Belawan Putih (Tristaniopsis whiteana): Antibacterial Compounds and Their Distribution in Peat and Heath Forests Central Kalimantan.

Abstract

Biodiversity of peat forest ecosystem is highly potential. Among these potentials is the use of forest plants as medicines. One of medicinal plants found in the peat swamp forest ecosystem is from genus Tristaniopsis, for example belawan putih (Tristaniopsis whiteana). Several studies have reported the potential of this plant as an antibacterial drug. In this report, bioactive antibacterial compounds of belawan putih leaves extract and mapping the distribution of the plant in peat and heath forests, Central Kalimantan, were studied. The sample was extracted gradually using four different solvents based on polarity (n-hexane, chloroform, ethyl acetate, and methanol). The chloroform extract showed the most active in inhibiting Escherichia coli and Staphylococcus epidermidis. Isolation and purification of the chloroform extract gave 2 pure compounds, compound 1 and 2, having the same minimum inhibitor concentration (MIC) value against E. coli were 128 μg/mL. MIC values of compound 1 and 2 against S. epidermidis were 128 and > 128 μg/mL, respectively. Based on structure elucidation using nuclear magnetic resonance proton (1H-NMR), compound 1 was estimated to have aromatic, alkoxy, methine, methylene, and methyl groups. Structure elucidation using ultraviolet and infrared spectrophotometers, 1H-NMR, 13C-NMR, DEPT, HMBC, and HMQC, compound 2 was found be betulinic acid. This is the first report of the occurrence of this compound in belawan putih and genus Tristaniopsis. One potential of belawan putih commonly used by people around forest areas is the use as medicines. Therefore, it is necessary to protect this species from the threat of extinction. One of the survey criteria in determining priority to protect the species is to find the distribution pattern of the species population. Ecological parameters of belawan putih in heath and peat forest Bawan, Central Kalimantan, was observed and measured on 6 plot in each forest by purposive sampling method. The plot was circle with radius of 10 m, so the 6 plot have area of 0.5 hectares. Based on Morissita method, the distribution pattern of belawan putih in heath and peat forest was clumped type.