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DOI: 10.1055/s-1999-14056
Georg Thieme Verlag Stuttgart · New York
Nitric Oxide/cGMP Mediates the Spasmolytic Action of 3,4′-Dihydroxy-5,5 ′-dimethoxybibenzyl from Scaphyglottis livida [*]
Publication History
May 15
July 26, 1998
Publication Date:
31 December 1999 (online)
Abstract:
Five aromatic compounds, 3,4′-dihydroxy-5,5′ -dimethoxybibenzyl (1), batatasin III (2), coelonin (3), 3,7-dihydroxy-2,4-dimethoxyphenanthrene (4), and 3,7-dihydroxy-2,4,8-trimethoxyphenanthrene (5) were isolated from the orchid Scaphyglottis livida (Lindley) Schltr. Compounds 1 -5 induced a concentration-dependent inhibition of the spontaneous contractions of the rat ileum with potencies comparable or higher to that of papaverine. The relaxation evoked by compounds 1-4 was blocked by L-NAME, an inhibitor of nitric oxide synthase. It was also demonstrated that 1 increased cyclic GMP content in rat ileum rings. Compound 1-induced elevation of cGMP was inhibited by L-NAME and ODQ, inhibitors of nitric oxide synthase and soluble guanylyl cyclase, respectively. These results indicate that nitric oxide/cGMP formation constitute the signaling pathway in the spasmolytic action of compound 1.
Key words:
Scaphyglottis livida - Orchidaceae - phenanthrenes - dihydrostilbenes - smooth muscle relaxation - nitric oxide - L-NAME - ODQ - soluble guanylyl cyclase
1 Chemical Studies on Mexican Plants Used in Traditional Medicine XXXIX. Taken in part from the PhD thesis of S. Estrada.
1 Chemical Studies on Mexican Plants Used in Traditional Medicine XXXIX. Taken in part from the PhD thesis of S. Estrada.