scholarly journals Isolation and Identification of Antibacterial and Antifungal Compounds from Praxelis clematidea R. M. King & H. Robinson as an Effective Potential Treatment against Rice Pathogens

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2366
Author(s):  
Cuong C. Nguyen ◽  
Thanh Q. C. Nguyen ◽  
Kenji Kanaori ◽  
Tran Duy Binh ◽  
Le Van Vang ◽  
...  

Bacterial leaf blight and blast diseases caused by the bacterium Xanthomonas oryzae pv. oryzae and the fungus Pyricularia oryzae, respectively, are among the most important infectious diseases affecting rice. We evaluated the antimicrobial effects of compounds derived from Praxelis clematidea on Xanthomonas oryzae and Pyricularia oryzae. The dried aerial parts of Praxelis clematidea were subjected to ethanol extraction, separated by solvent partitioning using hexane, chloroform, ethyl acetate, and water. In vitro assays demonstrated that the main antibacterial and antifungal activities were distributed in the ethyl acetate and chloroform fractions, respectively. These fractions were further separated using silica gel chromatography and reversed-phase chromatography. Finally, we isolated five compounds, 1–5, that inhibited the growth of Xanthomonas oryzae in vitro and four compounds, 6–9, that exhibited in vitro antifungal activity against Pyricularia oryzae. We evaluated their antimicrobial activities and identified their chemical structures by NMR and mass spectrometry analyses. This is the first study to isolate compound 2 (4,4′,4′′-nitrilotriphenol) as an alternative microbial from natural resources and evaluate its physiological activity. Moreover, this is the first report to demonstrate antibacterial activity in comparison with flavonoids. Praxelis clematidea extracts plausibly exert both antibacterial and antifungal effects, which should be further validated in field trials.

2019 ◽  
Vol 57 (1) ◽  
pp. 7
Author(s):  
Duc Long Le ◽  
Huu Tung Nguyen ◽  
Thi Thom Nguyen ◽  
Gyung Ja Choi ◽  
Dinh Hoang Vu ◽  
...  

Abstract-HCTN_16Methanol extract of the roots of Scutellaria baicalensis effectively inhibited the bacterial growth of human pathogenic bacteria Staphylococcus aureus ATCC 6538, Bacillus cereus ATCC 21768 and Bacillus subtilis ATCC 6633 at MICs of 2,000 µg/mL. n-Hexane, ethyl acetate and aqueous residues were prepared by successively partitioning the methanol extract with n-hexane and ethyl acetate. Among them, only ethyl acetate layer showed antibiotic effect; whereas n-hexane and aqueous layers were inactive against tested bacteria. The ethyl acetate residue was fractionated by silica gel column chromatography to afford three flavonoids and an oligosaccharide. Their chemical structures were elucidated as wogonin (SB1), baicalein (SB4), baicalin (SB5) and tetrasaccharide (SB10) on the basis of the analysis of NMR and MS spectroscopic data. The isolates were evaluated for in vitro inhibitory effect against human pathogenic bacteria using micro dilution bioassay method. Baicalein (SB4) showed a broad-spectrum inhibition against various human pathogenic bacteria. In particular, it was found to potently inhibit S. aureus ATCC 6538 and B. cereus ATCC 21768 with MICs of 9.5 and 38 µg/mL, respectively. The study results demonstrated antibiotic effect of the extracts from the roots of S. baicalensis and characterization of compounds isolated from the plant materials.


