title: Capsaicinol: synthesis by allylic oxidation and its effect on TRPV1-expressing cells and adrenaline secretion in rats.
abstract: Capsaicinol is an ingredient of hot red pepper. In this study, we developed a novel method for capsaicinol synthesis and examined capsaicinol's physiological effects on capsaicin receptor (TRPV1)-related actions. Allylic oxidation of capsaicin by palladium acetate (Pd(OAc)(2)) resulted in the formation of (+/-)-capsaicinol acetate at a 7.2% yield in a single step. The effectiveness of (+/-)-capsaicinol in TRPV1 activation (EC(50)=1.1 microM) was found to be weaker than that of capsaicin (EC(50)=0.017 microM), whereas the efficacy of (+/-)-capsaicinol reached 75% of that of capsaicin. Intravenous administration of (+/-)-capsaicinol in anesthetized rats dose-dependently enhanced adrenaline secretion from the adrenal gland. The response to a 5 mg/kg-dose of (+/-)-capsaicinol was comparable to that of a 0.05 mg/kg-dose of capsaicin. The relative pungency of capsaicinol to capsaicin was coincident with the relative effectiveness in inducing these TRPV1-related actions.
authors.affiliation: Graduate School of Nutritional and Environmental Sciences and COE program in the 21st century, University of Shizuoka, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kobata
authors.forename: Takahito
authors.initials: T
authors.lastname: Iwasawa
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Iwasaki
authors.forename: Akihito
authors.initials: A
authors.lastname: Morita
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Hiroe
authors.initials: H
authors.lastname: Kikuzaki
authors.forename: Nobuji
authors.initials: N
authors.lastname: Nakatani
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Watanabe
mesh_terms: D000085:Acetates / Q000737:chemistry; D000311:Adrenal Glands / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002211:Capsaicin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000378:metabolism*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007275:Injections, Intravenous; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry; D051381:Rats; D013237:Stereoisomerism; D050916:TRPV Cation Channels / Q000096:biosynthesis* / Q000187:drug effects* / Q000378:metabolism; D013997:Time Factors
chemical_list: D000085:Acetates; C514762:N-(4-hydroxy-3-methoxybenzyl)-7-hydroxy-8-methyl-5-nonenamide; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat; D010165:Palladium; D002211:Capsaicin; D004837:Epinephrine