Characterization, biological evaluation and molecular docking of mulberry fruit pectin

Biological potential, chemical profiling, and molecular docking study of Morus alba L. extracts

Morus alba L. is a plant with a long history of dietary and medicinal uses. We hypothesized that M. alba possesses a significant biological potential. In that sense, we aimed to generate the chemical, antimicrobial, toxicological, and molecular profile of M. alba leaf and fruit extracts. Our results showed that extracts were rich in vitamin C, phenols, and flavonoids, with quercetin and pterostilbene concentrated in the leaf, while fisetin, hesperidin, resveratrol, and luteolin were detected in fruit. Extracts exhibited antimicrobial activity against all tested bacteria, including multidrug-resistant strains. The widest inhibition zones were in Staphylococcus aureus ATCC 33591. The values of the minimum inhibitory concentration ranged from 15.62 μg/ml in Enterococcus faecalis to 500 μg/ml in several bacteria. Minimum bactericidal concentration ranged from 31.25 μg/ml to 1000 μg/ml. Extracts impacted the biofilm formation in a concentration-dependent and species-specific manner. A significant difference in the frequency of nucleoplasmic bridges between the methanolic extract of fruit (0.5 μg/ml, 1 μg/ml, 2 μg/ml), as well as for the frequency of micronuclei between ethanolic extract of leaf (2 μg/ml) and the control group was observed. Molecular docking suggested that hesperidin possesses the highest binding affinity for multidrug efflux transporter AcrB and acyl-PBP2a from MRSA, as well as for the SARS-CoV-2 Mpro. This study, by complementing previous research in this field, gives new insights that could be of great value in obtaining a more comprehensive picture of the Morus alba L. bioactive potential, chemical composition, antimicrobial and toxicological features, as well as molecular profile.

Development and comprehensive SBSE-GC/Q-TOF-MS analysis optimization, comparison, and evaluation of different mulberry varieties volatile flavor

Optimization of seven parameters of stir bar sorptive extraction (SBSE) on mulberry volatile components for the first time. A total of 347 volatile components were identified and quantified in 14 mulberry varieties, predominantly encompassing esters, aldehydes, terpenoids, hydrocarbons, ketones, alcohols, heterocyclics, acids, and phenols. Hexanal and (E)-2-hexenal were the dominant volatiles. Furthermore, 79 volatile compounds characterized by odor activity values (OAVs) > 1 were identified, making a significant contribution to the distinctive mulberry flavor. "Green" notes were the most intense, followed by "fatty" and "fruity". Utilizing odor ring charts, the volatile flavor characteristics of the 14 mulberry varieties could be intuitively distinguished. This study not only established a viable methodology for differentiating mulberry varieties but also laid a theoretical foundation for the quality evaluation and variety breeding of mulberry flavor.

Fabrication of mulberry leaf extract (MLE)- and tasar pupal oil (TPO)-loaded silk fibroin (SF) hydrogels and their antimicrobial properties

Biocomposites have gained tremendous advantages over synthetic composites due to their biocompatibility, sustainable degradation, and ability to easily combine with other substances. In the present study, we have prepared silk fibroin (SF) hydrogel, mulberry leaf extract (MLE), tasar pupal oil (TPO), and their composites, such as TPO-loaded SF hydrogel and MLE-loaded SF hydrogel, and characterized them by using a phase contrast microscope (PCM), scanning electron microscope (SEM) SEM- EDX, and Fourier transform infrared spectroscopy (FTIR). In addition, 1H-NMR was used for profiling of mulberry leaf extract and GC-MS was used to find tasar pupal oil composition. Further, the disc diffusion method evaluated their antimicrobial activities against S. aureus, E. coli, A. flavus, and A. brassicae. PCM, SEM, and FTIR results validated the conjugation of MLE and SF hydrogel composite; 1H-NMR confirmed the 41 metabolites in MLE, and GC-MS established the composition of tasar pupal oil. Since both composites, such as TPO-loaded SF hydrogel and MLE-loaded SF hydrogel, reduced the S. aureus and E. coli activities at all tested concentrations, the antibacterial results were unambiguous in their conclusion. S. aureus could only be inhibited by SF hydrogel at a high concentration (300 g/ml), despite suppressing E. coli growth at all tested concentrations. At 300 g/ml, MLE demonstrated antibacterial action against S. aureus. Furthermore, at a dosage of 300 g/ml, TPO inhibited both S. aureus and E. coli. Both mulberry leaf extract (at 200 and 300 g/ml) and the MLE-loaded SF hydrogel composite displayed antifungal activity against A. flavus at all tested concentrations (100, 200, and 300 g/ml).

