Mini-Reviews in Organic Chemistry - Volume 19, Issue 3, 2022

Abstract: Research for discovering chemical entities with antiproliferative properties to combat globally rising cancer cases has witnessed tremendous interest in recent years. Phenothiazines possess novel antiproliferative potentials and have often be described as crucial sources of scaffolds for anticancer drug discovery. Some several phenothiazine-hybrid compounds recently synthesised are effective against various cancer cell lines with improved multidrug resistance. In synthesising these phenothiazine-derivatives, therapeutic potentials of the phenothiazines are exploited, and they are enriched by molecular hybridisation with moieties known to possess great pharmacological profiles. This article critically reviews the anticancer properties of phenothiazine derivatives and focuses on the possibility of the derivation of the leads for a further spectrum of antiproliferative activities.

Abstract: In this mini-review article, we have mentioned the key roles of some of the most important herbal plants medicine containing flavonoids and phytochemicals with antiviral activities. All relevant information was searched by using the terms, influenza, phytochemicals, SARS, SARSCov- 2, flavonoids, and traditional medicinal plants uses, from reliable databases, such as PubMed, Science Direct, and Google Scholar. The most important medicinal herbs which contain flavonoids with antiviral activities are Limonium densiflorum, Oroxylum indicum, Tribulus terrestris L., Paulownia tomentosa Steud., Allophylus africanus, Houttuynia cordata, Moslea Herba, Mosla scabra, Scutellaria baicalensis, Berries, Genus Psoralea, Sophora tonkinensis, Trollius chinensis, Tilia cordata, Hippophae rhamnoides L. (Seabuckthorn), Paulownia tomentosa steud, and C. swietenia. Phytochemicals are chemicals of plant origin produced by plants through primary or secondary metabolism. The most important medicinal plants, which contain phytochemicals with antiviral activities are Blue honeysuckle (Lonicera caerulea L.), Forsythia suspense, Ligustrum lucidum, Radix Paeoniae Alba (Bai Shao), Banlangen (Radix Isatidis), Lysiphyllum strychnifolium, Phellinus baumii, Mesona chinensis, Sanguinaria Canadensis, Dodonaea viscosa, Isatis indigotica, Pelargonium sidoides, Entada Africana Guill., Pomegranate (Punica granatum), Goldenseal (Hydrastis canadensis), Lychee fruit extract, Lycoris radiate, Cistus incanus, Chaenomeles sinensis Koehne (Chinese quince), Geranium sanguineum L., and Tea polyphenols. Natural products from traditional herbal medicines, especially traditional Chinese and Persian medicines, have been found to exert antiviral impacts against influenza and human coronaviruses. The natural plant-derived compounds that have been used for treating various diseases are flavonoids and phytochemicals.

Abstract: This mini-review deals with the miscibility behaviour of two biopolymers, chitosan and alginate. It is well known that the miscibility in multifunctional polymer blends is favoured due to specific interactions, which origin a negative heat of mixing. Particular interest is focused on functionalized polymers because they are the most suitable way to obtain interacting polymers, producing a single-phase material. Due to the polyfunctionality of chitosan (CS) and other biopolymers, they can be taken into account as a basis of a strongly interacting polymer. They would allow obtaining compatible polymeric materials. For this reason, blends containing CS with different vinyl polymers have been studied. The most significant polymeric blends with these natural polymers will be analyzed in this review. Chitosan is obtained from the biopolymer chitin through sequential processes of demineralization, deproteinization and deacetylation. The native chitin is obtained by direct separation from the marine crustaceans’ shell, which is abundant on the sea coasts. Some classic results that relate to the polymeric blends containing amphiphilic polymers will be discussed. Another biopolymer of the coast is Sodium Alginate (SA). Alginate also allows the formation of compatible polymer blends. Results in this regard will also be analyzed in this review.

Abstract: The chemistry of 2-quinolones derivatives has received more attention in organic chemistry and medicinal chemistry. Moreover, several advancements in the application of this family of compounds are considered to be of great utility. In recent years, a variety of new, effective, and novel synthetic approaches (including green chemistry, catalyzed and microwave-assisted synthesis) have been discovered and developed for the designing of safe and non-toxic 2-quinolone-based scaffolds to investigate their antibacterial activities. This review summarizes the results of the literature on the synthesis strategies of 2-quinolones derivatives and their reactivity, as well as their antibacterial evaluations against different bacteria strains.

Abstract: The present account surveys the results of a myriad of works on the C-methylation of organic substrates with methanol as an eco-friendly methylating agent. The innumerable reports on this issue reveal the widespread use of a set of solid catalysts such as molecular sieves, zeolites, metal phosphates, metal oxides and transition metal complexes to accomplish such methylation. One related facet was the impact of the numbers of Brønstëd acid sites, Lewis acid sites, and Lewis base sites present in solid catalysts, such as zeolites, their ratios, and strengths that affect the distribution of the methylation products and their selectivities. Moreover, specific surface area and porosity of some solid catalysts, such as zeolites, play additional roles in the overall reaction. Not only do these catalyst properties influence the methylation outcome, the temperature, space velocity (WHSV, LHSV, GSHV), weight of catalyst per reactant flow rate (W/F), time of stream (TOS), and methanol/ substrate molar ratio also do. The treated substrates herein discussed were aromatic hydrocarbons (benzene, biphenyls, naphthalenes, toluene, xylenes), alkenes, phenolics (phenol, cresols, anisole), Nheteroarenes, carbonyls, alcohols, and nitriles. Methylation of benzene affords not only toluene as the main product but also polymethylated benzenes (xylenes, pseudocumene, hexamethylenebenzene, and also ethylbenzene as a side-chain product). Furthermore, toluene is sensitive to the reaction conditions, giving rise to ring methylation and to side-chain one (ethylbenzene and styrene), besides the formation of benzene as a disproportionation product. A number of results from the methylation of phenolic compounds bear witness to the interest of different investigators in this special research. With respect to these phenolics, concurrent O-methylation inevitably parallels the C-methylation, and the selectivity of the latter one remains dependent on the above-cited factors; ortho-cresol and 2,6-xylenol have been the main C-ring methylated phenols. Methylation of olefins with methanol over solid catalysts, leading to higher olefins, is of great interest. The chemistry involved in the methylation of N-heteroarenes, such as pyridines, indoles, and pyrroles, is significant. Application of the methylation protocols, using methanol as a reagent and transition of metal complexes as catalysts to ketones, esters, aldehydes, nitriles, and alcohols, ends up with some important molecules, such as acrylonitrile (a monomer) and isobutanol (a biofuel).