Preliminary Studies On The Antimicrobial Compounds From Leguminous Species Gleditsia Sinensis Lam. And Sophora Alopecuroides Linn.

This thesis is focus on the compounds with their antimicrobial activities of two leguminous plants Gleditsia sinensis Lam and Sophora alopecuroides Linn.Gleditsia sinensis Lam., which belongs to leguminous species, only distributes in almost all the provinces of China. Spina gleditsiae, the spina of Chinese medicinal plant G. sinensis, has its anticancer and antimicrobial activities. Petroleum ether, chloroform, ethyl acetate, n-butanol and aqueous fractions obtained from the EtOH extract of G sinensis spina were screened for their antimicrobial activities.With antimicrobial activity bioassay, nine compounds were isolated from ethyl acetate fraction. Based on the spectrum analysis of their ¹H-NMR, ¹³C-NMR and MS, their structures were identified, respectively as ethyl gallate (1), dihydrokaempferol (2), eriodictyol (3), quercetin (4), 3,3',5',5,7-pentahydroflavanone (5), (-) epicatechin (6), caffeic acid (7), 3-O-methylellagic acid-4'- (5"-acetyI) -a-L-arabinofuranoside (8), 3-Omethylellagic acid -4'-O-a-L-rhamnopyranoside (9). By literature study, compound 8 was thought as a new compound, others were isolated from this plant for the first time. The minimum inhibitory concentration (MIC) for compounds 1,2,4,5,7 ranged from 0.1 mg/ml to 1 mg/ml.Sophora alopecuroides Linn mainly distributes in disert of North China with its great resource. It is used as a traditional medicine for the treatment of laryngitis cough, eczema. Antimicrobial activity of the aerial part of S. alopecuroides was primarily studied. The petroleum ether fraction, alkaloid fraction, n-butanol fraction and aqueous fraction were successively partitioned from EtOH extracts of S. alopecuroides. The antimicrobial activities of different polar fracitons were in vitro screened with four tested bacteria and seven fungi. The results indicated that both n-butanol fraction and total alkaloid fraction showed significantly antimicrobial activity. The petroleum ether fraction showed moderate antimicrobial activity. Contrarily, water fraction promoted mycelial growth.Studies on antimicrobial compounds from G. sinensis and S. alopecuroides would benefit for providing leader compounds of chemical synthesis, for further elucidation the structure-activity relations in antimicrobial activities, also for studing chemotaxonomy of leguminous plants, as well as for development and untilization of plant resources in China.