Structural Characteristics, Rheological Properties, and Antioxidant and Anti-Glycosylation Activities of Pectin Polysaccharides from Arabica Coffee Husks

As primary coffee by-products, Arabica coffee husks are largely discarded during coffee-drying, posing a serious environmental threat. However, coffee husks could be used as potential material for extracting pectin polysaccharides, with high bioactivities and excellent processing properties. Thus, the present study aimed to extract the pectin polysaccharide from Arabica coffee husk(s) (CHP). The CHP yield was calculated after vacuum freeze-drying, and its average molecular weight (Mw) was detected by gel permeation chromatography (GPC). The structural characteristics of CHP were determined by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), proton nuclear magnetic resonance (¹H NMR), and scanning electron microscopy (SEM). Additionally, the rheological and antioxidant properties of CHP and the inhibition capacities of advanced glycation end products (AGEs) with different concentrations were evaluated. The interaction mechanisms between galacturonic acid (GalA) and the AGE receptor were analyzed using molecular docking. The results demonstrated that the CHP yield was 19.13 ± 0.85%, and its Mw was 1.04 × 10⁶ Da. The results of the structural characteristics results revealed that CHP was an amorphous and low-methoxyl pectic polysaccharide linked with an α-(1→6) glycosidic bond, and mainly composed of rhamnose (Rha, 2.55%), galacturonic acid (GalA, 45.01%), β-N-acetyl glucosamine (GlcNAc, 5.17%), glucose (Glc, 32.29%), galactose (Gal, 6.80%), xylose (Xyl, 0.76%), and arabinose (Ara, 7.42%). The surface microstructure of CHP was rough with cracks, and its aqueous belonged to non-Newtonian fluid with a higher elastic modulus (G'). Furthermore, the results of the antioxidant properties indicated that CHP possessed vigorous antioxidant activities in a dose manner, and the inhibition capacities of AGEs reached their highest of 66.0 ± 0.35% at 1.5 mg/mL of CHP. The molecular docking prediction demonstrated that GalA had a good affinity toward AGE receptors by -6.20 kcal/mol of binding energy. Overall, the study results provide a theoretical basis for broadening the application of CHP in the food industry.

Mulberry plant as a source of functional food with therapeutic and nutritional applications: A review

Medicinal plants from the family Moraceae have diverse applications in agriculture, cosmetics, food, and the pharmaceutical industry. Their extensive spectrum of pharmacological activity for treating numerous inflammatory illnesses, cancer, cardiovascular diseases, and gastrointestinal problems reflects their biological and therapeutic value. This article summarizes the molecular mechanisms related to the biological implications of mulberry extracts, fractions, and isolated bioactive compounds from different parts in various health-related ailments. Additionally, the food industry and animal nutrition applications are summarized. Phytochemicals such as steroids, saponins, alkaloids, glycosides, polysaccharides, and phenolic compounds including terpenoids, flavonoids, anthocyanins, and tannins are found in this medicinal plant. The aqueous, ethanolic, and methanolic extracts, as well as bioactive compounds, have anti-oxidative, hypoglycemic, nephroprotective, antimicrobial, neuroprotective, anti-mutagenic, hepatoprotective, anthelmintic, immune-modulatory, cardioprotective, and skin protecting activities. Mulberry supplementation in food products improves the stability of phenolics, sensory properties, antioxidant activity, and antimicrobial properties. Mulberry leaves in animal feed increase the nutrient digestibility, growth parameters, antimicrobial, and antioxidant properties. PRACTICAL APPLICATIONS: This review summarized the in vivo and in vitro biological activities of the mulberry and isolated constituents in various health conditions. In addition, the food uses such as antioxidant potential, antimicrobial, and physicochemical properties were discussed. Furthermore, in vivo studies revealed mulberry as a significant protein source and its flavonoids as potential animal foliage.

In Silico Evaluation of Binding of 2-Deoxy-D-Glucose with Mpro of nCoV to Combat COVID-19

COVID-19 has threatened the existence of humanity andthis infection occurs due to SARS-CoV-2 or novel coronavirus, was first reported in Wuhan, China. Therefore, there is a need to find a promising drug to cure the people suffering from the infection. The second wave of this viral infection was shaking the world in the first half of 2021. Drugs Controllers of India has allowed the emergency use of 2-deoxy-D-glucose (2DG) in 2021 for patients suffering from this viral infection. The potentiality of 2-deoxy-D-glucose to intervene in D-glucose metabolism exists and energy deprivation is an effective parameter to inhibit cancer cell development. Once 2DG arrives in the cells, it becomes phosphorylated to 2-deoxy-D-glucose-6-phosphate (2-DG6P), a charged molecule expressively captured inside the cells. On the other hand, 2DG lacks the ability to convert into fructose-6-phosphate, resulting in a hampering of the activity of both glucose-6-phosphate isomerase and hexokinase, and finally causing cell death. Hence, the potential and effectiveness of 2DG with the main protease (Mpro) of novel coronavirus (nCoV) should be investigated using the molecular docking and molecular dynamics (MD) simulations. The ability of 2DG to inhibit the Mpro of nCoV is compared with 2-deoxyglucose (2DAG), an acyclic molecule, and 2-deoxy-D-ribose (2DR). The binding energy of the molecules with the Mpro of nCoV is calculated using molecular docking and superimposed analysis data is obtained. The binding energy of 2DG, 2DR and 2DAG was −2.40, −2.22 and −2.88 kcal/mol respectively. Although the molecular docking does not provide reliable information, therefore, the binding affinity can be confirmed by molecular dynamics simulations. Various trajectories such as Rg, RMSD, RMSF, and hydrogen bonds are obtained from the molecular dynamics (MD) simulations. 2DG was found to be a better inhibitor than the 2DAG and 2DR based on the results obtained from the MD simulations at 300 K. Furthermore, temperature-dependent MD simulations of the Mpro of nCoV with promising 2DG was performed at 295, 310 and 315 K, and the effective binding with the Mpro of nCoV occurred at 295 K. With the use of DFT calculations, optimized geometry and localization of electron density of the frontier molecular orbitals were calculated.

