Exploring the Characterization of biodegradable plastic “polyhyroxybutrate” (PHB) from Bacillus siamensis PHB 01 (MW440618) isolated from termite mound soil of Western Ghats of Coimbatore, Tamil Nadu.

The present study was aimed to explore the characterization of polyhydroxy butrate extracted from the bacterial strain under optimized conditions for the production of bioplastic. Under optimized fermentation conditions, Polyhydroxy butrate (PHB) was extracted and subjected to examine their properties via Thin Layer Chromotogram (TLC), Gas Chromotogram- Mass Spectrometer (GC-MS), Fourier Transform Infrared spectrum (FTIR). The presence of a brown spot in the TLC plate indicates the presence of hydroxylgroup which is similar to the polymer group. GC-MS analysis of extracted PHB shows peaks at the retention time of 3.8, 11.6 which is corresponding to octadecanoic acid, hexadecanoic acid, butyl -2-ethylester confirms the presence of polymeric nature in the extracted PHB. The absorption bands of FTIR at 1719–1720 cm −1 indicate the presence of C=O group of PHB. The absorption peaks at wave numbers 500-1000 cm -1 , 1055 cm -1 and 1230 cm -1 denotes (OH) group, (C–O) stretch and (C=O) ester group. From these results, it was confirmed that the extracted PHB is having the potential to replace petroleum plastic.

Characteristics and Kinetics Study of Glycerolabietate from Glycerol and Abietic Acid from Rosin

Rosin is a natural resin from the coniferous tree sap, which separated from its oil content (terpenes). Rosin is brittle. Therefore modifications are needed to improve its mechanical properties. The main content of rosin is abietic acid which has a carboxylic group, so it can form an ester group when reacted with polyhydric alcohol (polyalcohol) such as glycerol. The research aimed to study the kinetics of the esterification reaction between the hydroxyl group in glycerol and the carboxylic group in abietic acid from rosin at various reaction temperatures and reactant compositions. This reaction is carried out in a three-neck flask at atmospheric pressure without a catalyst. The reaction temperatures used were 180˚C, 200˚C, and 220˚C, and the ratio of rosin and glycerol was 1:1, 1:3, and 1:5. The reaction kinetics calculations were analyzed with acid number data over the reaction time using three different models. The calculations showed that this reaction involves positioning a hydroxyl group on glycerol, which the primary and secondary hydroxyl groups contribute to forming a rosin ester (glycerolabietate). The rate of reaction constants of primary hydroxyl of glycerol and abietic acid were in the range 6.25x10-4 - 3.90x10-3 g/(mgeq.min), while reaction rate constants of secondary hydroxyl and abietic acid were in the range 1.06x10-5 - 1.15x10-4 g/(mgeq.min). FTIR analysis showed a change in the hydroxyl, carboxylate, and ester groups which were assigned by a shift of wavenumber and a difference of intensity at 3200-3570 cm-1, 1697.36 cm-1, and 1273.02 cm-1.

Meta-Analysis of Volatile Compounds from Vinegar Produced by the Slow Method and the Fast Method

Volatile compounds are one of the important characteristics of vinegar, where the content and composition of these compounds is an account for the aroma profile of vinegar. The difference in production technology used in making vinegar produces vinegar with different characteristics. There are two general methods commonly used in the production of vinegar, namely the slow method and the fast method. This meta-analysis was used to conclude several studies that examined the differences in volatile compounds in vinegar produced through the slow methods and the fast methods. From this study, it can be seen that comparison of volatile compounds characteristics in vinegar produced by the slow method and the fast method where the slow method tends to produce vinegar with a high concentration of acetate ester group and alcohol group, and the fast method tend to produced vinegar with a high concentration in a volatile acid group.

Development of an RNA-protein crosslinker to capture protein interactions with diverse RNA structures in cells

Characterization of RNA-protein interaction is fundamental for understanding metabolism and function of RNA. UV crosslinking has been widely used to map the targets of RNA-binding proteins, but is limited by low efficiency, requirement for zero-distance contact and biases for single-stranded RNA structure and certain residues of RNA and protein. Here, we report the development of an RNA-protein crosslinker (AMT-NHS) composed of a psoralen derivative and an N-hydroxysuccinimide ester group, which react with RNA bases and primary amines of protein, respectively. We show that AMT-NHS can penetrate into living yeast cells and crosslink Cbf5 to H/ACA snoRNAs with high specificity. The crosslinker induced different crosslinking patterns than UV and targeted both single- and double-stranded regions of RNA. The crosslinker provides a new tool to capture diverse RNA-protein interactions in cells.

Novel ratiometric fluorescent probe based on internal reference and its detection of hydrazine

In this work, dual-emissive ratiometric fluorescent system was constructed by the introduction of an ideal internal reference. By virtue of its unique alkalinity, N 2 H 4 could undergo a hydrazinolysis reaction with the ester group of F1 , inducing remarkable fluorescence enhancement while the blue fluorescence of the internal reference DPA remained constant. Consequently, the fluorescence intensity ratios (I 540 /I 440 ) were proportional to the concentrations of N 2 H 4 , which was beneficial for the exactly quantitative detection. The skillful strategy granted the sensing system advantages such as relative good solubility in aqueous media, easy-to-design, simple synthesis, large emission shift, good ratiometric response, as well as the successful application in real water samples and cell imaging.

