MOLECULAR DOCKING STUDIES OF RICINUS COMMUNIS PHYTOCHEMICALS AGAINST BETA-LACTAMASE FROM ENTEROCOCCUS FAECALIS AND STAPHYLOCOCCUS AUREUS

Objective: The objective of this study is to investigate the antibacterial activity of Ricinus communis phytochemicals against beta-lactamase from Enterococcus faecalis and Staphylococcus aureus through molecular docking studies. Methods: The three-dimensional (3D) structure of beta-lactamase from E. faecalis was modeled using modeler 9v9 and validated. The 3D structure of beta-lactamase from S. aureus (PDB ID: 1 GHP) was retrieved from PDB database. The 2D structures of 29 phytochemical compounds from the methanol leaf extracts of R. communis were drawn in ACD-Chemsketch and converted into 3D structures. The 3D structure of R. communis leaf compounds and cefotaxime (control) was virtually screened in the binding pockets of β-lactamase proteins from E. faecalis and S. aureus using FlexX docking program. Results: The docking studies revealed that ferulic acid and hyperoside exhibited promising minimum binding and docking energy that is closely related to the docking score of standard antibiotic cefotaxime. Conclusion: The result of the present study indicates that ferulic acid and hyperoside are potential compounds that could be effectively used in the treatment of infections caused by E. faecalis and S. aureus. However, further clinical studies are required to ascertain the antibacterial activity and potential toxic effects of ferulic acid and hyperoside in vivo.Â

Effects of fiber loadings and lengths on mechanical properties of Sansevieria Cylindrica fiber reinforced natural rubber biocomposites

© 2023 The Author(s). Published by IOP Publishing Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/In this present investigation, Sansevieria cylindrica fiber was used as a reinforcement in a natural rubber matrix. Various biocomposite samples with different fiber contents (lengths and loadings) were fabricated, using compression molding process and vulcanizing technique by maintaining the temperature around 150 °C. From the results obtained, mechanical properties: tensile strength, modulus elongation at break and tear strength of 10.44 MPa, 2.36 MPa, 627.59% and 34.99 N respectively, were obtained from the optimum composite sample with length and loading of 6 mm and 20 wt% composition, respectively. The maximum hardness was observed at 76.85 Shore A from the composite sample of 6 mm and 40 wt%. The optimum properties can be attributed to the presence of strong interfacial adhesion between the Sansevieria cylindrica fiber and the natural rubber matrix. The mechanisms of failure of the biocomposites at their interfaces were examined and analyzed, using scanning electron microscopy (SEM). The micrographs obtained from SEM further confirmed that the Sansevieria cylindrica fibers were surrounded with more amount of natural rubber which can exhibit strong interfacial bonding between fiber and matrix. The optimal composites of this work can be used in general, abrasion resistant conveyor belt.Peer reviewe

Investigation of Static and Dynamic Mechanical Properties of Coconut Tree Primary Flower Leaf Stalk Fiber Reinforced Polymer Composites

This study focuses on the determination of the mechanical characteristics of composites under static and dynamic conditions. The composites are prepared by reinforcing with 3 mm, 7 mm, and 10 mm short-treated coconut tree primary flower leaf stalk fiber (CPFLSF) in the polymer matrix. The 3 mm untreated CPFLSF composite (3UTCPFLSFC) reveals the lowest tensile, flexural, and impact properties, whereas 7 mm Alkali-Treated CPFLSF Composite (7ATCPFLSFC) indicate the maximum tensile strength of 34.31 MPa, tensile modulus of 1.81 GPa, flexural strength of 58.43 MPa, flexural modulus of 3.23 GPa, and impact strength of 8.25 kJ/m2. Dynamic mechanical analysis (DMA) reveals that the 7ATCPFLSFC had enhanced loss and storage modulus compared to untreated and other alkali-treated CPFLSF composites. The maximum decomposition is obtained for 7ATCPFLSFC in the region of 550°C temperature with a residual mass of 18% compared to other compositions. From the water absorption test, it was observed that, when increasing the soaking time of the composites, water intake properties gradually increased in the composite. However, the 7ATCPFLSFC absorbed water, compared to the other composites. A scanning electron microscope confirms better bonding in the composite, fracture of fiber, pull-out, fiber shearing, and tearing in the treated and untreated composites

