Design, synthesis and biological evaluation of novel semicarbazone-selenochroman-4-ones hybrids as potent antifungal agents

Biological evaluation of newly synthesized α-benzil monoxime thiocarbohydrazide derivatives as an antimicrobial and anticancer agent: In vitro screening and ADMET predictions

The current comprehensive study showcases a meticulous synthesis of novel class of α-benzilmonoxime thiocarbohydrazide (BMOTC) derivatives, and manifesting their multifaceted potential as antibacterial, antifungal, and anticancer agents. The synthesis of target compounds was performed in three phases using literature methods. In the first step, benzilmonoxime is synthesized using benzil and hydroxyl amine hydrochloride, followed by benzilmonoxime imine using thiocarbohydrazide. The final stage involves combining BMOTC imine with various aldehydes and ketones. The antibacterial and antifungal activities of the synthesized derivatives against five bacterial panels, both Gram-positive and Gram-negative, and one fungal pathogen have been screened. Twelve of the twenty-four synthetic derivatives showed noteworthy activity; eight derivatives exhibited growth inhibition (GI) >73 % against Acinetobacter baumannii, two exhibited GI >95 % against Escherichia coli, and two exhibited GI >93 % against Candida albicans at concentration 32 μg/mL. Further assessment revealed that two derivatives 5v and 5w, exhibited negligible cytotoxicity towards human embryonic kidney cells (HK-293) and human red blood cells (RBC), signifying their promising safety profile at concentration 32 μg/mL (GI against Candida albicans - 97.51 % and 93.71 % respectively). The synthesized compounds were subjected to in vitro cytostatic activity, where a rigorous scrutiny against a diverse panel of NCI 60 cancer cell lines representing various malignancies was carried out. A total of eleven compounds emerged as promising candidates, demonstrating significant growth percent (GP) at a concentration of 10 µM. Notably, compounds 5d, 5h, and 5x, turned up as standout performers, exhibiting potent anticancer activity across multiple cancer types, including colon, CNS, melanoma, and breast cancers. Of particular interest, compound 5d displayed notable antiproliferative effects against leukemia cancer cell lines RPMI-8226 & SR, while maintaining non-cytotoxicity against the same. Compound 5h showcased activity against ovarian, non-small cell lung, and prostate cancers, without inducing cytotoxic effects. Compound 5x demonstrated remarkable anticancer activity against leukemia and breast cancer cell lines, further bolstered by its non-cytotoxic nature. A compelling aspect of this study is the comparative analysis with the established drug molecule sunitinib, revealing that compounds 5d, 5h, and 5x exhibit superior potency. These findings not only highlight the therapeutic potential of the BMOTC derivatives but also underscore their viability as promising candidates for future drug development endeavours. This study serves as a pivotal step towards harnessing the untapped therapeutic potential of BMOTC derivatives in combating microbial infections and advancing cancer therapy.

Design, Synthesis, and Characterization of Novel Cannabidiol-Based Derivatives with Potent Antioxidant Activities

In recent years, extensive research has focused on cannabidiol (CBD), a well-studied non-psychoactive component of the plant-derived cannabinoids. CBD has shown significant therapeutic potential for treating various diseases and disorders, including antioxidants and anti-inflammatory effects. Due to the promising therapeutic effect of CBD in a wide variety of diseases, synthetic derivatization of this compound has attracted the attention of drug discovery in both industry and academia. In the current research, we focused on the derivatization of CBD by introducing Schiff base moieties, particularly (thio)-semicarbazide and aminoguanidine motifs, at the 3-position of the olivetolic ring. We have designed, synthesized, and characterized new derivatives based on CBD's framework, specifically aminoguanylhydrazone- and (thio)-semicarbazones-CBD-aldehyde compounds. Their antioxidant potential was assessed using FRAP and DPPH assays, alongside an evaluation of their effect on LDL oxidation induced by Cu2+ and AAPH. Our findings suggest that incorporating the thiosemicarbazide motif into the CBD framework produces a potent antioxidant, warranting further investigation.

Synthesis of Fluoromethylated Chromones and Their Heteroatom Analogues via Sodium Fluoromethanesulfinate-Enabled Direct Fluoromethylation

An array of biologically interesting tri/difluoromethylated chromones and their heteroatom analogues were conveniently synthesized from the reaction of chromones and their heteroatom analogues with CF3SO2Na or HCF2SO2Na in the presence of tert-butyl hydroperoxide under mild conditions. A mechanistic pathway involving the generation of the electrophilic tri/difluoromethyl radical, followed with the radical substitution of chromones and their heteroatom analogues, was postulated.

