ABSTRACT
The new methylated grindelane diterpenoid, 7ß-hydroxy-8(17)-dehydrogrindelic acid (1b), together with the known 7α-hydroxy-8(17)-dehydrogrindelic acid (2a), 6-oxogrindelic acid (3a), 4ß-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. CHCl3 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 IC50 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.
Subject(s)
Antifungal Agents/isolation & purification , Grindelia/chemistry , Skin Lightening Preparations/isolation & purification , Antifungal Agents/pharmacology , Diterpenes , Fusarium/drug effects , Magnetic Resonance Spectroscopy , Molecular Structure , Plant Extracts/chemistry , Skin Lightening Preparations/pharmacologyABSTRACT
From an Argentine collection of Senecio santelisis Phil., the new furanoeremophilanoids, (10betaH)-6beta-acetoxy-1alpha-hydroxyfuranoeremophilan-9-one (1) and (10betaH)-1alpha-hydroxy-6beta-(propanoyloxy)furanoeremophilan-9-one (2), together with the known (10alphaH)-6beta-acetoxy-1alpha-hydroxyfuranoeremophilan-9-one (3), (10alphaH)-1alpha,6beta-diacetoxyfuranoeremophilan-9-one (4), and (10alphaH)-1alpha-hydroxy-6beta-(propanoyloxy)furanoeremophilan-9-one (5) were isolated. Their structures and relative configurations were established on the basis of spectroscopic analysis. CHCl3 Extract and pure compounds were evaluated for their antifungal activity. Compound 5 exhibited remarkable mycelial growth inhibition against B. cinerea with an IC(50) value of 21.4 microg/ml.
Subject(s)
Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Botrytis/drug effects , Naphthalenes/chemistry , Naphthalenes/pharmacology , Senecio/chemistry , Antifungal Agents/isolation & purification , Furans/chemistry , Furans/isolation & purification , Furans/pharmacology , Molecular Structure , Naphthalenes/isolation & purification , Plant Extracts/chemistry , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Polycyclic Sesquiterpenes , SesquiterpenesABSTRACT
Antibacterial and molluscicidal activities of methanol and chloroform extracts of 16 plant species belonging to the families Compositae and Melastomataceae were evaluated. The chloroform extract of Vernonanthura tweediana and the methanol extract of Senecio santelisis resulted to be very toxic to brine shrimp nauplii (LC(50)=1 microg/ml). Chloroform extracts of S. santelisis and Senecio leucostachys as well as the methanol extract of Wedelia subvaginata displayed molluscicidal effects on Biomphalaria peregrina showing LC(100)<100 microg/ml. Moderate antibacterial action was produced by the chloroform extracts of Flaveria bidentis, Grindelia scorzonerifolia and Vernonia incana against two strains of Staphylococcus aureus.
