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