4-Methyl-7-hydroxycoumarin antifungal and antioxidant activity enhancement by substitution with thiosemicarbazide and thiazolidinone moieties

QSAR, molecular docking, and pharmacokinetic analysis of thiosemicarbazone-indole compounds targeting prostate cancer cells

Objectives

By 2030, prostate cancer is estimated to account for 1.7 million new cases and 499,000 deaths. The objectives of this research were to create a model revealing the activity of thiosemicarbazone-indole compounds as anticancer agents against the PC3 cell line; perform docking analysis between the compounds and the target enzyme; and predict the pharmacokinetics and drug-likeness of the compounds under investigation.

Methods

The quantitative structureactivity relationship (QSAR) method was used to build the model; molecular docking between the compounds and the target enzyme was performed; and the drug-likeness and pharmacokinetics of the inhibiting compounds was examined.

Results

The genetic function algorithm-multilinear regression approach was used for building the QSAR model. Build model 1 had the best performance, with R2 (coefficient of determination) = 0.972517, Radj (adjusted R-squared) = 0.964665, (CRp2) = 0.780922, and LOF (leave-one-out cross-validation) = 0.076524, demonstrated strongly indicated by the molecular descriptors. SHBd, SsCH3, JGI2, and RDF60P were highly dependent on proliferative activity. Compounds ID 7 and 22 had the potential to act as androgen receptor inhibitors, as suggested by molecular docking studies between the drugs and their target enzymes. Compounds ID 7 and 22 exhibited binding scores of -8.5 kcal/mol and -8.8 kcal/mol, respectively. The approved maximum medication molecules for oral bioavailability included the molecules with IDs 7 and 22.

Conclusion

This research provides valuable insights into the relationships among molecular descriptors, potential inhibitors, and pharmacokinetic properties in the treatment of PC3. These findings may contribute to the understanding and potential development of new therapeutic options for prostate cancer patients.

Newly synthesized derivatives with a thiosemicarbazide group reduce the viability of cancer cell lines. Acute toxicity assessment in Zebrafish (Danio rerio) early life stages

Due to the variability and ability of tumor to mutate, as well as the heterogeneity of tumor tissue, such drugs are sought that would act selectively and multidirectionally on the cancer cell. Therefore, two newly synthesized semicarbazide structured substances were evaluated for anticancer properties in our study: 1a and 1b. In order to evaluate the cytotoxicity and selectivity of the tested compounds, MTT and Neutral Red uptake assay on cell lines (HEK293, LN229, 769-P, HepG2 and NCI-H1563) and cell cycle analysis were performed. Acute toxicity and cardiotoxicity were also evaluated in the zebrafish model. The tested compounds (1a, 1b) showed cytotoxic activity, with the greatest selectivity noted against the glioblastoma multiforme cell line (LN229). However, compound 1b showed stronger selective activity than 1a. Both of compounds were shown to significantly affect the M phase of the cell cycle. Whereas, the conducted toxicological examination of newly synthesized thiosemicarbazide derivates showed, that direct exposition of Danio rerio embryos to compound 1a, but not 1b, causes a concentration-dependent increase in developmental malformations, indicating possible teratogenic effects.

A Comparative Analysis of Radical Scavenging, Antifungal and Enzyme Inhibition Activity of 3'-8″-Biflavones and Their Monomeric Subunits

Biflavonoids are dimeric forms of flavonoids that have recently gained importance as an effective new scaffold for drug discovery. In particular, 3'-8″-biflavones exhibit antiviral and antimicrobial activity and are promising molecules for the treatment of neurodegenerative and metabolic diseases as well as cancer therapies. In the present study, we directly compared 3'-8″-biflavones (amentoflavone, bilobetin, ginkgetin, isoginkgetin, and sciadopitysin) and their monomeric subunits (apigenin, genkwanin, and acacetin) and evaluated their radical scavenging activity (with DPPH), antifungal activity against mycotoxigenic fungi (Alternaria alternata, Aspergillus flavus, Aspergillus ochraceus, Fusarium graminearum, and Fusarium verticillioides), and inhibitory activity on enzymes (acetylcholinesterase, tyrosinase, α-amylase, and α-glucosidase). All the tested compounds showed weak radical scavenging activity, while antifungal activity strongly depended on the tested concentration and fungal species. Biflavonoids, especially ginkgetin and isoginkgetin, proved to be potent acetylcholinesterase inhibitors, whereas monomeric flavonoids showed higher tyrosinase inhibitory activity than the tested 3'-8″-biflavones. Amentoflavone proved to be a potent α-amylase and α-glucosidase inhibitor, and in general, 3'-8″-biflavones showed a stronger inhibitory potential on these enzymes than their monomeric subunits. Thus, we can conclude that 3'-8″-dimerization enhanced acetylcholinesterase, α-amylase, and α-glucosidase activities, but the activity also depends on the number of hydroxyl and methoxy groups in the structure of the compound.

