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假臭草[Praxelis clematidea(Griseb.)R.M.King&H.Rob.]为菊科(Compositae)假臭草属(Praxelis)的一种外来入侵植物,是一年生草本植物。起源于南美洲,在我国主要分布在福建、广东、海南、香港等热带及亚热带地区。目前,假臭草已经成为一种极具破坏潜力的外来恶性杂草,对入侵地区造成了严重的生态环境破坏及经济损失。本论文对假臭草的活性成分进行了研究,假臭草全株的75%乙醇提取物采用不同极性的有机溶剂萃取,并选取氯仿层进一步分离研究。综合运用硅胶柱色谱、ODS反相柱色谱、Sephadex LH-20柱色谱以及制备HPLC等方法对氯仿层进行系统的分离和纯化,共得到82个单体化合物。根据其理化性质,并运用波谱学技术等手段,鉴定了化合物的化学结构和立体构型。分别鉴定为:(1.黄酮类)5-hydroxy-7,4’-dimethoxyflavone(1),4’,5-dihydroxy-7-methoxyflavone(2),luteolin-7,3’,4’-trimethyl ether(3),4’-hydroxy-5,7-dimethoxyflavone(4),7-hydroxy-5,4’-dimethoxyflavone(5),5,7,4’-trimethoxyflavone(6),5,7,3’,4’-tetramethoxyflavone(7),4’-hydroxy-5,7,3’-trimethoxyflavone(8),5,6,7,4’-tetramethoxyflavone(9),4’-hydroxy-5,6,7-trimethoxyflavone(10),7-hydroxy-5,6,4’-trimethoxyflavone(11),6-hydroxy-5,7,4’-trimethoxyflavone(12),7,4’-dihydroxy-5,6-dimethoxyflavone(13),cirsimaritin(14),hispidulin(15),jaceosidin(16),6-hydroxy-5,7,3’,4’-tetramethoxyflavone(17),7,3’-dihydroxy-5,8,4’-trimethoxyflavone(18),6,7,8,3’,4’-pentamethoxyflavone(19),3,5,6,7,4’-pentamethoxyflavone(20),(S)-7,4’-dihydroxy-3’-methoxyflavanone(21),(S)-liquiritigenin(22),(S)-naringenintrimethyl ether(23),(S)-4’-hydroxy-5,7-dimethoxydihydroflavone(24),8-hydroxy-6,7,4’-trimethoxyflavanone(25),(-)-trans-4’-hydroxy-5,6,7-trimethoxy-dihydroflavonol(26),flavokawain A(27),flavokawain C(28),4,2’-dihydroxy-4’,5’,6’-trimethoxychalcone(29);(2.苯丙素类)cinnamic acid(30),coniferaldehyde(31),p-hydroxycinnamic acid(32),ferulic acid(33),cinnamic acid(34),ethyl caffeate(35),(E)-3-(4-hydroxy-3-methoxyphenyl)prop-2-enoic acid-(1,2-dihydroxycyclohexyl)-4-ester(36*),(-)-1-[2-(1,2-dihydroxy-1-methylethyl)-2,3-dihydro-6-hydroxy-5-benzofuranyl-ethanone(37),(-)-(7R,8S,7’E)-4-hydroxy-3,5,5’,9’-tetramethoxy-4’,7-epoxy-8,3’-neolign-7’-en-9-ol(38),(7S,8R)-ficusal(39),(7S,8R)-balanophonin(40),(7’R,8’S)-4,5,3’,4’-tetrahydroxy-2,7’-cyclolign-7-ene-9,9’-dioic acid diethyl ester(41*),4-[(3S)-(4-hydroxy-3,5-dimethoxyphenyl)-(2S)-hydroxymethyl-8-methoxy-2,3-dihydrobenzo-[1,4]dioxin-6-yl]-(3E)-buten-2-one(42*),(+)-erythro-syringylglycerol-β-O-4’-sinapyl ether(43),(+)-xanthiumnolic A(44),(-)-evofolin B(45),(+)-(7’R,8R,8’S)-4,4’,9’-trihydroxy-3,3’-dimethoxy-7,9’-epoxylignan-7-one,(46),(-)-(7’S,8S,8’R)-4,4’-dihydroxy-3,3’,5,5’-tetramethoxy-7’,9-epoxylignan-9’-ol-7-one(47),(-)-syringaresinol(48),(+)-(7R,7’R,7’’R,8S,8’S,8’’S)-4’,4’’-dihydroxy-3,3’,3’’-trimethyl-pentametho