Antifungal Activity and Isomerization of Octadecyl p-coumarates from Ipomoea carnea subsp. fistulosa (original) (raw)
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Antifungal activity and isomerization of octadecyl p-coumarates from Ipomoea carnea subsp. fistulosa
Natural product communications, 2011
Bioassay 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 and NMR spectral data. Important 1H NMR and 13C NMR signals could be separately assigned for the isomers using 2D NMR techniques.
Pharmacognosy Communications, 2016
Background: 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 cuc-umerinum. Conclusion: Additional studies conducted with the crude extractive of Ipomoea car nea subsp. fistulosa confirmed its antifungal activity against Phytoph thora nicotianae. Identification of octadecyl p-coumarates as antifungal active principles was confirmed by its activity against Cercospora capsici by modified mycelial growth inhibition study.
Evaluation of antifungal activities and structure-activity relationships of Coumarin Derivatives
Pest management science, 2016
Osthol is a natural coumarin and lead compound that has been developed into commercial fungicides in China. Natural coumarins comprise five major subtypes-simple coumarins, linear furanocoumarins, angular furanocoumarins, linear pyranocoumarins, and angular pyranocoumarins. Studies pertaining to the antifungal activities of linear pyranocoumarins are few, and no reports exist for the antifungal activities of angular pyranocoumarins. In order to discover more antifungal natural coumarins, we synthesized a series of simple natural coumarins and isolated several plant-based furanocoumarins and pyranocoumarins using previously described methods. The compounds were biologically evaluated against some plant fungal pathogens. Several of the 35 coumarins evaluated here exhibited strong activities against specific fungal species, including Compound 25 (Pd-D-V, a linear pyranocoumarin), Compound 26 (libanorin, an angular furanocoumarin), and Compound 34 (disenecioyl khellactone, an angular py...
Pesticide Science, 1987
Seven 6-alkyl-3-n-butyl-7-hydroxy-4-methylcoumarins and three other related substituted coumarins were synthesised, characterised and tested for their toxicity towards mycelial growth of seven phytopathogenic fungi in culture. Rhizoctonia solani, Alternaria alternate, and Drechslera oryzae exhibited maximum sensitivity to these compounds whereas Pythium aphanidermatum, Colletotrichum falcatum, Fusarium solani and Macro-phomina phaseolina were less sensitive. The 6-n-butyl and 6-n-pentyl derivatives possessed strongest toxicity towards all fungi except C. falcatum but the corresponding 6-n-propyl derivative was inhibitory to only D. oryzae and A. alternata.
Pesticide Science, 1989
Twelve 4-(substituted phenoxy)methyld-methyl coumarins were synthesised by the condensation of 4-chloromethyl-6-methyl coumarin with various phenols in the presence of potassium carbonate in dry acetone. The compounds were tested for their toxicity towards the mycelial growth of seven plant pathogenic fingi. Among the tested fungi, Pythium aphanidermatum, Colletotrichum falcatum, Drechslera oryzae, Alternaria alternata and Fusarium solani exhibited maximum sensitivity whereas Macrophomina phaseolina and Rhizoctonia solani were least sensitive to the test compounds. The 4-(4-tert-butylphenoxy)methyl and 444nitrophenoxy)methyl analogues possessed greatest toxicity towards the majority of the tested fungi. 53 Pestic. Sci. 0031-613X/88/$03.50 0 1989 Society of Chemical Industry. Printed in Great Britain R,
Pesticide Science, 1988
A series of substituted 4-methylcoumarins was synthesised and the members tested for their toxicity towards mycelial growth of seven phytopathogenic fungi in culture. Rhizoctonia solani, Alternaria alternata and Fusarium solani exhibited maximum sensitivity to these compounds whereas Pythium aphanidermatum, Colletotrichum falcatum, Drechslera oryzae and Macrophomina phaseolina were relatively less sensitive. 6-Ethyl-3-n- propyl-7-hydroxy4-methylcoumarin (I) was relatively toxic towards all fungi except C. falcatum, P. aphanidermatum and M. phaseolina. The 6-n-butyl (III) and 6-(1, 1, 3, 3-tetramethylbutyl) (VI) derivatives were highly toxic to R. solani with EC50, values of lμg ml−1.
