THE CHEMICAL CONSTITUENTS FROM THE FRUITS OF Johannesteijsmannia altifrons AND ANTIBACTERIAL ACTIVITY

Abstract

Isolation on the hexane extract of the fruits of Johannesteijsmannia altifrons by vacuum liquid and radial chromatography yielded three known compounds namely β-sitosterol, γ-taraxasterol and stigmasterol. Their structures were determined using one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy, fourier transform infra-red spectroscopy and mass spectrometry. All the isolated compounds were tested for their antibacterial activity using disc diffusion and minimum inhibitory concentration (MIC). All three compounds showed weak and moderate activities against all nine tested bacteria. This is the first report on the isolation of compounds from this species and on the antibacterial activity of γ-taraxasterol. Keywords:Johannesteijsmannia altifrons, β-sitosterol, γ-taraxasterol, stigmasterol, antibacterial Abstrak Pemencilan ke atas ekstrak heksana bagi buah Johannesteijsmannia altifrons dengan kromatografi cecair vakum dan radial menghasilkan tiga sebatian yang pernah ditemui bernama β-sitosterol, γ-taraksasterol dan stigmasterol. Strukturnya ditentukan dengan spektroskopi resonans magnet nukleus satu-dimensi dan dua-dimensi, spektroskopi infra-merah transformasi Fourier dan spektrosmetri jisim. Kesemua sebatian yang dipencilkan diuji aktiviti bakterianya dengan kaedah peresapan cakera dan kepekatan perencatan minimum (KPM). Kesemua tiga sebatian menunjukkan aktiviti yang lemah dan sederhana terhadap kesemua sembilan bakteria yang diuji. Ini merupakan laporan pertama mengenai pemencilan sebatian daripada spesies ini dan mengenai aktiviti antibakteria bagi γ-taraksasterol.

Antibacterial activity of lupeol from the bark of Dehaasia cuneate (Lauraceae)

“…The pure compound was assayed for antibacterial activity using disc diffusion methods which is the concentration of lupeol (1) 30 μg/disc as described by Sabri et al (2017).…”

“…The Gram-positive bacteria only have an outer peptidoglycan which is not effective permeability barrier compared to Gram-negative bacteria that have both outer membrane and peptidoglycan. This makes the Gram-negative bacteria cell wall impermeable to most of the drugs (Sabri et al, 2017). The inhibitory zone values for all compounds are shown in Table 1.…”