Antimycotic, antibiodeteriorative and antiaflatoxigenic potency of 2-​hydroxy-​4-​methoxybenzaldehyde isolated from Decalepis hamiltonii on fungi causing biodeterioration of maize and sorghum grains

We characterized the antimycotic, antibiodeteriorative and antiaflatoxigenic efficacy of the compd., 2-​hydroxy-​4-​methoxybenzaldehyde isolated from Decalepis hamiltonii Wight & Arn, against different species of fungi that cause biodeterioration of corn (Zea mays L.) and sorghum (Sorghum bicolor L.) grains during storage. Fungal species that cause biodeterioration were isolated from corn and sorghum grains by agar plating method and std. blotter method (SBM)​. Poisoned food technique was adopted to assess fungitoxicity of the compd. against fungal isolates. For different fungal species, the inhibitory concn. (IC50)​, minimal inhibitory concn. (MIC) and minimal fungicidal concn. (MFC) of 2-​hydroxy-​4-​methoxybenzaldehyde varied between 80 to 350μg​/mL, 350 to 800μg​/mL and 450 to 850μg​/mL, resp. Among the 14 fungal species tested, Aspergillus niger, A. columnaris and A. tamari were completely inhibited at higher concns., while Fusarium oxysporum, F. proliferatum, Drechslera tetramera and Aspergillus ochraceus were completely inhibited at low concns. The inhibitory effect of the compd. was of broad-​spectrum in activity and was concn.-​dependent. Comparative evaluation of the active compd. with the synthetic fungicides, Blitox and Thiram, at recommended dosages revealed that the antimycotic activity of 2-​hydroxy-​4-​methoxybenzaldehyde was superior than that of synthetic fungicides. In vivo evaluation of the compd., 2-​hydroxy-​4-​methoxybenzaldehyde at 0.5 g​/kg as seed treatment on corn and sorghum revealed that carbohydrates, water sol. proteins, lipids, aflatoxin B1 prodn. and dry matter losses (DML) were significantly conserved in treated compared with control untreated grains up to 120 days storage. D. hamiltonii being an edible plant can be exploited in the management of seed-​borne pathogenic fungi and in the prevention of biodeterioration of grains and mycotoxin prodn. during storage in an eco-​friendly way

Antifungal activity of 2-hydroxy-4-methoxybenzaldehyde isolated from decalepis hamiltonii (Wight & Arn.) on seed-borne fungi causing biodeterioration of paddy

In vitro antifungal activity assay of different concentrations of 2-hydroxy-4-methoxybenzaldehyde isolated from Decalepis hamiltonii against six important seed-borne fungal pathogens viz., Alternaria alternata, Drechslera tetramera, Fusarium oxysporum, F. proliferatum, Pyricularia oryzae and Trichoconis padwickii isolated from paddy seeds revealed that, the compound 2-hydroxy-4-methoxybenzaldehyde showed significant antifungal activity. Among the fungi tested, F. proliferatum showed highest inhibitory activity, whereas P. oryzae showed least inhibitory activity. The minimal inhibitory concentration (MIC) varied between 350 μg/ml and 650 μg/ml depending on the fungal species. Comparative evaluation of the active compound with the synthetic fungicide thiram at recommended dosage revealed that, the antifungal activity of the active compound obtained from the plant was almost equivalent. Evaluation for nutritional parameters and dry matter losses (DML) revealed that, total carbohydrates, water soluble proteins, lipids and dry matter losses were significantly confined in 2-hydroxy-4-methoxybenzaldehyde treated paddy seeds compared with control seeds. This plant being an edible one can be exploited in the management of seed-borne pathogenic fungi and in the prevention of biodeterioration of grains and mycotoxin production during storage in an eco-friendly way

Antibacterial Activity of Alkaloid Extracts and Active Constituents of some Selected Plants against Xanthomonas campestris

The present investigation evaluates the antibacterial activity of alkaloid extracts of Acacia catechu, A. ferruginea, Adenanthera pavonina, Albizia amara, A. saman, Breynia vitis-idaea, Senna spectabilis and Solanum indicum, and bioactive compounds budmunchiamine-A isolated from A. amara and pithecolobine from A. saman against an important phytopathogen Xanthomonas campestris. The results revealed that alkaloid extracts of all plants showed significant antibacterial activity with zone of inhibition (ZOI), minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) ranged from 9.1 to 12.5 mm, 31.25 to 500 µg/ml and 125 to 2000 µg/ml, respectively. The active compounds isolated from alkaloid extract of A. amara and A. saman have been identified as budmunchiamine-A and pithecolobine, respectively. The active compounds budmunchiamine-A and pithecolobine showed concentration-dependent anti-X. campestris activity with ZOI, MIC and MBC ranged from 12.6 to 20.3 mm, 15.6 to 31.2 µg/ml and 62.5 to 125 µg/ml, respectively. The results revealed that alkaloid extracts of these plants as well as budmunchiamine-A and pithecolobine could be used as an alternative strategy for the management of diseases caused by Xanthomonas spp