2020 ◽  
Vol 13 (7) ◽  
pp. 3390-3397
Author(s):  
Regina Kemunto Mayaka ◽  
Alice Wanjiku Njue ◽  
Moses Kiprotich Langat ◽  
Peter Kiplagat Cheplogoi ◽  
Josiah Ouma Omolo

The emergence of antibiotic resistant pathogens has continuously increased, leading to a growing worldwide health threat due to infectious diseases. And therefore in our search for antibacterial and antifungal compounds from the polypore Ganoderma adspersum, the dried, ground fruiting bodies of G. adspersum were extracted with methanol and solvent removed in a rotary evaporator. The extract was suspended in distilled water, then partitioned using ethyl acetate solvent to obtain an ethyl acetate extract. The extract was fractionated and purified using column chromatographic method and further purification on sephadex LH20. The chemical structures were determined on the basis of NMR spectroscopic data from 1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, and NOESY experiments. Antimicrobial activity against clinically important bacterial and fungal strains was assessed and zones of inhibition were recorded. Compound (1), ergosta-7,22-dien-3-one weakly inhibited the growth of Gram positive bacteria Streptococcus pneumonia and a fungus Cryptococcus neoformans. Compounds ergosta-7,22-dien-3-ol (2) and ergosta-5,7,22-trien-3-ol (3) also inhibited gram positive Streptococcus pyogenes bacteria.Keywords: Polypores, steroid compounds, antimicrobial activity.


2014 ◽  
Vol 9 (4) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Elena Cretu ◽  
Juha-Pekka Salminen ◽  
Maarit Karonen ◽  
Anca Miron ◽  
Christiana Charalambous ◽  
...  

A raw extract and four extractive fractions were obtained from Cedrus brevifolia (Cyprus cedar) bark. They were all studied regarding the phenolic content and profile using spectrophotometry and HPLC-DAD-ESI-MS. The antioxidant activity was investigated using in vitro assays: DPPH and ABTS radicals scavenging and reducing power assays. The ethyl acetate fraction had the highest total phenolic and proanthocyanidin contents; a taxifolin-O-hexoside, catechin, epicatechin and procyanidin oligomers (three dimers, two trimers) were identified in this fraction. The ethyl acetate fraction was found to possess the highest DPPH and ABTS radicals scavenging effects (EC50=13.9 ± 0.3 and 2.3 ± 0.0 μg/mL, respectively) and reducing capacity (EC50=9.1 ±0.1 μg/mL). Antioxidant effects were highly correlated with total phenolic and proanthocyanidin contents (r=0.89-0.99). These results suggest that Cedrus brevifolia bark is a new source of antioxidants.


Author(s):  
G. D. Shermatova

Abstract: The leaves and roots of Rumex confertus Willd were tested in vitro for antibacterial and fungal activity in the fractions of gasoline, chloroform, ethyl acetate and butanol. As a result, it was found that the leaves of the Rumex confertus Willd plant, chloroform and ethyl acetate fractions of the root part have antibacterial activity against fungi and gram-positive bacteria. Keywords: Rumex confertus Willd, fractions, extracts, antibacterial, antifungal


2021 ◽  
Author(s):  
Sibonokuhle F. Ncube ◽  
Lyndy J. McGaw ◽  
Emmanuel Mfotie Njoya ◽  
Hilton G.T. Ndagurwa ◽  
Peter J. Mundy ◽  
...  

Abstract Background This study evaluated the in vitro antioxidant activity and comparison of anti-inflammatory and cytotoxic activity of Harpagopytum zeyheri with diclofenac. Methods In vitro assays were conducted using water, ethanol and ethyl acetate extracts of H.zeyheri. The antioxidant activity was evaluated using the 2,2'-diphenyl-1-picrylhydrazy (DPPH) and 2,2'- azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS)assays. The anti-inflammatory activity was determined by measuring the inhibition of nitric oxide (NO) on lipopolysaccharide (LPS)-induced RAW 264.7 mouse macrophages as well as cytokine (TNF-α and IL-10) expression on LPS-induced U937 human macrophages. For cytotoxicity, cell viability was determined using the 3-(4, 5-dimethylthiazol- 2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Results The ethyl acetate extract had the lowest IC50 values in the DPPH (5.91µg/ml) and ABTS (20.5µg/ml) assay compared to other extracts. Furthermore, the ethyl acetate extracts effectively inhibited NO and TNF-α and proved to be comparable to diclofenac at some concentrations. All extracts of H. zeyheri displayed dose dependent activity and were associated with low levels of human-IL-10 expression compared to quercetin. Furthermore, all extracts displayed low toxicity relative to diclofenac. Conclusions These findings show that H. zeyheri has significant antioxidant activity. Additionally, similarities exist in inflammatory activity of H. zeyheri to diclofenac at some concentrations as well as low toxicity in comparison to diclofenac.


