Dagne ErmiasAbebe Abrham2018-06-122023-11-092018-06-122023-11-091994-06http://etd.aau.edu.et/handle/12345678/413The tropical genus Erythril1a, which belongs to the family Leguminosae (sub-family Papilionoideae), locally known as "Korch" (Amharic) and "Wolensu" (Oromo) has folk medicinal uses such as in the treatment of stomach pain and female infertility. The seeds of this plant have been investigated before, whereas no previous phytochemical work has been reported from the stem bark of E. melanacantha. The isolation and characterization of alkaloids and flavonoids from the seeds and stem bark, respectively, of this species constitute the subject of this study. As a result, the seeds and stem bark of E. melanacantha afforded eleven compounds, of which two are new natural prodUCts. From the seeds three known alkaloids, namely, erythraline (11), erymelanthine (50) and erysovine (3) have been identified. Chemical investigation of the stem bark resulted in the isolation of two new compounds characterized on the basis of spectroscopic data as 5-hydroxy-7 ,8-(hydroxyisopropyl dihydrofurano)flavanone (152) and a biflavanone (159). In addition, from the stem bark of this plant, five known flavonoids, namely, glabranin (153), obovatin (155), 7-hydroxy-8-prenylflavanone (156) 3'-0- methylorobol (157), 3'-methoxydaidzein (158) and a known cinnamate ester, erythrinasinate (160) have been isolated. Search in the chemical literature indicated that compounds 153, 155, 156 and 158 have not been reported before from the genus Erythril1a. Glabranin (153) is proposed as the biosynthetic precursor of the three compounds 152, 155 and 156, while compounds 152 and 153 serve as building blocks of the dimer 159.enAlkaloids and FlavonoidsThesis