大花栀子果实的化学成分研究

对茜草科植物大花栀子果实进行化学成分研究,分离得到8个化合物.经理化数据对照和波谱分析,鉴定化合物的结构为:(4R) - 4 - 羟基 - 2,6,6 - 三甲基 - 1 - 环己烯 - 1 - 甲酸(1)、西红花酸(2)、西红花苷 - 4(3)、西红花苷 - 3(4)、西红花苷 - 2(5)、西红花苷 - 1(6)、京尼平苷(7)和京尼平 -1 - β - D - 龙胆二糖苷(8).经检索,其中化合物2 ～ 6为首次从该植物中分离得到.     

新疆药桑枝条中抗氧化活性成分sanggenon A的分离鉴定

【目的】分离鉴定新疆药桑枝条中的抗氧化活性成分,揭示其抗氧化功效的物质基础,为发现新的天然抗氧化成分及新疆药桑的开发利用提供理论依据。【方法】将新疆药桑枝条利用70%乙醇冷浸的方法提取,滤液低温减压浓缩;TLC(薄层层析)与DPPH(1,1-二苯基-2-苦基苯肼)相结合的方式进行活性检测;以紫外显色、10%硫酸乙醇显色的方式进行物质检测;在活性跟踪下通过不同有机溶剂萃取分段、多次硅胶柱层析、凝胶柱层析及薄层层析,对新疆药桑枝条中抗氧化活性成分进行分离纯化。将分离得到的化合物以氘代氯仿为溶剂,TMS(四甲基硅烷)为内标,利用MS(质谱)及NMR(核磁共振)技术进行波谱测定及结构解析。以人工合成抗氧化剂BHT(2,6-二叔丁基-4-甲基苯酚)为对照,进行清除DPPH自由基、OH自由基及总还原力的测定。【结果】从新疆药桑枝条乙酸乙酯萃取部分中分离得到1种易溶于甲醇及乙酸乙酯的深黄色粉末,根据其理化性质初步判断为黄酮类化合物。结合其理化性质并通过MS,~1H-NMR,~(13)CNMR,DEPT的波谱数据分析,确定其为已知化合物sanggenon A(桑根酮A),分子式为C_(25)H_(24)O_7,分子量为436。抗氧化活性研究表明,其清除DPPH自由基和OH自由基的IC_(50)值分别为50.3和96.5 mg·L~(-1)(对照BHT分别为64.2和231.6 mg·L~(-1)),总还原力也明显高于对照。【结论】本文首次从桑树的枝条中分离得到该物质,拓展了提取分离该物质的原材料来源,可为新疆地区广泛种植的林业资源的开发利用提供理论基础。     

镰叶西番莲藤茎脂溶性化学成分的研究

为研究镰叶西番莲藤茎的化学成分,从其脂溶性成分中分离了6个化合物,通过IR、MS、NMR等波谱手段鉴定它们的结构为4-氧代-3,4-降-木栓烷-2-酸(Ⅰ)、2-羟基-3,4-断-木栓烷-3-酸乙酯(Ⅱ)、4-烯-3-谷甾酮(Ⅲ)、3-(2,4-二羟基苯基)-2-丙烯酸(Ⅳ)、碳十八酸甘油酯(Ⅴ)和正二十八醇(Ⅵ).其中化合物Ⅰ是首次经提取分离的天然产物,应用二维NMR技术归属了它的碳谱.结果表明,化合物Ⅰ与化学合成的4-oxo-3,4-seco-A(1)-norfriedelan-3-oic acid结构一致.化合物Ⅱ为新的人工化合物.     

栀子果实的化学成分研究

对茜草科植物栀子果实进行化学成分研究,分离得到7个化合物,经理化数据对照和波谱分析,鉴定化合物的结构为:异槲皮苷(1)、反式-2'(4″-对羟基桂皮酰基)-玉叶金花苷酸(2)、顺式-2'(4″-对羟基桂皮酰基)-玉叶金花苷酸(3)、京尼平苷(4)、西红花酸单乙酯(5)、西红花酸(6)、西红花苷-1(7).经文献检索,化合物1、2、3、5为首次从该属植物中分离得到.     

