Gaanty Pragas Maniam

Biodiesel production via transesterification of palm olein using waste mud crab (Scylla serrata) shell as a heterogeneous catalyst.

A recent rise in crab aquaculture activities has intensified the generation of waste shells. In the present study, the waste shells were utilized as a source of calcium oxide to transesterify palm olein into methyl esters (biodiesel). Characterization results revealed that the main component of the shell is calcium carbonate which transformed into calcium oxide when activated above 700 degrees C for 2 h. Parametric studies have been investigated and optimal conditions were found to be methanol/oil mass ratio, 0.5:1; catalyst amount, 5 wt.%; reaction temperature, 65 degrees C; and a stirring rate of 500 rpm. The waste catalyst performs equally well as laboratory CaO, thus creating another low-cost catalyst source for producing biodiesel. Reusability results confirmed that the prepared catalyst is able to be reemployed up to 11 times. Statistical analysis has been performed using a Central Composite Design to evaluate the contribution and performance of the parameters on biodiesel purity.

Biosynthesis of metallic nanoparticles using plant derivatives and their new avenues in pharmacological applications – An updated report

The field of nanotechnology mainly encompasses with biology, physics, chemistry and material sciences and it develops novel therapeutic nanosized materials for biomedical and pharmaceutical applications. The biological syntheses of nanoparticles are being carried out by different macro–microscopic organisms such as plant, bacteria, fungi, seaweeds and microalgae. The biosynthesized nanomaterials have been effectively controlling the various endemic diseases with less adverse effect. Plant contains abundant natural compounds such as alkaloids, flavonoids, saponins, steroids, tannins and other nutritional compounds. These natural products are derived from various parts of plant such as leaves, stems, roots shoots, flowers, barks, and seeds. Recently, many studies have proved that the plant extracts act as a potential precursor for the synthesis of nanomaterial in non-hazardous ways. Since the plant extract contains various secondary metabolites, it acts as reducing and stabilizing agents for the bioreduction reaction to synthesized novel metallic nanoparticles. The non-biological methods (chemical and physical) are used in the synthesis of nanoparticles, which has a serious hazardous and high toxicity for living organisms. In addition, the biological synthesis of metallic nanoparticles is inexpensive, single step and eco-friendly methods. The plants are used successfully in the synthesis of various greener nanoparticles such as cobalt, copper, silver, gold, palladium, platinum, zinc oxide and magnetite. Also, the plant mediated nanoparticles are potential remedy for various diseases such as malaria, cancer, HIV, hepatitis and other acute diseases.

Nutraceuticals as potential therapeutic agents for colon cancer: a review

Colon cancer is a world-wide health problem and the second-most dangerous type of cancer, affecting both men and women. The modern diet and lifestyles, with high meat consumption and excessive alcohol use, along with limited physical activity has led to an increasing mortality rate for colon cancer worldwide. As a result, there is a need to develop novel and environmentally benign drug therapies for colon cancer. Currently, nutraceuticals play an increasingly important role in the treatment of various chronic diseases such as colon cancer, diabetes and Alzheimer׳s disease. Nutraceuticals are derived from various natural sources such as medicinal plants, marine organisms, vegetables and fruits. Nutraceuticals have shown the potential to reduce the risk of colon cancer and slow its progression. These dietary substances target different molecular aspects of colon cancer development. Accordingly, this review briefly discusses the medicinal importance of nutraceuticals and their ability to reduce the risk of colorectal carcinogenesis.

