Non-enzymatic Method Research Articles

Simultaneous Detection of Glucose and Acetoacetate in Artificial Urine Samples Using 3D-Connector Microfluidic Paper Based Analytical Devices

Diabetic patients sometimes experience both hyperglycemia and hyperketonemia simultaneously. This condition requires proper management of glucose and ketone body biomarkers. The fluctuating intensity of these biomarkers necessitates regular monitoring. This study aims to develop concept non-enzymatic measurement method by integrating µPADs (microfluidic paper-based analytical devices) for detecting glucose and acetoacetate in artificial urine samples. The method uses silver nanoparticle formation for glucose detection and Schiff base reaction as well as the Rothera test for acetoacetate detection. Optimal conditions found include the glucose detection zone with volume ratio of AgNO3 500 mM : starch 3% (w/v) (1 : 1), and the acetoacetate detection zone with glycine 900 mM in phosphate buffer pH 9.4. The artificial urine sample combination consists of glucose, acetoacetate, and acetone with volume ratio of (1 : 1 : 1). The 3D-Connector for glucose uses NaOH 10 M : starch 3% (w/v) with volume ratio of (1 : 3), while for acetoacetate, sodium nitroprusside 15% (w/w) in DMF 5% (v/v). Validity for glucose measurement shows linearity (R² = 0.9664), precision (RSD = 4.56%), accuracy (88.75 – 99.62%), LOD (1.61 mM), and LOQ (5.37 mM). Conversely, acetoacetate measurement shows linearity (R² = 0.9636), precision (RSD = 1.24%), accuracy (99.44 – 99.73%), LOD (1.41 mM), and LOQ (4.69 mM).

Non-Enzymatic Detection of Glucose and Ketones in Urine using Paper-Based Analytical Devices

Diabetes, driven by unbalanced diets and unhealthy lifestyles, is highly prevalent. In Indonesia, its prevalence is projected to reach 28.6 million by 2045. Microfluidic paper-based analytical devices (μPADs) are paper-based analytical tools that use hydrophilic paper for measurement and hydrophobic barriers to control fluid flow. This research aims to develop a non-enzymatic method for detecting glucose and ketones in artificial urine using S2Z-μPADs. The fabrication of S2Z-μPADs involves printing the design on Whatman No. 1 paper using wax printing and applying silver nanoparticles for glucose detection and the Schiff base reaction for ketone detection. The results show that the optimum condition for glucose detection is achieved with an AgNO3 concentration of 500 mM. A NaOH concentration of 10 M. Acetoacetate detection is optimized with a glycine concentration of 1 M, sodium nitroprusside concentration of 15%, NaOH concentration of 1 M, a drying time of 8 minutes, and a reaction time of 10 minutes. Validation results demonstrate good linearity for glucose (R² = 0.9821) and ketones (R² = 0.995). High precision was achieved with relative standard deviation (RSD) values of 3.792% for glucose and 1.482% for ketones. The obtained limits of detection (LOD) and limits of quantification (LOQ) indicate that the developed S2Z-μPADs can differentiate between each category of diabetes. The accuracy of glucose and ketone detection ranges from 87.463% to 97.374%. The high accuracy of the μPADs highlights their potential for reliable diabetes management and effective disease monitoring.

Potential antioxidant and antiradical agents from Allium ascalonicum: Superoxide dismutase and density functional theory in silico studies.

Antioxidants are compounds that can inhibit excessive free radical reactions in the body. Excessive free radicals can cause system imbalances in the body which can trigger oxidative stress and cause serious illness. The limitations of antioxidants in the body can be overcome by consuming safe natural additional antioxidants that can be obtained from natural products. Isolating compounds of Allium ascalonicum leaves as antioxidant and antiradical agents in inhibiting excessive free radicals by in vitro and in silico. The extracted compounds were purified by column chromatography. The compounds obtained were then characterized using ultraviolet, infrared, NMR, and mass spectrometry. Determination of antioxidant activity was carried out by in vitro using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the non-enzymatic superoxide dismutase (SOD) methods. The in silico study used the density functional theory (DFT) calculation method with global descriptive parameters (GDP), donor acceptor map (DAM), and frontier molecular orbitals (FMO) analysis. Three compounds have been isolated, of which compound 1 is a new compound. In the DPPH method, compound 1 has more strong antioxidant activity than others, as well as in the non-enzymatic SOD method. Whereas, in the DFT calculation shows that compound 1 has the best reactivity and stability between other compounds and was categorized as the best antiradical. Compound 1 has the highest antioxidant activity compared to the other compounds by in vitro both the DPPH and non-enzymatic SOD methods. In silico, compound 1 has the potential as the best antiradical.

