浅谈配位反应在化学和生物中的应用

本文在配位化合物结构基础上,重点讨论配位化合物在化学和生物学方面的应用,展望了配位化学的发展前景。     

集中合成技术的精粹 扩大新药研制的领地

以从大学收集而来的化合物为基础，理化学研究所计划通过组合化学（Combikem）等方法使化合物的种类实现飞跃式的增长。新的化合物数据库计划于2006年开始运营。能否得到和公费投入相称的意义呢？     

手性源、手性池和手性农药中间体的开发研究

介绍手性源、手性池和手性分子化合物的基本概念;由手性池化合物制备手性衍生物;比较了手性化合物生物加工与化学加工过程的优、缺点,寻求高效、经济和最合理的综合工艺流程。     

应用化学基因组信息预测小分子化合物的潜在生物靶标的理论方法

在后基因组时代,化学基因组技术在药物作用靶点的确认、小分子化合物对通路的作用,以及小分子先导化合物的识别等方面都有着广泛的应用,为新药研发提供了新的技术方法。本文主要介绍了当前几种基于化学基因组信息来预测小分子化合物潜在生物靶标的理论方法（包括化学相似性搜索方法、反向分子对接方法、数据挖掘方法以及生物活性谱图分析方法）,并分析了这些方法的优缺点以及应用前景。     

齐墩果烷型降三萜化学成分研究进展

本文对国内外有关齐墩果烷型降三萜类化合物在植物中的分布、化学结构特征及药理活性的最新研究进展进行了综述,为该类型化合物进一步研究提供参考。     

多根硬皮马勃中子实体的化学成分

从多根硬皮马勃（Scleroderma polyrhizum Pers．）子实体中分离得到了3个含氮化合物,根据化学和光谱数据,它们的化学结构分别确定为：N,N-dimethylphenylalanine（1）,2-N,N,N-trimethyl-phenylalanine（2）,2-trimethyl-ammonio-3-（3-indolyl）propionate（3）。上述含氮化合物均首次从多根硬皮马勃中分离得到,其中化合物2首次从高等真菌中分离得到。     

植物化学发展趋势与战略

植物化学(phytochemistry)是植物科学中的一个重要分支。传统认为,植物化学研究对象是指植物体内的次生产物,即小分子化合物,如萜类化合物、生物碱、黄酮类化合物和其它酚性化合物。研究途径主要是从植物体中提取、分离和鉴定上述那些化学成分。其目的是要进行资源利用和发现新化合物,为医药、食品和工业上提供可潜在利用的化学成分。五十     

放线菌萜类化合物生物合成研究进展

萜类化合物(Terpenoids)是自然界中化学结构最为丰富的一类化合物。近年来,从放线菌中分离到了一系列结构新颖的萜类化合物。通过直接克隆或基因组采掘(Genome mining)的方法,它们的生物合成基因簇被相继分离和鉴定,从而推动了放线菌中萜类化合物生物合成途径及关键酶的分子作用机理的研究。文章主要综述了近5年放线菌萜类化合物生物合成研究进展。     

C7N氨基环醇家族的天然α-糖苷酶/淀粉酶抑制剂研究进展

C7N氨基环醇家族化合物是一类由放线菌产生的天然化合物,化学结构相对较新颖。其核心基团井岗胺赋予该家族化合物多种生物活性,其中最主要的是α-糖苷酶/淀粉酶抑制剂活性。该家族化合物在生物医学和农业领域中具有较大的应用价值。本文将结合作者的研究方向,综述已被报道的C7N家族α-糖苷酶/淀粉酶抑制剂的化学结构与生物活性。     

生漆化学的一个新研究领域 Ⅰ.饱和漆酚冠醚的合成及应用

本文以中国生漆中所含成份漆酚为原料,合成了一系列具有特殊性能的新型化合物——饱和漆酚冠醚,并开展了这类化合物的应用研究,从而展现了漆化学研究中的一个新的研究领域。     

Flora of the forest-steppe zone of West Siberia as a source of biologically active compounds

Plants of 76 species from 25 families growing in the forest-steppe zone of West Siberia are analyzed for the content of low-molecular biologically active compounds, such as flavonoids, tannins, catechins, coumarins, saponins, and alkaloids. It is established that 33 species hold promise as a source of flavonoids, 29 species tannins, 21 coumarins, 13 saponins, 13 alkaloids, and 1 catechins.     

Permeabilization and in situ adsorption studies during growth and coumarin production in hairy root cultures of Cichorium intybus L

Effect of addition of a permeabilizing agent dimethyl sulfoxide (DMSO) and a solid adsorbent, XAD -7, on growth and coumarin production in hairy root cultures of C. intybus was studied. Continuous permeabilization of the hairy root cultures of C. intybus with DMSO has been shown to be an effective strategy for enhanced release of coumarins while preserving the root viability. DMSO at 0.2% (v/v) level showed the maximum growth and coumarin production but was less as compared to control on day 28. Treatment of cells with increasing concentrations of DMSO (0.3 - 0.6 % v/v) to hairy root cultures of C. intybus, showed an inverse relationship with growth and coumarin production. Growth and production of coumarins increased with 1% media filtrate (MF) of cultures of Phytopthora parasitica var. nicotiana treatment. It was observed that treatment with DMSO (0.2% v/v) and 1% MF of P. parasitica showed the better growth and coumarin production with an increased release of coumarins as compared to the control and other treatments. It was observed that treatment of hairy root cultures with XAD-7 resulted in lesser growth and coumarin production as compared to control during the culture period. Addition of XAD-7 along with 1% MF of P. parasitica showed enhanced growth, coumarin production and increased adsorption as compared to control and lone XAD-7 treatment. Combined addition of DMSO/XAD-7 with fungal elicitor showed synergistic response in terms of biomass and coumarin production. Excretion of coumarins in both the cases was dependent on the presence of DMSO/XAD-7. These results showed that continuous permeabilization of hairy root cultures of C. intybus by using DMSO at 0.2% (v/v) level coupled with 1% MF of P. parasitica maintained viability of tissues and produced coumarins at higher level.     

