Voacangine 

Voacangine is an antagonist for TRPV1 and TRPM8 but as an agonist for TRPA1 (EC50=8 μM). Voacangine competitively blockes capsaicin binding to TRPV1 (IC50=50 μM). Voacangine competitively inhibits the binding of menthol to TRPM8 (IC50=9 μM) and it shows noncompetitive inhibition against icilin (IC50=7 μM). Voacangine selectively abrogates chemical agonist-induced TRPM8 activation and did not affect cold-induced activation. Voacangine is an alkaloid isolated from the root bark of Voacanga africana.