C-Prenylated flavonoids in Philippine propolis from nests of stingless bee (tetragonula biroi friese)
Date of Publication
Master of Science in Chemistry
College of Science
Consolacion Y. Ragasa
Defense Panel Chair
Glenn V. Alea
Defense Panel Member
Alicia M. Aguinaldo
Jaime Raul O. Janairo
The dichloromethane extract of Philippine propolis from nests of Tetragonula biroi Friese, collected in Sorsogon, afforded two C-prenylated flavonoids: the flavanone Propolin H or Macarangaflavanone A (TB-4), and the dihydroxyflavonol Glyasperin A (TB-1), along with six known triterpenes: a mixture of a-amyrin (TB-2a), b-amyrin (TB-2b), and lupeol (TB-2b), and a mixture of urs-12-ene-3-one (TB-6a), olean-12-ene-3-one (TB-6b), and lupenone (TB-6c). The structures TB-4 and TB-1 were elucidated using 1D and 2D NMR spectroscopy. Stereochemistry of TB-4 was determined using CD spectroscopy. This the first report on the isolation of Glyasperin A from propolis. Furthermore, this is the first report on the isolation of secondary metabolites in Philippine propolis.
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Ebajo, V. D. (2014). C-Prenylated flavonoids in Philippine propolis from nests of stingless bee (tetragonula biroi friese). Retrieved from https://animorepository.dlsu.edu.ph/etd_masteral/4689