title: C-prolinylquercetins from the yellow cocoon shell of the silkworm, Bombyx mori.
abstract: Two flavonoids containing the l-proline moiety, 6-C-[(2S,5S)-prolin-5-yl] quercetin (prolinalin A) and 6-C-[(2S,5R)-prolin-5-yl] quercetin (prolinalin B), were isolated from the cocoon shell of the silkworm, Bombyx mori. Their structural elucidation was achieved by application of acid hydrolysis and spectroscopic methods. These compounds were not found in the leaves of mulberry (Morus alba L.), the host plant of the silkworm, suggesting that the flavonoids are metabolites of the insect. This is the first time that flavonoids with an amino acid moiety have been found as naturally occurring compounds.
authors.affiliation: National Institute of Agrobiological Sciences, 1-2 Owashi, Tsukuba, Ibaraki 305-8634, Japan. hirayam@nias.affrc.go.jp
authors.forename: Chikara
authors.initials: C
authors.lastname: Hirayama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ono
authors.forename: Yasumori
authors.initials: Y
authors.lastname: Tamura
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D012831:Bombyx / Q000737:chemistry* / Q000254:growth & development*; D003116:Color; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011392:Proline / Q000737:chemistry*; D011794:Quercetin / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D011392:Proline; D011794:Quercetin