Fabrication of Norbixin-Sensitized Solar Cell and The Effect of Light Intensity on Its Performance and Reusability

Dye-sensitized solar cell (DSSC) is a third-generation solar cell that has been developed as one of the clean and renewable alternative energies. This study aims to fabricate norbixin-sensitized solar cell (NSSC). Norbixin was obtained from the saponification followed by acidification of bixin and characterized using UV-Visible and FTIR spectroscopy. The solar cell was assembled using anatase-TiO2 semiconductor, KI/I2/MPII in acetonitrile as the electrolyte, and a platinum paste-based cathode. The UV-Visible spectrophotometry analysis results showed three peaks of carotenoid characteristics at 434, 457, and 486 nm. The formation of norbixin was proved by the absence of a spectral peak for the C-O-C ester group of bixin at 1254 dan 1159 cm-1” The cells performance test showed that the maximum energy conversion efficiency of NSSC increased with increasing light intensity up to 0.08 W/cm2. Exposure to the light above this intensity causes a decrease in the maximum energy conversion efficiency due to the temperature factor. The data also showed that the cell assembled was reusable. It still showed relatively good performance until the third day of analysis.

Chemical Reactivity Descriptors and Molecular Docking Studies of Octyl 6-O-hexanoyl-β-D-glucopyranosides

The present study describes different chemical reactivity predictions of 6-O-hexanoylation of octyl β-D-glucopyranosides prepared from octyl β-D-glucopyranoside (OBG). Also, molecular docking of the OBGs was conducted against SARS-CoV-2 main protease (6LU7), urate oxidase (Aspergillus flavus; 1R51) and glucoamylase (Aspergillus niger; 1KUL). DFT optimization indicated that glucoside 1 and its ester derivatives 2-7 exist in 4C1 conformation with C1 symmetry. Interestingly, the addition of ester group(s) decreased the HOMO-LUMO gap (Δԑ) of glucosides indicating their good chemical reactivities, whereas the other chemical reactivity descriptors indicated their moderate reactive nature. This fact of moderate reactivity was confirmed by their molecular docking with 6LU7, 1R51 and 1KUL. All the esters showed a moderate binding affinity with these three proteins. More importantly, incorporation of the ester group(s) increased binding affinity with 6LU7 and 1R51, whereas decreased with 1KUL as compared to non-ester OBG 1.

Naphthalen-2-yl 1-(Benzamido(diethoxyphosphoryl)methyl)-1H-1,2,3-triazole-4-carboxylate

We have previously published new biheterocyclic phospohonic -amino esters of the 1,2,3-triazole-benzimidazole and 1,2,3-triazole-carbazole type. The aim of the present paper was to describe a new phosponic aminoester bearing a triazole ring substituted in position 5 by an ester group. Thus, according to the same catalytic process used previously, the compound naphthalen-2-yl 1-(benzamido(diethoxyphosphoryl)methyl)-1H-1,2,3-triazole-4-carboxylate was synthesized with an excellent yield and high regioselectivity via the copper (I)-catalyzed alkyne–azide cycloaddition reaction (CuAAC), using diethyl (-azido(benzamido)methyl)phosphonate (1) as a dipole and 2- naphthyl propiolate as a dipolarophile (2). The structure of the new compound was fully characterized by 1D (31P, 1H, 13C) and 2D (1H-1H and 1H-13C) NMR spectroscopy, IR, and HRMS.

The Synthesis and Evaluation of Aminocoumarin Peptidomimetics as Cytotoxic Agents on Model Bacterial E. coli Strains

This work presents the successful synthesis of a library of novel peptidomimetics via Ugi multicomponent reaction. Most of these peptidomimetics contain differently substituted aminocoumarin; 7-amino-4-methylcoumarin and 7-amino-4-(trifluoromethyl) coumarin. Inspired by the biological properties of coumarin derivatives and peptidomimetics, we proposed the synthesis of coumarin incorporated peptidomimetics. We studied the potential of synthesized compounds as antimicrobial drugs on model E. coli bacterial strains (k12 and R2–R4). To highlight the importance of coumarin in antimicrobial resistance, we also synthesized the structurally similar peptidomimetics, using benzylamine. Preliminary cellular studies suggest that the compounds with coumarin derivatives have more potential as antimicrobial agents compared to the compounds without coumarin. We also analyzed the effect of aldehyde, free acid group and ester group on the course of their antimicrobial properties.

Analysis of Aroma Compounds in Tofu from Lembang, Sumedang and Garut West Java, Indonesia

Tofu from Lembang, Tofu from Sumedang and Tofu from Garut are three types tofu that are produced in different places, but still close. Although made from the same raw material that is soy, every tofu will produce a different tofu, both in terms of taste, aroma, texture and suppleness. Differences in the type of flavour compouds used can also be a factor causing divergence of any tofu product. The characteristic of the tofu were determined by identifying the flavour compouds GC-MS, as well as organoleptic tests. To determine differences in compound-producing falvour in the tofu. The results extraction method was carried out on tofu samples using n-pentane as solvent then analyzed using GC-MS. Flavour compounds of all three types of tofu included into the ester group, alkenes and aldehydes. Organoleptic tests show that the panelists prefered. Tofu from Sumedang for test of colour appearance (82%), for the test texture panelists like Tofu from Garut (83%), for test of elasticity panelists prefered Tofu from Garut Lembang (75%), for taste test panelists prefered Tofu from Lembang (88%), panelists prefered Tofu from Lembang for flavour test (82%).