Khalid A.K.,El Buhouth St. |
El-Gohary A.E.,El Buhouth St.
International Food Research Journal
Essential oils extracted from aerial parts of Plectranthus amboinicus (Lour.) and its chemical constituents as affected by four seasonal, namely summer, winter, spring and autumn growing variation were investigated. The hydro - distilled essential oil content ranged from tr (< 0.1%) to 0.5%. The highest essential oil contents (0.2% or 0.5 ml plant-1) were recorded in summer. The lowest essential oil contents (tr % or 0.1 ml plant-1) were recorded in winter. The essential oils consists of carvacrol as the most abundant component, followed by thymol. The highest amount of carvacrol (15.9%) resulted from the essential oil extracted from herbs collected in autumn. On the other hand the highest amount of thymol (12.7%) produced from the essential oil extracted from herbs collected in spring. The chemical classes of essential oil such as oxygenated monoterpenes and oxygenated sesquiterpenes increased in summer and were recorded values of 62.3 and 11.5%, respectively compared with other seasons. On the other hand monoterpene hydrocarbons and sesquiterpene hydrocarbons were increased in winter and autumn seasons which recorded the values of 31.4 and 22%, respectively. Alcohols are the major constituents of the oxygenated monoterpenes of Plectranthus amboinicus (Lour.) essential oil. Carvacrol and thymol represented the highest concentrations among the alcohols. This indicates that Plectranthus amboinicus (Lour.) essential oil grown in Egypt belongs to the carvacrol and thymol chemo - type. © 2008 IFRJ, Faculty of Food Science & Technology, UPM. Source
Guneidy R.A.,El Buhouth St. |
Shokeer A.,El Buhouth St. |
Abdel-Ghany S.S.,El Buhouth St. |
Saleh N.S.M.,El Buhouth St. |
Hamed R.R.,El Buhouth St.
Research Journal of Pharmaceutical, Biological and Chemical Sciences
Glutathione S-transferases (GSTs) catalyze the transfer of glutathione (GSH) to a variety of xenobiotic and toxic endogenous compounds. GST was purified from ovary and testis of the freshwater fish Clariaslazera by affinity chromatography. Testis GST appeared to be a homodimer of two subunits each with a molecular weight of 27.5 kDa. While ovary GST appeared to be a heterodimer of two different subunits having molecular weights of 27.5 KDa and 25.1 KDa. Kinetic analysisrevealed high KmGSH value (2.5 mM) for testis GST compared to 0.5 mM for ovary GST. Ovary GST showed high activity toward the substrates para- nitrophenyl acetate(pNPA), phenthylisothiocyanate (phenthyl -ITC), benzyl isothiocyanate (benzyl-ITC) and styrene-7, 8-oxide (SO) (9.39 ± 0.39, 6.96 ± 0.266, 4.76 ± 0.55 and 4.37 ± 0.075 μmol/min/mg protein, respectively). Maximum activity was obtained with SO for testis GST (215 ± 34.5μmol/min/mg protein). Hematin is the most potent inhibitor for testis GST activity however it had no effect on ovary GST. The variation in the examined characters between C. lazeraGST ovary and testis account for structural composition difference between gonads GST and may suggest a critical role for GST in the reproduction process and sex differentiation. Source