K. Anver Basha

Oral delivery of DNA construct using chitosan nanoparticles to protect the shrimp from white spot syndrome virus (WSSV)

The protective efficacy of oral delivery of a DNA construct containing the VP28 gene of WSSV encapsulated in chitosan nanoparticles was investigated in black tiger shrimp (Penaeus monodon). The results showed that significant survival was obtained in WSSV-challenged shrimp at 7, 15 and 30 days post-treatment (relative survival, 85%, 65% and 50%, respectively) whereas 100% mortality was observed in the control shrimp fed with feed containing chitosan/pcDNA 3.1 or chitosan/PBS complex. The ability of the chitosan to form a complex with the pVP28 and to stabilize it from endonuclease degradation was studied by agarose gel electrophoresis. Cytotoxicity of chitosan-encapsulated pVP28 was also evaluated by the MTT assay, which showed 90% viability of SISK cells incubated with the pVP28/chitosan complexes. Transcription analysis of the chitosan-encapsulated pVP28 gene in different tissues of DNA-treated shrimp and SISK cell line was confirmed by an RT-PCR reaction. The present study also measured the changes in the level of important immunological parameters such as prophenoloxidase, superoxide dismutase and superoxide anion in hemolymph of chitosan-encapsulated VP28 DNA-treated and controls shrimp. The study also correlated the changes in the level of immunological parameters with the survival percentage and protective efficacy of oral route of DNA construct against WSSV in shrimp.

Antimicrobial activity of hyperbranched polymers: Synthesis, characterization, and activity assay study

Poly(cyanurateamine) and poly(triacrylatetrimine) hyperbranched polymers were synthesized for the first time by adopting Michael addition reaction. These polymers were obtained by reacting diethylenetriamine (A2) with 2,4,6-triallylcyanurate (B3) and trimethylolpropane triacrylate (B3), respectively, at room temperature. The polymers were characterized by spectroscopic techniques such as Fourier transform infrared, 1H-, and 13C-nuclear magnetic resonance spectroscopy. The antimicrobial activity of hyperbranched polymers was studied against Staphylococcus aureus ATCC 25923, Escherichia coli, Bacillus firmus, Bacillus subtilis MTCC 2423, Serratia marcescens, Pseudomonas aeruginosa, Micrococcus sp., and Acinetobacter beijerinckii. Both poly(cyanurateamine) and poly(triacrylatetrimine) show good antibacterial activity against gram-positive bacteria compared to gram-negative bacteria. Interestingly, poly(triacrylatetrimine) is better resistant to promising antibiotics and antiseptics bacteria, Pseudomonas aeruginosa and Serratia marcescens in comparison with poly(cyanurateamine).

Synthesis, Characterization, Thermal Stability and Antibacterial Activity of Coumarin Based Methacrylate Copolymers

Monomer of 7-methacryloyloxy-4-methylcoumarin (MAOMC) was synthesized and characterized by FTIR, 1H-NMR and 13C-NMR spectroscopy. Copolymers of MAOMC with butoxyethylmethacrylate (BOEMA) at different feed compositions were prepared by free radical solution polymerization at (70 ± 1) °C in ethylmethylketone (EMK) using benzyl peroxide (BPO) as an initiator. The copolymers were characterized by FTIR and 1H-NMR spectroscopy. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) of the copolymers showed moderate thermal stability and higher Tg values. Gel permeation chromatography (GPC) was used to find out the molecular weights of the different copolymers. Antibacterial activities of the copolymers were also investigated against the selected pathogenic bacteria’s. The antibacterial activity of the copolymer increases as the MAOMC content increases in the copolymer. This shows that coumarin moiety plays a very important role in the antibacterial activity.

Corrosion Protection Behavior of Poly(N-(p-bromophenyl)-2-methacrylamide-co-ethyl methacrylate) Coatings on Low Nickel Stainless Steel

The copolymer poly(N-(pbromophenyl)-2-methacrylamide-co-ethyl methacrylate) has been synthesized by free radical solution polymerization. Thermal stability of the synthesized copolymer was analyzed using thermogravimetric analysis and differential thermal analysis techniques. The corrosion performances of low nickel stainless steel specimens coated with different mole ratios of poly(PBPMA-co-EMA) were investigated with 1 M H2SO4 using potentiodynamic polarization, electrochemical impedance spectroscopic studies and chronoamperometric studies. Moreover, all the mole ratios of this copolymer showed good protection against corrosion. Surface and morphological investigation of the product have been studied with the help of scanning electron microscopic, atomic force microscopic, and energy dispersive X-ray analysis techniques, they were used to characterize the adherence and uniformity of the coatings, electrochemical corrosion test and surface analysis results have proved that poly(PBPMA-co-EMA) coatings served as a stable host matrix on low nickel stainless steel as environmentally more favored and best anticorrosive coating.

