Thionation of segetalins A and B, cyclic peptides with estrogen-like activity from seeds of Vaccaria segetalis.
Thionation of estrogen-like active cyclic peptides, segetalins A (1) and B (2), with Lawesson's reagent provided each two thiosegetalins; thiosegetalin A1 [Gly-1-psi(CS-NH)-Val-2; Trp-5-psi (CS-NH)-Ala-6]segetalin A, thiosegetalin A2 [Gly-1-psi(CS-NH)-Val-2; Ala-6-psi(CS-NH)-Gly-1]segetalin A, thiosegetalin B1 [Gly-1-psi (CS-NH)-Val-2; Ala-3-psi(CS-NH)-Trp-4]segetalin B, and thiosegetalin B2 [Gly-1-psi(CS-NH)-Val-2; Trp-4-psi(CS-NH)-Ala-1]segetalin B. Thiosegetalin A2 only showed estrogen-like activity against ovariectomized rats. On the basis of their conformations analysed by NMR experiments, the backbone conformation was considered to play an important role in estrogen-like activity for segetalins.
Morita
H
H
Department of Pharmacognosy, School of Pharmacy, Tokyo University of Pharmacy and Life Science, Japan.
Yun
Y S
YS
Takeya
K
K
Itokawa
H
H
Shirota
O
O
D000818:Animals; D004967:Estrogens / Q000737:chemistry* / Q000494:pharmacology; D005260:Female; D009682:Magnetic Resonance Spectroscopy; D009929:Organ Size / Q000187:drug effects; D010052:Ovariectomy; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000494:pharmacology; D011487:Protein Conformation; D051381:Rats; D012639:Seeds / Q000737:chemistry*; D013438:Sulfhydryl Compounds; D014599:Uterus / Q000187:drug effects
D004967:Estrogens; D010456:Peptides, Cyclic; D013438:Sulfhydryl Compounds; C101980:segetalin A; C101981:segetalin B