2020 ◽  
Vol 9 (1) ◽  
pp. 1-6
Author(s):  
Earnest Oghenesuvwe Erhirhie ◽  
Emmanuel Emeka Ilodigwe ◽  
Daniel Lotanna Ajaghaku ◽  
Blessing Ogechukwu Umeokoli ◽  
Peter Maduabuchi Eze ◽  
...  

Dryopteris filix mas (D filix-mas) is wildly used in ethnomedicine for the management of rheumatoid arthritis, wounds and other diseases. We investigated the anti-oxidant activities of its leaf extract, and chromatographic fractions. The ethanol leaf extract was partitioned into four fractions; n-hexane, ethyl acetate, n-butanol and water. Ferric reducing anti-oxidant power (FRAP), 1, 1-diphenyl-2-picrylhydrazil (DPPH) and nitric oxide (NO) scavenging in vitro assays were carried out on the extract and fractions at 6.25, 12.5, 25, 50, 100, 200, 400 and 800 µg/mL. The most active fraction (ethyl acetate fraction) was further purified using chromatographic techniques to isolate its major compound whose structure was elucidated using ID nuclear magnetic resonance (NMR) and mass spectrometry. The ethyl acetate fraction produced the highest free radical scavenging activity among the other fractions. The fraction (VLC-E7) from which the bioactive compound, quercetin-3-O-αL-rhamnopyranoside, was isolated had the best FRAP and DPPH scavenging activities with EC50 and IC50 values of 88.81 ± 3.41 and 26.87 ± 0.24 respectively more than the ethyl acetate fraction. This study revealed that the polyphenol flavonoid, quercetin-3-O-αL-rhamnopyranoside could be responsible for antioxidant activity of ethno-medicinal property of D filix-mas leaf.


2011 ◽  
Vol 46 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Maurício Batista Fialho ◽  
Maria Heloisa Duarte de Moraes ◽  
Annelise Roberta Tremocoldi ◽  
Sérgio Florentino Pascholati

The objective of this work was to evaluate the potential of an artificial mixture of volatile organic compounds (VOCs), produced by Saccharomyces cerevisiae, to control Sclerotinia sclerotiorum in vitro and in bean seeds. The phytopathogenic fungus was exposed, in polystyrene plates, to an artificial atmosphere containing a mixture of six VOCs formed by alcohols (ethanol, 3-methyl-1-butanol, 2-methyl-1-butanol and phenylethyl alcohol) and esters (ethyl acetate and ethyl octanoate), in the proportions found in the atmosphere naturally produced by yeast. Bean seeds artificially contamined with the pathogen were fumigated with the mixture of VOCs in sealed glass flasks for four and seven days. In the in vitro assays, the compounds 2-methyl-1-butanol and 3-methyl-1-butanol were the most active against S. sclerotiorum, completely inhibiting its mycelial growth at 0.8 µL mL-1, followed by the ethyl acetate, at 1.2 µL mL-1. Bean seeds fumigated with the VOCs at 3.5 µL mL-1 showed a 75% reduction in S. sclerotiorum incidence after four days of fumigation. The VOCs produced by S. cerevisiae have potential to control the pathogen in stored seeds.


Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2521 ◽  
Author(s):  
Larissa Silva ◽  
Jovelina Alves ◽  
Emerson da Silva Siqueira ◽  
Manoel de Souza Neto ◽  
Lucas Abreu ◽  
...  