Comparative Study of Thermal Degradation of N-vinylimidazole/Phenoxy- and Methoxyethylmethacrylate Copolymers

Copolymerization reactions involving N-vinylimidazole and its derivatives have stimulated great interest due to the wide possibilities of the preparation of new materials, including the synthetic analogues of biopolymers with imidazole fragments. The role of the imidazole group in polymers is very important, especially due to the high thermal stability at elevated temperatures when it is copolymerized with methacrylates, which contain highly electronegative atoms like oxygen [10,11]. Accordingly, copolymers of N-vinylimidazole with phenoxy- and methoxyethylmethacrylate have been prepared and subjected to thermogravimetric analysis to discover their thermal stability. Copolymers are also characterized by FTIR and 1H-NMR spectroscopic methods. Results show that the thermal stability is greater for N-vinylimidazole-co-phenoxyethylmethacrylate than for those with N-vinylimidazole-methoxyethylmethacrylate.

Copolymers of Phenoxyethyl Methacrylate with N‐Vinyl‐2‐pyrrolidone: Synthesis, Characterization and Reactivity Ratios

The free radical copolymerization of phenoxyethyl methacrylate (POEMA) and N‐vinyl‐2‐pyrrolidone (Vp) was carried out using α,α′‐azobisisobutyronitrile (AIBN) in 2‐butanone solution at 333 K±1. The copolymers were characterized by FTIR, 1H‐NMR and 13C‐NMR spectroscopic methods. Thermal properties of the copolymers were also studied by thermogravimetric analysis (TGA). The composition of the copolymers was established by 1H‐NMR analysis. The monomer reactivity ratios were computed using the Fineman–Ross (F‐R) and Kelen–Tüdos (K‐T) methods. These parameters were also estimated using a non‐linear computational fitting procedure, known as reactivity ratios error in variable model (RREVM). The mean sequence lengths determination indicates that the copolymer was random in nature.

Synthesis and Characterization of Methacrylate-Based Antibacterial Copolymers for Anticorrosive Application

ABSTRACT Functional methacrylate polymer coatings can help retard materials from corrosion. However, the antibacterial-based anticorrosive coating of methacrylate polymer is very limited. In this paper, a functional methacrylate, namely, p-acetamidophenyl methacrylate was copolymerized with N-vinylpyrrolidone and it was characterized by Fourier transform infrared spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy. Thermal analyses of copolymers were studied by thermogravimetric analysis. The polymers were tested for their in vitro antibacterial activity by well diffusion method against microbes using ampicillin as a standard. The corrosion behavior of mild steel specimens coated with different ratios of copolymers has been studied by potentiodynamic polarization and electrochemical impedance spectroscopic methods. It was showed that the copolymer-coated specimens exhibited high protection efficiency than uncoated one. GRAPHICAL ABSTRACT

HPLC METHOD DEVELOPMENT FOR DETERMINATION OF GLYOXAL CONTENT IN ONDANSETRON HCL DRUG SUBSTANCES BY DERIVATIZATION WITH 2,4 DNPH

A simple, sensitive, and reproducible stability-indicating high-performance liquid chromatography method was developed for the analysis of glyoxal content in ondansetron HCl by derivatization technique. Chromatographic separation was achieved on symmetry shield RP18 (250 mm length, 4.6 mm inner diameter with 5 µm with a mobile phase consisting of a mixture of monobasic potassium phosphate and acetonitrile and pH adjusted to 3.0 with orthophosphoric acid (95:5 v/v) as mobile phase A, and acetonitrile, methanol, and water (85:5:10 v/v/v) as mobile phase B. UV detection was performed at 385 nm, the flow rate was 1.0 mL/min, and the column oven temperature was maintained at 30 °C. The high correlation coefficient (r 2 > 0.999) values indicated clear correlations between the investigated compound concentrations and their peak areas within the test ranges. The repeatability and intermediate precision, expressed by the RSD, were less than 2.0%. The accuracy of the method was further ascertained by performing recovery studies via a spike method. The high recovery and low relative standard deviation confirm the suitability of the method for routine quantification of glyoxal content in ondansetron HCl. The method was validated according to the present ICH guidelines for, limit of detection, limit of quantification, linearity, accuracy, precision, ruggedness, and robustness.