Current Organic Chemistry - Volume 23, Issue 13, 2019

Organodiselenides are an important class of compounds characterized by the presence of two adjacent covalently bonded selenium nuclei. Among them, diaryldiselenides and their parent compound diphenyl diselenide attract continuing interest in chemistry as well as in close disciplines like medicinal chemistry, pharmacology and biochemistry. A search in SCOPUS database has revealed that in the last three years 105 papers have been published on the archetypal diphenyl diselenide and its use in organic catalysis and drug tests. The reactivity of the Se-Se bond and the redox properties of selenium make diselenides efficient catalysts for numerous organic reactions, such as Bayer- Villiger oxidations of aldehydes/ketones, epoxidations of alkenes, oxidations of alcohols and nitrogen containing compounds. In addition, organodiselenides might find application as mimics of glutathione peroxidase (GPx), a family of enzymes, which, besides performing other functions, regulate the peroxide tone in the cells and control the oxidative stress level. In this review, the essential synthetic and reactivity aspects of organoselenides are collected and rationalized using the results of accurate computational studies, which have been carried out mainly in the last two decades. The results obtained in silico provide a clear explanation of the anti-oxidant activity of organodiselenides and more in general of their ability to reduce hydroperoxides. At the same time, they are useful to gain insight into some aspects of the enzymatic activity of the GPx, inspiring novel elements for rational catalyst and drug design.

Matrix metalloproteinases (MMPs) are enzymes involved in various physiological processes essential for living beings, but the loss of the regulatory control by endogenous inhibitors of MMPs, leads to the development of serious diseases such as cardiovascular system affections, cancer, and metastasis. For these reasons, exogenous inhibitors are required for these enzymes, which are able to control the proteolytic activity and are selective towards the different MMPs, besides properties which, from the pharmacological point of view, are necessary to be effective under physiological conditions. Based on these expectations, some bioactive compounds that are abundant in the human diet, like procyanidins (PCs) have emerged as potential exogenous inhibitors of MMPs. This review presents the advances of experimental and computational investigations carried out to date on the structure and chemical reactivity of PCs, to support the basis of their potential use as MMP inhibitors. For such purpose, specific sites among MMPs identified for a selective inhibition, the role of PCs in the regulation of MMPs by posttranscriptional mechanisms at the level of microRNAs, modulation of reactive oxygen species (ROS), effects on tissue inhibitors of MMPs (TIMPs), the crosslinking of PCs with the extracellular matrix proteins, as well as direct interaction between PCs and MMPs, are discussed. Methods for isolation and synthesis of PCs, as well as hydrophilicity properties, bioavailability, and susceptibility to be metabolized in oral intake, are also addressed. The information gathered in this review could additionally help to visualize future research related to this topic.

In this review, we try to highlight the significance, mechanism propositions, computational and experimental assessments of Hantzsch dihydropyridine (DHPs) which readily oxidized to the corresponding pyridines as one of the most important aromatic heterocycles. We also try to give an overview to its ability in transfer hydrogenation, acting as hydride donors from computational and experimental points of view. Our survey is also extended to computational assessments on the structural and biological properties of Hantzsch DHPs.

The chemistry of C5 substituted pyrimidine nucleotide serves as a versatile molecular biology probe for the incorporation of DNA/RNA that has been involved in various molecular biology applications such as gene expression, chromosome, and mRNA fluorescence in situ hybridization (FISH) experiment, mutation detection on arrays and microarrays, in situ RT-PCR, and PCR. In addition to C5 substituted pyrimidine nucleotide, C5 substituted pyrimidine nucleoside displays a broad spectrum of biological applications such as antibacterial, antiviral and anticancer activities. This review focusses on the recent development in the synthesis of aminoallyl pyrimidine nucleotide, aminopropargyl pyrimidine nucleotide, fluorescent probes containing C5 substituted pyrimidine nucleotide, 2′-deoxycytidine nucleoside containing vinylsulfonamide and acrylamide modification, C5 alkenyl, C5 alkynyl, and C5 aryl pyrimidine nucleosides through palladium-catalyzed reaction, pyrimidine nucleoside containing triazole moiety through Click reaction, 5-isoxazol-3-yl-pyrimidine nucleoside, C5 azide modified pyrimidine nucleoside, 2′-deoxycytidine nucleotide containing photocleavable moiety, and uridine nucleoside containing germane and their biological applications are outlined.

Pyridoacridine alkaloids, distributed in marine organisms have emerged as an important class of compounds due to their uniqure chemical architecture, diversity and medicinal significance. These alkaloids are reported to exhibit a wide array of biological activities like anti-cancer, anti-bacterial, ant-viral, anti-fungal and anti-parasitic activities. The present review highlights the isolation, synthesis and medicinal significance of this important class of pyridoacridine alkaloids.