Prenylated flavonoids from Tephrosia purpurea seeds

Two new prenylated flavonoids, purpuritenin purpureamethide, have been characterized from the seeds of Tephrosia purpurea together with the known c     

Prenylated flavonoids from Moghania philippinensis

Five prenylated flavonoids, 8-(1,1-dimethylallyl)genistein (1), 5,7,3',4'-tetrahydroxy-2',5'-di(3-methylbut-2-enyl)isoflavone (2), 5,7,3'-trihydroxy-2'-(3-methylbut-2-enyl)-4',5'-(3,3-dimethylpyrano)isoflavone (3), (2R)-5,2',4'-trihydroxy-8,5'-di(3-methylbut-2-enyl)-6,7-(3,3-dimethylpyrano)flavanone (4a) and (2S)-5, 2', 4'-trihydroxy-8,5'-di(3-methylbut-2-enyl)-6,7-(3,3-dimethylpyrano)flavanone (4b), were isolated from the roots of Moghania philippinensis. The structures of these compounds were determined on the basis of spectroscopic and chemical means.     

A chalcone and an isoflavone from Millettia pachycarpa seeds

Chemical examination of the seeds of Millettia pachycarpa has yielded a new prenylated isoflavone and a new prenylated chalcone in addition to the previously reported isoflavones 5-hydroxy-4′-methoxy-6″,6″-dimethylpyrano (2″,3″:7,8)isoflavone, 5,7,4′-trihydroxy-6,8-diprenylisoflavone, 5,7,3′,4′-tetrahydroxy-6,8-diprenyl-isoflavone and pomiferin.     

Prenylated p-coumarates from Werneria stuebelii

The aerial parts of Werneria stuebelii afforded in addition to β-cedrene and bicyclogermacrene eight derivatives of methyl p-coumarate, all being formed by prenylation. The structures were elucidated by their molecular formulae and their ¹H NMR spectra. The chemotaxonomy of the Andean genus Werneria is discussed briefly.     

Antimicrobial agents from higher plants: Prenylated flavonoids and other phenols from Glycyrrhiza lepidota

Bioassay directed fractionation of extracts of American licorice, Glycyrrhiza lepidota (Leguminosae), resulted in identification of the known bibenzyl, 3,5-dihydroxy-4-(3-methyl-2-butenyl)-bibenzyl, and the known flavanones, glabranin and pinocembrin, as well as the isolation and structure determination of the new flavonol, glepidotin A and the new dihydroflavonol, glepidotin B as antimicrobial agents.     

Urease inhibitory isoflavonoids from different parts of Calopogonium mucunoides (Fabaceae)

The dichloromethane-methanol (1:1) soluble part of Calopogonium mucunoides (Fabaceae) resulted in the isolation of 10 isoflavones (4′-O-methylalpinumisoflavone, 4′-O-methylderrone, alpinumisoflavone, daidzeine, Calopogonium isoflavone A, atalantoflavone, 2′,4′,5′,7-tetramethoxyisoflavone, 7-O-methylcuneantin, cabreuvin and 7-O-methylpseudobaptigenin) and a rotenoid (6a,12a-dehydroxydegueline). Among these, daidzeine, 7-O-methylcuneantin, atalantoflavone and 6a, 12a-dehydroxydegueline have been isolated for the first time from C. mucunoides while remaining are already reported from this source. Structures of all the isolated constituents were elucidated with the aid of NMR spectroscopic and mass spectrometric techniques. Among all the isolated constituents, nine were evaluated for their urease inhibitory potential. However, six were found potent. These include 4′-O-methylderrone, daidzeine, atalantoflavone, 2′,4′,5′,7-tetramethoxyisoflavone, 7-O-methylcuneantin and 6a, 12a-dehydroxydegueline.     

补骨脂中异戊烯基黄酮类化合物及其药理作用研究进展

综述补骨脂(Psoralea corylifolia)中的异戊烯基黄酮类化合物及其药理作用的研究进展.     

异戊烯基化吲哚类生物碱的化学酶合成

异戊烯基化吲哚类生物碱广泛存在于麦角菌、青霉菌和曲霉菌中,具有一定的药理学活性,与未异戊烯基化的前体在生物活性方面具有明显的差异.曲霉菌中的某些异戊烯基化吲哚类生物碱具有抗癌活性,如烟曲霉毒素C（fumitremorgin C）、tryprostatin B,但其天然产量低且不易分离,利用化学酶合成法可很容易地将前体转化为异戊烯基化吲哚类生物碱.异戊烯基转移酶FtmPT1对二甲丙烯基二磷酸（dimethylallyl diphosphate,DMAPP）具有专一性,但可以接受不同的芳香族底物.早期研究发现,FtmPT1能接受含色氨酸的不同环二肽为底物,但以cyclo-L-Trp-L-Tyr和cyclo-L-Trp-L-Phe为底物时,酶的相对活性很低,其产物量少,无法用于合成产物.本实验通过优化酶反应条件来提高其产量.将已构建的含ftmPT1的质粒在大肠杆菌中诱导表达,经Ni-NTA亲和柱纯化后用于酶反应.实验结果表明,通过增加酶量（终浓度2.8 μmol/L）、延长培养时间（37 ℃,24 h）,以cyclo-L-Trp-L-Tyr和cyclo-L-Trp-L-Phe为底物的酶反应产率分别达到49.3%和21.3%,产物经¹H^-NMR、¹H-¹H-COSY和ESI-MS鉴定,其结果与预期吻合.据检索,这2个化合物均为新化合物,分别命名为cyclo-C2-1′-DMA-L-Trp-L-Tyr和cyclo-C2-1′-DMA-L-Trp-L-Phe.     