Non-enzymatic methods for isolation of stromal vascular fraction and adipose-derived stem cells: A systematic review.

Adipose-derived stem cells (ADSCs) and the stromal vascular fraction (SVF) have garnered substantial interest in regenerative medicine due to their potential to treat a wide range of conditions. Traditional enzymatic methods for isolating these cells face challenges such as high costs, lengthy processing time, and regu-latory complexities. This systematic review aimed to assess the efficacy and practicality of non-enzymatic, mechanical methods for isolating SVF and ADSCs, comparing these to conventional enzymatic approaches. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a comprehensive literature search was conducted across multiple databases. Studies were selected based on inclusion criteria focused on non-enzymatic isolation methods for SVF and ADSCs from adipose tissue. The risk of bias was assessed, and a qualitative synthesis of findings was performed due to the methodological heterogeneity of the included studies. Nineteen studies met the inclusion criteria, highlighting various mechanical techniques such as centrifugation, vortexing, and ultrasonic cavitation. The review identified significant variability in cell yield and viability, and the integrity of isolated cells across different non-enzymatic methods compared to enzymatic procedures. Despite some advantages of mechanical methods, including reduced processing time and avoidance of enzymatic reagents, the evidence suggests a need for optimization to match the cell quality and therapeutic efficacy achievable with enzymatic isolation. Non-enzymatic, mechanical methods offer a promising alternative to enzymatic isolation of SVF and ADSCs, potentially simplifying the isolation process and reducing regulatory hurdles. However, further research is necessary to standardize these techniques and ensure consistent, high-quality cell yields for clinical applications. The development of efficient, safe, and reproducible non-enzymatic isolation methods could significantly advance the field of regenerative medicine.

Mango Leaves (Mangifera indica)-Derived Highly Florescent Green Graphene Quantum Dot Nanoprobes for Enhanced On-Off Dual Detection of Cholesterol and Fe2+ Ions Based on Molecular Logic Operation.

In the present study, we have engineered a molecular logic gate system employing both Fe2+ ions and cholesterol as bioanalytes for innovative detection strategies. We utilized a green-synthesis method employing the mango leaves extract to create fluorescent graphene quantum dots termed "mGQDs". Through techniques like HR-TEM, i.e., high-resolution transmission electron microscopy, Raman spectroscopy, and XPS, i.e., X-ray photoelectron spectroscopy, the successful formation of mGQDs was confirmed. The photoluminescence (PL) characteristics of mGQDs were investigated for potential applications in metal ion detection, specifically Fe2+ traces in water, by using fluorescence techniques. Under 425 nm excitation, mGQDs exhibited emission bands at 495 and 677 nm in their PL spectrum. Fe2+-induced notable quenching of mGQDs' PL intensity decreased by 97% with 2.5 μM Fe2+ ions; however, adding 20 mM cholesterol resulted in a 92% recovery. Detection limits were established through a linear Stern-Volmer (S-V) plot at room temperature, yielding values of 4.07 μM for Fe2+ ions and 1.8 mM for cholesterol. Moreover, mGQDs demonstrated biocompatibility, aqueous solubility, and nontoxicity, facilitating the creation of a rapid nonenzymatic cholesterol detection method. Selectivity and detection studies underscored mGQDs' reliability in cholesterol level monitoring. Additionally, a molecular logic gate system employing Fe2+ metal ions and cholesterol as a bioanalyte was established for detection purposes. Overall, this research introduces an ecofriendly approach to craft mGQDs and highlights their effectiveness in detecting metal ions and cholesterol, suggesting their potential as versatile nanomaterials for diverse analytical and biomedical applications.

