rhynchophylline rhynchophylline rhynchophylline is an alkaloid found in certain uncaria species (rubiaceae), notably uncaria rhynchophylla and uncaria tomentosa. it also occurs in the leaves of mitragyna speciosa (kratom), a tree native to thailand. chemically, it is related to the alkaloid mitragynine. rhynchophylline names iupac name methyl (7r,16e)-17-methoxy-2-oxo-16,17-didehydro-20α-corynoxan-16-carboxylate systematic iupac name methyl (2e)-2--7′-yl]-3-methoxyprop-2-enoate other names rhyncophyllinemitrinerminmitrinerminerhynchophyllinrhynocophylline identifiers cas number 76-66-4 y 3d model (jsmol) interactive image chebi chebi:70069 chembl chembl519266 chemspider 4444758 echa infocard 100.208.612 kegg c09236 pubchem cid 3033948 unii 46bq79vj8d comptox dashboard (epa) dtxsid70878612 inchi inchi=1s/c22h28n2o4/c1-4-14-12-24-10-9-22(17-7-5-6-8-18(17)23-21(22)26)19(24)11-15(14)16(13-27-2)20(25)28-3/h5-8,13-15,19h,4,9-12h2,1-3h3,(h,23,26)/b16-13+/t14-,15-,19-,22+/m0/s1key: daxyudfnwxhgbe-kaxdatadsa-ninchi=1/c22h28n2o4/c1-4-14-12-24-10-9-22(17-7-5-6-8-18(17)23-21(22)26)19(24)11-15(14)16(13-27-2)20(25)28-3/h5-8,13-15,19h,4,9-12h2,1-3h3,(h,23,26)/b16-13+/t14-,15-,19-,22+/m0/s1key: daxyudfnwxhgbe-kaxdatadbc smiles cc1cn2cc3(2c1/c(=c\oc)/c(=o)oc)c4=cc=cc=c4nc3=o properties chemical formula c22h28n2o4 molar mass 384.476 g·mol−1 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). n verify (what is yn ?) infobox references rhynchophylline is a non-competitive nmda antagonist (ic50 = 43.2 μm) and a calcium channel blocker. uncaria species have had a variety of uses in traditional herbal medicine, such as for lightheadedness, convulsions, numbness, and hypertension. these uses have been associated with the presence of rhynchophylline and have encouraged its investigation as a drug candidate for several cardiovascular and central nervous system diseases; however, few clinically relevant studies have been conducted.