Pharmacology & Pharmacy, 2015
5 totally different endophytic fungal species were isolated from bark and leaf parts of Calophyllum inophyllum. Leaf part yielded Trichoderma harzianum and Alternaria species, whereas bark showed the presence of Fusarium species, Aspergillus species and unidentified fungi. Two solvents (hexane and methanol) were used for endophytic fungal extraction and the Alternaria species had shown the presence of coumarin whereas Trichoderma harzianum in methanol extract and Fusarium species in hexane extract had shown the coumarin(s) in all the four methods tested. The total coumarin yield was more in microwave assistance method, the methanol Alternaria species (3.941 ± 0.082) stood first, followed by hexane extract of Alternaria species (3.254 ± 0.082), Fusarium species (2.532 ± 0.082) and Trichoderma harzianum (2.294 ± 0.082), the plant extract showed 4.149 + 0.053. The methanol extract of Alternaria species inhibited the activity of HIV-Reverse Transcriptase (RT) (82.81 ± 1.0), integrase (98%) and protease (78) in maximum level followed by hexane extract of Alternaria species (71.12 ± 0.9, 89, 68), Fusarium species (63.92 ± 1.8, 67, 66) and Trichoderma harzianum (56.69 ± 0.9, 71, 63). The endophytic fungi Alternaria species inhibited all the three viral enzymes at maximum level and it was more than standard drug. However, in order to know possible anti-HIV, it is necessary to isolate active coumarin from the Alternaria species and the mechanism of action will be studied in future studies.
Molecules
One trend in agriculture is the replacement of classical pesticides with more ecofriendly solutions, such as elicitation, which is a promising approach consisting of stimulating the natural immune system of a plant to improve its resistance to pathogens. In this fashion, a library of p-coumaric-based compounds were synthesized in accordance with as many principles of green chemistry as possible. Then, these molecules were tested for (1) the direct inhibition of mycelium growth of two pathogens, Botrytis cinerea and Sclerotinia sclerotiorum, and (2) plasma membrane destabilization in Arabidopsis and rapeseed. Finally, the protective effect was evaluated on an Arabidopsis/B. cinerea pathosystem. Total inhibition of the growth of both fungi could be achieved, and significant ion leakage was observed using dihydroxylated fatty p-coumarate esters. A direct effect on plants was also recorded as a ca. three-fold reduction in the necrosis area.
Pharmacology & Pharmacy, 2015
5 totally different endophytic fungal species were isolated from bark and leaf parts of Calophyllum inophyllum. Leaf part yielded Trichoderma harzianum and Alternaria species, whereas bark showed the presence of Fusarium species, Aspergillus species and unidentified fungi. Two solvents (hexane and methanol) were used for endophytic fungal extraction and the Alternaria species had shown the presence of coumarin whereas Trichoderma harzianum in methanol extract and Fusarium species in hexane extract had shown the coumarin(s) in all the four methods tested. The total coumarin yield was more in microwave assistance method, the methanol Alternaria species (3.941 ± 0.082) stood first, followed by hexane extract of Alternaria species (3.254 ± 0.082), Fusarium species (2.532 ± 0.082) and Trichoderma harzianum (2.294 ± 0.082), the plant extract showed 4.149 + 0.053. The methanol extract of Alternaria species inhibited the activity of HIV-Reverse Transcriptase (RT) (82.81 ± 1.0), integrase (98%) and protease (78) in maximum level followed by hexane extract of Alternaria species (71.12 ± 0.9, 89, 68), Fusarium species (63.92 ± 1.8, 67, 66) and Trichoderma harzianum (56.69 ± 0.9, 71, 63). The endophytic fungi Alternaria species inhibited all the three viral enzymes at maximum level and it was more than standard drug. However, in order to know possible anti-HIV, it is necessary to isolate active coumarin from the Alternaria species and the mechanism of action will be studied in future studies.
African Journal of Microbiology Research, 2011
Inula viscosa, Inula graveolens and Inula crithmoïdes (Asteraceae) leaf and flower organic extracts (hexane, chloroform and methanol) were assessed for their antifungal activity against two Trichoderma species (Trichoderma harzianum and Trichoderma viride) and three formae speciales of Fusarium oxysporum. I. viscosa organic extracts showed an important inhibitory activity against all target fungal isolates. Growth inhibition percentage ranged between 17-61, 77-100, and 55-100% in presence of hexane, chloroform and methanol I. viscosa leaf extracts, respectively. Flower organic extracts reduced mycelial growth of all fungi by 32-66, 30-75, and 8-70%, respectively. For I. graveolens, Stem + leaf organic extracts showed more or less important inhibition depending on solvent nature, though, flower organic extracts were found to be the most effective against tested fungi: a total inhibition of growth was recorded with methanol fraction against all target fungi and with hexane fraction against F. oxysporum f. sp. melonis (FOM) and T. viride. In presence of I. crithmoïdes leaf organic extracts, a total growth inhibition was noted with the three extracts against T. harzianum, with hexane and methanol fraction against T. viride and with chloroform fraction against FOM. I. crithmoïdes flower extracts caused a highly significant growth inhibition of about 57-100, 66-100, and 100-100% with hexane, chloroform and methanol extracts, respectively. Therefore, I. viscosa, I. graveolens and I. crithmoïdes could be an important source of biologically active compounds useful for developing environmentally safe antifungal products.