Prenylated flavonoids from Deguelia hatschbachii and their systematic significance in Deguelia.

Chemical investigation of dichloromethane and petrol extracts from the roots of D. hatshbachii A. M. G. Azevedo furnished thirteen compounds from which five are described for the first time and their structures were determined to be 3-(4'-hydroxyphenyl)-5-methoxy-6-( 3,3-dimethylallyl)-2"2"-dimethylchromene-(5",6":8,7)-3-(propyl-2-one)-4H-1-benzo-2,3-dihydropyran-2,4-dione; 6,4'-dihydroxy-3-(3,3-dimethylallyl)-2",2"-dimethylchromene (5",6":5,4)-2-methoxy deoxybenzoin; 6.4'-dihydroxy-3-(3,3-dimethylallyl)-2",2"-dimethylchromene (5",6":5,4)-2-methoxy-8-(propyl-2-one) deoxybenzon; 6-(3,3-dimethylallyl)-2",2"-dimethylchromene (5",6":4.5)-4'-hydroxy-3-methoxy stilbene and 3,5-dimethoxy-4'-hydroxy-4-(3,3-dimethylallyl) stilbene by spectral analysis (UV, IR, MS and ID- and 2D- NMR experiments). The root extracts and some isolated compounds were bioactive, as revealed by bioautography and brine shrimp lethality assays.

Flavonoids from Lonchocarpus latifolius roots.

From the petrol extract of Lonchocarpus latifolius roots, 10 flavonoids were isolated. These included: 3,5-dimethoxy-2'',2''-dimethylpyrano-(5'',6'':8,7)-flavone, 3-methoxy-(2'',3'':7,8)-furanoflavanone, 3',4'-methylenedioxy-(2'',3'':7,8)-furanoflavanone, and (2,3-trans-3,4-trans)-3,4-dimethoxy-(2'',3'':7,8)-furanoflavan, as well as the previously known karanjachromene, karanjin, lanceolatin B, pongachromene, pongaglabrone and ponganpin. Only nine flavonoids could be quantified through HPLC analysis.