Background:
The marine red alga Plocamium naturally produces halogenated monoterpenes
with varied biological activities. In our continuing efforts to discover new lead compounds for the
treatment of HIV/AIDS as well as novel antibacterial compounds, various Namibian Plocamium species
have been investigated.
Methods:
A rare but known compound namely 1E,3R,4S,5E,7Z-1-bromo-3,4,8-trichloro-7-
(dichloromethyl)-3-methylocta-1,5,7-triene (1) was isolated from a Namibian Plocamium red alga. The
anti-HIV activity of compound 1 was investigated against three HIV enzymes namely, HIV protease,
reverse transcriptase and integrase. In addition, compound 1 was also screened for antibacterial activity
against selected microbes using the disc diffusion method.
Results:
Compound 1 demonstrated selective in vitro inhibition against HIV-1 integrase with a 50%
inhibition concentration of <0.06 mM. Weak inhibitory activity was observed against HIV-1 reverse
transcriptase and protease. Compound 1 also showed antibacterial activity against Staphylococcus
aureus (ATCC 25923), Alcaligenes faecalis (ATCC 8750) and Serratia marcescens (ATCC 8100) with
MIC values of 0.65 mM, and 1.29 mM for Klebsiella pneumonia (ATCC 13883).
Conclusion:
The results of this study highlight the potential of halogenated monoterpenes from red
seaweed as possible leads in the development of new anti-HIV and antimicrobial pharmaceuticals.