Synthesis and biological evaluation of 2-chloro-3-[(thiazol-2-yl)amino]-1,4-naphthoquinones

Exploiting the Anticancer, Antimicrobial and Antiviral Potential of Naphthoquinone Derivatives: Recent Advances and Future Prospects

Cancer remains a primary cause of mortality, with over 18.1 million new cases and 9.6 million deaths globally in 2018. Chemotherapy, which utilizes a spectrum of cytotoxic drugs targeting the rapidly dividing cancer cells, is a predominant treatment modality. However, the tendency of chemotherapeutics to induce drug resistance and exhibit non-specific cytotoxicity necessitates the development of new anticancer agents with heightened efficacy and minimized toxicity. In recent years, the discovery of safe and effective antibacterial/antiviral agents has also been a hot spot in medicinal chemistry. This paper comprehensively reviews the synthesis, anticancer/antibacterial/antiviral activity, and structure-activity relationships of natural 1,4-naphthoquinones and their derivatives. It highlights their potential as efficient and low-toxicity antitumor and anti-infectious drug candidates.

Unlocking the potential of 1,4-naphthoquinones: A comprehensive review of their anticancer properties

Cancer encompasses a group of pathologies with common characteristics, high incidence, and prevalence in all countries. Although there are treatments available for this disease, they are not always effective or safe, often failing to achieve the desired results. This is why it is necessary to continue the search for new therapies. One of the strategies for obtaining new antitumor drugs is the use of 1,4-naphthoquinone as a scaffold in synthetic or natural products with antitumor activity. This review focuses on compiling studies related to the antitumor activity of 1,4-naphthoquinone and its natural and synthetic derivatives over the last 10 years. The work describes the main natural naphthoquinones with antitumor activity and classifies the synthetic naphthoquinones based on the structural modifications made to the scaffold. Additionally, the formation of metal complexes using naphthoquinones as a ligand is considered. After a thorough review, 197 synthetic compounds with potent biological activity against cancer have been classified according to their chemical structures and their mechanisms of action have been described.

Exploration of Thiourea-Based Scaffolds for the Construction of Bacterial Ureases Inhibitors

A series of 32 thiourea-based urease inhibitors were synthesized and evaluated against native bacterial enzyme and whole cells of Sporosarcina pasteurii and Proteus mirabilis strains. The proposed inhibitors represented structurally diverse thiosemicarbazones and thiocarbohydrazones, benzyl-substituted thiazolyl thioureas, 1H-pyrazole-1-carbothioamides, and dihydropirimidine-2(1H)-thiones. Kinetic characteristics with purified S. pasteurii enzyme determined low micromolar inhibitors within each structural group. (E)-2-(1-Phenylethylidene)hydrazine-1-carbothioamide 19 (Ki = 0.39 ± 0.01 μM), (E)-2-(4-methylbenzylidene)hydrazine-1-carbothioamide 16 (Ki = 0.99 ± 0.04 μM), and N'-((1E,2E)-1,3-diphenylallylidene)hydrazinecarbothiohydrazide 29 (Ki = 2.23 ± 0.19 μM) were used in modeling studies that revealed sulfur ion coordination of the active site nickel ion and hydrogen bonds between the amide group and the side chain of Asp363 and Ala366 carbonyl moiety. Whole-cell studies proved the activity of compounds in Gram-positive and Gram-negative microorganisms. Ureolysis control observed in P. mirabilis PCM 543 (e.g., IC50 = 304 ± 14 μM for 1-benzyl-3-(4-(4-hydroxyphenyl)thiazol-2-yl)thiourea 52) is a valuable achievement, as urease is recognized as a major virulence factor of this urinary tract pathogen.

Antimalarial application of quinones: A recent update

Atovaquone belongs to a naphthoquinone class of drugs and is used in combination with proguanil (Malarone) for the treatment of acute, uncomplicated malaria caused by Plasmodium falciparum (including chloroquine-resistant P. falciparum/P. vivax). Numerous quinone-derived compounds have attracted considerable attention in the last few decades due to their potential in antimalarial drug discovery. Several semi-synthetic derivatives of natural quinones, synthetic quinones (naphtho-/benzo-quinone, anthraquinones, thiazinoquinones), and quinone-based hybrids were explored for their in vitro and in vivo antimalarial activities. A careful literature survey revealed that this topic has not been compiled as a review article so far. Therefore, we herein summarise the recent discovery (the year 2009-2020) of quinone based antimalarial compounds in chronological order. This compilation would be very useful towards the exploration of novel quinone-derived compounds against malarial parasites with promising efficacy and lesser side effects.

Synthesis and biological evaluation of bis-N2,N2'-(4-hydroxycoumarin-3-yl)ethylidene]-2,3-dihydroxysuccinodihydrazides

A series of N²,N²'-bis[4-hydroxycoumarin-3-yl)ethylidene]-2,3-dihydroxysuccino-hydrazides, containing 4-hydroxycoumarin, hydrazine and tartaric acid moieties, have been prepared and examined for possible biological activity. Several of these compounds exhibit promising HIV-1 integrase inhibition (IC₅₀ = 3.5 μM), and anti-T. brucei (32% viability) and anti-mycobacterial (Visual MIC90 = 15.63 μM) activity.