Hunting the main protease of SARS-CoV-2 by plitidepsin: Molecular docking and temperature-dependent molecular dynamics simulations

COVID-19 has shaken all the countries across the globe and researchers are trying to find promising antiviral to cure the patients suffering from infection and can decrease the death. Even, different nations are using repurposing drugs to cure the symptoms and these repurposing drugs are hydroxychloroquine, remdesivir, and lopinavir, and recently, India has recently given the approval for the 2-deoxy-d-glucose for emergency purpose to cure the patients suffering from the COVID-19. Plitidepsin is a popular molecule and can be used in treatment of myeloma. Plitidepsin was explored by scientists experimentally against the COVID-19 and was given to the patient. It is found to be more a promising repurposing drug against the COVID-19 than the remdesivir. Therefore, there is a need to understand the interaction of plitidepsin with the main protease of SARS-CoV-2. Molecular docking of the plitidepsin against Mpro of SARS-CoV-2 was performed and the binding energy was found to be − 137.992 kcal/mol. Furthermore, authors have performed the molecular dynamics simulations of the main protease of SARS-CoV-2 in presence of plitidepsin at 300 and 325 K. It was found that the plitidepsin binds effectively with the main protease of SARS-CoV-2 at 300 K.

Morus alba L. Plant: Bioactive Compounds and Potential as a Functional Food Ingredient

Morus alba L. (M. alba) is a highly adaptable plant that is extensively incorporated in many traditional and Ayurveda medications. Various parts of the plant, such as leaves, fruits, and seeds, possess nutritional and medicinal value. M. alba has abundant phytochemicals, including phenolic acids, flavonoids, flavonols, anthocyanins, macronutrients, vitamins, minerals, and volatile aromatic compounds, indicating its excellent pharmacological abilities. M. alba also contains high nutraceutical values for protein, carbohydrates, fiber, organic acids, vitamins, and minerals, as well as a low lipid value. However, despite its excellent biological properties and nutritional value, M. alba has not been fully considered as a potential functional food ingredient. Therefore, this review reports on the nutrients and bioactive compounds available in M. alba leaves, fruit, and seeds; its nutraceutical properties, functional properties as an ingredient in foodstuffs, and a microencapsulation technique to enhance polyphenol stability. Finally, as scaling up to a bigger production plant is needed to accommodate industrial demand, the study and limitation on an M. alba upscaling process is reviewed.

Promising inhibitors of nsp2 of CHIKV using molecular docking and temperature-dependent molecular dynamics simulations

Infection due to the Chikungunya virus (CHIKV) has taken the life of lots of people; and researchers are working to find the vaccine or promisng drug candidates against this viral infection. In this work, the authors have designed one component reaction based on the thia-/oxa-azolidineone and created a library of 2000 molecules based on the product obtained. Further, the compounds were screened through the docking using iGemdock against the non-structural protein 2 (nsp2) of CHIKV. Molecular docking gives the binding energy (BE) or energy for the formation of the complex between the designed compound and nsp2 of CHIKV; and CMPD222 gave the lowest energy. This is based on the energy obtained from van der Waal's interaction, hydrogen bonding and electrostatic instructions. Further, molecular dynamics simulations (MDS) of nsp2 of CHIKV with and without screened compound (222) were performed to validate the docking results and the change in free energy for the formation of the complex is -10.8327 kcal/mol. To explore the potential of CMPD222, the MDS of the CMPD222-nsp2 of CHIKV were performed at different temperatures (325, 350, 375 and 400 K) to understand the inhibition of the protease. MM-GBSA calculations were performed to determined change in entropy, change in enthalpy and change in free energy to understand the inhibition. Maximum inhibition of nsp2 of CHIKV with CMPD222 is observed at 375 K with a change in free energy of -19.3754 kcal/mol.Communicated by Ramaswamy H. Sarma.