Antifungal activity and isomerization of octadecyl p-coumarates from Ipomoea carnea subsp. fistulosa

Not AvailableBioassay monitored HPLC assisted isolation and purification of the chief antifungal fraction of the leaves of Ipomoea carnea subsp. fistulosa (Convulvulaceae) were achieved using Colletotrichum gloeosporioides and Cladosporium cucumerinum as test organisms. The activity of the purified fraction was further confirmed by the dose dependent inhibition of the spore germination of Alternaria alternata and A. porri. The active fraction was identified as a mixture of (E)-octadecyl p-coumarate and (Z)-octadecyl p-coumarate. The two isomers were detected on an HPLC column with substantially different retention times, but once eluted from the column, one form was partly converted to the other in daylight. Conclusive evidence for the structures and their isomerization were obtained from the HPLC behavior, IR, UV, HRESIMS, CIMS and NMR spectral data. Important 1H NMR and 13C NMR signals could be separately assigned for the isomers using 2D NMR techniques.Not Availabl

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Not AvailableDried latex (aloe drug) and extractives of aloe vera obtained by hexane, ethyl acetate and methanol were tested with the aim of assessing their activity against some phytopathogenic fungi and understanding the chemical nature of the active principles present in them. The activity of the extractives against Colletotrichum gloeosporioides, Colletotrichum capsici and Fusarium solani was assessed by poisoned food technique and their activity against Cladosporium cucumerinum was assessed by thin layer chromatographic bioautography. Polar extractives obtained by methanol and ethyl acetate showed higher activity than non-polar extractive obtained by hexane. The extractives showed higher activity against Colletotrichum species than F. solani. Two constituents namely aloin and aloe-emodin were identified as active principles by their activity against Colletotrichum gloeosporioides and Cladosporium cucumerinum.Not Availabl

Antifungal activity of Mucuna pruriens Seed Extractives and L-DOPA

Not AvailableThe seeds of Mucuna pruriens (L.) D.C. (Leguminosae) were extracted first with hexane, then with ethyl acetate, and finally with methanol. The solvents were removed to get the respective extractives. These were assessed for the mycelial growth inhibition of three phytopathogenic fungi - Colletotrichum gloeosporioides, Colletotrichum capsici, and Fusarium solani - by the poisoned - food technique. Methanol extractive showed highest activity against all the three test organisms. L - dopa [3 - (3,4 - Dihydroxyphenyl) - L - alanine], which was qualitatively detected in the ethyl acetate and methanol extractives and quantitatively assessed in the seeds, showed antifungal activity against all the three test organisms, showing that it is one of the active principles in these extractives.Not Availabl

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Not AvailableAntifungal activity assay of the methanol extract of the aerial parts of the plant Andrographis paniculata revealed that it exhibits mycelial growth inhibition of Fusarium solani and spore germination inhibition of Alternaria solani. Pure andrographolide present in the methanol extract also exhibited spore germination inhibition of A. solani. Quantitative estimation of andrographolide in the methanol extract by HPLC revealed that it had 6.82% andrographolide in it. This is probably the first report on the antifungal activity of andrographolide.Not Availabl

Additional studies on the antifungal activity of a methanol extract of Ipomoea carnea subsp. fistulosa and octadecyl p-coumarates

Not AvailableBackground: Ipomoea carnea subsp. fistulosa is a plant native to South America, but sparsely distributed in India and Bangladesh. Aphrodisiac, purgative, cathartic and sore curing properties have been attributed to the plant. Although there were several papers on the antifungal and antibacterial activities of on the crude extractives of the plant, the first report on the bioassay monitored isolation and characterization of the chief antifungal compounds as a mixture of E and Z isomers of octadecyl p-coumarates was published from this Institute. Material and Methods: The methanol extractive of Ipomoea carnea subsp. fistulosa exhibited antifungal activity against the mycelial growth of Phytophthora nictotiana by poisoned food technique. This is in addition to the reported activity against Colletotrichum gloeosporioides. Results and Discussion: Octadecyl p-coumarates isolated from the plant by column chromatography followed by HPLC exhibited activity against the mycelial growth of Cercospora capsici. This is in addition to the reported activity of octadecyl p-coumarates against the spore germination of Alternaria alternata, Alternaria porri and Cladosporium cucumerinum. Conclusion: Additional studies conducted with the crude extractive of Ipomoea carnea subsp. fistulosa confirmed its antifungal activity against Phytophthora nicotianae. Identification of octadecyl p-coumarates as antifungal active principles was confirmed by its activity against Cercospora capsici by modified mycelial growth inhibition study.Not Availabl