An accelerated route of glycerol carbonate formation from glycerol using waste boiler ash as catalyst

Waste boiler ash was successfully utilised as catalyst for the direct synthesis of glycerol carbonate from glycerol and urea. A series of catalysts were prepared using various calcination temperatures. The physico-chemical properties of the catalysts have been investigated by using XRD, BET, TGA, FESEM-EDX, ICP-MS, Hammett test and CO2-TPD. From the study it was found that boiler ash had significant catalytic activity towards conversion of glycerol into glycerol carbonate. It is believed that the potassium metal ion which detaches from potassium silicate had a major impact on the catalytic data where the potassium ion being a weak Lewis acid causes selective catalytic transformation of glycerol into glycerol carbonate. The mechanistic pathway through glycerol carbamate intermediate was confirmed through time online analysis study using 13C-NMR and ATR-FTIR, respectively. However, the selective transformation of glycerol carbamate into glycerol carbonate is reported to be different where it is formed in an accelerated manner. The highest catalytic activity resulted in an average percentage of 93.6 ± 0.4% glycerol conversion, 90.1 ± 1.0% glycerol carbonate selectivity and 84.3 ± 1.1% glycerol carbonate yield. Besides, for the first time the novel idea of using waste material, specifically boiler ash, is proposed as a catalyst for synthesis of glycerol carbonate from glycerol and urea. The current research employed suggests an alternative route for proper disposal of waste boiler ash.

Intracellular biosynthesis of Au and Ag nanoparticles using ethanolic extract of Brassica oleracea L. and studies on their physicochemical and biological properties

In this present study, we reported broccoli (Brassica oleracea L.) as a potential candidate for the synthesis of gold and silver nanoparticles (NPs) in green chemistry method. The synthesized metal nanoparticles are evaluated their antimicrobial efficacy against different human pathogenic organisms. The physico-chemical properties of gold nanoparticles were analyzed using different analytical techniques such as a UV-Vis spectrophotometer, Field Emission Scanning Electron Microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and a Fourier Transform Infrared spectrophotometer. In addition, gold and silver NP antimicrobial efficacy was checked by disc diffusion assay. UV-Vis color intensity of the nanoparticles was shown at 540 and 450 nm for gold and silver nanoparticles respectively. Higher magnification of the Field Emission Scanning Electron Microscopy image shows the variable morphology of the gold nanoparticles such as spherical, rod and triangular shapes and silver nanoparticles were seen in spherical shapes. The average spherical size of the particles was observed in 24-38 nm for gold and 30-45 nm for silver NPs. X-ray diffraction pattern confirmed the presence of gold nanoparticles and silver nanoparticles which were crystalline in nature. Additionally, the functional metabolites were identified by the Fourier Transform Infrared spectroscopy. IR spectra revealed phenols, alcohols, aldehydes (sugar moieties), vitamins and proteins are present in the broccoli extract which are accountable to synthesize the nanoparticles. The synthesized gold and silver NPs inhibited the growth of the tested bacterial and fungal pathogens at the concentration of 50 μg/mL respectively. In addition, broccoli mediated gold and silver nanoparticles have shown potent antimicrobial activity against human pathogens.

Novel utilization of waste marine sponge (Demospongiae) as a catalyst in ultrasound-assisted transesterification of waste cooking oil

This study demonstrates the potential of Na-silica waste sponge as a source of low cost catalyst in the transesterification of waste cooking oil aided by ultrasound. In this work an environmentally friendly and efficient transesterification process using Na-loaded SiO2 from waste sponge skeletons as a solid catalyst is presented. The results showed that the methyl esters content of 98.4±0.4wt.% was obtainable in less than an hour (h) of reaction time at 55°C. Optimization of reaction parameters revealed that MeOH:oil, 9:1; catalyst, 3wt.% and reaction duration of 30min as optimum reaction conditions. The catalyst is able to tolerant free fatty acid and moisture content up to 6% and 8%, respectively. In addition, the catalyst can be reused for seven cycles while maintaining the methyl esters content at 86.3%. Ultrasound undoubtedly assisted in achieving this remarkable result in less than 1h reaction time. For the kinetics study at 50-60°C, a pseudo first order model was proposed, and the activation energy of the reaction is determined as 33.45kJ/mol using Arrhenius equation.