Genipa americana is a medicinal plant popularly known as “jenipapo”, which occurs in Brazil and belongs to the Rubiaceae family. It is a species widely distributed in the tropical Central and South America, especially in the Cerrado biome. Their leaves and fruits are used as food and popularly in folk medicine to treat anemias, as an antidiarrheal, and anti-syphilitic. Iridoids are the main secondary metabolites described from G. americana, but few studies have been conducted with their leaves. In this study, the aim was to chemical approach for identify the main compounds present at the extract of G. americana leaves. The powdered leaves were extracted by maceration with EtOH: water (70:30, v/v), following liquid-liquid partition with petroleum ether, chloroform, ethyl acetate and n-butanol. A total of 13 compounds were identified. In addition three flavonoids were isolated from the ethyl acetate fraction: quercetin-3-O-robinoside (GAF 1), kaempferol-3-O-robinoside (GAF 2) and isorhamnetin-3-O-robinoside (GAF 3) and, from n-butanol fraction more two flavonoids were isolated, kaempferol-3-O-robinoside-7-O-rhamnoside (robinin) (GAF 4) and isorhamnetin-3-O-robinoside-7-rhamnoside (GAF 5). Chemical structures of these five flavonoids were elucidated using spectroscopic methods (MS, 1H and 13C-NMR 1D and 2D). These flavonoids glycosides were described for the first time in G. americana.


2015 ◽  
Vol 61 (3) ◽  
pp. 93-104
Author(s):  
Basel Saleh ◽  
Lila Al-Halab ◽  
Ayman Al-Mariri

Summary The current study aimed to investigate antimicrobial activity of methanol, ethanol, acetone, ethyl acetate and hot water (leaves and twigs fractions) Psidium guajava L. crude extracts against three bacteria and two fungi pathogens. Antimicrobial activity expressed by disc-diffusion assay (zone of inhibitions - ZIs), activity index (AI) and minimum inhibitory concentration (MICs) that were measured as reported in many investigations. Based upon the estimated ZIs, AI and MICs values, hot water twigs <1 cm diameter extract was the most potent against all tested microorganisms. The MICs value ranged between 4 and 7.2 mg/ml for bacteria, while, it was between 14.5 and 37.3 mg/ml for fungi. Moreover, ethyl acetate had the lowest antimicrobial activity compared to the other tested solvents. From the results obtained herein, it could be concluded that P. guajava serve as antibacterial and antifungal agent.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5820
Author(s):  
Kulsoom Zahara ◽  
Yamin Bibi ◽  
Saadia Masood ◽  
Sobia Nisa ◽  
Abdul Qayyum ◽  
...  

Gui Zhen Cao is an herbal formulation that has been documented in Chinese traditional medicine as a remedy for diarrhea, dysentery, inflammation, and toxicity. The sources of this formulation (Bidens pilosa L., Bidens biternata (Lour.) Merr. & Sherff, Bidens bipinnata L.) are also listed in ethnomedicinal reports all over the world. In this study, all these plants are tested for in vitro anticandida activity. A quantitative evaluation of the phytochemicals in all these plants indicated that their vegetative parts are rich in tannins, saponins, oxalates, cyanogenic glycoside and lipids; moreover, the roots have high percentages of alkaloids, flavonoids, and phenols. The results indicated significant anticandida activity, especially for the hexane extract of B. bipinnata leaves which inhibited C. albicans (42.54%), C. glabrata (46.98%), C. tropicalis (50.89%), C. krusei (40.56%), and C. orthopsilosis (50.24%). The extract was subjected to silica gel chromatography and 220 fractions were obtained. Purification by High Performance Liquid Chromatography with Diode-Array Detection (HPLC–DAD) and Gas Chromatography tandem Mass Spectrometry (GC-MS/MS) analysis led to the identification of two anticandida compounds: dehydroabietic and linoleic acid having an inhibition of 85 and 92%, respectively.


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