[1,2,4]Triazolo[3,4-b]benzothiazole Scaffold as Versatile Nicotinamide Mimic Allowing Nanomolar Inhibition of Different PARP Enzymes

We report [1,2,4]triazolo[3,4-b]benzothiazole (TBT) as a new inhibitor scaffold, which competes with nicotinamide in the binding pocket of human poly- and mono-ADP-ribosylating enzymes. The binding mode was studied through analogues and cocrystal structures with TNKS2, PARP2, PARP14, and PARP15. Based on the substitution pattern, we were able to identify 3-amino derivatives 21 (OUL243) and 27 (OUL232) as inhibitors of mono-ARTs PARP7, PARP10, PARP11, PARP12, PARP14, and PARP15 at nM potencies, with 27 being the most potent PARP10 inhibitor described to date (IC₅₀ of 7.8 nM) and the first PARP12 inhibitor ever reported. On the contrary, hydroxy derivative 16 (OUL245) inhibits poly-ARTs with a selectivity toward PARP2. The scaffold does not possess inherent cell toxicity, and the inhibitors can enter cells and engage with the target protein. This, together with favorable ADME properties, demonstrates the potential of TBT scaffold for future drug development efforts toward selective inhibitors against specific enzymes.

Drug design strategies for the treatment azole-resistant candidiasis

INTRODUCTION

Despite the availability of novel antifungals and therapeutic strategies, the rate of global mortality linked to invasive fungal diseases from fungal infection remains high. Candida albicans account for the most invasive mycosis produced by yeast. Thus, the current arsenal of medicinal chemists is focused on finding new effective agents with lower toxicity and broad-spectrum activity. In this review article, recent efforts to find effective agents against azole-resistant candidiasis, a common fungal infection, are covered.

AREAS COVERED

Herein, the authors outlined all azole-based compounds, dual target, and new scaffolds (non-azole-based compounds) which were effective against azole-resistant candidiasis. In addition, the mechanism of action and SAR studies were also discussed, if the data were available.

EXPERT OPINION

The current status of fungal infections and the drawbacks of existing drugs have encouraged scientists to find novel scaffolds based on different methods like virtual screening and fragment-based drug discovery. Machine learning and in-silico methods have found their role in this field and experts are hopeful to find novel scaffolds/compounds by using these methods.

Selenium as an emerging versatile player in heterocycles and natural products modification

The diverse pharmacological activities of organoselenium compounds are closely correlated to their ability to scavenge and induce reactive oxygen species (ROS), their intrinsic oxidative properties, and their Se(0) release property. The incorporation of selenium into small molecules, and particularly into heterocycles and natural products, has shown great potential in altering the potency and selectivity of these molecules. Therefore, selenium will play an important role in drug discovery in the near future. We summarize how different organoselenium species affect cellular oxidative stress levels, and try to correlate the structural properties of selenium-containing heterocycles and natural product derivatives to their biological activities and therapeutic applications. We also provide some information to guide the rational design of selenium-containing drugs.

Incorporating Selenium into Heterocycles and Natural Products─From Chemical Properties to Pharmacological Activities

Selenium (Se)-containing compounds have emerged as potential therapeutic agents for the treatment of a range of diseases. Through tremendous effort, considerable knowledge has been acquired to understand the complex chemical properties and biological activities of selenium, especially after its incorporation into bioactive molecules. From this perspective, we compiled extensive literature evidence to summarize and critically discuss the relationship between the pharmacological activities and chemical properties of selenium compounds and the strategic incorporation of selenium into organic molecules, especially bioactive heterocycles and natural products. We also provide perspectives regarding the challenges in selenium-based medicinal chemistry and future research directions.

Synthesis and in vitro antimicrobial activity of new steroidal hydrazone derivatives

Background

For many years, various drugs have been used for the treatment of infectious diseases but some bacterial microorganisms have induced resistance to several drugs. In a search of new antimicrobial agents, a series of new steroidal hydrazones were designed and synthesized.

Result

The structures of the compounds were established based on the spectral data. The in vitro antimicrobial activity of some newly synthesized compounds against bacteria and fungi was studied.

Conclusion

New compounds showed better or similar antimicrobial activity. Designing more efficient steroidal hydrazones from ketosteroid based on the current study may successfully lead to the development of antimicrobial agent.

