Phytotoxic withanolides from Jaborosa rotacea.
Twelve new withanolides were isolated from the aerial part of Jaborosa rotacea: five had a spiranoid delta-lactone (1-5); one contained a 26,12-delta-lactone and a C-12-C-23 bond (6); five corresponded to trechonolide-type withanolides with configuration at C-23 opposite of those previously isolated (7, 8, 10-12); two of these have an additional oxido-bridge between C-21 and C-24; finally a withanolide with a hemiketal ring formed between a 21-hydroxyl and a 12-ketone (13) and the closely related jaborosalactone R were also isolated. New compounds were fully characterized by a combination of spectroscopic methods (1D and 2D NMR and MS). The structures of the spiranoid withanolide and of the epimer of trechonolide A were confirmed by X-ray diffraction studies. Compounds 4, 5, 6, and 8 showed selective phytotoxicity toward monocotyledoneous and dicotyledoneous species.
Nicotra
Viviana E
VE
Departamento de Química Organica and IMBIV, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, 5000 Córdoba, Argentina.
Ramacciotti
Natalia S
NS
Gil
Roberto R
RR
Oberti
Juan C
JC
Feresin
Gabriela E
GE
Guerrero
Cecilia A
CA
Baggio
Ricardo F
RF
Garland
M Teresa
MT
Burton
Gerardo
G
D001118:Argentina; D018360:Crystallography, X-Ray; D004875:Ergosterol / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development; D008968:Molecular Conformation; D015394:Molecular Structure; D031783:Phalaris / Q000187:drug effects / Q000254:growth & development; D036226:Seedlings / Q000187:drug effects* / Q000254:growth & development*; D019657:Solanaceae / Q000737:chemistry*
D004875:Ergosterol