Devihalli Chikkaiah Mohana

Antioxidant, antibacterial, and ultraviolet-protective properties of carotenoids isolated from Micrococcus spp.

Carotenoids are the most common naturally occurring bioactive terpenoid pigments, which are commonly produced by a wide variety of plants and microbes. The present study was aimed to evaluate the antioxidant, antimicrobial and radio-protective properties of carotenoid pigments isolated from ultraviolet (UV)-C resistant Micrococcus spp. The UV-C resistant Micrococcus roseus and Micrococcus luteus were isolated from the soil samples of Savandurga hills region, Karnataka (India), and their pigments were identified as carotenoids based on spectral analysis. The UV-protective efficacies were determined by cling-film assay. Further, the antioxidant activities of pigments were evaluated by 2,2-diphenyl-1-picrylhydrazyl assay, and antibacterial activities by disc diffusion and broth microdilution assays. The optimum growth and pigment production by M. roseus and M. luteus were observed at temperature ranged between 35°C and 37°C, pH 7.0-8.0, NaCl 5.0-7.0%, and sucrose as major carbon and KNO 3 as major nitrogen sources. In the present investigation, the isolated carotenoid pigments of M. roseus and M. luteus showed significant UV protective activity along with antioxidant (IC 50 3.5-4.5 mg/mL) and antibacterial (minimal inhibitory concentration 0.25-2.0 mg/mL) properties.

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 extract, to isolate its active constituent 4-o-methyl gallic acid (4-o-MGA), and to determine the antioxidant and antiaflatoxigenic properties. The bioassay-guided fractionation of methanol extract led to the isolation of active compound 4-o-methylgallic acid. The methanol extract showed the highest amount of phenolic content (290 mg GAE/g dry extract), which indicated the involvement of phenolic compounds in the radical scavenging activity observed by the methanol extract. The antioxidant capacity of 4-o-MGA was greater than the standard butylated hydroxytoluene, followed by methanol extract. The concentration-dependent growth inhibitory activity was observed 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 observed between fungal biomass and aflatoxin production in control and treatment, there was a decrease in biomass of A. flavus and aflatoxin production with increasing concentration. The aflatoxin production was completely inhibited in vitro by methanol extract at 1 mg/mL and 4-o-MGA at 2 mg/mL, but the mycelial growth was not inhibited completely. The inhibition of aflatoxin production was relatively higher than the mycelial growth inhibition of A. flavus, such behaviors might have been determined by the presence of hydrolysable tannin 4-o-MGA in the extract, 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.

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

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.

Evaluation of some pharmacological activities of Budmunchiamine - A isolated from Albizia amara

The present investigations were aimed to evaluate the antimicrobial and antioxidant efficacies of budmunchiamine-A (BUA) of Albizia amara . The activity-guided isolation leaded to isolate the bioactive compound budmunchiamine-A from alkaloid extract of A. amara . The budmunchiamine-A showed significant broad-spectrum antimicrobial activity with zone of inhibition (ZOI), minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) values varied from 7.3 to 24.5 mm, 0.95 to 62.5 μg/mL, and 1.9 to 250 μg/mL, respectively. The budmunchiamine-A exhibited moderate antioxidant activity with inhibitory concentration 50% (IC 50 ) value of 400 μg/mL in 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and percent inhibition of β-carotene/linoleic acid was 67.8%. The results suggest the possible use of budmunchiamine-A as a molecular entity for drug development in pharmaceutical industry.

Antifungal and Antifumonisin Activities of Chemically Characterized Essential Oil of Artabotrys odoratissimus

ABSTRACT The antifungal and antifumonisin activities of Artabotrys odoratissimus essential oil (AOEO) were evaluated. The GC-MS analysis of AOEO confirmed the presence of 14 phytoconstituents, among which, 3-carene (44.91%), β-caryophyllene (19.17%), α-humulene (8.78%), α-copaene (6.59%) and caryophyllene oxide (5.55%) were recorded as major phytoconstituents. The AOEO showed promising antifungal activity against 15 field and storage fungi with percent mycelial growth inhibition, minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) ranging between 11.45 and 42.53% at 1 µL mL–1, 0.078 and 1.25 µL mL–1 and 2.5 to >10.0 µL mL–1, respectively. The fumonisin B1 (FB1) and ergosterol productions were completely inhibited by AOEO at 8 µL mL–1. The results revealed that AOEO could be explored for management of mold and mycotoxin contaminations in food and animal feed.

