STUDY ON ANTIMICROBIAL ACTIVITIES IN VITRO BY FRACTIONS OF COPTOSAPELTA FLAVESCENS KORTH. RUBIACEAE

Abstract

Coptosapelta flavescens Korth. Rubiaceae (CF) was reported as a potential herbal with various biological activities, especially antimicrobial activity. To provide more scientific information, this research was conducted to evaluate the antimicrobial activity in vitro of this herbal. CF’s crude extract was collected in Ninh Thuan province in March 2021. Fraction extracts were prepared by partitioning method with solvents of increasing polarity, including n-hexane, chloroform, dichloromethane, ethyl acetate, and methanol. Their antimicrobial activities were determined by agar disc diffusion and agar dilution method. The n- hexane and methanol extracts showed no inhibitory effect on all tested microorganisms. The chloroform and dichloromethane extracts exhibited weak antibacterial activities, against tested Gram-positive bacteria. It was interesting when the ethyl acetate extract resisted all tested microorganisms. In particular, in tested microorganisms, the ethyl acetate extract inhibited the growth of S. aureus ATCC 25923 strongest with MIC of 0.512 mg/mL and diameter of inhibition zone of 22.67 mm. Because S. aureus is a popular agent that causes skin and soft tissue infections, the extract will be a potential active ingredient for developing some preparations for the treatment of tissue infection.