Two Steps Non-Enzymatic Synthesis of Molnupiravir, which is Free from Mutagenic Impurity and Analytical Method Development for Estimation of Genotoxic Impurity (Hydroxylamine Hydrochloride Content) by using RP-HPLC Technique

Genotoxic impurity free Molnupiravir was synthesised by a novel and an elegant non-enzymatic method, which is simple operationally and ecologically. The genotoxic raw material, Hydroxylamine, was used in the initial stages of synthesis to get the mutagenic impurity free Molnupiravir. A new and sensitive HPLC method was developed and validated for the determination of hydroxylamine in Molnupiravir drug substance according to ICH guidelines. The HPLC method was developed and optimized on Zorbax SB C18 150×4.6mm, 3.5µm column with oven temperature maintained at 40°C. 1.0 mL of Orthophosphoric acid in 1000 mL water was selected as mobile phase in isocratic reverse phase mode. Chromatographic parameters are flow rate: 0.8 ml/min, wavelength detection: 252 nm, injection volume: 10µl and run time: 20 min. Based on the validation data; the method was found to be specific, sensitive, accurate and precise. This method can be used as a good quality control tool for quantification of hydroxylamine at the low level. The experimental data was deliberated in detail in this research paper.

A Simple and Effective Mechanical Method for Adipose-Derived Stromal Vascular Fraction Isolation.

Over the last decades, there has been ongoing and evolving research concerning regenerative medicine, specifically, stem cells. The most common source of adult mesenchymal stem cells (MSCs) remains the adipose tissue and the easiest way to obtain such tissue is lipoaspirate. The fatty tissue obtained can be processed either in an enzymatic way, which is time-consuming and expensiveand carries several dangers for the viability of the stem cells included, or with mechanical means which are fast, inexpensive, yield enough viable cells, and can be readily used for autologous transplantation in one-stage procedures. Herein, we demonstrate our non-enzymatic method for obtaining adipose-derived stromal vascular fraction comprising MSCs. The stromal vascular fraction was isolated via centrifugation, and the characteristics and numbers of the cells isolated have been tested with flow cytometry assay, cell culture, and differentiation. Over 91% of viable MSCs were isolated using the mechanical method. The cells retained the ability to differentiate into osteocytes, adipocytes, and chondrocytes. The method presented is simple, requiring no special equipment, and yields a viable population of stem cells in large numbers. These cells can be readily used in several operations (orthopedic, dentistry, fistulas, etc.) making feasible "one-stage" procedures, thus proving their benefits for the patient and the health care system.

A Comprehensive Investigation of Tenderization Methods: Evaluating the Efficacy of Enzymatic and Non-Enzymatic Methods in Improving the Texture of Squid Mantle — A Detailed Comparative Study

AbstractIn this study, enzymatic [papain (P), bromelain (B), and A. oryzae-derived fungal protease (FP); enzyme ratios: 0.012 (v/v), 38 °C, 50 min] and non-enzymatic [control (C; saline), mineral water (95%)–lemon juice (5%) (ML) (1/2:w/v), 38 °C, 50 min)] tenderizing methods on European squid mantle (Loligo vulgaris Lamarck, 1798) were investigated. Scanning electron microscope (SEM) imaging, water holding capacity (WHC), cooking loss (CL), total free amino acids (TFAA), total soluble protein (TSP), hydroxyproline (Hyp), and Fourier-transform infrared spectroscopy (FTIR) analyses were performed on uncooked samples. pH, water activity (aw), color, nutritional changes, amino acids (AA), total volatile basic-nitrogen (TVB-N), Warner-Bratzler shear (WBS), texture profile analysis (TPA), and sensory evaluations were performed on both uncooked and cooked samples. A significant decrease in protein content was observed in group P (12.86%) compared to untreated (U) squid (15.16%). During frying, group P absorbed more cooking oil (8.37%) than the other groups. A higher degree of hydrolysis was observed in the enzymatically tenderized groups than in non-enzymatic groups, and a shift in secondary protein structures in favor of random coils. Hydrolysis was confirmed by Hyp and AA analyses. The total AA content order was found as B < P < FP < C < ML < U. ML and FP groups have relatively higher total bitter and umami AA compositions, especially in uncooked samples. FP and ML groups had more favorable results across all analyses, especially in terms of the sensory results, nutritional values, and TPA results of cooked samples. It is concluded that both methods are very convenient regarding industrial usage.