A brief review of para-xylene oxidation to terephthalic acid as a model of primary C-H bond activation

Abstract The oxidation of para-xylene to terephthalic acid has been commercialised as the AMOCO process (Co/Mn/Br) that uses a homogeneous catalyst of cobalt and manganese together with a corrosive bromide compound as a promoter. This process is conducted in acidic medium at a high temperature (175–225 °C). Concerns over environmental and safety issues have driven studies to find milder oxidation reactions of para-xylene. This review discussed past and current progress in the oxidation of para-xylene process. The discussion concentrates on the approach of green chemistry including (1) using heterogeneous catalysts with promising high selectivity and mild reaction condition, (2) application of carbon dioxide as a co-oxidant, and (3) application of alternative promoters. The optimisation of para-xylene oxidation was also outlined.

Versatile boiler ash containing potassium silicate for the synthesis of organic carbonates

In this study, boiler ash containing potassium silicate (BA 900) and potassium silicate (K2SiO3) were proven to be feasible Lewis acid catalysts for the synthesis of different organic carbonates (glycerol carbonate, ethylene carbonate, and propylene carbonate) from different polyol (glycerol, ethylene glycol, and propylene glycol) feedstocks. In addition, the developed catalytic reaction has the ability to produce propylene carbonate at milder reaction temperatures. BA 900 and K2SiO3 were reusable for three consecutive reaction cycles without the loss of activity. The reusable characteristics of catalysts were confirmed through several characterisation techniques, i.e. XRD, FTIR, XRF, N2 physisorption, FESEM-EDX, and Hammett test. All organic carbonates synthesised had a similar synthetic mechanistic pathway, which involved decomposition of intermediate carbamates into their respective carbonates.

Homology modeling and molecular docking studies on Type II diabetes complications reduced PPARγ receptor with various ligand molecules

Peroxisome proliferator-activated receptor gamma (PPARγ), a type II nuclear receptor present in adipose tissue, colon and macrophages. It reduces the hyperglycemia associated metabolic syndromes. Particularly, type II diabetes-related cardiovascular system risk in human beings. The fatty acid storage and glucose metabolism are regulated by PPARγ activation in human body. According to recent reports commercially available PPARγ activating drugs have been causing severe side effects. At the same time, natural products have been proved to be a promising area of drug discovery. Recently, many studies have been attempted to screen and identify a potential drug candidate to activate PPARγ. Hence, in this study we have selected some of the bio-active molecules from traditional medicinal plants. Molecular docking studies have been carried out against the target, PPARγ. We Results suggested that Punigluconin has a efficient docking score and it is found to have good binding affinities than other ligands. Hence, we concluded that Punigluconin is a better drug candidate for activation of PPARγ gene expression. Further studies are necessary to confirm their efficacy and possibly it can develop as a potential drug in future.

Biosynthesized Gold Nanoparticle Developed as a Tool for Detection of HCG hormone in Pregnant Women Urine Sample

Abstract Introduction Biosynthesized gold nanoparticles is one of the novel benchmark for using medical commercial industry. Recently gold nanoparticles were used for the detection of tumor, hormones, glucose and other biomolecules in health care sectors. Due to the different functional properties AuNPs was used for hormone detection was carried out in this study. Objectives Biosynthesized gold nanoparticles were used to qualitatively determine the hCG hormone in pregnancy women urine sample. Methods The biosynthesis of gold nanoparticles using C.nudiflora plant extract. Synthesized gold nanoparticles were characterized by different analytical techniques such as FESEM, XRD and FTIR. The synthesized gold nanoparticles was used to perform hCG hormone detection on both pregnancy positive and negative urine sample.500 μL of the prepared gold solution and an equal volume of the test sample were mixed and used for assays. After that, the solution was tested using a pregnancy test strip. Results & Discussion The mixture of gold nanoparticles in the urine sample changed color into pink that confirmed pregnancy. Otherwise it turned into gray color that showed the absence of pregnancy. Conclusion The method was supported 100% accurate in diagnosis of pregnancy and it may be a good alternative method for urine pregnancy test.