Mini Reviews in Medicinal Chemistry - Volume 22, Issue 6, 2022

10,11-Dehydrocurvularin is a natural benzenediol lactone (BDL) with a 12-membered macrolide fused to a resorcinol ring produced as a secondary metabolite by many fungi. In this review, we summarized the pieces of literature regarding biosynthesis, chemical synthesis, biological activities, and assumed work mechanisms of 10,11-dehydrocurvularin, which presented a potential for agricultural and pharmaceutical uses.

Some bacterial species use a cell-to-cell communication mechanism called Quorum Sensing (QS). Bacteria release small diffusible molecules, usually termed signals which allow the activation of beneficial phenotypes that guarantee bacterial survival and the expression of a diversity of virulence genes in response to an increase in population density. The study of the molecular mechanisms that relate signal molecules with bacterial pathogenesis is an area of growing interest due to its use as a possible therapeutic alternative through the development of synthetic analogues of autoinducers as a strategy to regulate bacterial communication as well as the study of bacterial resistance phenomena, the study of these relationships is based on the structural diversity of natural or synthetic autoinducers and their ability to inhibit bacterial QS, which can be approached with a molecular perspective from the following topics: i) Molecular signals and their role in QS regulation; ii) Strategies in the modulation of Quorum Sensing; iii) Analysis of Bacterial QS circuit regulation strategies; iv) Structural evolution of natural and synthetic autoinducers as QS regulators. This mini-review allows a molecular view of the QS systems, showing a perspective on the importance of the molecular diversity of autoinducer analogs as a strategy for the design of new antimicrobial agents.

This review article aims to address the main features of breast cancer. Thus, the general aspects of this disease have been shown since the first evidence of breast cancer in the world until the numbers today. In this way, there are some ways to prevent breast cancer, such as the woman's lifestyle (healthy eating habits and physical activities) that helps to reduce the incidence of this anomaly. The first noticeable symptom of this anomaly is typically a lump that feels different from the rest of the breast tissue. More than 80% of breast cancer are discovered when the woman feels a lump being present and about 90% of the cases, the cancer is noticed by the woman herself. Currently, the most used method for the detection of cancer and other injuries is the Magnetic Resonance Imaging (MRI) technique. This technique has been shown to be very effective, however, for a better visualization of the images, Contrast Agents (CAs) are used, which are paramagnetic compounds capable of increasing the relaxation of the hydrogen atoms of the water molecules present in the body tissues. The most used CAs are Gd³⁺ complexes, although they are very efficient, they are toxic to the organism. Thus, new contrast agents have been studied to replace Gd³⁺ complexes; we can mention iron oxides as a promising substitute.

Endogenous nitric oxide (NO) is an important effector molecule and signal transduction molecule, which participates in the regulation of multiple functions in organisms, involving various a variety ofphysiological and pathological processes, especially playing a very important role in the cardiovascular, immune, and nervous systems. NO is a gaseous substance with a short half-life in the body and is unstable in aqueous solutions. Therefore, many researchers focus on the release and activity of NO donors and their derivatives. However, NO donors can release free NO or NO analogues under physiological conditions to meet the human need. NO donors can be coupled with the corresponding active basic nucleus, so that they have the biological activity derived from both the basic nucleus and the NO donors, thus performing better bioactivity. This paper reviewed the routes of synthesis and advance activities of NO donor derivatives.

Pyrimidine and its derivatives are a very important class of heterocyclic compounds that show interesting applications in the field of medicinal chemistry. Pyrimidine not only plays an important role as an organic reaction intermediate but also has a wide range of interesting biological activities viz. antibacterial, antifungal, anticancer, anti-inflammatory, antiviral, and antiprotozoal activities, etc. Numerous methods are available for the formation of pyrimidine derivatives that have been reported in the literature. The advantage of pyrimidine as a starting material for different therapeutically potent derivatives has given momentum to this research. This review aims to report the new work on the synthesis of marketed drugs which consist pyrimidine moiety.

