Three New O-Methyltransferases Are Sufficient for All O-Methylation Reactions of Ipecac Alkaloid Biosynthesis in Root Culture of Psychotria ipecacuanha
作者:Taiji Nomura、Toni M. Kutchan
DOI:10.1074/jbc.m109.086157
日期:2010.3
ipecacuanha produces ipecacalkaloids, a series of monoterpenoid-isoquinoline alkaloids such as emetine and cephaeline, whose biosynthesis derives from condensation of dopamine and secologanin. Here, we identified three cDNAs, IpeOMT1-IpeOMT3, encoding ipecacalkaloid O-methyltransferases (OMTs) from P. ipecacuanha. They were coordinately transcribed with the recently identified ipecacalkaloid beta-glucosidase
Simplified Tetrandrine Congeners as Possible Antihypertensive Agents with a Dual Mechanism of Action
作者:Patricio Iturriaga-Vásquez、Raquel Miquel、M. Dolores Ivorra、M. Pilar D'Ocon、Bruce K. Cassels
DOI:10.1021/np030022+
日期:2003.7.1
A series of O- and/or N-substituted derivatives of (+/-)-coclaurine (1a) were synthesized as simplified structural mimics of the antihypertensive alkaloid tetrandrine (2) and assayed for binding to brain cortical sites labeled with the alpha(1)-adrenergic radioligand [H-3]prazosin or the calcium channel radioligand [H-3]-diltiazem. The introduction of O-benzyl groups on the coclaurine molecule, which exhibits only adrenergic antagonist activity, led to the appearance of calcium channel blocking activity comparable to that of tetrandrine while retaining adrenolytic activity in the same concentration range. Contraction of aortal rings with noradrenaline or KCl was relaxed more potently by some of these coclaurine derivatives than by tetrandrine, suggesting leads for the development of novel antihypertensive drugs with a dual mechanism of action.
Tomita et al., Yakugaku Zasshi/Journal of the Pharmaceutical Society of Japan, 1950, vol. 70, p. 152
作者:Tomita et al.
DOI:——
日期:——
Yamaguchi, Yakugaku Zasshi/Journal of the Pharmaceutical Society of Japan, 1958, vol. 78, p. 692