Molecular and structural insights of ß-boswellic acid and glycyrrhizic acid as potent SARS-CoV-2 Envelope protein inhibitors.

Background: Over million people have been infected with SARS-CoV-2 virus worldwide, with around 3% reported deaths till date. A few conventional antiviral treatments have been tried to mitigate the coronavirus. However, many alternative therapeutics are being evaluated worldwide. In the present study, we investigated traditional Indian medicinal compounds antiviral potencies as an effective drug for targeting SARS-CoV-2E. SARS-CoV-2 E protein plays a key role in coronavirus life cycle and is an interesting target for the development of anti-SARS-CoV-2 E drugs. Methods: Molecular docking studies of medicinal compounds possessing wide range of pharmacological and antiviral activities against enveloped viruses were evaluated with the computer-aided drug design screening software; PyRx. Twelve medicinal compounds isolated from plants were screened and visualized on Biovia Discovery-Studio. Moreover, SARS-CoV-2 E protein's secondary structural insights were deciphered using Swiss Model and ProFunc web server. Results: Glycyrrhizic acid, triterpene glycoside isolated from plants of Glycyrrhiza (licorice) showed interactions with envelope protein at chain A: Arg 61, chain B: Phe 23, chain B: Tyr 57, and chain C: Val 25. ß- boswellic acid, an ayurvedic herb (pentacyclic terpenoid are produced by Boswellia) represented direct interactions and indirect binding with chain C. Their pharmacological aspects and drug-likeness properties were deduced by DruLiTo. Toxicological assessment, along with their ADME profiling, was validated using vNNADMET. The findings showed that ligands, ß-boswellic acid, and glycyrrhizic acid possessed the best bindings, with the target having binding affinity (-9.1 kcal/mol) amongst compounds tested against SARS-CoV-2 E. In-vitro studies reveals the promising effect as potent SARS-CoV-2 E inhibitors. Functionality loss and structural disruptions with ∼90% were observed by UV-spectra and fluorescent based analyses. Conclusion: The study demonstrated that ß-boswellic acid, and glycyrrhizic acid are strong SARS-CoV-2 E protein inhibitors. In addition, the work linked GA antiviral activity to its effect on SARS-CoV- 2 E protein that can pave the way for designing antiviral therapeutics.

Effect of Psidium guajava leaves extracts on thermo-lipid oxidation and Maillard pathway born food toxicant acrylamide in Indian staple food.

Deep frying of food is a common practice that leads to the formation of lipid oxidation products. These lipid oxidation products have a role in the Maillard reaction, which ultimately leads to the formation of cancer-causing and neurotoxic substance acrylamide. In this regard, the Psidium guajava leaves extract-treated sunflower oil on oxidative stability and acrylamide content in pooris a popular deep-fried staple food in India were studied and compared with synthetic antioxidant butylated hydroxytoluene (BHT) till four frying cycles. P. guajava leaves contain 173.33 ± 1.95 mg GAE/g extract total phenolic content and 20.43 ± 0.25 mg RUE/g extract total flavonoid content. Some of the phytochemicals in the extract were identified and quantified by HPTLC. P. guajava leaves extract (1 g) contained 0.039 mg gallic acid, 0.196 mg rutin, 0.021 mg naringenin, 0.059 mg ferulic acid. The IC50 values for guava leaves extract, BHT, and ascorbic acid were 61.4, 30.4, 26.6 µg/mL, respectively. The peroxide and p-anisidine values indicated that P. guajava leaves extract inhibited lipid oxidation and provided oxidative stability. Pooris fried in P. guajava leaves extract-treated, BHT treated sunflower oil contained a lower acrylamide than pooris fried in control sunflower oil. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at (10.1007/s13197-021-04984-y).

A Chemosensor Based on Gold Nanoparticles and Dithiothreitol (DTT) for Acrylamide Electroanalysis.

