Multispectroscopic insight,morphological analysis and molecular docking studies of CuII-based chemotherapeutic drug entity with human serum albumin (HSA) and bovine serum albumin (BSA)

The interaction studies of Cu^II nalidixic acid–DACH chemotherapeutic drug entity, [C₃₆H₅₀N₈O₆Cu] with serum albumin proteins, viz., human serum albumin (HSA) and bovine serum albumin (BSA) employing UV–vis, fluorescence, CD, FTIR and molecular docking techniques have been carried out. Complex [C₃₆H₅₀N₈O₆Cu] demonstrated strong binding affinity towards serum albumin proteins via hydrophobic contacts with binding constants, K?=?3.18?×?10⁵ and 7.44?×?10⁴ M^–1 for HSA and BSA, respectively implicating a higher binding affinity for HSA. The thermodynamic parameters ΔG, ΔH and ΔS at different temperatures were also calculated and the interaction of complex [C₃₆H₅₀N₈O₆Cu] with HSA and BSA was found to be enthalpy and entropy favoured, nevertheless, complex [C₃₆H₅₀N₈O₆Cu] demonstrated higher binding affinity towards HSA than BSA evidenced from its higher binding constant values. Time resolved fluorescence spectroscopy (TRFS) was carried out to validate the static quenching mechanism of HSA/BSA fluorescence. The collaborative results of spectroscopic studies indicated that the microenvironment and the conformation of HSA and BSA (α–helix) were significantly perturbed upon interaction with complex [C₃₆H₅₀N₈O₆Cu]. Hirshfeld surfaces analysis and fingerprint plots revealed various intermolecular interactions viz., N–H····O, O–H····O and C–H····O linkages in a 2–dimensional framework that provide crucial information about the supramolecular architectures in the complex. Molecular docking studies were carried out to ascertain the preferential binding mode and affinity of complex [C₃₆H₅₀N₈O₆Cu] at the target site of HSA and BSA. Furthermore, only for Transmission electroscopy microscopy micrographs of HSA and BSA in presence of complex [C₃₆H₅₀N₈O₆Cu] revealed major protein morphological transitions and aggregation which validates efficient delivery of complex by serum proteins to the target site.

Communicated by Ramaswamy H. Sarma     

Optimization of an improved,efficient and rapid in vitro micropropagation protocol for Petunia hybrida Vilm. Cv. “Bravo”

An efficient protocol for in-vitro propagation of an important ornamental crop, Petunia hybrida Vilm. Cv. “Bravo” was developed. The explants that were used to carry out the experiment were Leaf segments, nodal segments and shoot tips. Nodal segments recorded highest per cent asepsis followed by shoot tips and leaf segments. Asepsis was found to be highest when the explants were sterilized with Fungicide (Carbendazim) 0.02% for the duration of 30 min followed by 0.1% HgCl₂ for duration of 10 min and then ethanol 70% for 10 s. Longer duration of the sterilant treatment showed more necrotic effects on the explants, thus mercuric chloride treatment when given for 5 min proved to be more effective in terms of survival of the explants. Maximum establishment per cent was recorded in Murashige and Skoog (MS) media fortified with BAP (1.5 mg L⁻¹) and IBA (0.5 mg L⁻¹) in shoot tips and nodal segments, i.e. 97.90 and 95.74% respectively. Callus was efficiently induced and developed when PGR amalgamation of BAP (0.1 mg L⁻¹) and 2,4-D (1.5mg L⁻¹) was used. Kinetin at the concentration of 2.0 mg L⁻¹ along with IBA at 0.5mg L⁻¹ recorded highest callus regeneration in both leaf and internodal segment derived callus. Maximum proliferation percent of shoots (97.90%), highest number of shoots (20.50 explant⁻¹) and maximum length of shoot (2.70 cm) was recorded in PGR combination of IBA and BAP both at 0.5 mg L⁻1 concentration level. Rhizogenesis was recorded to be highest in the MS media containing IBA 1.00 mg L⁻¹. Best hardening media which recorded maximum survival per cent 92.50% was noticed on the media formulation comprised of equal ratio of perlite and vermiculite mix, under poly house conditions.     

Synthesis of cyclobutane nucleoside analogues 3: Preparation of carbocyclic derivatives of oxetanocin

Abstract

A synthesis of cyclobutene nucleoside analogs in which the nucleobase is tethered by a methylene group is described. The coupling of 6-chloropurine with 3-hydroxymethyl-cyclobutanone proceeds via its triflate to give both N-7 and N-9 regioisomers with relative yields corresponding to the calculated charge distribution of the 6-chloropurinyl anion. The stereoselective reduction of the N-alkylated ketones yielded quantitatively one stereoisomer in each case. The structural assignments were based on spectroscopic data and single crystal X-ray diffraction. Attempts to photoexcite the N-7 and N-9 ketones in order to promote ring-expansion did not ensue. Preliminary evidence suggests a photodecarbonylation to cyclopropanes took place.     

