Citrus fruits are one of the most popular sources of dietary flavonoids, such as hesperidin, hesperetin, naringin, naringenin, quercetin, rutin, diosmin, diosmetin, kaempferol, myricetin, nobiletin, tangeretin, and so on. Flavonoids are polyphenols and aromatic bioactive compounds occurring in plants as secondary metabolites. These participate in various biochemical processes in the human body and help in promoting health. Citrus flavonoids are well-known for their antioxidant and anti-inflammatory properties. They promote wound healing and antimelanoma in addition to free radical scavenging, apoptosis, modulation of lipid metabolism, improvement of insulin sensitivity, and endothelial dysfunction. Citrus flavonoids serve as efficient therapeutics for treating various skin-related issues, such as skin aging/photoaging, skin pigmentation, and maintenance of overall healthy skin. This review is an attempt to compile relevant information from recently published articles addressing the roles of Citrus flavonoids in health-promoting activities, particularly skin health. In addition, it also provides a discussion on the recent progress in developing efficient topical delivery techniques to solve the challenge of flavonoids’ poor water solubility and limited permeability into the skin. The review aims to provide a better understanding of the current trends in research and development in Citrus flavonoid biochemistry and their usage in the production of plant-based medicinal and pharma-/nutraceuticals for topical applications.

Methylene chloride (MC) or dichloromethane is a halogenated organic solvent of choice used in many chemical industries such as pharmaceutical, insecticide, paint, and polymer industries. Several health hazards associated with the use of MC are known to us through available literature. MC is reported to be a potential neurotoxic, cardiotoxic, cancer-causing, and tissue-damaging agent. Inhalation and direct skin contact are the major routes of exposure to MC in occupational environments. Most government agencies and environment, health and safety forums throughout the world have recognized MC as a hazardous solvent and have kept strict regulatory control on the usage of MC. MC is a Class 2 solvent as per ICH guidelines. This review article presents some case studies where MC has been replaced in commercial synthetic processes and column chromatography by other solvents and solvent mixtures, demonstrating that it is possible to either reduce the usage or replace MC in process chemistry. Many industrial and academic efforts have brought in place several solvent selection guides helpful for effectively replacing MC from existing or planned synthetic processes. Sustainable and environment-friendly synthetic processes can be developed by implementing the concept of green chemistry, such as replacing the use of MC in the existing chemical processes and avoiding the use of MC in future chemical processes. Successful introduction of MC-free chemical processes in the pharmaceutical industry can surely be achieved with continuous efforts in this direction.

Introduction: SARS-CoV-2 belongs to the coronavirus family, a large family of viruses infecting avian and mammalian hosts. Accumulated mutations over time in the genome of SARS-CoV-2 have given rise to different variants differing in type and sequence. Variants that did not affect transmissibility, infectivity, and severity have gone unnoticed, and mutations that made the virus unfit for survival were deleted eventually from the gene pool. An emerging variant in the host population needs to be monitored closely for its infection consequences. In addition, the variants of concern (VOC) need to be focused on developing effective disease-fighting regimes. As viral epidemics are better fought using effective vaccines, several vaccines have been developed and used since December 2020. The central point of the present study is the continuous variation in the genome of SARS-CoV-2, instigating the researchers to refine their modus operandi to fight against COVID-19. Methods: Prominent medical and literature databases were searched using relevant keywords to gather study results, reports, and other data helpful in writing this traditional, narrative review. Results: This article successfully collates information about the structure and life cycle of SARS-CoV-2, followed by types and nomenclature of mutations in SARS-CoV-2. Variants B.1.1.7 (Alpha), B.1.351 (Beta), P.1 (Gamma), B.1.617.2 (Delta), and B.1.1.529 (Omicron) are current VOCs due to their widespread transmission capability and probable immune evasion. Furthermore, this review article presents information about the major vaccines available and those under development. Based on the original and new strains of SARS-CoV-2, 19 vaccines have been granted emergency use or conditional marketing approvals, 141 are under clinical development, and 194 in preclinical development stages worldwide. Conclusion: Continuous variation in the genome of SARS-CoV-2, presenting new VOCs frequently, has posed a compelling need to amend and evolve current and future vaccine development strategies to overpower the ever-evolving virus.

Writing a research article is no mean feat, as it challenges the author to communicate the original ideas and research results to readers of the specific community as well as general readers. Writing a manuscript demands logically presenting an analysis of the new work done along with a quick round-up of previous literature on the topic. The conveyed information should be an answer to specific research questions as well as a means to open new avenues for further research. The language used for drafting the manuscript needs to be clear, concise, and free from excessive use of subject-specific jargon. This may look a bit difficult but can surely be achieved with a little practice and a thorough understanding of the manuscript structure. A manuscript is divided into certain sections; and in-depth guidelines for writing every section may be covered in separate write-ups. This article conveys basic guidelines on how a research paper should be structured and encourages readers to use the same, while preparing their manuscript.

Viruses use the host cell’s biochemical machinery for replication and survival; and also undergo mutations to evade the immune response and achieve better transmission. These features make it challenging to develop selective drugs to kill viruses only and not the host cells. New and effective pharmaceutical agents are required to overcome this challenge. Tetrazole moiety, as a bio-isostere of carboxylic acid/amide group, has been extensively used as a potent pharmacophore in several bioactivities. Intrigued by the necessity of finding new antiviral compounds and tendency of tetrazole scaffolds to render various bioactivity profiles, this review article comprising literature reports of tetrazole-based synthetic compounds with promising antiviral activity is presented. This review comprises significant literature reports from the scientific databases published during the past four decades. It is found that tetrazole based molecules are promising endeavor for the development of potential agents against influenza virus, HIV, HCV and other viruses.