Rapid and simple electroanalysis of acrylamide (ACR) was feasible by a gold electrode modified with gold nanoparticles (AuNPs) and dithiothreitol (DTT) with enhanced detection sensitivity and selectivity. The roughness of bare gold (Au) increased from 0.03 µm to 0.04 µm when it was decorated with AuNPs. The self-assembly between DTT and AuNPs resulted in a surface roughness of 0.09 µm. The DTT oxidation occurred at +0.92 V. The Au/AuNPs/DTT surface exhibited a surface roughness of 0.24 µm after its exposure to ACR with repeated analysis. SEM imaging illustrated the formation of a polymer layer on the Au/AuNPs/DTT surface. Surface plasmon resonance analysis confirmed the presence of AuNPs and DTT on the gold electrode and the binding of ACR to the electrode's active surface area. The peak area obtained by differential pulse voltammetry was inversely proportional to the ACR concentrations. The limit of detection (LOD) and the limit of quantitation (LOQ) were estimated to be 3.11 × 10-9 M and 1 × 10-8 M, respectively, with wide linearity ranging from 1 × 10-8 M to 1 × 10-3 M. The estimated levels of ACR in potato chips and coffee samples by the sensor were in agreement with those of high-performance liquid chromatography.

Immobilization of L-asparaginase on magnetic nanoparticles: Kinetics and functional characterization and applications.

L-asparaginase shows great potential as a food enzyme to reduce acrylamide formation in fried and baked products. But for food applications, enzymes must be stable at high temperatures and have higher catalytic efficiency. These desirable characteristics are conferred by the immobilization of enzymes on a suitable matrix. The present study aimed to immobilize the L-asparaginase enzyme on magnetic nanoparticles to reduce acrylamide content in the food system. Immobilized preparations were characterized using SEM, TEM, FTIR, UV-spectrometry, and XRD diffraction analyses. These nanoparticles enhanced the thermal stability of the enzyme up to four-fold at 70 °C compared to the free enzyme. Kinetic parameters exhibited an increase in Vmax, Km, and catalytic efficiency by ~ 38% than the free counterpart. The immobilized preparations were reusable for up to five cycles. Moreover, their application in the pre-treatment coupled with blanching of potato chips led to a significant reduction (greater than 95%) of acrylamide formation.

Stability of Therapeutic Enzymes: Challenges and Recent Advances.

Enzymes are biocatalysts that have found profound applications in the current biotherapeutic industry and play a crucial role in diagnosis, prevention, and biochemical analysis of major diseases. However, stability, protein degradation and immunogenicity in the body present unique challenges that are faced upon sustained use of such enzymes. The present chapter is an attempt to dissect the state-of-the-art in relation to the challenges of development of therapeutic enzymes and the recent advances to address them. At the very outset, diseases where enzymes have found effective applications and the various causes of enzyme instability have been discussed. In recent times, polymer or nano- conjugated resistant delivery methods, as well as mutagenesis have led to manifold increase in enzyme stability against thermal denaturation, acidic gut environment, proteolysis and immunogenicity. Further, methods of analytical characterization of proteins have been highlighted and explored to shape future research directions.

Asparaginase conjugated magnetic nanoparticles used for reducing acrylamide formation in food model system.

Acrylamide is a potent carcinogen and neurotoxin formed by the Maillard reaction when l-asparagine reacts with starch at high temperature. It is formed in food materials mainly deep fried and bakery products. Enzymatic pretreatment of these food products with asparaginase enzyme leads to reduction in acrylamide. However, enzymatic process is quite expensive due to high cost, low catalytic efficiency as well as problem with enzyme reusability. Present work deals with these problems by exploring l-asparaginase from Bacillus aryabhattai. Asparaginase enzyme was immobilized on APTES modified magnetic nanoparticles. It was found to be more than three-fold increase their thermal stability from free enzyme and retained 90% activity after fifth cycle. The immobilized enzyme also showed better affinity towards its substrate. During pretreatment of asparagine in a starch-asparagine food model system and it was clearly demonstrated that asparaginase nanoconjugates had reduced the formation of acrylamide by more than 90% within 30 min.