Mini Reviews in Medicinal Chemistry - Volume 23, Issue 5, 2023

The cell cycle has the capacity to safeguard the cell’s DNA from damage. Thus, cell cycle arrest can allow tumor cells to investigate their own DNA repair processes. Cancer cells become extremely reliant on G1-phase cyclin-dependent kinases due to mutated oncogenes and deactivated tumor suppressors, producing replication stress and DNA damage during the S phase and destroying checkpoints that facilitate progression through the S/G2/M phase. DNA damage checkpoints activate DNA repair pathways to prevent cell proliferation, which occurs when the genome is damaged. However, research on how cells recommence division after a DNA lesion-induced arrest is insufficient which is merely the result of cancer cells’ susceptibility to cell cycle arrest. For example, defects in the G1 arrest checkpoint may cause a cancer cell to proliferate more aggressively, and attempts to fix these complications may cause the cell to grow more slowly and eventually die. Defects in the G2-M arrest checkpoint may enable a damaged cell to enter mitosis and suffer apoptosis, and attempts to boost the effectiveness of chemotherapy may increase its cytotoxicity. Alternatively, attempts to promote G2-M arrest have also been linked to increased apoptosis in the laboratory. Furthermore, variables, such as hyperthermia, contact inhibition, nucleotide shortage, mitotic spindle damage, and resting phase effects, and DNA replication inhibitors add together to halt the cell cycle. In this review, we look at how nucleotide excision repair, MMR, and other variables, such as DNA replication inhibitors, hyperthermia, and contact inhibition, contribute to the outlined processes and functional capacities that cause cell cycle arrest.

Background: LncRNAs are an emerging category of non-coding RNAs. LncRNAs are usually greater than 200 nucleotides in length and do not possess protein editing capabilities. DSCAM-AS1 is a highly valued member of the lncRNAs family. Numerous studies have revealed the involvement of the oncogene DSCAM-AS1 in multiple biological processes, including metastasis, aggressiveness and cell proliferation. This review discusses the molecular mechanisms and clinical significance of DSCAM-AS1 in various tumor types. Methods: This paper analyzes and summarizes current research by searching PubMed using “DSCAM-AS1” and “tumor” as keywords. Results: DSCAM-AS1 is a valuable tumor-associated lncRNA with significant oncogenic effects. It is abnormally expressed in a variety of cancers, such as non-small cell lung cancer, cervical cancer, osteosarcoma, colorectal cancer, breast cancer, gastric cancer and endometrial cancer. The overexpression of DSCAM-AS1 promotes cancer progression by modulating cancer cell proliferation, invasion, distant metastasis, and resistance. Conclusion: DSCAM-AS1 is upregulated and acts as an oncogene in multiple tumors. As more systematic studies are performed, DSCAM-AS1 may prove to be a promising therapeutic target or tumor biomarker.

Heterocyclic compounds constitute the most important part of medicinal as well as organic chemistry. Most of the marketed drugs possess therapeutic activity because of the presence of heterocyclic scaffolds as part of their structure. A slight change in the structure of the heterocyclic moieties may result in a major change in the therapeutic response of the drug candidate. Among all heterocycle compounds, the compounds containing nitrogen and sulfur atoms serve as a unique resource for drug development, such as benzothiazoles. Benzothiazole is a benzofused heterocyclic that is widely reported as a constituent of naturally occurring chemicals and chiefly responsible for their pharmacological potential. It was also reported that the pharmacological activity of BTA may also be influenced by its coupling with aldehydes, ketones, or hydrazines to form respected benzothiazole-hydrazone derivatives. The present comprehensive review consists of various synthesis methods, biological activities, and structure-activity relationships of and targets of benzothiazole and benzothiazole-hydrazone derivatives to provide a wide range of information to medicinal chemists for future research work.

Background: SARS-CoV and SARS-CoV-2 are exceedingly contagious and typically result in major respiratory illnesses (acute respiratory syndrome). The public health is facing enormous challenges across all the nations due to these newly emerging pathogens. Reliable and systematic examination of SARS-CoV and COVID-19 will assist in identifying infectious persons accurately. Based on the biological, chemical, and genetic link of SARS CoV-2 towards SARS-CoV, the recurrence of different anti-SARS-CoV natural drug molecules may be beneficial in the advancement of anti-COVID-19 herbal drug molecules. Here in this review, we evaluated SAR research that has recently been published as well as molecular docking analysis of previously synthesised compounds that have been targeted against SARS-CoV and SARS-CoV-2, respectively. This investigation might assist scientists in creating novel and revolutionary molecules that could target SAR-CoV-2. Objectives: The review highlights the heterocyclic inhibitors' ability to successfully inhibit SARSCoV and SARS-CoV-2. The meticulously described structure-activity relationship of potential SARS-CoV and SARS-CoV-2 inhibiting compounds has been addressed in this review. Evidence Acquisition: We conducted a thorough literature assessment employing electronic databases for scientific articles highlighting potential heterocyclic inhibitors for SARS-CoVand SARSCoV- 2, published from 2010 to 2021. We recovered 415 articles, but only 220 were involved and conversed in this manuscript. The article apprehended appropriate research considering three areas: 1) SAR activity, 2) Molecular docking, and 3) Biological activity and future prospects on SARS-CoV-2. Methods: The potential compounds with decent inhibitory activity have been discussed and reviewed along with their inhibition potential, expressed in terms of IC50 value. Results: Heterocyclic scaffolds reflect an extensive spectrum of therapeutic activity and might function as an initiating concept for the designing and discovery of potential inhibitors for SARS-CoV and SARS-CoV-2 treatment. Conclusion: The points highlighted here may prove to be a vital tool for medicinal chemists working/ investigating more potent and efficacious scaffolds in treating SARS-CoV and SARS-CoV-2.

Five-membered heterocycles, including furan and thiophene, play a prominent role in drug design as structural units of bioactive molecules. This review is intended to demonstrate the importance of the furan-2-yl, furan-3-yl, thien-2-yl and thien-3-yl substituents in the medicinal chemistry of purine and pyrimidine nucleobases, nucleosides and selected analogues. Data presented in the article are limited to compounds containing heteroaromatic ring connected through a bond and not fused to other systems. The impact of bioisosteric replacement of aryl substituents with heteroaryl ones on activities was assessed by comparison of the title compounds with their aryl counterparts. A total of 135 heteroaryl-substituted and 35 aryl-substituted derivatives are mentioned in the text and shown in the figures. The following classes of compounds are included in the article: (i) 5-heteroaryl-2’-deoxyuridines and related compounds; (ii) 8-heteroaryl- 2,9-disubstituted adenine derivatives; (iii) O⁶-(heteroarylmethyl)guanines; (iv) 6-heteroaryl tricyclic guanine analogues; (v) 6-heteroaryl-9-benzylpurines and analogous compounds; (vi) N⁴- furfurylcytosine, N⁶-furfuryladenine, their derivatives and analogues; (vii) 6-heteroaryl purine and 7- deazapurine ribonucleosides; (viii) 7-heteroaryl-7-deazaadenosines, their derivatives and analogues; (ix) 4-heteroaryl fused 7-deazapurine nucleosides. In most cases various modifications of the lead compound structure performed in order to obtain the most favorable activity and selectivity are briefly discussed. The reviewed structure-activity relationship studies exemplify the search for compounds with optimized antiviral, antitumor, antimycobacterial or antiparkinsonian action.