xy-7,9,7’,9’-diepoxy-4,8’’-oxy-8,8’-sesquineolignan-7’’,9’’-diol(49),(-)-(7R,7’R,7’’R,8S,8’S,8’’S)-4’,4’’-dihydroxy-3,3’,3’’,5,5’-pentamethoxy-7,9,7’,9’-diepoxy-4,8’’-oxy-8,8’-sesquineolignan-7’’,9’’-diol(50),(+)-(7R,7’R,7’’R,8S,8’S,8’’S)-4’,4’’-dihydroxy-3,3’,3’’,5,5’,5’’-hexamethoxy-7,9,7’,9’-diepoxy-4,8’’-oxy-8,8’-sesquineolignan-7’’,9’’-diol(51),(-)-(7R,7’R,7’’S,8S,8’S,8’’S)-4’,4’’-dihydroxy-3,3’,3’’-trimethyl-pentametho xy-7,9,7’,9’-diepoxy-4,8’’-oxy-8,8’-sesquineolignan-7’’,9’’-diol(52),(-)-(7R,7’R,7’’S,8S,8’S,8’’S)-4’,4’’-dihydroxy-3,3’,3’’,5,5’-pentamethoxy-7,9,7’,9’-diepoxy-4,8’’-oxy-8,8’-sesquineolignan-7’’,9’’-diol(53),(-)-(7R,7’R,7’’S,8S,8’S,8’’S)-4’,4’’-dihydroxy-3,3’,3’’,5,5’,5’’-hexa-methoxy-7,9,7’,9’-diepoxy-4,8’’-oxy-8,8’-sesquineolignan-7’’,9’’-diol(54);(3.萜类)loliolide(55),isololiolide(56),isodauc-6-ene-10β,14-diol(57),trilobolide-6-O-methacrylate(58),trilobolides-6-O-isobutyrate(59),wedelolide F(60),wedelolides A(61),wedelolides B(62);(4.生物碱类)indole-3-carboxaldehyde(63),3-(hydroxyacetyl)indole(64),(1H-indol-3-yl)oxoacetic acid methyl ester(65);(5.其他类)(R)-5-hydroxy-6-acetyl-2-(1,2-hydroxy-1-methyl)benzofuran(66*),(S)-11-hydroxy-10,11-dihydroeuparin(67),1-{2-[(1S,4S)-7-acetyl-4,8-dihydroxy-4-hydroxymethyl-1,2,3,4-tetrahydrodibenzo[b,d]-furan-1-yl]-5-hydroxy-1-benzofura-6-yl}ethanone(68*),1-{2-[(1R,4S)-7-acetyl-4,8-dihydroxy-4-hydroxymethyl-1,2,3,4-tetrahydrodibenzo[b,d]furan-1-yl]-5-hydroxy-1-benzofuran-6-yl}ethanone(69*),methyl 4-[3-oxo-2-(2’-pentynyl)-4-cyclopentenyl]butyrate(70*),4-[3-oxo-2-(2-pentynyl)-4-cyclopentenyl]octanoate(71),(S)-4-methyl octanoate-2-en-1,4-olide(72*),(S)-hydroxydihydrobovolide(73),3-hydroxy-5,6-epoxy-7-megastigmen-9-one(74),(3R)-4-[(2R,4S)-2-hydroxy-2,6,6-trimethyl cyclohexylidene]-3-buten-2-one(75),ethyl 3,4-dihydroxybenzoate(76),ethyl 3,4-dihydroxyphenylacetate(77),1,2-diol-4-cyclohexyl benzoate(78),vanillin(79),isovanillic acid(80),anillic acid(81),syringic aldehyde(82)。其中,化合物36、41、42、66、68-70、72为8个新化合物。本文还对假臭草提取物及萃取层的总黄酮含量进行分析。假臭草75%乙醇提取物经环己烷、乙酸乙酯、正丁醇萃取,提取物和乙酸乙酯萃取部分的总黄酮含量分别为75.43±3.74 mg/g及296.47±6.59mg/g。运用UPLC-DAD对乙酸乙酯萃取部分的黄酮成分进行定性定量分析,在乙酸乙酯部分含量较大的化合物为2、9、25,含量分别为41.25±2.12、23.40±0.40和30.30±2.25 mg/g。在化学成分研究的基础上,对部分单体化合物的体外抗炎活性和降糖活性进行了评价。所测定的大部分化合物表现出了显著的抗神经炎活性,化合物35、38、40、44、49、52、68、69、71对LPS诱导的BV-2小胶质细胞的NO释放显示出强于阳性对照米诺环素(IC50=23.15±1.04μM)的抑制作用。其中,化合物71抑制NO释放的活性最强(IC50=10.56±1.02μM)。并通过蛋白免疫印迹法、实时定量PCR和免疫荧光染色法,进一步阐明了新化合物42、68和69的抗炎活性。同时,测定了分离得到的29个黄酮类化合物的降糖活性,结果显示,部分化合物表现出一定的α-葡萄糖苷酶抑制活性,其中化合物16的抑制作用最为显著(IC50=260.36±21.03μM),其活性与阳性对照阿卡波糖相当。本研究为外来恶性杂草假臭草的资源化利用提供了科学依据,也为进一步研究其在医药方面的利用提供了研究基础。