Current Advances in Chemistry and Biochemistry Vol. 2

In the present work, three new thiabendazole derivatives (4b and 6a-c) and their intermediates (3a-b) were synthesised by the reaction of inexpensive easily available amines with 4-cyanothiazole in moderate to good yields. The preliminary in vitro antimicrobial evaluation was conducted for all the compounds (3a-b, 4b and 6a-c) by the whole cell growth inhibition assays method towards Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, Candida albicans and Cryptococcus neoformansvar. Our research efforts identified the highly potent antibacterial agent 3b which displayed strong growth inhibition (77.12%) towards gram-negative bacteria Acinetobacter baumannii.

The effect of three different types of soil in Saudi Arabia on SABIC carbon steel grade X60 (SCSX60) specimens was investigated. The results showed that the environment effect of different condition was very clear, indicating that the studied soils were very corrosive toward SCSX60 specimens. The composition and morphology of corrosion products were different in the tested soil based on moisture content and immersion period. In addition, the results showed that bacteria play a significant role in the corrosion of SCSX60. The morphologies of corrosion products were characterized using scanning electron microscopy (SEM) to further elucidate the complex systems found in the studied soil.

Immobilization of active molecules by attachment onto solid surfaces is a well-established practice in many processes and applications. Silica micro- and nano-particles are attractive candidates as support for active molecules as result of a combination of desirable properties. The present study deals with grafting of functional UV active molecules onto silica surfaces via hydrosilylation reactions using multivalent organosilicon spacers.

Different types of organosilicon precursors based on dimethylsiloxysilanes containing multiple SiH groups were used as spacers between vinyl-modified silica surface and the benzotriazole UV-absorber (UVA). First, the surface of silica was modified with vinyltrimetoxsisilane coupling agent. Subsequently, the UVA molecules were attached to the silica-vinyl by a two-step procedure involving hydrosilylation reaction. UV active molecules has been successfully attached onto vinyl-modified silica surface using different types of multivalent organosilicon precursors, which were used as spacers between vinyl-modified silica surface and the UV-absorber. The successful grafting was confirmed by FTIR, TGA and UV-Vis characterization.

More than fivefold increase in UVA loading was found for the MH30 multifunctional spacer, which contains approximately 75 SiH groups per molecule, when compared to a four-functional spacer. Furthermore, a branched, bulky six functional spacer outperforms the linear spacer of the same functionality. UV activity of functionalized silica was study by UV-VIS spectroscopy, confirming that the immobilization of UVA onto silica surface has not altered its UV absorbance properties.

The escalating use of antioxidant supplements has been questioned repeatedly although the potential side effects of antioxidants have neither been adequately assessed nor understood. This work represents a comprehensive insight into the literature seeking potential targets of antioxidants in tissues and cells, with which they would interact to produce their toxic effects. Oxidants are cellular components that drive some cellular key metabolic processes in cancer cells, yet they appear to weaken certain other metabolic pathways in the same cells. Excess deactivation by antioxidants may enhance cellular survival through abating apoptotic pathways and enhancing energy production from glycolysis. Furthermore, oxidants are important effectors of immune reactivity as well as metabolic activators of the immune cells that carry out anti-microbial and anti-tumoral activities, hence, abolishing oxidant activity may hinder these vital functions. It is hypothesized that the critical balance of oxidants-antioxidants can be disrupted by excessive antioxidant consumption, setting a new state of “antioxidant stress”, leading to enhanced growth of cancer cells and to compromised immunity. A critical balance of antioxidants intake needs to be assessed for the clinical situation. In addition, the potential molecular mechanisms that may lead to this stress have been thoroughly explored.

A 60-days feeding trial was conducted to study the effect of different feeding strategies with normal and low protein diet on digestive and metabolic activity in Labeo rohita fingerlings. Labeo rohita is the most important Indian Major Carp (IMC), which is cultivated commercially across the country. One hundred thirty five fingerlings were distributed in triplicate groups of each treatment. Three experimental isocaloric (401.32 to 410.28 kcal/100 g) diets of 30%, 25% and 20% crude protein designated as diet A, diet B and diet C respectively were prepared, using locally available feed ingredients. Three different feeding schedules of normal protein diet continuously (diet A-30%) throughout the experiment, alternate feeding of 1-day diet A followed by 1-day diet B (1A/1B) and alternate feeding of 1-day diet A followed by 1-day diet C (1A/1C) through- out the experiment were tested by feeding the fishes at 5% body weight daily. Results showed that digestive enzymes activity such as protease and amylase was higher in the group fed 1A/1B. Glucose 6 phosphatase (G6Pase) were also analysed. The metabolic enzymes such as lactate dehydrogenase (LDH), malate dehydrogenase (MDH) are reported to be significantly difference (p<0.05) in among the different feeding schedules. The proteolytic activity such as alanine amino transaminase (ALT), aspartate amino transaminase (AST), alkaline phosphatise (ALP) were reported to be higher in the group fed with 1A/1B feeding schedule.