Prenylated flavanones from the twigs of Dorstenia mannii

Investigation of the twigs of Dorstenia mannii gave 6,8-diprenyl-5,7,3′4′-tetrahydroxyflavanone and four new prenylated flavanones, named dorsmanins E-H and characterized as 5,6-7,8-bis-(2,2-dimethylchromano)-3′,4′-dihydroxyflavanone, 7,8-[2″-(1-hydroxy-1-methylethyl)-dihydrofurano]-6-prenyl-5,3′,4′-trihydroxyflavanone, 6,7-[2″-(1-hydroxy-1-methylethyl)dihydrofurano]-8-prenyl-5,3′,4′-trihydroxyflavanone and 6-prenyl-8-(2-hydroxy-3-methylbut-3-enyl)-5,7,3′,4′-tetrahydroxyflavanone, respectively, on the basis of spectral analysis and chemical evidence for the chromano derivative.     

Prenylated flavonoids from the aerial parts of Dorstenia mannii

Four new prenylated flavanones, dorsmanins 1, J and epi-dorsmanins F, G, identified, respectively, as 6,7-(2,2-dimethylpyrano)-8-prenyl-5,3',4'-trihydroxyflavanone, 6,7-(2,2-dimethyldihydropyrano)-8-prenyl-5,3',4'-trihydroxflavanone, and 2'-epimers of dorsmanins F and G were isolated from the aerial parts of Dorstenia mannii together with 13 known flavonoids: 4-hydroxylonchocarpin, 4-methoxylonchocarpin, 6-prenylchrysoeriol, 6,8-diprenyleriodictyol, gancaonin P and dorsmanins A-H. The structures of these secondary metabolites were determined by spectroscopic means and by comparison with published data and with authentic specimens for some of the known compounds.     

Protein deamidases from germinating seeds

Enzymes catalyzing the deamidation of seed storage proteins were found in germinating seeds of kidney beans ( Phaseolus vulgaris L. cv. Moldavian) and squash ( Cucurbita pepo L. cv. Mozoleevskaya). They were partially purified and characterized. The properties of these enzymes closely resemble those of the protein deamidase in germinating wheat grains. The detection of similar protein deamidases in germinating seeds of plants belonging to phytogenetically unrelated species indicates that protein deamidases are of considerable physiological significance.     

two 3-oxo steroids in Thea sinensis seeds

Spinasterone and 22,23-dihydrospinasterone were isolated from the seed oil of Thea sinensis which contains spinasterol and 22,23-dihydrospinasterol as the two major sterol constituents.     

Organic fertilizer applications influence on the shoot and root biomass production and plant nutrient of Calopogonium mucunoides from crude oil-contaminated soils

The impact of crude oil-contaminated soil on the shoot and root biomass yield and nutrients uptake of Calopogonium mucunoides Desv. using two types of composted manure (COM) as soil amendments were investigated. This was with a view to assessing the growth response of the test plant under different levels of crude oil soil contamination. Five levels [0, 2.5, 5, 10, and 20% (v/v)] of crude oil, each was replicated thrice to contaminate 3 kg of soil when 12 g pot^?1 COM; 12 g pot^?1 neem-fortified composted manure (NCM) and control, soil without manure application (C) were imposed as manure treatments. The mean fresh shoot biomass yield at zero crude oil soil contamination and with COM application was 2.67 g pot^?1. This value was significantly (p < 0.05) higher than 2.05 g pot^?1 for NCM and 1.67 g pot^?1 for the control. Also, the mean fresh root yield at zero crude oil soil contamination with COM application was 4.02 g pot^?1. This value was significantly (p < 0.05) higher than 2.41 g pot^?1 for NCM and 1.71 g pot^?1 for the control. The dry shoot and root biomass yield followed similar pattern. The shoot and root yield of C. mucunoides significantly (p < 0.05) reduced with increase in crude oil soil contamination. The nutrients uptake of C. mucunoides, particularly N, P, Ca, Mg, and Fe, were enhanced with COM fertilization having higher available P, K, and Na values; and by implication, suggesting the importance of adequately formulated composted manure usage in the rehabilitation studies of crude oil-contaminated soil.     

Pyrrolizidine alkaloids from seeds of Crotalaria scassellatii

Three pyrrolizidine alkaloids were isolated from the seeds of Crotalaria scassellatii. Axillaridine and axillarine were the two major alkaloids whereas the third minor alkaloid was a new compound. Its structure was determined as desoxyaxillarine.     

Prenylated flavonoids from Desmodium caudatum and evaluation of their anti-MRSA activity

Seven prenylated flavonoids and a prenylated chromanochroman derivative, together with eight known flavonoids, were isolated from roots of Desmodium caudatum. The 15 structures were elucidated by extensive spectroscopic analyses. The antibacterial activity of many of other compounds was evaluated against methicillin-resistant Staphylococcus aureus (MRSA: COL and 5) by a disc diffusion method, and the minimum inhibitory concentrations (MICs) to MRSA were determined.     

Glabrachalcone,a chromenochalcone from Pongamia glabra seeds

Glabrachalcone, a new chromenochalcone has been isolated along with a known chromenochalcone from an ethanolic extract of the seed oil of Pongamia glabra. The structure of glabrachalcone has been established as 2′-hydroxy-2,4,5-trimethoxy-6″,6″-dimethylchromeno(4′,3′:2″,3″)chalcone on the basis of spectral evidence and was confirmed by synthesis.