A New Depigmenting‐Antifungal Methylated Grindelane from Grindelia chiloensis |
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Authors: | María de los A. Mesurado María L. Arias Cassará Rosana Misico Alicia Bardón María I. Ybarra Elena Cartagena |
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Affiliation: | 1. Instituto de Química Orgánica, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Tucumán, Argentina;2. Departamento de Química Orgánica and UMYMFOR (CONICET‐UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina |
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Abstract: | The new methylated grindelane diterpenoid, 7β ‐hydroxy‐8(17)‐dehydrogrindelic acid ( 1b ), together with the known 7α ‐hydroxy‐8(17)‐dehydrogrindelic acid ( 2a ), 6‐oxogrindelic acid ( 3a ), 4β ‐hydroxy‐6‐oxo‐19‐norgrindelic ( 4a ), 19‐hydroxygrindelic acid ( 5a ), 18‐hydroxygrindelic acid ( 6a ), 4α ‐carboxygrindelic acid ( 7a ), 17‐hydroxygrindelic acid ( 8a ), 6α ‐hydroxygrindelic acid ( 9a ), 8,17‐bisnor‐8‐oxagrindelic acid ( 10a ), 7α ,8α ‐epoxygrindelic acid ( 11a ), and strictanonic acid ( 12a ) as methyl esters were obtained from an Argentine collection of Grindelia chiloensis (Cornel .) Cabrera . Their structures and relative configurations were established on the basis of spectroscopic analysis. CHC l3 extract from the aerial parts and their pure compounds were evaluated for their antifungal and depigmenting effects. Methyl ester derivative of 10a ( 10b ) exhibited a remarkable mycelial growth inhibition against Botritis cinerea with an IC 50 of 13.5 μg ml?1. While the new grindelane 1b exerted a clear color reduction of the yellow‐orange pigment developed by Fusarium oxysporum against UV ‐induced damage. |
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Keywords: | Grindelia chiloensis Grindelane diterpenoids and derivatives Antifungal and depigmenting effects Botrytis cinerea Fusarium oxysporum |
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