A New Bioactive Thiophenolic Glycoside From The Leaf Of Massularia Acuminata (G. Don Bullock) Ex Hoyle (Rubiaceae)

Background: Massularia acuminata is a small tree or shrub of tropical rainforest. The leaves are used in Nigerian ethno-medicine for the treatment of microbial infections and pharmacological report suggested the leaf extract as possessing antioxidant activity. This study was therefore carried out to determine the most antioxidant and antimicrobial active  fraction(s) of Massularia acuminata leaf and the constituent(s) responsible for the activities.Matherials and Methods: The leaf of Massularia acuminata was investigated for in vitro antioxidant and antimicrobial activities, using a  2,2- diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and agar  dilution method respectively.Results: The ethyl acetate fraction demonstrated the best activities among the partitioned fractions tested. Bioassay guided purification of the most active ethyl acetate fraction led to isolation of a new thiophenolic glycoside, characterized as 4-(3´,3´-dihydroxy-1-mercaptopropyl)phenyl glycosylpyranoside.Conclusion: The isolated compound from the leaf of Massularia acuminata demonstrated antioxidant and antimicrobial activities and may be responsible for the activities of leaf extract and its ethyl acetate fraction, hence this may justify its ethnomedicinal use.Key words: Massularia acuminata, antioxidant, antimicrobial, DPPH, agar dilution, thiophenolic glycosid

VARIATION STUDIES ON THE VOLATILE OIL OF EUGENIA UNIFLORA

The volatile oil content of the leaves of Eugenia uniflora L. growing in Nigeria was found to be between 0.63-1.09%v/w. From this study, the species is considered an economic source of the oil. The volatile oil content was highest at flowering of the plant and lowest at fruiting. The morphological part of the plant, stage of growth, time and season of collection of the leaves were found to be important factors that determine the amount of the oil produced. Also conditions for storage of the oil and its commercial exploitation were studied. Keywords: Eugenia uniflora, Myrtaceae, volatile oil, variation Nig. J. Nat. Prod. And Med. Vol.1 1997: 28-3

MOLLUSCIDIAL, INSECTICIDAL AND PISCICIDAL ACTIVITIES OF BARRINGTONIA RACEMOSA

The aqueous, methanol, chloroform, ethyl acetate, petroleum ether extracts of Barringtonia racemosa Blume pericarp and seed were evaluated for molluscicidal, larvicial and pisicidal activity against Biomphalaria glabrata, larvae of Aedes aegypti and fish (Clarias lazera and Tilapia nilotica) respectively. The mollusciicidal, larvicidal and piscicidal assays involved incubation of B. glabrata snails, larvae of A. aegypti and fish with extracts of the fruit and seed of B. racemosa compared with niclosamide and T. tetraptera. The pericarp extracts contain more potent molluscicidal components (LC 50 =367.3 — 625.0 ppm) than the seed extracts of the fruit (LC50= 530.53 - 704.27 ppm). The rank order of toxicity for the pericarp extracts tested was for the snails: CHCl3 extract 367.3 ppm >Ethyl acetate extract 390.3 ppm. > methanol extract 530.4 ppm > petroleum ether extract 704.27 ppm. The larvicidal active agents are higher in the seed extracts (LC50 = 588.44 — 1,604.2 ppm) than in the pericarp extracts of the fruit (LC50 = 1,507.0 — 4,000.0 ppm). The rank order of toxicity of the seed extract for the larvae of A. aegypti was: CHCl3 extract 588.44 ppm > MeOH extract 762.5 ppm > petroleum ether extract 1,244.2 ppm > Ethyl acetate extract 1,604.2 ppm. The C. lazera was more resistant to Niclosamide, aqueous extracts of the pericarp and Tetrapleura tetraptera than T. nilotica. These biological activities suggest possible role for B. racemosa in the control of snail intermediate hosts of schistosomiasis and dengue fever. Key Words: Barringtonia racemosa, Leeythidaceae, Aedes aegypti, Dengue, Biomphalaria glabrata, mollusicides, schistosomiasis, piscicides Nig. J. Nat Prod. And Med. Vol.5 2001: 56-5