Yogesh B. Pakade

Development of biodegradable nanoparticles for delivery of quercetin.

The antioxidant molecule quercetin has been encapsulated on poly-D,L-lactide (PLA) nanoparticles by solvent evaporation method for the improvement of its poor aqueous solubility and stability. The surface morphology and average size of PLA and quercetin loaded PLA nanoparticles are 170+/-25 and 130+/-30 nm respectively. The antioxidant activities of the PLA encapsulated quercetin nanomedicine are identical to free quercetin. The nanoencapsulation efficiency of quercetin evaluated by HPLC and antioxidant assay is 96.7%. The in vitro release kinetics under physiological condition show initial burst release followed by slow and sustained release. The complete release and maximum retention of quercetin is 72 and 96h respectively. The less fluorescence quenching efficiency of quercetin-PLA nanoparticles than free quercetin on BSA confirms the controlled release of quercetin from PLA nanoparticles. These properties of PLA encapsulated quercetin molecule pave way for encapsulating various therapeutically less useful highly active antioxidant molecules towards the development of better therapeutic compounds.

Analytical methods for estimation of organophosphorus pesticide residues in fruits and vegetables: a review.

Use of pesticides has turned out to be an obligatory input to agriculture and public health. Versatile use of pesticides had resulted in contamination of all basic necessities of life, i.e. air, water and food. Among various pesticides, organophosphorus pesticides (OPPs), derivative of phosphoric acid, are the most extensively used insecticides or acaricides in many crops. Due to low persistency and high killing efficiency of OPPs, many agriculturalists regularly use this group of pesticides for various vegetables and fruits crops. The continuous use of pesticides has caused the deleterious effects to ecosystem. In response to this, a number of methods have been developed by several regulatory agencies and private laboratories and are applied routinely for the quantification and monitoring of multi pesticide residues in vegetables and crops. The present review pertains to various extraction and quantification procedures used world wide to analyze OPPs residues in various vegetables and fruits.

Nanoencapsulation and characterization of Albizia chinensis isolated antioxidant quercitrin on PLA nanoparticles

The plant isolated antioxidant quercitrin has been encapsulated on poly-d,l-lactide (PLA) nanoparticles by solvent evaporation method to improve the solubility, permeability and stability of this molecule. The size of quercitrin-PLA nanoparticles is 250±68nm whereas that PLA nanoparticles is 195 ± 55nm. The encapsulation efficiency of nanoencapsulated quercitrin evaluated by HPLC and antioxidant assay is 40%. The in vitro release kinetics of quercitrin under physiological condition reveals initial burst release followed by sustained release. Less fluorescence quenching is observed with equimolar concentration of PLA encapsulated quercitrin than free quercitrin. The presence of quercitrin specific peaks on FTIR of five times washed quercitrin loaded PLA nanoparticles provides an extra evidence for the encapsulation of quercitrin into PLA nanoparticles. These properties of quercitrin nanomedicine provide a new potential for the use of such less useful highly active antioxidant molecule towards the development of better therapeutic for intestinal anti-inflammatory effect and nutraceutical compounds.

Development and applications of single-drop microextraction for pesticide residue analysis: A review.

Single-drop microextraction (SDME) has become more popular than other microextraction techniques because it is simple, cost-effective, easy to operate and nearly solvent-free. The technique has been employed successfully for trace analysis in environmental, biomedical and food applications. In view of the increasingly stringent regulatory limits for many pesticides, which are below the LOD of the existing instruments, SDME may provide a cost-effective solution for reducing the LOD of pesticides. The present review focuses on recent development in SDME technique, and its application coupled with various analytical techniques, such as GC-MS, GC and HPLC for pesticide residue analysis in different matrices. The advantages, limitations and outlook on the future of SDME technique for its wider applications are also discussed.

Analytical techniques for estimation of heavy metals in soil ecosystem: A tabulated review

Soil, an important environmental medium, is exposed to a number of pollutants including toxic heavy metals by various natural and anthropogenic activities. Consequently heavy metal contaminated soil has the potential to pose severe health risks and hazards to humans as well as other living creatures of the ecosystem through various routes of exposure such as direct ingestion, contaminated drinking ground water, food crops, contact with contaminated soil and through food chain. Therefore, it is mandatory to explore various techniques that could efficiently determine the occurrence of heavy metals in soil. A number of methods have been developed by several regulatory agencies and private laboratories and are applied routinely for the quantification and monitoring of soil matrices. The present review is an initiative to summarize the work on pollution levels of soil ecosystem and thus pertains to various extraction and quantification procedures used worldwide to analyze heavy metals in soil.