Wear Properties and Post-Moisture Absorption Mechanical Behavior of Kenaf/Banana-Fiber-Reinforced Epoxy Composites

The contribution of natural lignocellulosic fibers to the reduction in wear damage in polymer resins is of interest, especially when two of these fibers can combine their respective effects. Wear properties of hybrid kenaf/banana epoxy composites have been investigated using three different total amount of fibers, 20, 30 and 40 wt.%, at loading forces up to 30 N and to sliding distances of up to 75 m. This demonstrated that the introduction of the highest level of fibers proved the most suitable for consistency of results and containment of wear with increasing load, as was also found from the morphological evaluation of wear degradation using scanning electron microscopy (SEM). Subsequently, tensile, flexural and impact properties of as-received and post-water-saturation hybrid composites were examined. The tests revealed a limited reduction in tensile and flexural strength, not exceeding 10% of the initial values, which were very high compared to similar materials, almost reaching 140 MPa for tensile strength and exceeding 170 MPa for flexural strength. In contrast, a higher standard deviation of values was found for impact strength, although the decrease in average values was only slightly above 10%. The results suggest the availability of these hybrids for wear-resisting applications in high-moisture environments, and the even more limited water absorption conferred by banana fibers added to kenaf ones

Wear Properties and Post-Moisture Absorption Mechanical Behavior of Kenaf/Banana-Fiber-Reinforced Epoxy Composites

The contribution of natural lignocellulosic fibers to the reduction in wear damage in polymer resins is of interest, especially when two of these fibers can combine their respective effects. Wear properties of hybrid kenaf/banana epoxy composites have been investigated using three different total amount of fibers, 20, 30 and 40 wt.%, at loading forces up to 30 N and to sliding distances of up to 75 m. This demonstrated that the introduction of the highest level of fibers proved the most suitable for consistency of results and containment of wear with increasing load, as was also found from the morphological evaluation of wear degradation using scanning electron microscopy (SEM). Subsequently, tensile, flexural and impact properties of as-received and post-water-saturation hybrid composites were examined. The tests revealed a limited reduction in tensile and flexural strength, not exceeding 10% of the initial values, which were very high compared to similar materials, almost reaching 140 MPa for tensile strength and exceeding 170 MPa for flexural strength. In contrast, a higher standard deviation of values was found for impact strength, although the decrease in average values was only slightly above 10%. The results suggest the availability of these hybrids for wear-resisting applications in high-moisture environments, and the even more limited water absorption conferred by banana fibers added to kenaf ones

Sliding Wear Analysis of Ultra High Strength Steel Using Full Factorial Design Approach

This study describes multi-factor-based experiments that were applied to investigate the sliding wear behaviour of quenched and tempered wear resistant steel. This study was aimed to evaluate the effect of input parameters (such as applied load, sliding velocity and sliding time) on wear rate. Full factorial design through design of experiments approach was used for investigation by establishing an empirical relationship between wear loss and input parameters and determining the optimal combination of testing parameters for minimum and maximum wear losses. Sliding wear tests were carried out using pin-on-disc type apparatus at room temperature under dry sliding wear conditions. Detailed investigation revealed that applied load was the most significant factor affecting the wear performance followed by sliding velocity and sliding time. The maximum weight loss due to wear was found to be 33.48 mg when experimentation was conducted at maximum levels of input variables and minimum wear loss of 3.12 mg was obtained at the minimum levels of load, sliding velocity and sliding time. The scanning electron microscopy of the worn pin surfaces shows that adhesion and plastic deformation were the dominating mechanisms involved during experimentation that resulted in maximum wear of the pins, and on the other hand no such mechanism persisted when the pins were worn under minimum sliding wear conditions