Site- and Stereoselective Glycomodification of Biomolecules through Carbohydrate-Promoted Pictet-Spengler Reaction.

Carbohydrates play pivotal roles in an array of essential biological processes and are consequently involved in many diseases. To meet the needs of glycobiology research, chemical enzymatic and non-enzymatic methods have been developed to generate glycoconjugates with well-defined structures. Herein, harnessing the unique properties of C6-oxidized glycans, we report a straightforward and robust strategy for site- and stereoselective glycomodification of biomolecules with N-terminal tryptophan residues by a carbohydrate-promoted Pictet-Spengler reaction, which is not adapted to typical aldehyde substrates under biocompatible conditions. This method reliably delivers highly homogeneous glycoconjugates with stable linkages and thus has great potential for functional modulation of peptides and proteins in glycobiology research. Moreover, this reaction can be performed at the glycosites of glycopeptides, glycoproteins and living-cell surfaces in a site-specific manner. Control experiments indicated that the protected α-O atom of aldehyde donors and free N-H bond of the tryptamine motif are crucial for this reaction. Mechanistic investigations demonstrated that the reaction exhibited a first-order dependence on both tryptophan and glycan, and deprotonation/rearomatization of the pentahydro-β-carbolinium ion intermediate might be the rate-determining step.

Recombinant therapeutic proteins degradation and overcoming strategies in CHO cells.

Mammalian cell lines are frequently used as the preferred host cells for producing recombinant therapeutic proteins (RTPs) having post-translational modified modification similar to those observed in proteins produced by human cells. Nowadays, most RTPs approved for marketing are produced in Chinese hamster ovary (CHO) cells. Recombinant therapeutic antibodies are among the most important and promising RTPs for biomedical applications. One of the issues that occurs during development of RTPs is their degradation, which caused by a variety of factors and reducing quality of RTPs. RTP degradation is especially concerning as they could result in reduced biological functions (antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity) and generate potentially immunogenic species. Therefore, the mechanisms underlying RTP degradation and strategies for avoiding degradation have regained an interest from academia and industry. In this review, we outline recent progress in this field, with a focus on factors that cause degradation during RTP production and the development of strategies for overcoming RTP degradation. KEY POINTS: • The recombinant therapeutic protein degradation in CHO cell systems is reviewed. • Enzymatic factors and non-enzymatic methods influence recombinant therapeutic protein degradation. • Reducing the degradation can improve the quality of recombinant therapeutic proteins.

Microbial alcohol dehydrogenases: recent developments and applications in asymmetric synthesis.

Alcohol dehydrogenases are a well-known group of enzymes in the class of oxidoreductases that use electron transfer cofactors such as NAD(P)+/NAD(P)H for oxidation or reduction reactions of alcohols or carbonyl compounds respectively. These enzymes are utilized mainly as purified enzymes and offer some advantages in terms of green chemistry. They are environmentally friendly and a sustainable alternative to traditional chemical synthesis of bulk and fine chemicals. Industry has implemented several whole-cell biocatalytic processes to synthesize pharmaceutically active ingredients by exploring the high selectivity of enzymes. Unlike the whole cell system where cofactor regeneration is well conserved within the cellular environment, purified enzymes require additional cofactors or a cofactor recycling system in the reaction, even though cleaner reactions can be carried out with fewer downstream work-up problems. The challenge of producing purified enzymes in large quantities has been solved in large part by the use of recombinant enzymes. Most importantly, recombinant enzymes find applications in many cascade biotransformations to produce several important chiral precursors. Inevitably, several dehydrogenases were engineered as mere recombinant enzymes could not meet the industrial requirements for substrate and stereoselectivity. In recent years, a significant number of engineered alcohol dehydrogenases have been employed in asymmetric synthesis in industry. In a parallel development, several enzymatic and non-enzymatic methods have been established for regenerating expensive cofactors (NAD+/NADP+) to make the overall enzymatic process more efficient and economically viable. In this review article, recent developments and applications of microbial alcohol dehydrogenases are summarized by emphasizing notable examples.

Isolation and Quantification of Palmatine from Fibraurea tinctoria Lour: In Vitro Antioxidant Activity and In Silico Antidiabetic Activity Evaluation.

