Screening for antimicrobial compounds in Gardenia volkensii fruits (Rubiaceae)

Abstract

A modified iridoid (GV2) was isolated as a yellow powder in the yield of 0.3% of the dichloromethane crude extract of Gardenia volkensii fruits. It showed some antimicrobial activity on Escherichia coli with a Minimum Inhibitory concentration (MIC) of less than 20 μL of 10 mg/mL solution. The Inhibition Concentration (IC50) for for the Gardenia volkensii stem was 1166.809 mg/mL and for Doxycycline® antibiotic was 0.335 mg/mL. The stem bark IC50 was found to be 3,483 times active as compared to Doxtcycline® antibiotic, an indication that the plant can be used to treat microbial diseases though a higher dose is needed.