Inhibitory Activity of Plant Extracts on Aflatoxin B1 Biosynthesis by Aspergillus flavus

The inhibitory activities of aqueous and solvent extracts of twelve selected medicinal plants were evaluated against biosynthesis of aflatoxin B1 (AFB1) by Aspergillus flavus. The A. flavus was isolated from maize, and aflatoxin B1 biosynthesis was confirmed by comparison with standard AFB1 using TLC method. In vivo antiaflatoxigenic efficacies of activity guided solvent extracts were determined in maize model system. All the extracts showed varying degree of antifungal and AFB1 inhibitory activities, but chloroformic extract of Albizia amara, Cassia spectabilis and Solanum indicum, and methanolic extract of Acacia catechu, Albizia saman andAnogeissus latifolia showed the highest activity. Further investigations on identification of active principles from these plants are needed to develop plant based formulations for management of A. flavus growth and AFB1 contamination in food grains

Inhibitory effect of alkaloids of Albizia amara and Albizia saman on growth and fumonisin B1 production by Fusarium verticillioides

The investigation was aimed to evaluate the antifungal and antifumonisin activities of budmunchiamine A and pithecolobine against Fusarium verticillioides. The budmunchiamine A was isolated from Albizia amara and pithecolobine from Albizia saman. The results demonstrated that both budmunchiamine A and pithecolobine significantly inhibited the growth and fumonisin B1 production by F. verticillioides in a dose dependent manner. The MIC and MFC values ranged from 0.125 to 0.25 mg/ml and 0.25 to 0.5 mg/ml, respectively. In vitro evaluation showed that the fumonisin B1 production was completely inhibited by budmunchiamine A and pithecolobine at 0.25 mg/ml and 0.5 mg/ml, while in vivo evaluation showed complete inhibition at 0.25 g/kg and 0.5 g/kg, respectively. The present findings indicate the possible use of budmunchiamine A and pithecolobine as alternative agents to control the fungal and mycotoxin contaminations in food grains

Antimicrobial efficacy and phytochemical analysis of Albizia amara (Roxb.) Boiv. an indigenous medicinal plant against some human and plant pathogenic bacteria and fungi

The present investigation evaluates the antimicrobial activity of six different solvent exts. and isolated constituents of leaves of Albizia amara against a total of 21 microorganisms which consisted of seven human pathogenic bacteria, a phytopathogenic Xanthomonas campestris (NCIM 2954) and thirteen seed-​borne phytopathogenic fungi. Our result showed that, among the six solvent exts. tested, the chloroform ext. showed a higher antibacterial and antifungal activity followed by methanol, ethanol and hydro-​methanolic exts. resp. The chloroform, methanol and ethanol exts. exhibited antibacterial activity with zone of inhibition ranging from 5.25 to 23.75, 6.25 to 23.25 and 7.25 to 22.7 mm resp. at 1mg​/mL concn. The minimal inhibitory concn. (MIC) of the chloroform ext. ranged from 15μg​/mL to 500μg​/mL depending upon bacterial species. The most susceptible organism in the present investigation was Streptococcus faecalis (NCIM 5025)​, while the most resistant was Proteus vulgaris (NCIM 2027)​. Highest antifungal activity was obsd. in chloroform ext. followed by methanol ext. with percent of inhibition ranging from 30​% to 77.4​% and 17.4​% to 71.7​% resp. The IC50 value of chloroform ext. ranged from 0.5mg​/mL to 5.0mg​/mL depending upon fungal species. Among the tested fungi, Fusarium lateratum was highly sensitive and Aspergillus flavus was least sensitive. Chloroform ext. was subsequently fractionated and monitored for antibacterial activity guided assay leading to the isolation of active fraction and was confirmed as alkaloid by further phytochem. anal. The present study thus confirms antimicrobial property of A. amara and also demonstrated the role of A. amara used in traditional medicine

Antifungal and Antimycotoxigenic Potency of Solanum torvum Swartz. Leaf Extract: Isolation and Identification of Compound Active against Mycotoxigenic Strains of Aspergillus flavus and Fusarium verticillioides