This study aimed to isolate and characterize palmatine from Fibraurea tinctoria Lour stems, quantify its content, and determine its antioxidant and antidiabetic activities. Palmatine was isolated from the methanol extract of Fibraurea tinctoria Lour stems by silica gel column chromatography. Structural elucidation of the isolated compounds was performed using spectral data analysis and comparison with the literature. High-Performance Liquid Chromatography (HPLC) was used to quantitatively determine palmatine in the crude methanol extract and fractions. The DPPH and non-enzymatic SOD mimic methods were used to assess the antioxidant activity of the methanol extract, fractions, and isolated compounds. The antidiabetic activity was evaluated in silico by the molecular docking method of alpha-glucosidase and DPP-IV enzymes. Palmatine was used as a test ligand and was compared with berberine and its native ligand or standard compounds. The isolated compound was identified as palmatine. Quantification of palmatine compound by HPLC showed that palmatine was found in the extract and all fractions. In the in vitro antioxidant activity test using the DPPH method, fraction 4 showed the highest activity, with an IC50 value of 91 ppm. In contrast, using the non-enzymatic SOD mimic method, the methanol extract, fraction 5, and isolated compound (palmatine) exhibited very strong antioxidant activity, with IC50 values of 18, 20, and 28 ppm, respectively. The in silico antidiabetic activity of palmatine is thought to have the potential to inhibit these two enzymes. These results showed that Fibraurea tinctoria Lour stems have potential as an antioxidant and antidiabetic agent. Further research on phytochemical and pharmacological is required to validate the use of this plant species for the treatment of various diseases, especially diabetes mellitus.

Quorum sensing and its inhibition mechanisms

The article is a brief literature review. This article provides an overview of the Quorum Sensing system in bacterial communities, highlighting the peculiarities of the system for gram-positive and gramnegative microorganisms. Basic information about the three existing Quorum Sensing systems is presented. Information is also given about different types of autoinducers, which are signaling molecules that trigger a cascade of behavioral reactions. The importance of the Quorum Sensing system as one of the fundamental mechanisms in the formation and regulation of bacterial biofilms is described, emphasizing the significance of biofilm microorganisms for modern clinical medicine and their impact on aggravating the issue of antibiotic resistance. The main mechanisms of inhibiting bacterial quorum, including by other microorganisms, are presented. The work discusses enzymatic and non-enzymatic methods of inhibiting the Quorum Sensing system, points of application and mechanisms of action. Some microorganisms with confirmed enzymatic activity by Quorum Quenching are indicated. Also presented are registered cases of suppression of other bacteria by microorganisms through the Quorum Sensing inhibitors system.

Establishment of Capra hircus somatic cells and induction of pluripotent stem-like cells.

Capra hircus (goat) induced pluripotent stem cells (giPSCs) harbor enormous scientific value and contribute to cellular agriculture, animal cloning, etc. Conventional approaches to giPSC generation suffer from complexity and low preparation efficiency. In the present study, we introduced the episomal vectors carrying the human pluripotent genes in goat somatic cells to generate the giPSC-like colonies. Initially, a simple non-enzymatic method was used to isolate the goat dermal fibroblast cells and, further, a cell line was established. Later, goat fibroblast cells were transfected with commercially available episomal vectors carrying the human pluripotent genes and successfully generated the iPSC-like colonies which exhibited the expression of goat endogenous pluripotent genes and positive staining with alkaline phosphatase. Moreover, giPS-like cells formed embryoid bodies (EBs)-like aggregates and weekly expressed the marker genes of two germ layers. Reprogramming of goat fibroblast using episomal vectors carrying human pluripotent genes could lead to the development of an efficient and time- and cost-effective approach to giPSC generation.

ANTIOXIDANT ACTIVITY AND PHYSICO-CHEMICAL PROPERTIES OF GREEN SYNTHESIZED ZINC OXIDE NANOPARTICLES USING ERUCA SATIVA LEAF EXTRACT