Sesquiterpene coumarins

Plants have a long history as therapeutic tools in the treatment of human diseases and have been used as a source of medicines for ages. In search of new biologically active natural products, many plants and herbs used in traditional medicine are screened for natural products with pharmacological activity. In this paper, we present a group of natural products, the sesquiterpene coumarins isolated from plants, and describe their wide range of biological activity. Sesquiterpene coumarins are found in some plants of the families Apiaceae (Umbelliferae), Asteraceae (Compositae) and Rutaceae. The coumarin moiety is often umbelliferone (7-hydroxycoumarin) but scopoletin (7-hydroxy-6-methoxycoumarin) and isofraxidin (7-hydroxy-6,8-dimethoxycoumarin) are also found. These coumarins are linked to a C₁₅ terpene moiety through an ether linkage. Another group of sesquiterpene coumarins is the prenylated 4-hydroxycoumarins where the link between the coumarin and the C₁₅ terpene moiety is a C–C-bond at carbon 3 of the coumarin moiety. Finally, the prenyl-furocoumarin-type sesquiterpenoids are a separate group of sesquiterpene coumarins based on the suggested biosynthetic pathway. Our relatively limited knowledge on the biosynthesis of sesquiterpene coumarins is reviewed.     

Effect of various coumarins on the intestinal absorption of galactose in vivo (author's transl)]

The effect of various coumarins on the active transport of galactose by small intestine in chick and rat was studied, using the in vivo technique of sucessive absorptions. A 10(-4) M concentration of the different coumarins inhibits the absorption of galactose in the chick. This effect persists in successive absorptions without coumarin. In rat, inhibition of galactose active transport by coumarins was observed at 10(-3) M concentration.     

Antioxidant activity of coumarins and flavonols from the resinous exudate of Haplopappus multifolius

The antioxidant activity of eight coumarins and two flavonols isolated from Haplopappus multifolius was studied with the DPPH radical method. Results show that a high concentration of phenolic coumarins and the presence of quercetin and rhamnetin in the exudates could account for the protection of the plant against oxidative stress. Structures for the coumarins 6-hydroxy-7-[(E,E)-3',7'-dimethyl-2',4',7'-octatrienyloxy] coumarin and 7-[(E)-3'-methyl-4'-hydroxy-2'-butenyloxy] coumarin are proposed on the basis of spectroscopic evidence.     

Structure-activity relationships for naturally occurring coumarins as β-secretase inhibitor

The present study was demonstrated to evaluate the effects of naturally occurring coumarins (NOCs) including simple coumarins, furanocoumarins, and pyranocoumarins on the inhibition of β-secretase (BACE1) activity. Of 41 NOCs examined, some furanocoumarins inhibited BACE1 activity, but simple coumarins and pyranocoumarins did not affect. The most potent inhibitor was 5-geranyloxy-8-methoxypsoralen (31), which has an IC(50) value of 9.9 μM. Other furanocoumarin derivatives, for example, 8-geranyloxy-5-methoxypsoralen (35), 8-geranyloxypsoralen (24), and bergamottin (18) inhibited BACE1 activity, with the IC(50) values <25.0 μM. Analyses of the inhibition mechanism by Dixon plots and Cornish-Bowden plots showed that compounds 18, 31 and 35 were mixed-type inhibitor. The kinetics of inhibition of BACE1 by coumarins 24 was non-competitive inhibitors.     

Structure-activity relationship in two series of aminoalkyl substituted coumarin inhibitors of gyrase B.

Two series of aminosubstituted coumarins were synthesised and evaluated in vitro as inhibitors of DNA gyrase and as potential antibacterials. Novel novobiocin-like coumarins, 4-(dialkylamino)methylcoumarins and 4-((2-alkylamino)ethoxy)coumarins, were discovered as gyrase B inhibitors with promising antibacterial activity in vitro.     

The reaction of coumarins with horseradish peroxidase

The peroxidase catalyzed oxidation of indole-3-acetate is inhibited by naturally occurring coumarins such as scopoletin. This inhibition is due to the preferential reactivity of the coumarins with the peroxidase compounds I, II, and III. In view of the possible growth regulatory role of coumarins in plants, the mechanism of oxidation of scopoletin by horse-radish peroxidase has been investigated.     

Effect of coumarins on mitochondrial function.

Several derivatives of coumarin inhibited mitochondrial respiration and ATPase activity. The extent of inhibition depended on the concentration of the coumarins as well as on the substituents of the coumarin ring. Some of the coumarins stimulated ATPase activity, but all of them inhibited uncoupler-stimulated ATPase activity. Coumarins with free or substituted phenolic groups were found to exert profound effects on respiration and ATPase activity.     

Synthesis and antifungal activity of coumarins and angular furanocoumarins.

Angelicin, a naturally occurring furanocoumarin, that showed antifungal activity, was considered as a lead structure for a group of synthetic coumarins. Antifungal activities of the synthesized coumarins and angelicin derivatives were reported against Candida albicans, Cryptococcus neoformans, Saccharomyces cerevisiae and Aspergillus niger. Human cell line cytotoxicity of several coumarins was evaluated against KB cells. Angelicin and several potent antifungals showed to be non-toxic in this assay.