应用FTIR和NMR研究短梗霉多糖分子结构

短梗霉多糖是出芽短梗霉产生的一种胞外多糖,具有极好的成膜、成纤维、阻气、粘接、易加工、无毒性等特性,是微生物多糖中最令人瞩目的多糖之一．本研究应用ＦＴＩＲ和ＮＭＲ技术对由出芽短梗霉胞外产生的短梗霉多糖进行了分析．短梗霉多糖的红外光谱（４０００～４００ｃｍ－１）,具有明显的多糖特征吸收峰,证明多糖是由α－Ｄ－吡喃葡萄糖残基组成．应用先进的一维和二维核磁共振技术,在绝对温度３４３Ｋ下获得短梗霉多糖１Ｈ－ＮＭＲ谱和１３Ｃ－ＮＭＲ谱,确证短梗霉多糖的结构单元是α－１,４麦芽三糖,归属了短梗霉多糖的１Ｈ和１３Ｃ的全部化学位移     

中国鸡皮衣属地衣化学成分研究

作者通过对隶属于３５个分类单位的近４００号中国鸡皮衣属地衣标本的化学测定,在本文中报道了我国鸡皮衣属地衣中存在的２３个化合物,首次报道鸡皮衣属地衣中存在的有分类意义的化学成分１种,即ｍａｌｏｎｏｐｒｏｔｏｃｅｔｒａｒｉｃａｃｉｄ。化学测定结果表明：至少在中国鸡皮衣属种中,４,５－二氯地衣酮（４,５－ｄｉｃｈｌｏｒｏｌｉｃｈｅｘａｎｔｈｏｎｅ）可能局限于Ｐｅｒｔｕｓａｒｉａ亚属;β－地衣酚类（β－ｏｒｃｉｎｏｌ）化合物是主导的髓层化学成分;β－地衣酚类缩酚酸（β－ｏｒｅｉｎｏｌｄｅｐｓｉｄｅｓ）和β－地衣酚类原岛衣酸型缩酚酸环醚（β－ｏｒｃｉｎｏｌｐｒｏｔｏｃｅｔｒａｒｉｃａcｉｄ－ｔｙｐｅｄｅｐｓｉｄｏｎｅｓ）是Ｐｉｏｎｏｓｐｏｒａ亚属的特征性化学成分,β－地衣酚类斑点酸型缩酚酸环醚（β－ｏｒｃｉｎｏｌｓｔｉｃｔｉｃ　ａｃｉｄ－ｔｙｐｅｄｅｐｓｉｄｏｎｅｓ）是Ｐｅｒｔｕｓａｒｉａ亚属的特征化学成分。形态和化学特征在鸡皮衣属内存在着平行的或独立的进化路线。     

龙牙楤木种群分化研究(Ⅱ)薄层色谱的聚类分析

通过应用薄层色谱分析法,对采自黑龙江省小兴安岭、张广才岭和完达山地区的龙牙楤木叶的化学成分进行比较分析,发现不同种群之间叶的化学成分具有较大差异。通过对其化学成分的聚类分析,可将本区域的龙牙楤木划分为两个类群。这个结果与前文对其形态特征分析所得结果完全一致,充分说明本区域龙牙楤木属于同一种物种的两个变种,即原变种Aralia elata var. elata的新组合变种-东北楤木Aralia elata var. mandshurica (Rupr. et Maxim.)W. H. Ye。     

Opportunities at the interface of chemistry and biology

The combination of the tools and principles of chemistry, together with the tools of modern molecular biology, allow us to create complex synthetic and natural molecules, and processes with novel biological, chemical and physical properties. This article illustrates the tremendous opportunity that lies at this interface of chemistry and biology by describing a number of examples, ranging from efforts to expand the genetic code of living organisms to the use of combinatorial methods to generate biologically active synthetic molecules.     

