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.

The fine powders of young tubers of Hydnophytum formicarum was extracted by Soxhlet methanol extraction for 18 hours in three days continuously. The filtrate then was evaporated by rotary evaporator until it became concentrated solution. The fractionation and purification of the extract by vacuum liquid chromatography and radial chromatography has led to the discovery of four compounds namely sinapinic acid, β-sitosterol acetate, β-sitosterol and stigmasterol. Structures of the compounds were established by interpreting mass spectral data, 1 H and 13 C-APT NMR, Infrared and by comparison with literature data. Keywords:Hydnophytum formicarum, sinapinic acid, β-sitosterol acetate, β-sitosterol, stigmasterol Abstrak Serbuk halus tuber muda Hydnophytum formicarum telah diekstrak melalui pengekstrakan Soxhlet selama 18 jam dalam tiga hari secara berturutan. Hasil penurasan kemudian telah disejat menggunakan penyejat berputar sehingga menjadi larutan yang likat. Pemfraksian dan penulenan ekstrak menggunakan kromatografi cecair vakum dan kromatografi radial membawa kepada penemuan empat sebatian yang bernama asid sinapinik, β-sitosterol asetat, β-sitosterol dan stigmasterol. Struktur sebatian ini telah ditentukan dengan mentafsirkan data spektrum jisim, RMN 1 H dan 13 C-APT, Inframerah serta secara membandingkannya dengan data kepustakaan.

A new compound namely 2-[(1′E)-3′-hydroxyl-1′-methyl-1′-propen-1′-yl]-6-methoxy-7-[(2′′-methylheptyl)oxy]-5benzofurancarboxylic acid and three known compounds of β-sitosterol, γ-taraxasterol and stigmasterol were isolated from the n-hexane extracts of the rhizomes and fruits of Johannesteijsmannia altifrons using vacuum liquid, column and radial chromatography. The structures of the isolated compounds were determined by means of 1D and 2D NMR, FT-IR, UV-VIS spectroscopy and mass spectrometry.

The fine powders from young tubers of Hydnophytum formicarum were soaked and extracted by Soxhlet in methanol. Both methanol solutions were evaporated with rotary evaporator to yield cold and hot methanol extracts. Chromatographic separation on the extracts by vacuum liquid and radial chromatography gave two new compounds namely hydnophaldehyde [4,4′,10′,13′,14′-pentamethylgona-7′,9′(11′)-dien-17′-yl(6)-2,2-dimethylheptanal] (1) and 2-(2′-methoxyphenyl)ethyl palmitate (2). The structures of the above compounds were established by interpreting their spectral data of mass, 1-D Nuclear Magnetic Resonance (NMR), 2-D NMR, and Infrared (IR).

Dehaasia is a member Lauraceae. It is locally known as ‘gajus hutan’ or ‘pekan’. A triterpenoid, lupeol was isolated from the bark of Dehaasia cuneate. The structure of the isolated compound was determined using spectroscopic methods, such as UV–vis, FT-IR, 1D and 2D NMR, and mass spectrometer. The isolated compound was tested against Gram-negative and positive bacteria using agar disc diffusion technique. The results showed that lupeol had a moderate inhibition zone value of 10.0±0.00 mm against Gram-negative Serratia marcescens ATCC 14756 whereas low inhibition which is 7.0±0.00 mm against Escherichia coli ATCC 25922, Vibrio fluvialis ATCC 33809, Bacillus subtilis ATCC 6633, and Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300.