Antibacterial activity of bioactive compounds from radish (Raphanus sativus) leaves against Escherichia coli and its chemical compounds

Abstract

Virganita J, Wahyuni DSC, Nugraheni ER. 2009. Antibacterial activity of bioactive compounds from radish (Raphanus sativus) leaves against Escherichia coli and its chemical compounds. Biofarmasi 7: 94-98. Indonesia has many kinds of plants, some of them are medicinal plants that were used to cure various diseases. One of medicinal plants is radish (Raphanus sativus L.), known as vegetable. That is the reason conducting the research to find out the bioactive compounds from plants, which can be used as raw materials of drug. Other reasons are expensive drug prices in the market, the death case due to microbial infection, and the increasing of bacterial resistance because of ineffectiveness usage of antibiotic. This study aimed to determine the antibacterial effect of bioactive compounds from radish leaves against Escherichia coli. Bioactive compounds were found by extraction dan partition using centrifugation. Dry powder from radish leaves was extracted with chloroform and methanol. After the antibacterial testing, methanol extract resulted in an antibacterial effect was separated in a partition by ethyl acetate into soluble and insoluble parts. The soluble part of ethyl acetate resulted in an antibacterial effect on the concentration of 30-50% was shown by a clear zone (average 10 mm). It was separated again into soluble and insoluble fractions with dichloromethane. Dichloromethane soluble fraction formed a clear zone about 8.30 mm on 10% concentration and 8.42 mm on 20% concentration. Furthermore, the chemical constituent profile of the most active fraction was monitored using KLT method and detected with spray chemicals. The results indicated that radish leaves had bioactive compounds from phenolic group. It was proved by ammonia detection which giving a yellow color, and dark blue with FeCl3 detection.