# Rapid Bioassay-Guided Isolation of Antibacterial Clerodane Type Diterpenoid from Dodonaea viscosa (L.) Jaeq

## TL;DR

Researchers isolated a new antibacterial compound from Dodonaea viscosa using a fast method combining HPLC and a bacterial bioassay.

## Contribution

The first report of antibacterial activity of a clerodane type diterpenoid from Dodonaea viscosa.

## Key findings

- A clerodane type diterpenoid was identified with bacteriostatic activity against S. aureus and E. coli.
- The compound has a minimum inhibitory concentration of 64–128 µg/mL against test bacteria.

## Abstract

Plant extracts are complex matrices and, although crude extracts are widely in use, purified compounds are pivotal in drug discovery. This study describes the application of automated preparative-HPLC combined with a rapid off-line bacterial bioassay, using reduction of a tetrazolium salt as an indicator of bacterial metabolism. This approach enabled the identification of fractions from Dodonaea viscosa that were active against Staphylococcus aureus and Escherichia coli, which, ultimately, resulted in the identification of a clerodane type diterpenoid, 6β-hydroxy-15,16-epoxy-5β, 8β, 9β, 10α-cleroda-3, 13(16), 14-trien-18-oic acid, showing bacteriostatic activity (minimum inhibitory concentration (MIC) = 64–128 µg/mL) against test bacteria. To the best of our knowledge, this is the first report on antibacterial activity of this metabolite from D. viscosa.