Removal of Pb from Water by Adsorption on Apple Pomace: Equilibrium, Kinetics, and Thermodynamics Studies

The adsorption-influencing factors such as pH, dose, and time were optimized by batch adsorption study. A 0.8 g dose, 4.0 pH, and 80 min of contact time were optimized for maximum adsorption of Pb on AP. The adsorption isotherms (Langmuir and Freundlich) were well fitted to the data obtained with values of (16.39 mg/g; ) and (16.14 mg/g; ), respectively. The kinetics study showed that lead adsorption follows the pseudo-second-order kinetics with correlation coefficient () of 0.999 for all of the concentration range. FTIR spectra also showed that the major functional groups like polyphenols (–OH) and carbonyl (–CO) were responsible for Pb binding on AP. The thermodynamic parameters as , (33.54 J/mol), and (1.08 J/mol/K) were also studied and indicate that the reaction is feasible, endothermic, and spontaneous in nature.

Assessment of Bioaccumulation of Heavy Metal by Pteris Vittata L. Growing in the Vicinity of Fly Ash

Pteris vittata L. subsp. vittata, a potential arsenic hyperaccumulator fern, growing naturally in the vicinity of fly ash was analyzed for the concentration of nine heavy metals (Fe, Cu, Zn Ni, Al, Cr, Pb, Si, and As) from five different sites around of Kanti Thermal Power Station at Muzaffarpur in Bihar State, India. Metal accumulation in P. vittata was correlated with the level of pollution at five selected sampling sites. The results revealed significantly more accumulation of these metals in the above ground parts of the plant than the parts below ground. Statistical parameters such as the coefficient of variation (CV%) showed a higher for As, Cu, Cr, and a lower one for Fe, Ni, Al. There was high spatial variability in the total metal concentration at different sites. The present study confirmed that P. vittata is a heavy metals accumulator and that it is a highly suitable candidate for phytoremediation of metal contaminated wastelands.

Screening of bioconstituents and in vitro cytotoxicity of Clematis gouriana leaves

Clematis gouriana (Ranunculaceae), a perennial herb, is used by the local inhabitants of the western Himalayan region for its medicinal properties. Major bioconstituents of C. gouriana leaves using different solvent extracts were obtained and analysed. The results revealed promising contents of phenolics (from 18.19 ± 0.10 to 22.17 ± 0.10 mg g− 1) as gallic acid and flavonoids (from 2.83 ± 0.01 to 6.52 ± 0.08 mg g− 1) as quercetin equivalent in different extracts. Aqueous acetone extract showed higher antioxidant activity with IC50 value of 129.11 and 25.35 μg mL− 1 against DPPH and ABTS free radicals, respectively. Antioxidant yield ranged from 16.87 ± 0.27 to 24.48 ± 0.13 mg g− 1 of Trolox equivalent in different extracts as measured by the FRAP assay. Furthermore, ethylacetate extract exhibited strong in vitro cytotoxicity against Chinese hamster ovary and glioma cell lines. Proximate composition (proteins, fats, ash and minerals) of C. gouriana leaves was also assessed. Results demonstrated the potential of C. gouriana bioconstituents as nutraceuticals.

Analytical Method for Determination of Organochlorine Pesticides in Tea Brews using Single-Drop Microextraction with GC-ECD

The single drop microextraction method was developed for the determination of ten organochlorine pesticides in tea brews using gas chromatograph-electron capture detector. The optimized parameters for effective extraction required a 2 μL drop of n-hexane at the tip of a microsyringe immersed in 5 mL of a diluted tea brew sample for 25 min and stirred at 600 rpm. The limit of detection in the range of 0.01 to 0.025 μg/L, with relative standard deviation of repeatability and reproducibility, was in the range of 1–10 and 8–24%. The relationship of the measured signal was a linear function (>0.9863) of concentration and the recovery method ranged from 92–116%. The single drop microextraction method showed the advantage of being easy to operate, low consumption of organic solvent, and high extraction efficiency.