第一部分薤的化学成分研究薤(Allium chinense G. Don)又名藠头,为百合科葱属植物,主产于长江流域及其以南各省,始载于《神农本草经》,被2010年版《中国药典》收载并将其与同属植物小根蒜(A. macrostemon Bunge)作为中药薤白的主要来源。中药薤白具有温中通阳、理气宽胸、还阳散结之功效,中医临床用于治疗胸痹、心痛彻背等,在汉代名医张仲景的瓜蒌薤白白酒汤、瓜蒌薤白半夏汤、枳实薤白桂枝汤中都有使用。作为药食两用中药,薤在国内外也被广泛用于制作蔬菜和调味品,具有广泛的药理作用和保健功能。本文综合利用D-101大孔吸附树脂、硅胶柱色谱、ODS柱色谱、Sephadex LH-20柱色谱以及制备型反相HPLC等各种色谱学手段,从薤的60%甲醇提取物中分离得到了35个化合物。通过化学和现代光谱学方法鉴定了它们的结构,分别为：Laxogenin(1), Laxogenin3-O-β-D-glucopyranoside(2), Laxogenin3-O-{α-L-arabinopyranosyl(1→>6)-β-D-glucopyranoside}(3), Laxogenin3-O-{O-(4-O-acetyl-a-L-arabinopyranosyl)-(1→6)-β-D-glucopyranoside}(4), Laxogenin3-O-{β-D-xylopyranosyl(1→4)-β-D-glucopyranoside}(5), Laxogenin3-O-{β-D-xylopyranosyl-(1→4)-O-[α-L-arabinopyranosyl-(1→6)]-β-D-glucopyranoside}(6), Laxogenin3-O-β-D-glucopyranosyl(1→4)-[α-L-arabinopyranosyl(1→6)]-β-D-glucopyranoside(7),(25R)-3β-hydroxy-5β-spirostan-6-one3-O-β-D-xylopyranosyl(1→4)-[a-L-arabinopyranosyl-(1→6)]-β-D-glucopyranoside(8),(25R)-3β-hydroxy-5a-spirostan-6-one3-O-{O-β-D-glucopyranosyl-(1→3)-O-β-D-xylopyranosyl-(1→4)-O-[α-L-arabinopyrano syl-(1→6)]}-β-D-glucopyranoside(9),(25S)-24-O-p-D-glucopyranosyl-3β,24β-dihydroxy-5a-spirostan-6-one(10),(25S)-3β,24β-dihydroxy-5a-spirostan-6-one3-O-[α-L-arabinopyranosyl-(1→6)]-β-D-glucopyranoside(11),26-O-β-D-glucopyranosyl3β,22a,26-trihydroxy-25(R)-5α-furostan-6-one(12),26-O-β-D-glucopyranosyl3β,22a,26-trihydroxy-25(R)-5α-furostan-6-one3-O-β-D-glucopyranoside(13),26-O-β-D-glucopyranosyl3β,22,26-tridyroxy-25(R)-5a-turostan-6-one3-O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside(14),26-O-β-D-glucopyranosyl3-β,22,26-tridyroxy-25(R)-5a-furostan-6-one3-O-β-D-xylopyranosyl(1→4)-[α-L-arabinopyranosyl(1→-6)]-β-D-glucopyranoside(15),26-O-β-D-glucopyranosyl3β,26-dihydroxy-25(R)-5a-furostan-20(22)-en-6-one(16),26-O-β-D-glucopyranosyl3β,26-didyroxy-25(R)-5a-furostan-20(22)-en-6-one3-O-β-D-xylopyranosyl(1→4)-[α-L-arabinopyranosyl(1→6)]-β-D-glucopyranoside(17),3-O-β-D-glucopyranosyl-22-O-β-D-glucopyranosyl-(3β,16β,22)-trihydroxycholest-6-one (18), Neogitogenin(19),(25R,S)-5a-spirostane-2a,3β-diol-3-O-{O-β-D-glucopyranosyl-(1→2)-O-β-D-glucopyran osyl-(1→4)-β-D-galactopyranoside}(20),5a-spirostane25(27)-ene2a,3β-diol-3-O-{O-β-D-g]ucopyranosyl-(1^2)-O-β-D-glucopyranosyl-(1→4)-β-D-galact opyranoside}(21),(25S)-5a-spirostane-3β-ol-3-O-{O-β-D-glucopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside}(22),(25R,S)-5a-spirostane-3β-ol-3-O-{O-β-D-glucopyranosyl-(1→2)-O-[β-D-glucopyranosyl-(1→3)]-O-β-D-glucopyranosyl-(1-+4)-β-D-galactopyranoside}(23),(25R)-5a-spirostan-3β-yl3-O-acetyl O-β-D-glucopyranosyl-(1→2)-O-[β-D-glucopyranosyl-(1→3)]-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside(24),(25R)-26-O-β-D-glucopyranosyl-5a-furost-3-β,26-didyroxy-3-O-{O-β-D-glucopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranosid e}(26), Macrostemonoside C(27),(25R)-26-O-β-D-glucopyranosyl-22-hydroxy-furostane-2a,3β,26-triol-3-O-β-D-glucopyr anosyl(1→2)-[β-D-glucopyranosyl (1→3)]-β-D-glucopyranosyl (1→4)-β-D-galactopyranoside(28), N-p-coumaroyltyramine (29), N-p-hydroxy-cis-coumaroyltyramine(30), Acanthoside D (31), β-D-Fructopyranose (32), Methyl-β-D-fructofuranoside (33), β-Sitosterol (34), Daucosterine (35)。