Objective: The aim of the present study was to determine the effect of storage time and temperature on laboratory results of routine clinical biochemistry analytes in sera from apparently healthy volunteers.

Materials and Methods: Ten healthy volunteers were instructed to fast overnight and 10 ml of blood was collected from each subject without anticoagulant (in red capped vacutainer). Samples were allowed to clot at room temperature for 20 min, centrifuged and serum separated which was stored in various aliquots.  Baseline analysis (“0” day values) of 18 analytes in serum of each subject was done without delay on the same day of collection.

Other aliquots were stored at 0° C and 4±1° C with cover of aluminium foil to avoid exposure of direct light and analysed  on  3, 7, 15 and 30 days.

Results: Urea, uric acid, phosphorus, TG and HDL were stable till 7 days whereas ALP was stable till 15 days but SGOT was stable upto 30 days at both 0° C and 4±1° C. ALP, Amylase and urea were stable up to 30 days at 0° C temperature.

All analytes showed significant variation on 3^rd day which were stored in room temperature except calcium which was stable. But glucose, creatinine, inorganic phosphorus and potassium were least stable and should be determined within 48 hours at 4±1° C and 24 hours at 23±1° C for these analytes.

Conclusion: Various routine biochemical analytes were stable using the storage conditions tested in this study at least up to 7 days in usual refrigerator. This evidence can be used in exceptional circumstances because processing of any analyte on the same day should be done for better reproducibility. We recommend that samples should be analysed in the laboratory within preferably 24 h of collection to ensure valid results with the turn-around time from sample drawing to reporting the analytical result could be shortened.

Beyond all this, it is even very important and useful to check the reliability of technical and instrumental resources that the laboratory will use during the study because molecular alterations of the analytes due to variable storage conditions can cause misleading results.

The color properties and antioxidant capacity of purple sweet potato anthocyanin co-pigmented with green tea extract were investigated. The co-pigmentation process was done using green tea extract with varying concentration of polyphenol (2.5%; 5%; 7.5% and 10% b/v). The co-pigmentation of purple sweet potato anthocyanin with green tea extract could enhance the color intensity which was observed through the hyperchromic effects and bathochromic shifts. The co-pigmentation was optimal using the 5% of polyphenol concentration, where the bathochromic shifts (??_max) was 4 nm and the hyperchromic effects (?A) was 0.565. The color observed with the CIELAB system showed that the co-pigmentation decreased the lightness (L*) value and increase the a* value. The result of antioxidant capacity assessment showed that the purple sweet potato anthocyanin co-pigmented with green tea extract has higher the antioxidant capacity than without co-pigment. Besides increased the color intensity, the co-pigmentation of the purple sweet potato anthocyanin with green tea extract also could increase the antioxidant capacity. This co-pigmentation was prospective to developed in the production of the anthocyanin from purple sweet potato with attractive color and high antioxidant capacity.

This study proposed the synthesis, characterization, solubility determination and solution thermodynamic properties of a cardiovascular drug 6-phenylpyridazin-3(2H)-one (PPD) in twelve different pharmaceutical solvents at temperatures “T = 298.2-318.2 K” and pressure “p = 0.1 MPa”. The measured solubilities of PPD were regressed well with “van’t Hoff and Apelblat models”. The solid phases of pure and equilibrated PPD were characterized using differential scanning calorimetry and powder X-ray diffractometry and results indicated no transformation of PPD into solvates/hydrates/polymorphs after equilibrium. The solubilities of PPD in mole fraction at “T = 318.2 K” were found to be maximum in dimethyl sulfoxide [DMSO] (0.473) followed by polyethylene glycol-400 [PEG-400] (0.412), Transcutol^® (0.346), ethyl acetate [EA] (6.81 x 10^-2), 2-butanol (2.18 x 10^-2), 1-butanol (2.11 x 10^-2), propylene glycol [PG] (1.50 x 10^-2), isopropyl alcohol [IPA] (1.44 x 10^-2), ethylene glycol [EG] (1.27 x 10^-2), ethanol (8.22 x 10^-3), methanol (5.18 x 10^-3) and water (1.26 x 10^-5). Similar trends were also recorded at other temperatures studied. The results of thermodynamic evaluation showed an endothermic and entropy-driven dissolution of PPD in all pharmaceutical solvents. The results of activity coefficients indicated maximum interaction at molecular level in PPD-DMSO, PPD-PEG-400 and PPD-Transcutol compared with other combination of solute and solvents studied. In conclusion, the results of this study indicated that pharmaceutical solvents such as DMSO, PEG-400 and Tarnscutol could be successfully utilized in the solubilization of PPD.