中的鞘氨醇类代谢产物

从中国香港红树林的两株南海海洋真菌(2526#和1850#)的代谢产物中分离到4个化合物，通过完整的波谱数据分别解析为鞘氨醇类化合物N-(2’，3‘-二羟基二十四碳酰基)-1，3-二羟基-2-氨基十八烷(A)、n-(2’，3‘-二羟基二十六碳酰基)-1，3-二羟基-2-氨基十八烷(B)、2‘-dehydroxycerebroside D(C)和cerebroside D(D)。化合物A和B未见文献报道。     

决明子中蒽醌类化学成分的研究

对决明子中蒽醌类化学成分进行了研究.采用硅胶柱色谱从决明子氯仿萃取物中分离得到7种蒽醌化合物,通过化学和波谱分析方法分别鉴定为:大黄酚(Ⅰ)、大黄素甲醚(Ⅱ)、大黄素(Ⅲ)、黄决明素(Ⅳ),大黄酚-8-甲醚(Ⅴ)、大黄素-1-甲醚(Ⅵ)、1,2-二甲氧基-8--羟基-3-甲基-9,10-蒽醌(Ⅶ).化合物Ⅴ～Ⅷ为首次从该属植物中分得.     

黄根化学成分的研究

采用溶剂提取法,正相硅胶柱色谱及半制备高效液相色谱法等现代分离技术对黄根的乙醇提取物进行了分离纯化,得到6个化合物,并通过现代波谱学的手段和理化性质鉴定了它们的结构,分别鉴定为：2-甲基蒽醌(1),甲基异茜草素-1-甲醚(2),2-甲基-3-羟基蒽醌(3),甲基异茜草素(4),3β-乙酰基齐墩果醛(5),3β-乙酰基齐墩果酸(6),其中化合物3、5、6为首次从黄根中分离得到。     

岩木瓜根皮化学成分研究

应用柱色谱技术对岩木瓜根皮的化学成分进行了分离纯化,并对分离所得的化合物采用核磁共振及质谱鉴定了化舍物结构.从岩木瓜根皮中分离、鉴定了9个化合物,根据化合物的理化常数和波谱数据鉴定其结构,分别鉴定为β-香树脂醇乙酸酯(1)、蒲公英赛酮(2)、蒲公英赛醇(3)、2α-羟基齐墩果酸(4)、齐墩果酸(5)、β-谷甾醇(6)、...     

银杏叶中烷基酚化合物的分离与鉴定

介绍了银杏叶烷基酚化合物的分离过程，并鉴定出烷基酚化合物单体3类6种，其中银杏酸类化合物2种，白果酚类化合物3种，白果二酚类化合物1种。这些化合物经UV、IR、MS、^1HNMR、^13CNMR等波谱鉴定为：3-（8-十五碳烯基）苯酚；3-[4（Z），7（Z）-十七碳二烯基]苯酚；3-（10-十七碳烯基）苯酚；6-（8-十五碳烯基）水杨酸；6（10-十七碳烯基）十七碳烯基）水杨酸；5-（8-十五碳烯基）间苯二酚。     

圆齿野鸦椿枝条化学成分及其抗炎活性研究

对圆齿野鸦椿枝条化学成分进行研究,从中分离得到15个化合物,通过理化性质与波谱分析分别鉴定为1-(4-羟基-3-甲氧基苯基)-2[4-(4′-羟丙基)-2′-甲氧基苯氧基]-1,3-丙二醇(1),acernikol(2),罗汉松脂素-4-O-β-D-葡萄糖苷(3),罗汉松脂素-4′-O-β-D-葡萄糖苷(4), 2-[4-(1-羟丙基)-3-甲氧基苯氧基]-1,3-丙二醇(5), 5,7-二羟基-2-甲基色原酮(6), 5,7-二羟基-2-甲基色原酮-6-C-β-D-葡萄糖苷(7), 5,7-二羟基-2-甲基色原酮-8-C-β-D-葡萄糖苷(8),槲皮素-3-O-α-L-阿拉伯糖(9),没食子酸(10), 4-羟基-3-甲氧基苯甲醛(11),硬脂酸(12), 19α-羟基熊果酸(13),β-谷甾醇(14)和胡萝卜苷(15)。除化合物7、8、14和15外,其他化合物均为首次从该属植物中分离得到。抗炎活性评价结果显示:当浓度为10μmol/L时,化合物2和4对脂多糖诱导的小鼠巨噬细胞白介素-6的分泌抑制率分别为(63.4±7.1)%和(58.6±4.6)%,显示中等抑制活性,略低于阳性对照药地塞米松的(85.8±5.3)%。     

Progress of oxidation of non-phenolic lignin moiety in an oxygen bleaching process via the conversion of non-phenolic into phenolic lignin moiety