The aim of this work is to synthesize zinc oxide (ZnO) nanoparticles from Eurca Sativa water extract which is a medicinal plant cultivated in home gardens in Kurdistan Region-Iraq. The biosynthesis of nanoparticles has been extensively studied due to their numerous applications. Among them, zinc oxide nanoparticles (ZnO NPs) have gained significant attention for wide range of its applications. To investigate the optical, chemical, structural, and morphological properties, different techniques; UV-VIS spectrophotometer, Fourier Transform Infrared Analysis (FT-IR), X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray spectroscopy (EDX) were used. The results revealed that typical ZnO absorption spectra exhibit a well-defined exciton band at 371.6 nm that is near the bulk exciton absorption of ZnO (373 nm) with an energy band gap of 3.029 eV, confirming the production of ZnO nanoparticles. FTIR study demonstrated the existence of bioactive compounds such as flavonoids, polyphenols, tannins, and saponins that can function as reducing and capping agents of ZnO nanoparticles. FESEM picture revealed that ZnO NPs show spherical morphologies with an average diameter of 71.07 nm. The antioxidant activities of biosynthetic ZnO NPs were studied using non-enzymatic methods; 2,2-diphenyl-1-picrylhydrazyl (DPPH), reducing power assay, and total antioxidant activities. The results showed that the biosynthesized ZnO-NPs nanoparticles had significant antioxidants compared with ascorbic acid as a reference. The obtained results showed that the present method is eco-friendly, less cost-effective, and safe for human health and this method plays a vital role in the industrial and biomedicine fields.

Antioxidant Activity of Egg Yolk Protein Hydrolysates Obtained by Enzymatic and Sub-Critical Water Hydrolysis

Obtaining peptides with antioxidant properties by enzymatic hydrolysis has been widely described; however, the use of non-enzymatic methods to obtain peptides with antioxidant capacities has been poorly investigated. In this study, non-soluble proteins obtained from delipidated egg yolk granules were hydrolyzed with trypsin, and with a non-enzymatic method using sub-critical water hydrolysis under a non-oxidizing (nitrogen) and oxidizing (oxygen) atmosphere. The effect of the sub-critical water hydrolysis on the amino acids’ composition of the hydrolysates was assessed. Furthermore, the antioxidant capacities of the hydrolysates were evaluated using the ABTS•+ scavenging assay, the DPPH radical scavenging activity assay, and by measuring the reducing power of the peptides, the peptides’ ferrous ion chelating capacities, and the antioxidant effect of the peptides on beef homogenates. The hydrolysate obtained by sub-critical water hydrolysis under a nitrogen stream showed similar or better results in the antioxidant tests than those obtained using trypsin hydrolysis, except in the ferrous chelating capacity, where the trypsin hydrolysate showed the best performance. The oxidizing environment promoted by the oxygen in the other sub-critical water hydrolysis method tested produced the peptides with the lowest antioxidant capacities, due to changes in the primary structure of the peptides. These results suggest that the sub-critical water hydrolysis method under a nitrogen stream, in comparison with the enzymatic hydrolysis, is a reliable method to obtain peptides with good antioxidant capacities.

Colorimetric sensing of uric acid based on sawdust-deposited silver nanoparticles via an eco-friendly and cost-effective approach

Uric acid is directly linked to gout, arthritis, neurological, cardiovascular, and kidney-related disorders. It is a byproduct obtained from the breakdown of purines and a significant indicator of hyperuricemia observed in both urine and blood. In the absence of any enzyme, it's quite difficult to develop a novel, cost-effective, and clinical method for uric acid detection. Herein, we report a very simple, low-cost, and non-enzymatic method for the selective identification and quantification of uric acid using green synthesized silver nanoparticles (Ag NPs). The desired Ag NPs were synthesized by the hydrothermal method using Erythrina suberosa sawdust as a deagglomeration agent and Psidium guajava extract as a reductant. The synthesis of the sensing platform, i.e., sawdust-deposited Ag NPs, was confirmed through different techniques such as UV-Vis spectrophotometer, FTIR, XRD, EDX, and scanning electron microscopy (SEM). Sawdust can offer a good, environmentally friendly, and cost-effective strategy to overcome the problem of agglomeration in nanoparticles. The enzyme mimic, with the help of H2O2, oxidizes the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to oxidized TMB with a blue-green color. The addition of uric acid reduces the oxidized TMB to a colorless product, resulting in a colorimetric change. For quality improvement, different reaction parameters, including pH, time, TMB, and NPs concentration, were optimized. Our proposed sensor responds in linear ranges of 0.04–0.360 μM, with a limit of quantification of 0.01 μM and a limit of detection of 0.004 μM. The suggested enzyme mimic detected uric acid in blood samples, with particular specificity in the presence of competitive analytes.