LC-MS/MS-based metabolic profiling of Escherichia coli under heterologous gene expression stress

Escherichia coli is frequently exploited for genetic manipulations and heterologous gene expression studies. We have evaluated the metabolic profile of E. coli strain BL21 (DE3) RIL CodonPlus after genetic modifications and subjecting to the production of recombinant protein. Three genetically variable E. coli cell types were studied, normal cells (susceptible to antibiotics) cultured in simple LB medium, cells harboring ampicillin-resistant plasmid pET21a (+), grown under antibiotic stress, and cells having recombinant plasmid pET21a (+) ligated with bacterial lactate dehydrogenase gene grown under ampicillin and standard isopropyl thiogalactoside (IPTG)-induced gene expression conditions. A total of 592 metabolites were identified through liquid chromatography-mass spectrometry/mass spectrometry analysis, feature and peak detection using XCMS and CAMERA followed by precursor identification by METLIN-based procedures. Overall, 107 metabolites were found differentially regulated among genetically modified cells. Quantitative analysis has shown a significant modulation in DHNA-CoA, p-aminobenzoic acid, and citrulline levels, indicating an alteration in vitamin K, folic acid biosynthesis, and urea cycle of E. coli cells during heterologous gene expression. Modulations in energy metabolites including NADH, AMP, ADP, ATP, carbohydrate, terpenoids, fatty acid metabolites, diadenosine tetraphosphate (Ap4A), and l -carnitine advocate major metabolic rearrangements. Our study provides a broader insight into the metabolic adaptations of bacterial cells during gene manipulation experiments that can be prolonged to improve the yield of heterologous gene products and concomitant production of valuable biomolecules.     

Comparison of organic and inorganic amendments for enhancing soil lead phytoextraction by wheat (Triticum aestivum L.)

Phytoextraction has received increasing attention as a promising, cost-effective alternative to conventional engineering-based remediation methods for metal contaminated soils. In order to enhance the phytoremediative ability of green plants chelating agents are commonly used. Our study aims to evaluate whether, citric acid (CA) or elemental sulfur (S) should be used as an alternative to the ethylene diamine tetraacetic acid (EDTA)for chemically enhanced phytoextraction. Results showed that EDTA was more efficient than CA and S in solubilizing lead (Pb) from the soil. The application of EDTA and S increased the shoot biomass of wheat. However, application of CA at higher rates (30 mmol kg(-1)) resulted in significantly lower wheat biomass. Photosynthesis and transpiration rates increased with EDTA and S application, whereas these parameters were decreased with the application of CA. Elemental sulfur was ineffective for enhancing the concentration of Pb in wheat shoots. Although CA did not increase the Pb solubility measured at the end of experiment, however, it was more effective than EDTA in enhancing the concentration of Pb in the shoots of Triticum aestivum L. It was assumed that increase in Mn concentration to toxic levels in soil with CA addition might have resulted in unusual Pb concentration in wheat plants. The results of the present study suggest that under the conditions used in this experiment, CA at the highest dose was the best amendment for enhanced phytoextraction of Pb using wheat compared to either EDTA or S.     

Antioxidant Activity and Total Phenolic Content of Kale Genotypes Grown in Kashmir Valley

Green leafy vegetable extracts of six genotypes of kale (Brassica oleracea acephala) were evaluated for ascorbic acid, carotenoids, total phenolics and antioxidant activity. Ascorbic acid ranged from 142 mg per 100 g in Wappal Hakh to 164 mg per 100 g fr wt in Knol khol. Wild genotypes Wappal and Pumb, had significantly high phenolic content (285 and 227 mg per 100 g fr wt) and possessed highest antioxidant activities (840 and 780 µmol FRAP per g fr wt) than cultivated genotypes. A positive and strong correlation (R² = 0.807) between total phenolic content and antioxidant activity suggests that kale has enormous potential to enhance the antioxidant potential of our daily food supply. Wild genotypes, Wappal and Pumb can be incorporated into the breeding programmes in order to increase the antioxidant potential of cultivated varieties.     

Urea and urine are a viable and cost-effective nitrogen source for Yarrowia lipolytica biomass and lipid accumulation

Applied Microbiology and Biotechnology - Yarrowia lipolytica is an industrial yeast that has been used in the sustainable production of fatty acid-derived and lipid compounds due to its high growth...