To examine whether non-phenolic lignin moiety is converted into the new phenolic counterpart by the participation of active oxygen species (AOS) under oxygen bleaching conditions, a β-O-4 type dimeric lignin model compound, 2-(2-methoxyphenoxy)-1-(3,4-dimethoxyphenyl)propane-1,3-diol (I), 2-(3,5-difluorophenoxy)-1-(4-hydroxy-3-methoxyphenyl)propane-1,3-diol (III), or 2-(3,5-difluorophenoxy)-1-(3,4-dimethoxyphenyl)propane-1,3-diol (IV), was treated under conditions similar to those for oxygen bleaching. A phenolic compound, 4-hydroxy-3-methoxybenzyl alcohol, was added together to generate AOS in the reaction of compound I or IV. The results obtained suggested that AOS attack the side chains of compounds I, III, and IV accompanied by the β-O-4 bond cleavages and the liberations of the corresponding phenolic compounds, 2-methoxyphenol (II), 3,5-difluorophenol (V), and compound V, respectively. However, the rapid liberation of compound V in the oxygen-alkali treatment of compound III may mainly be caused by alkaline-induced reactions and/or some oxidation reactions of the primary degradation product of compound III, a muconic acid derivative.     

Antimicrobial and cytotoxic activities of Laportea crenulata

Crude extracts and 2alpha,3beta,21beta,24beta,28-pentahydroxy-olean-12-ene (1) obtained from the root of Laportea crenulata exhibited remarkable antibacterial activities against both Gram (+) and Gram (-) bacteria. The antifungal activities of crude extracts and compound (1) were also determined. The cytotoxic activities of crude extracts and compound (1) were observed by brine shrimp bioassay and LC(50) value of the compound (1) was found to be 27.54 microg/ml.     

脱氢枞基苯并咪唑希夫碱和酰腙衍生物与DNA作用的比较研究

合成了脱氢枞胺和脱氢枞酸的衍生物脱氢枞基-1-甲基苯并咪唑希夫碱(1)和脱氢枞基-1-甲基苯并咪唑酰腙(2),并通过红外、质谱、元素分析和核磁等方法对其进行了表征。运用荧光光谱,黏度分析和图二色(CD)光谱等方法研究了化合物1、2和鲑鱼精DNA的相互作用,在荧光光谱中,通过在DNA-溴化乙锭(EB)体系中加入不同浓度的1和2,随着化合物浓度的增加,DNA-EB体系的荧光强度发生了明显的猝灭效应,由此推测化合物可能与EB一样插入到了DNA的碱基对中,再根据Stern-Volmer方程分析得出,化合物1与DNA作用强于2;黏度分析中,随着化合物1和2浓度的增加,DNA的黏度逐渐增加,且化合物1增加的幅度大于2;CD光谱中,相同浓度的不同化合物使DNA的CD信号的改变量不同,并且化合物1对DNA构型的影响要强于2,三者的实验结果均表明化合物以插入作用的方式与DNA作用。凝胶电泳实验表明,在抗坏血酸(Vc)存在的条件下,化合物1和2均能够对PBR322 DNA质粒进行单股切割,在Vc不存在的条件下,1能够对DNA质粒进行单股切割。结果表明:化合物1具有更强的与DNA作用的能力。     

Protective effect of a new amide compound from Pu-erh tea on human micro-vascular endothelial cell against cytotoxicity induced by hydrogen peroxide

A new amide, N-(3,4-dihydroxybenzoyl)-3,4-dihydroxybenzamide (1), was isolated from the Pu-erh tea made with the leaf of Camellia assamica (Mast.) Chang by special fermentation techniques with bacteria and fungus. Its structure was established by means of spectroscopic data analyses, including mass spectrometry and both 1D and 2D NMR spectroscopy. Human micro-vascular endothelial cell (HMEC) injured with H₂O₂ was used as the model to test protective effect of compound 1 in contrast with other known compounds isolated from Pu-erh tea. These results suggested that compound 1 is a very useful compound to prevent H₂O₂-induced cell death of HMEC.     

Identification of two compounds correlated with lack of rooting capacity of chestnut cuttings

Cuttings from mature chestnut (Castanea spp.) trees are very difficult to root, whereas juvenile or etiolated cuttings root easily. The HPLC chromatograms from mature cuttings consistently showed two well-defined peaks that were absent from juvenile or etiolated cuttings. The compounds responsible for these two peaks were isolated and identified as derivatives of ellagic acid, 3,3',4-tri-O-methylellagic acid (compound 1) and 3,4,4'-tri-O-methylellagic acid (compound II). Compound I significantly inhibited rooting as measured by the bean test; a concentration of 3.0 x 10(-5) M caused a 32% inhibition in number of roots formed compared with controls grown in 10(-5) M IAA. When compound I was mixed with an equal quantity of IAA, the rooting activity of the auxin was reduced by 31.5%. An insufficient amount of compound II was available for the bean assay.     

