厚节仙掌藻化学成分研究

从厚节仙掌藻Halimedaincrassata中分离到2种化合物，经元素分析和波谱方法鉴定为穿贝海绵甾醇（化合物Ⅲ）和海藻红素（化合物Ⅳ），其中化合物Ⅳ为首次从该种属中得到。现报道化合物Ⅲ和化合物Ⅳ的波谱数据。

Antioxidant and antibacterial activities and identification of bioactive compounds of various extracts of Caulerpa racemosa from Algerian coast

Objective:To evaluate the antibacterial and antioxidant activities and to identify the volatile bioactive compounds present in different crude extracts of the seaweed Caulerpa racemosa var.cylindracea.Methods:Caulerpa racemosa harvested from the intertidal zone of Mostaganem coast(N 35?54’37.94",E 0?3’17.37")was subjected to Soxhlet extraction using methanol,chloroform,and hexane solvents.Antioxidant properties were assessed by using 2,2’-diphenyl-1-picrylhydrazyl(DPPH),2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)andβ-carotene bleaching assays.The antibacterial activity was evaluated on six standard bacterial strains using the agar disc diffusion method.The GC-MS analysis was performed using non-polar and polar capillary columns.Results:The chloroform extract of Caulerpa racemosa exhibited higher contents of polyphenols[(123.91±1.46)mg gallic acid equivalent/g dry extract]and tannins[(59.28±5.43)mg catechin equivalent/g dry extract](P<0.001)and was the most effective in scavenging DPPH[(1.98±0.08)mg/m L]and ABTS[(1.66±0.05)mg/m L]radicals.The hexane extract displayed the best antibacterial activity against Staphylococcus aureus,Bacillus cereus,and Pseudomonas aeruginosa,producing inhibition zones of(11.16±0.76),(9.00±0.00)and(9.33±1.15)mm,respectively.The l-(+)-ascorbic acid 2,6-dihexadecanoate and 4-hydroxy-2 methylproline were among the most abundant volatile compounds.Besides conventional fatty acids,cis-10-heptadecenoic acid,nonahexacontanoic acid,and dodecanoic acid,3-hydroxy-were identified.Two phytosterols were identified:stigmast-5-en-3-ol-(12.9%)and stigmast-5-en-3.beta.-ol,(24 S)-(4.57%).Conclusions:The preliminary identification of the volatile compounds reveals the presence of some new bioactive components not reported previously in Caulerpa racemosa from other geographical areas.Some of these compounds possess an interesting potential for pharmaceutical/nutraceutical applications.

鹿藿的化学成分研究

目的研究鹿藿Rhynchosia volubilis的化学成分。方法采用硅胶、ODS、Toyopearl HW-40C、Sephadex LH-20柱色谱以及半制备HPLC等方法进行纯化,根据理化性质及波谱数据对化合物进行结构鉴定。结果从鹿藿石油醚提取物中分离得到13个化合物,分别鉴定为(-)-sigmoidin E(1)、lupinifolin(2)、precatorin B(3)、木豆酮(4)、槐花多糖B(5)、5,3′-二羟基-4′-甲氧基-5′-γ,γ-二甲基烯丙基-2″,2″-二甲基吡喃并[5,6:6,7]异黄烷酮(6)、染料木素(7)、甘草异黄酮A(8)、erylatissin B(9)、neo-bavaisoflavone(10)、羽扇豆醇(11)、桦木醛(12)、穿贝海绵甾醇(13)。化合物1~10均为含异戊烯基的黄酮类,其中化合物1、2为二氢黄酮、3~6为二氢异黄酮、7~10为异黄酮。化合物11~12为羽扇豆烷型三萜,化合物13为甾醇类。结论化合物1、5~6、8~10、12、13均为首次从鹿藿属植物中分离得到,化合物1~3、5~13均为首次从该植物中分离得到。