Kaempferol-7-o-glucoside and their antimicrobial screening isolate from cassia renigera wall

Cassia species have been of keen interest in phytochemical and pharmacological research due to their excellent medicinal values. Different classes of natural products, possessing potent physiological and pharmacological activities have been isolated from Cassia renigera. They include anthracene derivatives, flavonoids and polysaccharides. Some of these compounds have been shown to possess considerable antimicrobial activity. The present study deals with the isolation, purification of flavonoids in different parts of C. renigera and their antimicrobial activity. A new flavonoid kaempferol-7-O-glucoside was identified and characterized and it showed significant antimicrobial activities. The higher level of total flavonoids was measured in flowers of C. renigera (1.15 mg/gdw) and, Similarly higher levels of total qurecetin (F+B) were measured in flowers of C. renigera (0.34 mg/gdw). Higher levels of total kaempferol (F+B) were measured in flowers of C. renigera (0.60 mg/gdw). Similarly higher levels of kaempferol-7-O-glucoside were measured in flowers of C. renigera (0.21 mg/gdw). The isolated flavonoids were effective against all test bacteria and fungi but the quercetin was found more effective against Escherichia coli, Aspergillus flavus, Aspergillus niger, Fusarium moniliformae and Rhizoctonia bataticola, therefore the MIC value 2×103 mg/disc was recorded and MIC value for other bacteria and fungi was recorded as 3×103 mg/disc. Kaempferol was more effective against A. flavus, A. niger, F. moniliformae and R. bataticola, therefore the MIC value 2×103 mg/disc was recorded. MIC value for kaempferol-7-O-glucoside (a new flavonoid) was 2×103 mg/disc for E. coli, A. flavus and A. niger but MIC value for S. aureus, P. aeurinosa and S. typhi was recorded 3×103 mg/disc.