Graphical abstract

Discovery of 1,2,3-selenadiazole analogues as antifungal agents using a scaffold hopping approach

With the increasing incidence of antifungal resistance, new antifungal agents having novel scaffolds hence are in an urgent need to combat infectious diseases caused by multidrug-resistant (MDR) pathogens. In this study, we reported the design, synthesis, and pharmacological evaluation of novel 1,2,3-selenadiazole analogues by scaffold hopping strategy. Preliminary results of antifungal activity demonstrated that the new class of compounds showed broad-spectrum fungistatic and fungicidal activity. Most importantly, these newly synthesized compounds can eliminate these azole-resistant fungi and inhibit the formation of C. albicans biofilm. In particular, compound S07 showed promising antifungal activity against five azole-resistant strains with MIC values ranging from 4 to 32 μg/mL. Then, further target identification and mechanistic studies indicated that representative compound S07 exert its inhibitory activity by inhibiting fungal lanosterol 14α-demethylase enzyme (CYP51). Interestingly, representative compounds showed low cytotoxicity on mammalian cell lines. In addition, the molecular docking studies elucidated the binding modes of these compounds toward CYP51. Altogether, these results suggest that compound S07 with novel skeleton is a promising CYP51 inhibitor for treatment of fungal infections.

Lead optimization generates selenium-containing miconazole CYP51 inhibitors with improved pharmacological profile for the treatment of fungal infections

A series of selenium-containing miconazole derivatives were identified as potent antifungal drugs in our previous study. Representative compound A03 (MIC = 0.01 μg/mL against C.alb. 5314) proved efficacious in inhibiting the growth of fungal pathogens. However, further study showed lead compound A03 exhibited potential hemolysis, significant cytotoxic effect and unfavorable metabolic stability and was therefore modified to overcome these drawbacks. In this article, the further optimization of selenium-containing miconazole derivatives resulted in the discovery of similarly potent compound B17 (MIC = 0.02 μg/mL against C.alb. 5314), exhibiting a superior pharmacological profile with decreased rate of metabolism, cytotoxic effect and hemolysis. Furthermore, compound B17 showed fungicidal activity against Candida albicans and significant effects on the treatment of resistant Candida albicans infections. Meanwhile, compound B17 not only could reduce the ergosterol biosynthesis pathway by inhibiting CYP51, but also inhibited biofilm formation. More importantly, compound B17 also shows promising in vivo efficacy after intraperitoneal injection and the PK study of compound B17 was evaluated. In addition, molecular docking studies provide a model for the interaction between the compound B17 and the CYP51 protein. Overall, we believe that these selenium-containing miconazole compounds can be further developed for the potential treatment of fungal infections.

Novel Steroidal 5α,8α-Endoperoxide Derivatives with Semicarbazone/Thiosemicarbazone Side-chain as Apoptotic Inducers through an Intrinsic Apoptosis Pathway: Design, Synthesis and Biological Studies

A series of novel steroidal 5α,8α-endoperoxide derivatives bearing semicarbazone (7a–g) or thiosemicarbazone (7h–k) side chain were designed, synthesized and evaluated for their cytotoxicities in four human cancer cell lines (HepG2, HCT-116, MCF-7, and A549) using the MTT assay in vitro. The results showed that compound 7j exhibited significant cytotoxic activity against HepG2 cells (IC₅₀ = 3.52 μM), being more potent than ergosterol peroxide. Further cellular mechanism studies in HepG2 cells indicated that compound 7j triggered the mitochondrial-mediated apoptosis by decreasing mitochondrial membrane potential (MMP), which was associated with up-regulation of Bax, down-regulation of Bcl-2, activation levels of the caspase cascade, and formation of reactive oxygen species (ROS). The above findings indicated that compound 7j may be used as a promising skeleton for antitumor agents with improved efficacy.

Preparation of 2,6-diurea-chitosan oligosaccharide derivatives for efficient antifungal and antioxidant activities

In this study, 2-urea-chitosan oligosaccharide derivatives (2-urea-COS derivatives) and 2,6-diurea-chitosan oligosaccharide derivatives (2,6-diurea-COS derivatives) were successfully designed and synthesized via intermediate 2-methoxyformylated chitosan oligosaccharide. All samples were characterized and compared based on FT-IR, ¹H NMR spectroscopy, and elemental analysis. The antifungal effects of COS derivatives were tested against Fusarium oxysporum f. sp. niveum, Phomopsis asparagus, and Botrytis cinereal. Their antioxidant properties, including superoxide radicals' scavenging activity, hydroxyl radicals' scavenging activity, and DPPH radicals' scavenging activity were also explored within different concentrations. COS derivatives bearing urea groups showed improved bioactivity compared with pristine COS and 2,6-diurea-COS derivatives had a higher biological activity than 2-urea-COS derivatives in tested concentrations. Additionally, L929 cells were used to carry out cytotoxicity test of COS and COS derivatives by CCK-8 assay. The results indicated that some of samples showed low cytotoxicity. These findings offered a suggestion that COS derivatives bearing urea groups are promising biological materials.