title: Samaderin B and C from Samadera indica.
abstract: Samaderin B, or (1R,2S,5R,5aR,7aS,11S,11aS,11bR,14S)-1,7,7a,11,11a,11b-hexahydro-1,11-dihydroxy-8,11a,14-trimethyl-2H-5a,2,5-(methanoxymetheno)naphth[1,2-d]oxepine-4,6,10(5H)-trione, C(19)H(22)O(7), and samaderin C, or (1R,2S,5R,5aR,7aS,10S,11S,11aS,11bR,14S)-7,7a,10,11,11a,11b-hexahydro-1,10,11-trihydroxy-8,11a,14-trimethyl-2H-5a,2,5-(methanoxymetheno)naphth[1,2-d]oxepine-4,6(1H,5H)-dione, C(19)H(24)O(7), were isolated from the seed kernels of Samadera indica and were shown to exhibit antifeedant activity against Spodoptera litura third-instar larvae. The replacement of the carbonyl group in samaderin B by a hydroxy group in samaderin C causes conformational changes at the substitution site, but the overall conformation is not affected; however, the compounds pack differently in the crystal lattice.
authors.affiliation: Department of Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India.
authors.forename: R
authors.initials: R
authors.lastname: Malathi
authors.forename: S S
authors.initials: SS
authors.lastname: Rajan
authors.forename: G
authors.initials: G
authors.lastname: Suresh
authors.forename: G N
authors.initials: GN
authors.lastname: Krishnakumari
authors.forename: G
authors.initials: G
authors.lastname: Gopalakrishnan
mesh_terms: D018360:Crystallography, X-Ray; D008958:Models, Molecular; D015394:Molecular Structure; D036702:Quassins / Q000737:chemistry / Q000302:isolation & purification*; D029641:Simaroubaceae / Q000737:chemistry*
chemical_list: D036702:Quassins; C432980:samaderin C; C432981:samaderin B