Abstract |
Chemical fractionation of Brickellia paniculata methanolic extract by monitoring its inhibitory effect on K(+)-induced contraction in guinea-pig ileum in vitro led to the isolation of 5,4'-dihydroxy-6,7,8-trimethoxyflavone ( xanthomicrol) and the labdane-diterpene 3 alpha-angeloyloxy-2 alpha-hydroxy-13,14 Z-dehydrocativic acid (AAHDD). Both compounds inhibited the tonic contraction the effect being highly potent when a mixture in a proportion of 3 : 1 ( xanthomicrol/AAHDD) was assayed. The phasic component of the contractile response with K(+) was also reduced by the compounds. Xanthomicrol depressed the spasms induced with ACh, Hist, and BaCl(2) and its effect on Ca (2+) concentration-response curve showed a type of non-surmountable calcium blocking action; unlike the flavonoid, AAHDD produced a parallel rightward shift of the concentration-response curve to calcium, suggesting a competitive antagonism with an estimated pA(2) of 4.66. Obtained results support, in part, the popular use of B. paniculata as a spasmolytic remedy.
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Authors | Mariana Meckes, Fernando Calzada, Daniel Paz, Jaime Rodríguez, Héctor Ponce-Monter |
Journal | Planta medica
(Planta Med)
Vol. 68
Issue 5
Pg. 467-9
(May 2002)
ISSN: 0032-0943 [Print] Germany |
PMID | 12058331
(Publication Type: Letter, Research Support, Non-U.S. Gov't)
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Chemical References |
- 3-angeloyloxy-2-hydroxy-13,14-dehydrocativic acid
- Barium Compounds
- Chlorides
- Diterpenes
- Flavones
- Flavonoids
- Naphthalenes
- Pentanoic Acids
- Plant Extracts
- labdane
- barium chloride
- xanthomicrol
- Potassium Chloride
- Histamine
- Acetylcholine
- Calcium
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Topics |
- Acetylcholine
(pharmacology)
- Animals
- Asteraceae
- Barium Compounds
(pharmacology)
- Calcium
(pharmacology)
- Chlorides
(pharmacology)
- Diterpenes
(pharmacology)
- Flavones
- Flavonoids
(chemistry, isolation & purification, pharmacology)
- Guinea Pigs
- Histamine
(pharmacology)
- Ileum
(drug effects)
- In Vitro Techniques
- Muscle Contraction
(drug effects)
- Muscle, Smooth
(drug effects)
- Naphthalenes
(chemistry, isolation & purification, pharmacology)
- Pentanoic Acids
(chemistry, isolation & purification, pharmacology)
- Plant Extracts
(chemistry, isolation & purification, pharmacology)
- Potassium Chloride
(pharmacology)
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