Current Organic Chemistry - Volume 28, Issue 8, 2024

Cartilage tissue presents challenges in terms of repair and regeneration due to its inherent limitations in self-healing and the scarcity of available donors. Cartilage damage can result in the development of joint problems characterized by symptoms, such as pain, swelling, and osteoarthritis. Collagen scaffolds are extensively used as biomimetic substances for cartilage engineering due to their ability to offer structural, biochemical, and mechanical signals for chondrocytes. Nevertheless, traditional techniques for producing collagen scaffolds frequently yield inadequate pore architecture, diminished mechanical robustness, and restricted form accuracy. Hence, 3D printing is a developing method that can surpass these restrictions by allowing accurate manipulation of the shape, porousness, and makeup of the scaffold. 3D printing has the capability to include various materials and cells in the scaffolds, resulting in the production of intricate and personalized tissue structures. This research examines the latest progress in utilizing 3D printing to create collagen scaffolds for the purpose of regenerating cartilage. This text discusses the different sources of collagen, methods of cross-linking, techniques for printing, and strategies for post-processing that are employed to improve the performance of scaffolds. Furthermore, it discusses the difficulties and potential future paths of utilizing 3D printing to create collagen scaffolds for the purpose of regenerating cartilage.

The pyranoquinoline frameworks have a wide distribution in natural products and have displayed a great amplitude of biological activities, attracting the attention of synthetic and medicinal chemists due to their usefulness in agrochemical and pharmaceutical industries. Among the twenty possible isomeric pyranoquinoline frameworks, research reports for only six of them that were found during the period of time covered in this review article (i.e. 2000 to 2023). According to the literature reports during this frame of time, the synthesis of pyranoquinoline derivatives was achieved by following three general synthetic approaches [i.e. (i) via multicomponent cyclizations (MCC), (ii) via bimolecular cyclizations (BMC) and via intramolecular cyclizations (IMC)], mediated by catalyst-free conditions or by diverse environmentally friendly catalysts, in which mechanistic proposal was discussed for several of such processes. Additionally, various obtained pyranoquinoline derivatives reported in this review were subjected to diverse biological evaluations, such as Parkinson´s and Alzheimer´s diseases, as antibacterials, antifungals, and anticancer drugs, among others, indicating the promising biological potential of this class of heterocyclic structure.

In this work, we present the synthesis of a newer series of 15 chalcone-based pyrimidine compounds 4a-o. All the compounds were characterized by elemental analysis, melting point determination, mass, FTIR, and NMR analysis. We have evaluated the antimicrobial activity of these compounds. The compounds showed good inhibition activity towards different bacterial and fungal species such as S. aureus, S. pneumonia, E. coli, P. aeruginosa, Candida albicans, Aspergillus niger, and Alternaria alternata. Compounds 4c, 4h, 4k, and 4g showed comparable activities to those of commercially available drugs. Molecular docking study showed good interaction between each of the compounds and DNA gyrase enzyme. The docking score of the compounds ranges between -8.0 to -8.9 kcal/mol. Further, the ADMET analysis indicated the potential of the compounds as a drug candidate.

An efficient direct oxidation method was developed to oxidize some aromatic and aliphatic aldehydes to esters by the dual utilization of NaIO4 and Pd-C. At ambient conditions, various aldehydes were employed in a clean esterification reaction to afford numerous esters in good to excellent yields. By this adopted method, some multifunctional aldehydes, high-energy-containing aromatic and unsaturated aldehydes, were advantageously oxidized to esters without noticeable difficulties. Moreover, no over-oxidation occurred to alcohols, and mostly by products were not formed during this oxidation process. Conventional and some modern methods lag behind owing to their easier operability and easy work-up process. This investigation has proven that the required oxidant (NaIO4) or catalyst (Pd-C) is useless to employ in excess, although some current methods utilize hugely expensive reagents for such conversions. Mundane reaction set-up, easy product recovery technique, nontoxic catalyst, and cheap and available starting materials are the noteworthy advantages of this method.