Thiophene interconversions in Tagetes patula hairy-root cultures

Arroo, Randolph R.J.; Jacobs, John J.M.R.; De Koning, Edward A.H.; De Waard, Mirjam; Van De Westerlo, Els; Van Galen, Peter M.; Swolfs, Ad E.M.; Klunder, Anton J.H.; Croes, Anton F.; Wullems, George J.

Phytochemistry 38(5): 1193-1197


ISSN/ISBN: 0031-9422
DOI: 10.1016/0031-9422(94)00763-j
Accession: 002721883

Download citation:  

Article/Abstract emailed within 0-6 h
Payments are secure & encrypted
Powered by Stripe
Powered by PayPal

On the basis of feeding experiments with 35S-labelled intermediates, we present a modified biosynthetic pathway of the bithienyls in Tagetes. The monothiophene 2-(but-3-en-1-ynyl)-5-(penta-1,3-diynyl)-thiophene, which is present in small amounts in Tagetes hairy roots, is the precursor of all bithienyls that have been described for this species but not of alpha-terthienyl. The current hypothesis that 5-(3-buten-1-ynyl)-2,2'-bithienyl originates from 5'-methyl-5-(3-buten-1-ynyl)-2,2'-bithienyl after oxidative decarboxylation proved untrue. The latter compound is only converted into (5'-but-3-en-1-ynyl-(2,2')bithiophenyl-5-yl)-methyl acetate, probably via (5'-but-3-en-1-ynyl-(2,2')bithiophenyl-5-yl)-methanol. Substitution of the butenynyl side chain of 5-(3-buten-1-ynyl)-2-2'-bithienyl results in the formation of 5-(3,4-dihydroxy-1-butynyl)-2,2'-bithienyl and 5-(4-hydroxy-1-butynyl)-2,2'-bithienyl, which are subsequently converted into respectively 5-(3,4-diacetoxy-1-butynyl)-2,2'-bithienyl and 5-(4-acetoxy-1-butynyl)-2,2'-bithienyl. The end products of this biosynthetic pathway are all bithienyl-acetate esters.