Aims The main objective of this study was to investigate the antifungal effect of Solanum torvum leaves against different field and storage fungi, and to identify its active compound. In addition, to evaluate in vitro and in vivo inhibitory efficacy on toxigenic strains of Aspergillus flavus and Fusarium verticillioides. Methods and Results Leaves of S. torvum were sequentially extracted with petroleum ether, toluene, chloroform, methanol and ethanol. The antifungal compound isolated from chloroform extract was identified as torvoside K based on spectral analysis. The antifungal activity of chloroform extract and torvoside K was determined by broth microdilution and poisoned food techniques. The minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC) and zone of inhibition (ZOI) were recorded. Further, inhibitory effects of chloroform extract and torvoside K on growth of A. flavus and F. verticillioides, and their toxin productions were evaluated using in vitro and in vivo assays. Torvoside K showed the significant activity against tested fungi with ZOIs and MICs ranging from 33·4 to 87·4% and 31·25–250 μg ml-1, respectively. Further, torvoside K showed concentration-dependent antimycotoxigenic activity against aflatoxin B1 and fumonisin B1 production by A. flavus and F. verticillioides, respectively. Conclusions It was observed that the compound torvoside K significantly inhibited the growth of all fungi tested. Growth of A. flavus and F. verticillioides, and aflatoxin B1 and fumonisin B1 productions were completely inhibited in vitro and in vivo by torvoside K with increasing concentration. Significance and Impact of the Study Control of mycotoxigenic fungi requires compounds that able to inhibit both fungal growth and mycotoxin production. The antimycotoxigenic potential of torvoside K of S. torvum is described in this study for the first time. The results indicate the possible use of S. torvum as source of antifungal agents against postharvest fungal infestation of food commodities and mycotoxin contaminations

Evaluation of Phyllanthus polyphyllus L. Extract and its Active Constituent as a Source of Antifungal, Anti-​Aflatoxigenic, and Antioxidant Activities

The present investigation was carried out to evaluate the antifungal activities of Phyllanthus polyphyllus L. leaf ext., to isolate its active constituent 4-​o-​Me gallic acid (4-​o-​MGA)​, and to det. the antioxidant and antiaflatoxigenic properties. The bioassay-​guided fractionation of methanol ext. led to the isolation of active compd. 4-​o-​methylgallic acid. The methanol ext. showed the highest amt. of phenolic content (290 mg GAE​/g dry ext.)​, which indicated the involvement of phenolic compds. in the radical scavenging activity obsd. by the methanol ext. The antioxidant capacity of 4-​o-​MGA was greater than the std. butylated hydroxytoluene, followed by methanol ext. The concn.-​dependent growth inhibitory activity was obsd. against the tested fungi, in which the field fungi were susceptible, while the storage fungi were found to be more resistant including aflatoxigenic A. flavus. A correlation was obsd. between fungal biomass and aflatoxin prodn. in control and treatment, there was a decrease in biomass of A. flavus and aflatoxin prodn. with increasing concn. The aflatoxin prodn. was completely inhibited in vitro by methanol ext. at 1 mg​/mL and 4-​o-​MGA at 2 mg​/mL, but the mycelial growth was not inhibited completely. The inhibition of aflatoxin prodn. was relatively higher than the mycelial growth inhibition of A. flavus, such behaviors might have been detd. by the presence of hydrolysable tannin 4-​o-​MGA in the ext., which is known to inhibit the aflatoxin biosynthesis. The significant antioxidant and aflatoxin inhibitory activities of P. polyphyllus could be exploited for its application in preventing oxidative deterioration and fungal spoilage of food products

Evaluation of antimicrobial and antioxidant properties of pithecolobine isolated from Albizia saman

Pithecolobine isolated from alkaloid extract of Albizia saman showed antimicrobial activity against seven human pathogenic bacteria and two yeasts with minimum inhibitory concentrations (MIC) values of 1.9-125 g mL-1. In addition, it also exhibited antioxidant activity with IC50 value at 250g mL-1. Pithecolobine may be useful as a natural bioactive molecule for developing potent antimicrobial and antioxidant agents. © 2015 Taylor and Francis Group, LLC

Studies on seed-borne mycoflora and aflatoxin B1 contaminations in food based seed samples: Molecular detection of mycotoxigenic Aspergillus flavus and their management.

In the present study the mould incidence, ergosterol and aflatoxin B1 (AFB1) contaminations were evaluated in different food based seed samples viz., chickpea, cowpea, green gram, groundnut, Indian bean, maize, sorghum, soya bean and sunflower collected from different agro-climatic regions of Karnataka (India). The agar plate and standard blotter methods were employed for determination of the fungal incidence, and the ergosterol and AFB1 contents were estimated qualitatively and quantitatively by TLC and spectrophotometric methods. For detection of aflatoxigenic isolates of A. flavus, the target gene specific primer aflR-F and aflR-R were used in PCR amplification. The antifungal and antiaflatoxigenic activities of some selected edible vegetable extracts were evaluated by measuring mycelial dry weight and AFB1 content. The results revealed that 15 diverse fungal species belonging to 11 genera were observed. Among the seed samples analyzed, the highest fungal incidence, ergosterol and AFB1 were observed in sorghum samples followed by maize and chickpea. The PCR amplification showed positive results only for aflatoxigenic isolates of A. flavus and no amplification was observed in nonaflatoxigenic isolates and A. flavus isolate-2 produced highest AFB1, showed 99 similarity with an authenticated aflatoxigenic A. flavus isolate emb|FN398161.1|. The aqueous extract of Amorphophallus campanulatus showed highest antifungal and antiaflatoxigenic activities. The results confirmed that the ergosterol and AFB1 contents were correlated with the percent mould incidences. © All Rights Reserved