在分离得到的35个化合物中,有26个甾体皂苷类化合物(2-18,20-28),两个甾体皂苷元(1,19),两个氨基酸类化合物(29,30),其中11个为未见文献报道的新甾体皂苷(4,8,9,10-13,16,18,21,24)。此外,本文对薤总甾体皂苷在高脂血症小鼠模型体内的降脂和抗氧化活性进行了研究,结果表明薤总甾体皂昔能够显著降低高脂血症小鼠血清和肝脏总胆固醇、甘油三酯水平以及谷丙转氨酶、谷草转氨酶水平,提高血清高密度脂蛋白-胆固醇含量,并能提高其肝脏的抗氧化能力和减少体重的增加,对高脂饮食引起的小鼠高脂血和肥胖具有一定的预防和治疗作用。第二部分桑葚的化学成分与生物活性研究桑葚为桑属植物桑(Morus alba L.)的成熟果实,在《本草纲目》、《中药大辞典》等中医药名著中都有记载,具有滋阴补血,生津润燥,补肝益肾等功效,常被用作滋补、强壮,提高免疫力等。桑葚既可入药,又可食用,桑葚果肉质鲜美、多汁,富含人体必需的矿物元素、维生素、氨基酸等营养成分。大量研究表明,桑葚提取物具有抗氧化、抗炎、降血糖、降血脂、抗肿瘤等广泛的药理活性。本文对桑葚70%乙醇提取物不同极性溶剂萃取部分的总黄酮和总酚的含量,以及体外抗氧化和抑制a-葡萄糖苷酶活性进行了测定,发现乙酸乙酯萃取层的总黄酮和总酚含量最高,体外抗氧化和抑制α-葡萄糖苷酶活性最强。在此基础上,进一步研究了总酚部分在STZ诱导的高血糖小鼠体内的降糖和抗氧化活性。结果表明桑葚提取物乙酸乙酯萃取部分能够显著降低高血糖小鼠的空腹血糖和糖化血清蛋白,并能提高其血液和脏器的抗氧化酶的活力。综合运用各种色谱学手段,从桑葚的70%乙醇提取物中分离得到了58个化合物,通过化学和波谱学方法鉴定了它们的结构,分别是：Quercetin (1), Quercetin-3-O-β-D-glucopyranoside (2), Quercetin3-O-(6"-O-acetyl)-p-D-glucopyranoside (3), Quercetin3-0-β-D-rutinoside (4), Quercetin7-O-β-D-glucopyranoside (5), Quercetin3,7-di-O-β-D-glucopyranoside (6), Kaempferol3-O-β-D-glucopyranoside (7), Kaempferol3-O-β-D-rutinoside (8),5,7,3’-trihydroxy-flavanone-4’-O-β-D-glucopyranoside (9),5,7,4’-trihydroxy-flavanone-3’-O-β-D-glucopyranoside (10), Dihydrokaempferol7-O-β-D-glucopyranoside (11), Isobavachalcone (12),2,4,2’,4’,-tetrahydroxy-3’-(3-methyl-2-butenyl)-chalcone (morachalcone)(13),(2E)-1-[2,3-dihydro-4-hydroxy-2-(1-methylethenyl)-5-benzofuranyl]-3-(4-hydroxyphenyl)-1-propanone (14),2-O-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxyphenylacetic acid (15), Jaboticabin (16), p-Hydroxyl-benzoic acid (17), Protocatechuic acid (18), vanillic acid (19), Protocatechuic acid methyl ester (20), Protocatechuic acid ethyl ester (21),4-hydroxyphenylacetic acid methyl ester (22),5,7-dihydroxychromone (23),2-(4-hydroxyphenyl)ethanol (24), Pyrocatechol (25),3,4-dihydroxyphenyl aldehyde (26), Cis-p-hydroxycinnamic acid (27), p-Coumaric acid (28),5-O-caffeoylquinic acid methyl ester (29),3-O-caffeoylquinic acid methyl ester (30),4-O-caffeoylquinic acid (31), Chlorogenic acid (32), Umbelliferone (33), Scopoletin (34), Pinoresinol (35), Moracin C (36), Artoindonesianin O (37), Moracin D (39), Moracin E (40), Chalcomoracin (41), Mulberrofuran E (42), Aurantiamide (43), Cytochalasin B (44),4-[Formyl-5-(methoxymethyl)-1H-pyrrol-1-yl] butanoate (45),(22E)-24-methyl-5a-cholesta-7,22-diene-3β,5a,6β-triol (46),(22E)-5a,8a-Epidioxyergosta-6,22-dien-3β-ol (47), β-Sitosterol (48), Daucosterine (49),7β-hydroxysitosterol (50),2-Phenylethyl-β-D-glucopyranoside (51),1’-O-phenethyl-β-D-apiofuranosyl-(1→2)-β-D-glucopyranoside (52), Benzyl-O-β-D-glucopyranoside (53),5-Hydroxymethylfural (54), Dibutyl-phthalate (58)。分离鉴定的58个化合物包括42个酚类化合物(1-42),3个含氮化合物(43-45),5个甾类化合物(46-50)。酚类化合物中14个黄酮类化合物(1-14),7个苯并呋喃类化合物(36-42)。对化合物1-25进行了体外抗氧化和抑制α-葡萄糖苷酶活性测试,结果显示化合物1-6,11,15,16,25具有较好的体外清除DPPH自由基和超氧阴离子自由基的能力,化合物1,2,4,7,8,12,13,15,16具有较强的抑制α-葡萄糖苷酶的活性。