A phytochemical study was conducted on the stems and leaves of Hedychium malayanum (Zingiberaceae). Three steroids
namely stigmasterol (1), sitostenone (2) and stigmast-4-ene-3,6-dione (3) as well as one triterpene, lupenone (4) and
one oxygenated sesquiterpene, caryophyllene oxide (5) were successfully isolated from the respective stems and leaves,
utilizing several chromatographic techniques. Their structures were elucidated by spectroscopic means (IR, MS, NMR),
and by comparison with the literature data.
Selenocompounds have been widely synthesized for their potential in pharmacology. Ebselen, a selenazole oxide, is a
glutathione peroxidase mimic which is known to possess high antioxidant activity. Four derivatives of 3-(2-amino-1,3-
selenazol-4-yl)-2H-chromen-2-ones were synthesized by reacting 3-(2-bromoacetyl)-chromen-2-one derivatives with
selenourea through Hantzsch reaction using NaF as a catalyst in methanol-water (1:1) at room temperature. These
reactions were completed in 30 min and purified using column chromatography eluted with n-hexane-ethyl acetate (7:3)
to give 50-83% yields. All the compounds were successfully characterized using IR, 1H and 13C NMR as well as mass
spectrometry. The synthesized compounds were tested with DPPH assay to determine the free radical scavenging activity
and were compared to gallic and ascorbic acids as standard. Nonetheless, all compounds exhibited weak free radical
scavenging activity with IC50 value ranging from 672.13 to 984.03 µM signifying that the derivatives may possess weak
antioxidant activities.
Palm kernel cake (PKC), the most useful by-product resulted from palm kernel oil production. In this study, PKC-derived protein product was found suitable for use as an antimicrobial agent with potent antibacterial activity, particularly against Bacillus species, after enzymatic hydrolysis with alcalase. The hydrolysate was further purified by gel filtration chromatography. The purified fraction was found to have 14.63±0.70% (w/w) protein, a molecular mass of 2.4kDa and low hemolytic activity (<50% hemolysis of human erythrocytes at concentration of 1000μg/ml). The presence of lysine and the major component lauric acid derivative, as indicated by electrospray ionisation-mass spectrometry (ESI-MS) direct infusion and nuclear magnetic resonance (NMR) spectroscopy, may have contributed to the antibacterial effect of purified PKC fraction. This study suggests that the antibacterial PKC compound may be not a pure peptide but instead a peptide-containing compound high in lauric acid derivative.