase assay, finding that apigenin-7-O-(6″-O-β-D-apiofuranosyl)-β-D-glucopyranoside (3), 6β-n-butoxy-7,8-dehydropenstemonoside (14), 8-epi-7-deoxyloganin (21), 7,8-dehydropenstemonoside (26), andβ-D-glucopyranoside-(2→1)-β-D-glucopyranoside (49) had the desired, apparent NFκB inhibition activities, in a dose-dependant manner in the range of the detection concentration.The medicinal plant often comprises a complex mixture of different phytochemicals (plant secondary metabolites) and these ingredients work“synergistically”for the therapeutic effects. Previous studies have revealed that flavonoids and phenylethanoid glucosides are the main activity components in L. rotata, and the determination of one or two compounds could not give a complete picture of the herb, while quantification of all compounds is extremely difficult. Hence, we chose three flavonoids (apigenin-7-O-β-D-glucopyranoside, luteolin-7-O-β-D-glucopyranoside and luteolin-7-O-β-D-(6″-O-acetyl)-glucopyranoside) and two phenylethanoid glucosides (verbascoside and forsythoside B) as the“marker compounds”that were in large amounts L. rotata. There is no method in analysis of both flavonoids and PhGs of L. rotata in the previous reported methods, this newly developed HPLC-VWD method for simultaneous determination of both flavonoids and PhGs provided much higher specificity, precision and accuracy. By quantification of the five major compounds, the quality of L. rotata could be effectively evaluated initially. Besides, to obtain a full assessment about L. rotata, the analytical method described here is needed to be developed.Twenty-nine compounds, including nine limonoids (60-62, 67-72), eleven diterpenoids (63-66, 73-79), five sesquiterpenoids (80-84) and four compounds in other types (85-88) were isolated from T. ciliata Roem. var. yunnanensis (C. DC.) of the Toona genus (Meliaceae). Three limonoids (toonaciliatins N-P, 60-62) and four pimaradiene-type diterpenoids (toonacilidins A-D, 63-66) were isolated as new compounds. Toonaciliatin N (60), a new limonoid bearing a 1,11-oxygen bridge-1-one moiety, H-2βof which exchanged to D-2βvia a possible enolized intermediate when it was kept in the solvent of CD3OD for about two days, and this was a reversible progress when treated with CH3OH. Toonacilidin A (63) and eudesm-4(15)-ene-1β,6α-diol (83) showed moderate inhibitory activity against H. pylori-SS1 at the level of MIC of 50μg/mL. Compared the limonoids isolated from T. ciliata Roem. var. ciliata and T. ciliata Roem. var. yunnanensis (C. DC.), the latter seems have a more close relationship with T. ciliata than the former. Thus, a proposed biosynthetic map that encompassed all the routes to the isolated limonoids in T. ciliata was successfully applied in T. ciliata Roem. var. yunnanensis (C. DC.), which supported the rationality that they might share a common precursor.Thirty limonoids were isolated from C. tabularis var. velutina of the Chukrasia A. Juss genus (Meliaceae), twenty-nine of which were phragmalin-type limonoids (89-117) except xyloccensin K (118). These phragmalin-type limonoids could be be divided into about six different sub-groups depending on partial structural transformations of the basic phragmalin skeleton, including six 1,8,9-phragmalin-type limonoids (89-93, 99), five 8,9,11-phragmalin-type limonoids (109-113), two 8,9,30- phragmalin-type limonoids (114, 115), thirteen limonoids that possess a biosynthetically extended propionyl or acetyl group at C-15 and a characteristic ketal moiety between the limonoid skeleton and the acyl substituent at C-15 (95-97, 101-108, 116-117), two limonoids with an unprecedented 1,3-dioxolan-2-one formed a pentacyclic carbonate ester (94, 100), and one in other type (118). Nine of these limonoids (velutinasins A-I, 89-97) were isolated as new compounds. Velutinasins A-D (89-92) were a class of C-15-acyl 1,8,9-phragmalin type limonoids, featuring aδ-lactone ring, and theβ-dicarbonyl groups were presented as a relative steabyα-hydroxy-α,β-unsaturated ester system. Velutinasin A (89) comprised a C-16/C-17δ-lactone ring while velutinasins B-D (90-92) comprised C-16/C-30δ-lactone rings. It was the second time to find that class of kinds, and their absolute configurantions were determined by the CD exciton chirality method.Sixteen compounds, including two new apotirucallane-type triterpenoids (119, 120), four known apotirucallane-type (121, 125-127) and four known tirucallane-type (122-124, 128) triterpenoids, four known sesquiterpenoids (129-132) and two known steroids (133, 134) were isolated from C. paniculatus (Roxb.) Hiern of the Chisocheton genus (Meliaceae). The strcture of ghisiamol G (119) was elucidated on the basis of spectroscopic and chemical methods. To the best of our knowledge, this is the first report of a tetracyclic triterpene with a 21,23-lactone ring (ghisiamols G and H, 119 and 120) from the genus Chisocheton.Twelve compounds, including one new tirucallane-type triterpenoids (135), six known tirucallane-type triterpenoids (136-141), one known steroid (142), two known rocaglamides (143, 144) and two known sesquiterpenoids (143, 144) and were isolated from A. roxburghiana Miq.of the Aglaia genus (Meliaceae).Limonoids are secondary metabolites characteristic of the plant family Meliaceae, from which many structurally diversified and chemosystematically significant limonoids have been isolated in the past several decades, attracting people’s great interest due to their diverse structures and significant biological activities.Most of the drugs currently in use are chiral compounds, and called chiral drugs. Although they have the same chemical structure, most isomers of chiral drugs exhibit marked differences in biological and pharmacological effects. A limonoid molecule often has at least one asymmetric carbon, which could be recognized as chiral center. As a consequence, assignment of absolute stereochemistry for limonoids is a vital field of research, which is necessary to known their chemical and biological behavior. This article reviews some different techniques used for the assignment of absolute stereochemistry for limonoids in recent years.更多还原