Browsing Faculty of Science by Author "Dongo, E."
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Abegaz, B.M.; Ngadjui, B.T.; Dongo, E.; Ngameni, B.; Nindi, M.N.; Bezabih, M. (Elsevier Science Ltd. www.elsevier.com/locate/phytochem, NaN, 2002)[more][less]
Abstract: The twigs of Dorstenia prorepens furnished the digeranylated chalcone, 5,30-(3,7-dimethyl-2,6-octadienyl)-3,4, 20,40-tetrahydroxychalcone while Dorstenia zenkeri yielded the 30,40-(3-hydroxy-2,2-dimethyldihydropyrano)-4,20-dihydroxychalcone and a bichalcone. 4-Hydroxylonchocarpin was found in both plants. D. prorepens also yielded the known compounds: psoralen, bergapten, b-sitosterol and its D-glucopyranosyl derivative. D. zenkeri yielded p-hydroxybenzaldehyde, dorsmanin A, 4,20,40-trihydroxychalcone and 4,20,40-trihydroxy-30-prenylchalcone. Structures of the new compounds were established by UV, IR, MS and 2-D NMR analysis. URI: http://hdl.handle.net/10311/254 Files in this item: 2
Chalcones and other constituents.pdf (3.760Mb)license.txt (1.998Kb) -
Ngadjui, B.; Dongo, E.; Abegaz, B.; Fotso, S.; Tamboue, H. (Elsevier Science Ltd. www.elsevier.com/locate/phytochem, NaN, 2002)[more][less]
Abstract: Three prenylated flavonoids, dinklagins A, B and C identified, respectively, as ( )-6-(3,3-dimethylallyl)-7-hydroxy-6000, 6000-dimethylchromeno-( 40,30,2000,3000)-flavanone, (+)-5,40,500x-trihydroxy-600,600-dimethylchromano-(7,6,200,300)-flavone and (+)6-(2x-hydroxy- 3-methyl-3-butenyl)-5,7,40-trihydroxyflavone were isolated from the twigs of Dorstenia dinklagei together with the known 6-prenylapigenin, 4-hydroxylonchocarpin, stipulin and 5,40-dihydroxy-600,600-dimethylchromano-(7,6,200,300)-flavone. Their structures were determined on the basis of spectral data and by comparison with data reported in the literature and with authentic specimens for known compounds. URI: http://hdl.handle.net/10311/262 Files in this item: 2
license.txt (1.998Kb) -
Abegaz, B.M.; Ngadjui, B.T.; Folefoc, G.N.; Fotso, S.; Ambassa, P.; Bezabih, M.; Dongo, E.; Rise, F.; Petersen, D. (Elsevier Ltd. www.elsevier.com/locate/phytochem, NaN, 2003)[more][less]
Abstract: A monoprenylated flavan and two monoterpenoid substituted furanocoumarins were isolated from the twigs of Dorstenia elliptica along with 3-(3,3-dimethylallyl)-4,20,40-trihydroxylchalcone, psoralen, bergapten, O-[3-(2,2-dimethyl-3-oxo-2H-furan-5-yl)butyl] bergaptol, b-sitosterol and its b-d-glucopyranoside. The structure of the flavan was determined as 6(1,1-dimethylallyl)-7,40- dihydroxylflavan and the monoterpenoid substituted furanocoumarins were assigned as O-[3-(2,2-dimethyl-3-oxo-2H-furan-5-yl)-3- hydroxybutyl]-bergaptol and O-[2-(5-hydroxy-2,6,6-trimethyl-3-oxo-2H-pyran-2-yl)ethyl]bergaptol, respectively, using spectroscopic analysis, especially, 2D NMR spectra. URI: http://hdl.handle.net/10311/286 Files in this item: 1
Prenylated flavonoids,.pdf (3.692Mb)
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