Effect of harvest time on essential oil composition of Chromolaena odorota (L.) leaves from Nigeria .

Essential oils were obtained from fresh leaves of Chromolaena odorota (L.) harvested at different times of the day (morning and afternoon) by hydro distillation using the Clevenger apparatus.  The oils were analyzed by Gas Chromatography (GC) and Gas Chromatography – Mass Spectrometry (GC-MS).  Caryophyllene (6.40%) and aromadendrene (5.56%) were the major sesquiterpenoids in the morning sample while ?- pinene (9.09%) and ?- pinene (5.10%)  were the main monoterpenoids detected. The principal sesquiterpenoids in the leaf oil of the afternoon sample are Germacrene D (4.70%), aromadendrene , ?-amorphene  and ?-muuolene  which were detected in the same amount of 4.12% while the main monoterpenoids detected are ?-pinene  (5.63%) and ?-pinene (4.83%). Key words: Chromolaena odorata, GC-MS, aromadendrene, terpenes, asteracea

Isolation and Identification of β-sitosterol, 7-hydroxystigmast-22-en-3,6-dione and 3β, 24(S)-dihydroxycholesta-5, 25-diene-7-one from stem bark of Nauclea pobeguinii

The stem bark of the Nauclea pobeguinii was collected, air-dried, and pulverized and was extracted with solvent of varying polarity (n-hexane, ethyl acetate, and ethanol) to obtain the crude extracts. Silica gel column and thin layer chromatographic separation afforded three compounds whose structures were elucidated as β-sitosterol (1), 7-hydroxystigmast-22-en-3.6-dione (2), and 3β, 24(S)-dihydroxycholesta-5, 25-dien-7-one (3) by analysis of their chemical and spectral characteristic from 1D and 2DNMR, FTIR and by comparing of data with those reported in the literature

Characterization and Identification of Novel Steroids from Nauclea pobeguinii Leaves

Nauclea pobeguinii is a plant in the Rubiaceae family endemic to the swamp forest region of the world. Its extract is widely used in traditional medicine for the treatment of a wide variety of ailments such as malarial, Jaundice, gonorrhea, fever, and stomach discomfort. While other parts of the plant have been examined for the bioactive principles responsible for the medicinal properties, limited information is available in the literature as regards the leaves, hence this study. N. pobeguinii leaves were collected, air-dried, and pulverized. The pulverized sample was extracted with solvents (n-hexane, ethyl acetate, and ethanol) of varying polarity to obtain the crude extracts. Repeated column and thin layer chromatographic separation of the crude extracts afforded three compounds, which were characterized by their IR, 1H, 13C-NMR, and 2D-NMR spectral data. A comparison of the data with literature confirmed the compounds to be 2-hydroxylstigmastane acetate (1), Ergosta-5,6-epoxy-22-en-3-yl-acetate (2), and β-sitosterol (3). Compounds 1 and 2 are novel to N. pobeguinii

Phytochemical Quantification and Efficacy of Persea Americana Extracts on some Selected Pathogenes

Medicinal and aromatic plants are increasingly becoming the focus of many researchers in the search for alternative antimicrobial agents due to their large number of diverse bioactive compounds called phytochemicals. Persea americana (Avocado) is an evergreen tree plant known for its healthy fruit and has been used in the management of disease and infections. The stem bark of P. americana was investigated for its phyto-constituents and antimicrobial activity using standard methods. The stem bark was preponderant in polyphenolic compounds of which flavonoid was found to be abundant (480.01), the antimicrobial activity study of the extracts also showed good inhibitory activity on all the tested strains with K. oxytoca (27.50 ± 0.67 mm) and A. flavus (88.89%) mostly susceptible in a concentration-dependent manner. The study revealed that P. americana extracts could be explored in the search for alternative antimicrobial agents