The synthesis of monocyclic and bicyclic molecules and their antioxidant properties

Cutting-edge innovations in lignin-based nanoparticles: A review of synthesis techniques, characterization, and diverse applications

Lignin is the most prevalent by-product of the pulp and paper industry and the world's second most abundant naturally occurring renewable biopolymer, after cellulose. Among various lignin-based materials, lignin nanoparticles (LNPs) are inexpensive and easily biodegradable by fungi and bacteria in nature, considered as a valuable class of renewable resources. Additionally, LNPs are not biotoxic and do not cause tissue rejection. Recent studies have shown that LNPs exhibit bright and promising applications in biocatalysts, energy storage devices, drug and tissue engineering, and hybrid nanocomposites. These nanoparticles can be synthesized from different lignin by utilizing various chemical, physical, and biological processes, resulting in diverse morphology, shape, size, yield, and stability. The purpose of this review is to discuss the current state of lignin-based nanoparticles, with an emphasis on their viability and commercialization. To understand the concept, mechanism of formation, synthesis techniques, and applications, as well as future perspectives and challenges.

Synthesis of Schiff Bases and Secondary Amines with Indane Skeleton; Evaluation of Their Antioxidant, Antibiotic, and Antifungal Activities

In this study, Schiff bases were synthesized by utilizing the reaction of 4- and 5-aminoindane with substituted benzaldehydes. After the reduction of isolated Schiff bases with NaBH4 , the corresponding secondary amine derivatives were obtained. The structures of all synthesized molecules were confirmed by 1 H-NMR, 13 C-NMR, FT-IR, and ESI-MS. Antioxidant activities of all synthesized molecules were investigated by DPPH method, and IC50 values were calculated. In addition, antibacterial activities of targets were investigated by the well diffusion method, and then MIC99 values were calculated. While only four of the sixteen synthesized molecules showed a high level of antioxidant activity, all of the molecules exhibited biological activity against Gram-positive and Gram-negative bacteria to varying degrees. In addition, all the synthesized molecules showed high antifungal activity. In antioxidant capacity studies, the IC50 values of 2-(((2,3-dihydro-1H-inden-5-yl)amino)methyl)-6-methoxyphenol (4 d) and 2-(((2,3-dihydro-1H-inden-4-yl)amino)methyl)-6-methoxyphenol (7 d) were determined to be 18.1 μg and 35.1 μg, respectively, and these values are much stronger than BHT (butylated hydroxytoluene) and BHA (butylated hydroxyanisole) used as positive controls. The fact that targets have the same core structure with different substituents has revealed a good structure-activity relationship.