128807-15-8Relevant academic research and scientific papers
Eremophilane sesquiterpenes from capsidiol
Zhao, Yuxin,Schenk, David J.,Takahashi, Shunji,Chappell, Joe,Coates, Robert M.
, p. 7428 - 7435 (2007/10/03)
A series of eremophilane sesquiterpene alcohols and hydrocarbons was prepared from the phytoalexin capsidiol (1) for mechanistic studies with epiaristolochene synthase and epiaristolochene dihydroxylase. Among them, 3-deoxycapsidiol (10) was obtained through selective derivatization and reductive cleavage of the equatorial 3α hydroxyl group. Two novel isomers of aristolochene and eremophilene were accessed from the 1- and 3-deoxycapsidiol isomers. 4-Epieremophilene (17) was obtained by conjugate reduction of epiaristolochen-1-one tosylhydrazone with catecholborane followed by sulfinate elimination and diimide rearrangement. Epimerization of epiaristolochen-3-one (27a) at the C4 methyl followed by reductions led to the previously unknown aristolochene isomer, eremophila-9(10),11(12)-diene (30). Optical rotations and characteristic 1H NMR data for the related eremophilenols and dienes are collected in Tables 1 and 2. Finally, bioassays were used to assess the antifungal potencies of capsidiol and its synthetic derivatives. The minimum inhibitory concentration for capsidiol (3-10 ng) was at least 1 order of magnitude lower than that of any of the derivatives and considerably lower than those previously reported for ketoconazole, nystatin, and propiconazole.
SYNTHESIS OF (+)-5-EPI-ARISTOLOCHENE AND (+)-1-DEOXYCAPSIDIOL FROM CAPSIDIOL
Whitehead, Ian M.,Ewing, David F.,Threlfall, David R.,Cane, David E.,Prabhakaran, P. C.
, p. 479 - 482 (2007/10/02)
(+)-5-epi-Aristolochene, a common precursor of the phytoalexins capsidiol and debneyol, was synthesized from capsidiol (ex.Capsicum annum) via (+)-1-deoxycapsidiol.It is identical (TLC, GC, GC-MS, 1H NMR) with the enzymic product from cell-free preparations from elicitor-treated suspension cultures of Nicotiana tabacum incubated with either 14C>isopentenyl pyrophosphate or E,E-3H2>farnesyl pyrophosphate.The (+)-1-deoxycapsidiol was identical (GC, MS, 13C and 1H NMR) to a natural sample previously obtained from elicitor-treated fruits of C. annum.An isomer of 1-deoxycapsidiol, formed during the synthesis of this compound, was identified as 4-epi-eremophila-1(10),11-diene.
