A sensitive and accurate high performance liquid chromatography with ultraviolet/visible light detection (HPLC-UV/VIS) method for the quantification of 2,6-bis-(4-hydroxy-3-methoxybenzylidene)-cyclohexanone (BHMC) in rat plasma was developed and validated. BHMC and the internal standard, harmaline, were extracted from plasma samples by a simple liquid-liquid extraction using 95% ethyl acetate and 5% methanol. Plasma concentration of BHMC and internal standard were analyzed by reversed phase chromatography using a C₁₈ column (150 × 4.6 mm I.D., particle size 5 µm) and elution with a gradient mobile phase of water and methanol at a flow rate of 1.0 mL/min. Detection of BHMC and internal standard was done at a wavelength of 380 nm. The limit of quantification was 0.02 µg/mL. The calibration curves was linear (R² > 0.999) over the concentration range of 0.02-2.5 µg/mL. Intra- and inter-day precision were less than 2% coefficient of variation. The validated method was then applied to a pharmacokinetic study in rats by intravenous administration of BHMC at a single dose of 10 mg/kg. Pharmacokinetic parameters such as half-life, maximum plasma concentration, volume of distribution, clearance and elimination rate constant for BHMC were calculated.
This study was aimed to investigate the chemical compositions of the essential oils from Goniothalamus macrophyllus and Goniothalamus malayanus growing in Malaysia. The essential oils were obtained by hydrodistillation and fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Analyses of the essential oils from G. macrophyllus and G. malayanus resulted in 93.6 and 95.4% of the total oils, respectively. The major components of G. macrophyllus oil were germacrene D (25.1%), bicyclogermacrene (11.6%), α-copaene (6.9%) and δ-cadinene (6.4%), whereas in G. malayanus oil bicyclogermacrene (43.9%), germacrene D (21.1%) and β-elemene (8.4%) were the most abundant components.
The rich and diversified Malaysian flora represents an excellent resource of new chemical structures with biological activities. The genus Xylopia L. includes aromatic plants that have both nutritional and medicinal uses. This study aims to contribute with information about the volatile components of three Xylopia species essential oils: Xylopia frutescens, Xylopia ferruginea, and Xylopia magna. In this study, essential oils were extracted from the leaves by a hydrodistillation process. The identification of the essential oil components was performed by gas chromatography (GC-FID) and gas chromatography-coupled mass spectrometry (GC-MS). The major components of the essential oils from X. frutescens were bicyclogermacrene (22.8%), germacrene D (14.2%), elemol (12.8%), and guaiol (12.8%), whereas components of the essential oils from X. magna were germacrene D (35.9%), bicyclogermacrene (22.8%), and spathulenol (11.1%). The X. ferruginea oil was dominated by bicyclogermacrene (23.6%), elemol (13.7%), guaiol (13.4%), and germacrene D (12.3%).