Study on the non-enzymatic electrochemical glucose quantitative detection method in Na2S2O3 neutral solution environment

ABSTRACT In order to find a green and safe solution as the base solution for the quantitative detection of glucose, the neutral solution Na2S2O3 was selected as the base solution. A three-electrode electrochemical system was designed. In this system, the working electrode was copper sheet, the counter electrode was platinum electrode, and the reference electrode was saturated KCl calomel solution electrode. Cyclic voltammetry (CV) and chronoamperometry(i-t) methods were used for the experiment. CV scanning results showed that glucose could produce the oxidation-reduction reaction on the surface of the copper electrode, and the parameters of i-t were adjusted. According to the results of i-t scanning, the quantitative detection model of glucose was established. The model was x = e − 0.3305 ∗ ln y − 0.1039 ∗ 2 π ∗ 0.4065 8.3459 ∗ 10 − 4 + ln 7.3672 ∗ 10 − 4 1 + 0.3305 . The regression parameter R2 was 0.99672. Glucose was tested with different base solutions. Results showed that Na2S2O3 solution was a good base solution. The i-t control experiments showed that the proposed method were effective in Na2S2O3 solution.

Paradigm shift: Bacterial quorum sensing and possible control targets

QS Designates a cell-to-cell communication process that enables bacteria to collectively modify their behaviour in response to changes in the cell density and species composition of the surrounding microbial community. These processes involve the production, release and group-wide detection of extracellular signalling molecules, which are generically called Autoinducers (AIs). It controls various genes which are responsible for various phenotypes like bioluminescence, the secretion of virulence factors, and the formation of biofilms in bacteria. Quorum quenching inhibits QS and the substances that inhibit it are called quorum sensing inhibitors. Several chemical compounds and enzymes mediate inhibition of QS, such as, lactonases, acylases and oxidoreductases. Other than these, there are some non-enzymatic methods for quorum quenching and also some plant phytochemicals have been found to inhibit it. Blocking of QS by QS Inhibition (QSI) may play an important role to disrupt biofilm formation in a device associated infection and chronic drug resistant infection. More researches are required in this area related with QS and QSI. However, some chemicals have been found to be mimicking the quorum sensing AIs activities like serotonin and rosmaric acid.

Pharmacognostical and Pharmacological Evaluation of leaves of Citrullus lanatus L.

Citrullus lanatus (Watermelon) is commonly available throughout India and traditionally used in treatment of various ailments. This plant is well-explored for its fruit but the potential of its leaves is still unexplored. Thus, the present study focuses on pharmacognostical and pharmacological evaluation of leaves of Citrullus lanatus. In pharmacognostical evaluation, all macroscopic, microscopic, qualitative, quantitative and microbiological analysis were performed. In pharmacological evaluation, the study mainly focuses on the potential of leaves for antioxidant and antidiabetic activities. The antioxidant activity has been performed by various methods such as DPPH and phospho-molybdenum method. The antidiabetic activity has been performed by non-enzymatic glycosylation of hemoglobin assay method, glucose uptake in yeast cells method, alpha amylase inhibition assay method and alpha glucosidase inhibition assay method. The results of antioxidant activity shows that the plant extract possess good free radical scavenging properties due to the presence of vitamin C, polyphenol and flavonoid content. The results of antidiabetic activity by non-enzymatic glycosylation method shows that the plant extract of C. lanatus exhibit significant inhibition of glycosylation as compared with standard drug alpha tocopherol. In glucose uptake by yeast cells method, the extract showed greater efficiency in increasing the glucose uptake by yeast cells as compared to standard drug acarbose. In alpha amylase inhibition method, Alpha amylase inhibitors bind to alpha bond of polysaccharide and prevent breakdown of polysaccharide in mono and disaccharide which shows significant activity of plant extract as compared to an acarbose standard drug. Thus from the above findings, it can be concluded that C. lanatus leaves possess a great potential for antioxidant and antidiabetic activity and this plant should be more researched and formulation should be marketed in the recent future.
 Keywords: Citrullus lanatus (Cucurbitaceous), Watermelon, Anti-oxidant Activity, Anti-diabetic Activity