Inclusion of drugs in liposomes offers the potential for localized and sustained delivery to mucosal surfaces. Liposomes are lipid vesicles that contain an aqueous solution of the active substance in their internal space or incorporate it into their shell. The inclusion of the carrageenan matrix with echinochrome A ((Ech) - the active substance of the drug Histochrome) in liposomes was studied. According to the spectral characteristics, Ech was not oxidized and retained stability after encapsulation in the liposomes and the lyophilization process. Loading the liposomes with negatively charged polysaccharide results in the increase in the zeta potential to more negative values (from -14.6 to -24.4 mV), that together with an increasing in the sizes of liposomes (from 124.7±2.2 to 159.3±5.8 nm) propose of the formation of the polymer coating on liposomes. The interactions of liposomes with porcine stomach mucin was determined by the DLS and SEM methods. The changes in the zeta-potential and size of the mucin particles were observed as the result of the interaction of liposomes with mucin. To evaluate the mucoadhesive properties of liposomes and the penetration of Ech in the mucosa, was used a fresh-frozen inner surface of the small intestine of the pig as a model of mucous tissue. Polysaccharide-coated liposomes exhibit very good mucoadhesive properties - 50% of Ech remains on the mucosa.

The gas-phase thermal tautomerization reaction between imidazole-4-acetic (I) and imidazole-5-acetic (II) acids was monitored using the traditional hybrid functional (B3LYP) and the long-range corrected functionals (CAM-B3LYP and ?B97XD) with 6-311++G** and aug-cc-pvdz basis sets. The roles of the long-range and dispersion corrections on their geometrical parameters, thermodynamic functions, kinetics, dipole moments, Highest Occupied Molecular Orbital–Lowest Unoccupied Molecular Orbital (HOMO–LUMO) energy gaps and total hyperpolarizability were investigated. All tested levels of theory predicted the preference of I over II by 0.750–0.877 kcal/mol. The origin of predilection of I is assigned to the H-bonding interaction ( ). This interaction stabilized I by 15.07 kcal/mol. The gas-phase interconversion between the two tautomers assumed a 1,2-proton shift mechanism, with two transition states (TS), TS1 and TS2, having energy barriers of 47.67–49.92 and 49.55–52.69 kcal/mol, respectively, and an sp³-type intermediate. A water-assisted 1,3-proton shift route brought the barrier height down to less than 20 kcal/mol in gas-phase and less than 12 kcal/mol in solution. The relatively high values of total hyperpolarizability of I compared to II were interpreted and discussed. The long-range correction is quite essential for total hyperpolarizability DFT evaluation as the traditional hybrid functional overestimate it. Finally, the computation of _tot values is basis set independent.

Two-dimensional gel electrophoresis (2DE) is an important and well-established technical platform enabling extensive top-down proteomic analysis. However, the long-held but now largely outdated conventional concepts of 2DE have clearly impacted its application to in-depth investigations of proteomes at the level of protein species/proteoforms. It is time to popularize a new concept of 2DE for proteomics. With the development and enrichment of the proteome concept, any given “protein” is now recognized to consist of a series of proteoforms. Thus, it is the proteoform, rather than the canonical protein, that is the basic unit of a proteome, and each proteoform has a specific isoelectric point (pI) and relative mass (M_r). Accordingly, using 2DE, each proteoform can routinely be resolved and arrayed according to its different pI and M_r. Each detectable spot contains multiple proteoforms derived from the same gene, as well as from different genes. Proteoforms derived from the same gene are distributed into different spots in a 2DE pattern. High-resolution 2DE is thus actually an initial level of separation to address proteome complexity and is effectively a pre-fractionation method prior to analysis using mass spectrometry (MS). Furthermore, stable isotope-labeled 2DE coupled with high-sensitivity liquid chromatography-tandem MS (LC-MS/MS) has tremendous potential for the large-scale detection, identification, and quantification of the proteoforms that constitute proteomes. Overall, the beauty and power of this coupled 2DE-LC-MS/MS methodology is its inherent capacity to capitalize on the combination of refined top-down and bottom-up analytical approaches. The capacity for genuine deep proteome analysis at the critical proteoform level is now a definite reality.