ABSTRACT
Bioactivity guided chemical investigation on active anti-diabetic constituents of the fruits of Cycas pectinata Griff. (FCP) characterized EAFr-5 as the most potent sub fraction which significantly reduced the blood glucose level to normal in STZ induced diabetic rats. It was shown to contain the biflavonoids amentoflavone (1) and 2,3-dihydroamentoflavone (2) which exhibited significantly high inhibitory potency against α-glucosidase (IC50 8.09 ± 0.023 and 9.77 ± 0.032 µM, respectively) and α-amylase (IC50 73.6 ± 0.48 and 39.69 ± 0.39 µM, respectively). This is the first report of bioactivity guided isolation of anti-diabetic constituents from the traditionally used fruits of Cycas pectinata Griff.
Subject(s)
Biflavonoids/pharmacology , Cycas/chemistry , Diabetes Mellitus, Experimental/drug therapy , Hypoglycemic Agents/pharmacology , Animals , Biflavonoids/metabolism , Fruit/chemistry , Inhibitory Concentration 50 , Molecular Structure , Rats, Wistar , alpha-Amylases/antagonists & inhibitors , alpha-Amylases/metabolism , alpha-Glucosidases/metabolismABSTRACT
The absolute stereochemistry of the new antifungal and antibacterial antibiotic produced by Streptomyces sp.201 has been established by achieving the total synthesis of the product. A series of analogues have also been synthesized by changing the side chain and their bioactivity assessed against different microbial strains. Among them, 1e (R = C8H17) was found to be the most potent with MIC of 8 microg/mL against Mycobacterium tuberculosis, 12 microg/mL against Escherichia coli and 16 microg/mL against Bacillus subtilis 6 microg/mL against Proteus vulgaris. This was followed by 1b (R = C5H11) with MIC of 10-20 microg/mL range and 1d (R = C7H15) with MIC of 14-24 g/mL, whereas 1a (R = C4H9) and 1f (R = C18H35) were found to be completely inactive. Besides, 1c (R = C6H13) showed certain extent of antibacterial activity in the range of 24-50 microg/mL. Mycobacterium tuberculosis was very sensitive to 1e (R = C8H17) with MIC of 8 microg/mL. Antifungal activity of analogues 1d (R = C7H15) and 1e, (R = C8H17) against Fusarium oxysporum and Rhizoctonia solani were found promising with MFCs in the 15-18 microg/mL range.