Isolation and utilization of Dictyosphaerium ehrenbergianum Nageli for biodiesel production: lipid extraction and biodiesel property analysis

ABSTRACT The present investigation evaluates the lipid production, fatty acid profile and biodiesel properties of Dictyosphaerium ehrenbergianum. The extracted lipids were estimated quantitatively using the gravimetric method and qualitatively using fluorescence microscopy and fluoro-spectrophotometric analysis. Among the 14 microalgal isolates, the highest lipid content was observed in isolate five, which was identified as D. ehrenbergianum using 18S rDNA sequence analysis and morphological study. A total of 10 fatty acids were identified from the transesterified lipid of D. ehrenbergianum using gas chromatography mass spectroscopy analysis, among which oleic acid, palmitic acid and linoleic acid were recorded as major fatty acids. The optimum lipid production from D. ehrenbergianum was observed at pH 8.0, a temperature of 28.0 ± 2°C, NaCl concentration of 0.2 mg l–1, sucrose as carbon source and NH4NO3 as a nitrogen source. The transesterified lipid of D. ehrenbergianum showed kinematic viscosity 3.56 cSt at 40°C, flash point was 103°C, density at 15°C was 0.86 kg m–3, and ash content was 0.017% with no acid number. The percentage of biodiesel was found to be 54.05%. The obtained results confirm that the lipid extracted from D. ehrenbergianum could be used as an alternative source for biodiesel production.

Antifungal and antimycotoxigenic properties of chemically characterised essential oil of Boswellia serrata Roxb. ex Colebr.

ABSTRACT In the present investigation, the antifungal and antimycotoxigenic activities of Boswellia serrata essential oil were evaluated in vitro and in viable maize. The GC-MS analysis of B. serrata essential oil showed a total of 29 constituents, among which, 3-carene (34.74%), β-ocimene (13.78%), D-limonene (8.25%), β-caryophyllene (6.65%) and terpinolene (5.39%) recorded the highest percentage. The B. serrata essential oil showed promising antifungal activity against 15 different field and storage fungi with percentage of mycelial inhibition ranged between 15.9–56.3% at 1µL mL˗1. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values were ranged between 0.039–0.625 µL mL˗1 and 2.5–>10.0 µL mL˗1, respectively, against the same fungi tested. The production of aflatoxin B1 and fumonisin B1 were completely inhibited by B. serrata essential oil at 6 µL mL˗1in vitro. The ergosterol content was drastically decreased with the increasing concentration of B. serrata essential oil in vitro. Viable maize model confirmed that aflatoxin B1 and fumonisin B1 contents were significantly inhibited with increasing seedling vigour of maize. The results revealed that B. serrata essential oil could be explored for management of mould and mycotoxin contaminations in food grains and feedstuffs.

Evaluation of Antimicrobial and Antioxidant Properties of Pithecolobine Isolated fromAlbizia 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 μg mL−1. In addition, it also exhibited antioxidant activity with IC50 value at 250μg mL−1. Pithecolobine may be useful as a natural bioactive molecule for developing potent antimicrobial and antioxidant agents.

Antifumonisin Efficacy of 2-Hydroxy-4-Methoxybenzaldehyde Isolated from Decalepis hamiltonii

Fumonisins are mycotoxins primarily produced by Fusarium verticillioides that grow on food and feedstuffs. In the present investigation, the antifumonisin activity of 2-hydroxy-4-methoxybenzaldehyde isolated from Decalepis hamiltonii was evaluated. The results demonstrated that the compound 2-hydroxy-4-methoxybenzaldehyde exhibited dose-dependent antifungal activity with the zone of inhibition, minimum inhibitory concentration and minimum fungicidal concentration values 14.8 mm (at 500 μg/disc), 100 and 500 μg/mL, respectively. The fumonisin B1 production was completely inhibited at 400 mg/L under in vitro and 750 mg/kg under in vivo. There were no adverse effects observed in treated seed samples. The present findings indicate the possible use of 2-hydroxy-4-methoxybenzaldehyde as an alternative agent for management of fusarial growth and mycotoxins contamination.