Significance of benzylic hydroxymethylene group in the reaction of lignin side-chain with active oxygen species under oxygen bleaching conditions

To examine the effect of the presence of benzylic hydroxyl group on the reaction of β-O-4 type lignin moiety with active oxygen species (AOS) under oxygen bleaching conditions, a specially designed β-O-4 type model compound carrying the benzylic methoxyl group, 2-(3,5-difluorophenoxy)-3-methoxy-3-(3,4-dimethoxyphenyl)propan-1-ol (IV), was treated together with a phenolic compound, 4-hydroxy-3-methoxybenzyl alcohol (II), under oxygen bleaching conditions. In this reaction system, AOS were generated by reactions of compound II with dioxygen and attacked compound IV. Compound IV was rather stable, while an analogous model compound carrying the benzylic hydroxyl group, 2-(3,5-difluorophenoxy)-1-(3,4-dimethoxyphenyl)propane-1,3-diol (I), was rather degraded. This result and the previous knowledge on the relatively high stability of 3,4-dimethoxybenzyl alcohol carrying only the hydroxymethyl group as side-chain under the identical reaction conditions suggested that the existence of benzylic hydroxymethylene group is essential in the extensive reaction of side-chain of β-O-4 type lignin moiety with AOS. To compare the reactivity of AOS toward different types of hydroxyl and aryloxyl carbons, 2-(3,5-difluorophenoxy)propane-1,3-diol (VI) or 3-(3,5-difluorophenoxy)propane-1,2-diol (VII) was also subjected to this reaction system. Compound VII was degraded by AOS more extensively than compound VI.     

森林资源蓄积量预测技术初探

以福建省三明市森林资源二类调查资料为基础数据,采用VB编程语言,自主开发了森林资源蓄积量预测系统,用GM(1,1)模型、复利公式和BP人工神经网络模型分别对森林资源蓄积量进行宏观预测.3种方法的预测结果显示:BP人工神经网络模型拟合效果较好,其次是灰色系统模型,平均相对误差最大的是复利公式.最后分析了3种方法的优劣,探讨进一步优化的方法.     

Flavonol glycosides from Aconitum vulparia

The isolation of five flavonol glycosides (1-5) from the flowers of Aconitum vulparia is reported, together with the 1H- and 13C-NMR spectral data in CD(3)OD of compound 3 and 5.     

Synthesis of β-O-4 type oligomeric lignin model compound by the nucleophilic addition of carbanion to the aldehyde group

A synthetic method for obtaining lignin oligomer that contains only the β-O-4 structure is described in detail. This method consists of three reaction steps: (1) the synthesis of t-butoxycarbonylmethyl vanillin (2), (2) the nucleophilic addition oligomerization of compound 2, and (3) the reduction of the oligomeric β-hydroxyl ester. In the first step, compound 2 was synthesized from vanillin in 96.8% yield. In the second step, compound 2 was oligomerized with commercial lithium diisopropylamide (LDA) to obtain oligomeric β-hydroxyl ester (3) in 87.2% yield; the repeating units of this oligomer were joined only by β-O-4 linkages as confirmed by nuclear magnetic resonance (NMR) spectroscopy. In the third step, the oligomeric β-hydroxyl ester (3) was reduced with LiAlH₄ to give compound 4 in 42.4% yield. On the basis of NMR, matrix-assisted laser desorption ionization time-of-flight mass spectrometry, and gel permeation chromatography analyses of compound 4, it was concluded that compound 4 was an oligomeric lignin model compound containing only β-O-4 interunit linkages. The number average degree of polymerization (DPn) of obtained compound 4 was about 7.0 (M _w/M _n = 1.42). Using this oligomeric lignin model compound, conventional degradation and analytical methods will give new information.     

1-(3-Hydroxy-4-methoxy-5-methylphenyl) ethanone, a new compound from the stem bark of Lamprothamnus zanguebaricus

The chloroform extract of the stem bark of Lamprothamnus zanguebaricus has yielded two ethanones; 1-(3-hydroxy-4-methoxy-5-methylphenyl)ethanone (I) (a new compound) and 1-(3-hydroxy-4-methoxyphenyl)ethanone (II). The structures of both compounds were established by spectroscopic methods.