New Thiazolidine-4-One Derivatives as SARS-CoV-2 Main Protease Inhibitors.

It has been more than four years since the first report of SARS-CoV-2, and humankind has experienced a pandemic with an unprecedented impact. Moreover, the new variants have made the situation even worse. Among viral enzymes, the SARS-CoV-2 main protease (Mpro) has been deemed a promising drug target vs. COVID-19. Indeed, Mpro is a pivotal enzyme for viral replication, and it is highly conserved within coronaviruses. It showed a high extent of conservation of the protease residues essential to the enzymatic activity, emphasizing its potential as a drug target to develop wide-spectrum antiviral agents effective not only vs. SARS-CoV-2 variants but also against other coronaviruses. Even though the FDA-approved drug nirmatrelvir, a Mpro inhibitor, has boosted the antiviral therapy for the treatment of COVID-19, the drug shows several drawbacks that hinder its clinical application. Herein, we report the synthesis of new thiazolidine-4-one derivatives endowed with inhibitory potencies in the micromolar range against SARS-CoV-2 Mpro. In silico studies shed light on the key structural requirements responsible for binding to highly conserved enzymatic residues, showing that the thiazolidinone core acts as a mimetic of the Gln amino acid of the natural substrate and the central role of the nitro-substituted aromatic portion in establishing π-π stacking interactions with the catalytic His-41 residue.

Recent Progress in Synthesis, POM Analyses and SAR of Coumarin-Hybrids as Potential Anti-HIV Agents-A Mini Review.

The human immunodeficiency virus (HIV) is the primary cause of acquired immune deficiency syndrome (AIDS), one of the deadliest pandemic diseases. Various mechanisms and procedures have been pursued to synthesise several anti-HIV agents, but due to the severe side effects and multidrug resistance spawning from the treatment of HIV/AIDS using highly active retroviral therapy (HAART), it has become imperative to design and synthesise novel anti-HIV agents. Literature has shown that natural sources, particularly the plant kingdom, can release important metabolites that have several biological, mechanistic and structural representations similar to chemically synthesised compounds. Certainly, compounds from natural and ethnomedicinal sources have proven to be effective in the management of HIV/AIDS with low toxicity, fewer side effects and affordability. From plants, fungi and bacteria, coumarin can be obtained, which is a secondary metabolite and is well known for its actions in different stages of the HIV replication cycle: protease, integrase and reverse transcriptase (RT) inhibition, cell membrane fusion and viral host attachment. These, among other reasons, are why coumarin moieties will be the basis of a good building block for the development of potent anti-HIV agents. This review aims to outline the synthetic pathways, structure-activity relationship (SAR) and POM analyses of coumarin hybrids with anti-HIV activity, detailing articles published between 2000 and 2023.

Developing cellulosic waste products as platform chemicals: protecting group chemistry of α-glucoisosaccharinic acid.

Alpha and beta-glucoisosaccharinic acids ((2S,4S)-2,4,5-trihydroxy-2-(hydroxymethyl)pentanoic acid and (2R,4S)-2,4,5-trihydroxy-2-(hydroxymethyl)pentanoic acid) which are produced when cellulosic materials are treated with aqueous alkali are potentially valuable platform chemicals. Their highly functionalised carbon skeleton, with fixed chirality at C-2 and C-4, makes them ideal starting materials for use in synthesis. In order to assess the potential of these saccharinic acids as platform chemicals we have explored the protecting group chemistry of the lactone form of alpha-glucoisosaccharinic acid (α-GISAL). We report here the use of single and multiple step reaction pathways leading to the regioselective protection of the three different hydroxyl groups of α-GISAL. We report strategies for protecting the three different hydroxyl groups individually or in pairs. We also report the synthesis of a range of tri-O-protected α-GISAL derivatives where a number of the products contain orthogonal protecting groups.

Utilization of Human Papillomavirus DNA Detection for Cervical Cancer Screening in Women Presenting With Abnormal Cytology in Lokoja, Nigeria.

BACKGROUND: Cervical cancer is regarded as the second highest cause of cancer deaths in Nigeria, with an overall prevalence similar to most developing countries. Screening for cervical cancer is primarily performed using papanicolaou (PAP) staining procedure, in Nigeria. OBJECTIVES: This study aimed to use human papillomavirus (HPV) DNA typing, as a means of ascertaining the presence of high risk HPV in cytology samples, which are positive for the presence of cervical intraepithelial neoplasia (CIN), using the PAP screening procedure. PATIENTS AND METHODS: Amplification of DNA was done using polymerase chain reaction. Gene sequencing was carried out to determine the presence of high risk HPV from cervical smears that were positive for abnormal cytology, from a cross-sectional study involving women between the ages of 16 - 65 years, screened for CIN and cervical cancer, in Lokoja, Nigeria. RESULTS: Result showed a 100% presence of high risk HPV in all the samples with abnormal cytology. The HPV genotype 35 accounted for the highest percentage of the HPVs cases, with a 40% incidence. The HPV genotype 31 accounted for 30% of samples, while HPV genotype 16 and 18 accounted for 20% and 10% of samples, respectively. CONCLUSIONS: The high prevalence of HPV in abnormal cytology underlines to the fact that the presence of HPV is a critical factor in the development of cervical cancer. The use of HPV DNA techniques could actually become an effective and fast means of ascertaining the presence of HPV in abnormal cytology.