Background: Depression is the most common mental disorder. The symptoms of depression include loss of energy, changes in appetite, more or less sleep, anxiety, low concentration, uncertainty, restlessness, feelings of worthlessness, guilt, or despair, and thoughts of self-harm or suicide. In order to provide safe, efficient, and cost-effective medication, the plant-based principles in isolation or combination with traditional antidepressants are gaining increasing attention for depression therapy. Methods: This study includes the information regarding the present review and its contents collected from published literature materials in different international journals. We have used different search engines such as PubMed, Medline, ResearchGate, Google Semantic Scholar, and Science Direct. For this purpose, the data obtained were properly organized and analyzed to include in this article. Results: Most of the phytomolecules isolated from the medicinal plants display antidepressant effects through the synaptic regulation of levels of neurotransmitters such as dopamine, serotonin, and noradrenaline in different parts of the brain. The mechanism of action of phytomolecules also involves negative regulation of the activities of monoamine oxidase (MAO) and acetylcholinesterase (AChE) and prevention of hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. In addition, the strong antioxidative and anti-inflammatory potential of these phytochemicals offer synergy to their antidepressant as well as antipsychosomatic functions. Conclusion: The application of phytochemicals has proved it to be a safe, cost-effective, and efficient therapeutic agent to treat patients suffering from mild to severe states of depression and other psychiatric disorders. The potential phytochemicals may be further optimized using in silico tools to develop better antidepressants and antipsychotic agents in the future.

Quinoxaline (C8H6N2), commonly called 1,4-diazanaphthalene, 1,4-benzodiazine, or benzopyrazine, is a very potent nitrogenous heterocyclic moiety consisting of a benzene ring fused with the pyrazine ring. A number of different methods for the synthesis of quinoxaline derivatives have been reported in the literature, but the most effective method, commonly used for the synthesis of quinoxaline analogues involves the condensation of substituted o-phenylenediamines with 1, 2- dicarbonyl compounds in the presence of different catalyst(s). The presence of different types of catalysts and their concentration affects the overall yield of the product. Quinoxaline not only plays an important role as an organic reaction intermediate but also has a wide spectrum of interesting biological activities viz. antibacterial, antifungal, anticancer, anti-inflammatory, antiviral, and antiprotozoal activity, etc. Some commercially available drug molecules containing quinoxaline moiety are echinomycin (as antibacterial, antineoplastic, and nucleic acid inhibitor), triostins (cyclic desipeptide as an antibacterial agent), dioxidine and mequindox (as antibacterial agents), carbadox (controlling swine dysentery), desoxycarbadox (as swine growth promoter) and panadipion (as hepatoprotective agent), etc. A large number of quinoxaline analogues possessing different biological activities and their synthetic procedures have been patented worldwide.

Alzheimer's Disease (AD) is usually caused by intellectual deterioration which occurs due to the degeneration of cholinergic neurons. Donepezil is employed for cholinesterase enzyme Inhibition (ChEI) to treat AD in a wider population. Over the years, researchers finding difficulties prompted through traditional dosage forms particularly in geriatric patience. To avoid swallowing difficulties brought about with the aid of the AD population, researchers majorly focused on Oral Thin-Film technology (OTF). This technology strongly eliminates issues caused by solid oral dosage forms. It is one of the quality strategies to alternate a drug that is used in the first-pass metabolism or pre systematic metabolism. The solubility of the drug is a bigger problem and it can expand by way of lowering particle size. Nanofibers are need of the day to minimize the drug particles at the submicron stage which can increase the drug release rate drastically. It can be prepared by Electrospinning technology by incorporating polymeric material into poorly soluble drugs. Mostly natural and biodegradable polymers prefer in all pharmaceutical preparations. Polymers employed for oral delivery should be stable, possess mucoadhesive properties, and should release the drug by diffusion, degradation, and swelling mechanism. The objective of the present review explains various thin-film and nanofiber formulations used for faster drug release in the treatment of Alzheimer's disease.