金针菇栽培基质组分的降解及相关酶活的变化

研究了金针菇三明1号、16号、杂交19号在棉籽壳-麦麸基质上生长期间基质中主要化学组分及相关酶活的变化,以及低温刺激对子实体形成生长阶段胞外酶活性、菇的发生及菇外观的影响。结果表明：三明1号具有微弱的降解木质素的能力;基质组分降解速率的变化与胞外酶活性具有一定的对应关系：菇外观的优劣在一定程度上与菇蕾发生后菌的代谢活动能力的强弱有关;低温刺激增加了三明1号菇曹发生后胞外酶活性、使之表现出良好的诺外观,而对杂交19号的菇外观无明显影响。     

Chemical signals in gametogenesis, spawning, and larval settlement and defense of the soft coral Sinularia polydactyla

 Mass spawning strategies of hard and soft corals on the Great Barrier Reef, Australia have been described in recent years. Nonetheless, the applicability of those studies to corals on other reef systems has not been well documented. Here we describe the mass spawning behavior of the soft coral Sinularia polydactyla on coral reefs surrounding Guam; specifically we describe the events in an annual gametogenic cycle including steroidogenesis, spawning, settlement and early life history defense. The gametogenic cycle of female colonies lasted 12 months while male colonies produced viable sperm within 9 months. Sinularia polydactyla exhibited a split spawn between March and June that correlated with a significant reduction in tissue concentrations of progesterone and testosterone. Estradiol was released into the water column, apparently by female colonies, just prior to spawning. There was a trend for preferential larval settlement in the presence of the crustose coralline algae Hydrolithon reinboldii rather than coral rubble, a natural biofilm, or filtered seawater. The defensive compounds pukalide and 11β-acetoxypukalide were found in eggs and larvae at adult level and three-fold lower than adult-level concentrations, respectively. These compounds provided some predator deterrent and antimicrobial protection against an ecologically relevant omnivorous fish Canthigaster solandri and a sympatric microbe Vibrio sp. Accepted: 10 September 1998     

The Chemical Constituents of Duzhong (The Bark of Eucommia ulmoides Oilv.)

Seven constituents have been isolated from the bark of Eucommia ulmoides Oliv. Based on spectral analysis and determination of Physico-chemical constants they have been identified as: nonacosane (Ⅰ), n-triacontanol (Ⅱ), β-sitosterol (Ⅲ), betulin (Ⅳ), betulic acid (Ⅴ), ursolic acid (Ⅵ), vanillic acid (Ⅶ).     

Analysis of bioactive compounds and chemical composition of Malaysian stingless bee propolis water extracts

Propolis is a resinous substance collected by stingless bees containing bioactive compounds which exert various biological properties. The present study focused on the evaluation of chemical profiles produced by three Indo-Malayan stingless bee propolis extracted using water. Fresh propolis was collected from the same area and ecosystem conditions in Selangor, Malaysia, namely Tetrigona apicalis, Tetrigona binghami, and Heterotrigona fimbriata. The bioactive compounds and chemical composition of propolis extracts were then analyzed using gas chromatography–mass spectrometry (GC–MS). Results showed that propolis from the three different stingless bee species consisted of major groups such as sugar (31.4%), carboxylic acid (17.1%), terpenoid (14.3%), sugar alcohol (11.4%), hydrocarbon (5.7%), aldehyde (5.7%) amino acid (2.9%) and other constituents (11.4%). Heterotrigona fimbriata displayed the highest amount for both total phenolics (13.21 mg/mL) and flavonoids (34.53 mg/mL) compared to other propolis extracts. There is also no significant difference detected between all samples since p ≤ 0.05. In conclusion, this study shows that Malaysian stingless bee propolis contain bioactive components that have great potential to be used for their therapeutic and medicinal benefits. However, more investigations and analysis of stingless bee propolis need to be carried out in order to enhance the understanding and applications of propolis in the future.     

豺皮樟叶挥发油化学成分的研究

利用GC－MS联用技术从豺皮樟（Litsea rotundifolia var.oblongifolia)叶挥发油中分离和鉴定了27个化合物,占挥发油总量的88．75％,其中主要成分是十二烷酸（43．68％）,肉豆蔻酸（14．61％）,十一烷酸（4．70％）,棕榈酸（4．15％）。     

The ability of the amphipod Corophium volutator (Pallas) to follow chemical signals from con-specifics

The amphipod Corophium volutator (Pallas) is a tube-dwelling species that only occasionally leaves its burrow. Animals that do crawl on the sediment are mainly males, apparently in search of females. This study was designed to determine whether C. volutator males and females release chemical signals that attract con-specifics, and if so, whether these signals are gender specific. Laboratory experiments were conducted on the over-wintering generation during their reproductive season, using a Y-maze choice test apparatus. The results show that C. volutator females release chemical signals that attract males. In the field, the attractant may guide males in search of burrowed females. In addition, male odour tends to attract males, while females do not follow chemical signals from con-specifics. We thereby show on gender-specific chemical attraction of this species.