Planta Med 1994; 60(6): 512-515
DOI: 10.1055/s-2006-959561

© Georg Thieme Verlag Stuttgart · New York

In Vitro Antispasmodic Activity of Peracetylated Penstemonoside, Aucubin and Catalpol

A. V. Ortiz de Urbina1 , M. L. Martín1 , B. Fernández1 , L. San Román1 , L. Cubillo2
  • 1Laboratorio de Farmacognosia y Farmacodinamia, Departamento de Fisiología y Farmacología, Facultad de Farmacia, Universidad de Salamanca, E-37007 Salamanca, Spain
  • 2Departamento de Química Orgánica, Facultad de Químicas, Universidad de Salamanca, E-37008 Salamanca, Spain
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Publication History



Publication Date:
05 January 2007 (online)


In vitro, the peracetates of penstemonoside, aucubin and catalpol, iridoids isolated from Parentucellia latifolia, antagonize the uterine muscular contractions induced by acetylcholine and calcium, in a similar way to papaverine. The antagonism is non-competitive against acetylcholine (pD2′ values: 5.60 for the peracetates of penstemonoside, 5.74 for aucubin, 5.59 for catalpol, and 5.32 for papaverine) and competitive against calcium (pA2 values: 6.60 for the peracetates of penstemonoside, 6.34 for aucubin, 6.48 for catalpol, and 6.23 for papaverine). The two components, phasic and tonic, of the response of the vas deferens to potassium are reduced by the three iridoids. The reduction is similar for both phases. The antispasmodic activity of the three iridoids, similar to papaverine, is related to an inhibiting effect of extracellular calcium, intracellular or both.