Sylvia A. Opiyo

Triterpenes of Commiphora holtziana oleo-gum resin

Chemical analysis of the acetone extract of Commiphora holtziana gum resin has led to the isolation of triterpenes characterized as methyl 3-oxo-1α,19α,28-trihydroxyurs-12-en-24-oate (1), methyl 3β...

Cyclooxygenase inhibitory compounds from Gymnosporia heterophylla aerial parts

Gymnosporia heterophylla (Celastraceae) is an African medicinal plants used to treat painful and inflammatory diseases with partial scientific validation. Solvent extractions followed by repeated chromatographic purification of the G. heterophylla aerial parts led to the isolation of one new β-dihydroagarofuran sesquiterpene alkaloid (1), and two triterpenes (2-3). In addition, eight known compounds including one β-dihydroagarofuran sesquiterpene alkaloid (4), and six triterpenes (5-10) were isolated. All structures were determined through extensive analysis of the NMR an MS data as well as by comparison with literature data. These compounds were evaluated for the anti-inflammatory activities against COX-1 and -2 inhibitory potentials. Most of the compound isolated showed non selective COX inhibitions except for 3-Acetoxy-1β-hydroxyLupe-20(29)-ene (5), Lup-20(29)-ene-1β,3β-diol (6) which showed COX-2 selective inhibition at 0.54 (1.85), and 0.45 (2.22) IC50, in mM (Selective Index), respectively. The results confirmed the presence of anti-inflammatory compounds in G. heterophylla which are important indicators for development of complementary medicine for inflammatory reactions; however, few could be useful as selective COX-2 inhibitor.

Phytoecdysteroids from the stem bark of Vitex doniana and their anti-inflammatory effects.

With reference to the ethnopharmacological significance of Vitex doniana Sweet (Lamiaceae) leaves in the treatment of stomach and rheumatic pains as well as inflammatory disorders, biological studies on its stem bark extracts have also reported anti-inflammatory and analgesic activities, with no attempt to identify the active components. Chromatographic and spectroscopic procedures identified three new phytoecdysteroids: 21-hydroxyshidasterone (1), 11β-hydroxy-20-deoxyshidasterone (2), and 2,3-acetonide-24-hydroxyecdysone (3) from the stem bark methanol extracts along with known ecdysteroids shidasterone (4), ajugasterone C (5), 24-hydroxyecdysone (6), and 11β,24-hydroxyecdysone (7). The compounds (1-7) showed significant (p ≤ 0.05) inhibitory effect at 100 mg/kg dose on rat paw oedema development due to carrageenan-induced inflammation in Sprague Dawley rats. These results suggest a possible contribution of ecdysteroids to the anti-inflammatory effect of some V. doniana stem bark extracts.

Chemical constituents of essential oils from three Eucalyptus species acclimatized in Ethiopia and Kenya.

Abstract Essential oils obtained by steam distillation of three Eucalyptus species acclimatized in Ethiopia and Kenya were analyzed using GC and GC-MS. The species were Eucalyptus citriodora, Eucalyptus globulus and Eucalyptus camaldulensis. Results showed that the oils from E. globulus and E. citriodora from trees grown in the two countries were quite comparable. The major component of the essential oil of E. globulus was 1,8-cineole while that for E. citriodora was citronellal. The oils from E. camaldulensis grown in the two countries, however, were found to differ. While trees from Kenya afforded an oil rich in 1,8-cineole, those from Ethiopia yielded p-cymene and cryptone as major components. Oils from E. camaldulensis grown in two different locations in Ethiopia were also found to vary in their p-cymene content; one had 35 %while the other gave 21.2 %.