Getahun Tadesse Gurmessa, R R T Majinda and I B Masesane
Ethiopia
Posters & Accepted Abstracts: Nat Prod Chem Res
The aim of this study was to carry out phytochemical investigation on Erythrina brucei, a plant endemic to Ethiopia, and analyze antibacterial and antioxidant properties of compounds isolated from it. Phytochemical investigations on stem bark, root bark and twigs of Erythrina brucei yielded 23 compounds. The isolated compounds fall into different classes that include pterocarpans, isoflavanones, isoflavones, alkaloids, terpenes, stigmasterol, a long chain aliphatic alcohol and sugar. Of these, two isoflavanones were isolated for the first time, namely: (3S)-5,7-dihydroxy-2',5'-dimethoxy-6",6"dimethyldihyd ropyrano[2",3":3',4'] isoflavanone erybrucein A and (3S)-5, 7-dihydroxy-2'-methoxy-6", 6"-dimethyldihydropyrano[2", 3":3;, 4']isoflavanone erybrucein B. The rest are either new to the species, new to the genus or have been re-isolated. The structures of the compounds were determined using mass spectrometry and 1-D and 2D-NMR spectroscopy. Furthermore, Circular dichroism (CD) spectroscopy was used to determine the stereochemistry of chiral compounds. The antibacterial efficacy and anti-oxidant properties of some selected compounds including the new ones were determined. The new isoflavanone erybrucein B showed promising antibacterial activity against B. cereus (Gram positive bacteria) (MIC=0.062 mg/ml) compared to the reference standard antibiotic (chloramphenicol). On the other hand, the radical scavenging properties of some isolates were evaluated using the DPPH assay methods and compounds eryvarin J and erycrisagallin demonstrated good antioxidant activity compared to reference standard trolox, with IC50 value of 1.4, 1.1 and 0.6 μg/ml, respectively. getahun.tadese@gmail.com