The antidiabetic effect of methanolic extract of Holarrhena pubescens seeds is mediated through multiple mechanisms of action

Holarrhena pubescens is widely used in Indian and Chinese medicine in the treatment of diabetes. The current work determined the oral hypoglycemic and antidiabetic effects of seed extract in rats. The probable mechanism of action was evaluated in-vitro by α - glucosidase inhibition, glucose metabolism in insulinoma (INS-1) cells to reflect secretion of insulin, and protein glycation inhibition. Its potential for herb-drug interaction was evaluated in the cytochrome P450 3A4 (CYP3A4) inhibition assay. The seed extract increased serum insulin levels and reduced serum blood glucose levels in the oral glucose tolerance test. It also reduced the serum glucose levels in streptozocin-induced diabetes. The extract also inhibited α -glucosidase enzyme activity and demonstrated that it can increase the secretion of insulin from INS to 1-rat insulinoma cell line cells in-vitro in a concentration-dependent manner. However, it had a very weak inhibitory effect on protein glycation and it did not affect the activity of CYP3A4. The results of the study showed that H. pubescens seed extract increases insulin secretion and inhibits glucose absorption both in-vivo and in-vitro with a weak protein glycation inhibitory effect. The herb is devoid of CYP3A4 inhibitory effect indicating that it may not have pharmacokinetic interaction with the drug metabolized by this enzyme.

Synthesis of thiazole-based-thiourea analogs: as anticancer, antiglycation and antioxidant agents, structure activity relationship analysis and docking study

This work reports the convenient approach for the synthesis of thiazole based thiourea derivatives (1-21) from 2-bromo-1-(4-fluorophenyl)thiazole-1-one and phenyl isothiocyanates. The scope and diversity were achieved from readily available phenyl isothiocyanates. This protocol involves an oxidative C-S bond formation. Moreover, hybrid thiazole based thiourea scaffolds (1-21) according to literature known protocol were screened in vitro for anticancer Potential against breast cancer, antiglycation and antioxidant inhibitory profile. All newly developed scaffolds were showed moderate to good inhibitory potentials ranging from 0.10 ± 0.01 µM to 11.40 ± 0.20 µM, 64.20 ± 0.40 µM to 385.10 ± 1.70 µM and 8.90 ± 0.20 µM to 39.20 ± 0.50 µM against anticancer, antiglycation and antioxidant respectively. Among the series, compounds 12 (IC50 = 0.10 ± 0.01 µM), 10 (IC50 = 64.20 ± 0.40 µM) and 12 (IC50 = 8.90 ± 0.20 µM) with flouro substitution at phenyl ring of thiourea were identified to be the most potent among the series having excellent anticancer, antiglycation and antioxidant potential. The structure of all the newly synthetics scaffolds were confirmed by using different types of spectroscopic techniques such as HREI-MS, 1H- and 13C-NMR spectroscopy. To find structure-activity relationship, molecular docking studies were carried out to understand the binding mode of active inhibitors with active site of enzymes and results supported the experimental data.Communicated by Ramaswamy H. Sarma.

Phenotypic and in silico studies for a series of synthetic thiosemicarbazones as New Delhi metallo-beta-lactamase carbapenemase inhibitors

The past two decades have been marked by a global spread of bacterial resistance to β-lactam drugs and carbapenems derivatives are the ultimate treatment against multidrug-resistant bacteria. β-lactamase expression is related to resistance which demands the development of bacterial resistance blockers. Drug inhibitor combinations of serine-β-lactamase and β-lactam were successful employed in therapy despite their inactivity against New Delhi metallo-beta-lactamase (NDM). Until now, few compounds are active against NDM-producing bacteria and no specific inhibitors are available yet. The rational strategy for NDM inhibitors development starts with in vitro assays aiming to seek compounds that could act synergistically with β-lactam antibiotics. Thus, eight thiosemicarbazone derivatives were synthesized and investigated for their ability to reverse the resistant phenotype in NDM in Enterobacter cloacae. Phenotypic screening indicated that four isatin-beta-thiosemicarbazones showed Fractional Inhibitory Concentration (FIC) ≤ 250 µM in the presence of meropenem (4 µg/mL). The most promising compound (FIC= 31.25 µM) also presented synergistic effect (FICI = 0.34). Docking and molecular dynamics studies on NDM-thiosemicarbazone complex suggested that 2,3-dihydro-1H-indol-2-one subunit interacts with catalytic zinc and interacted through hydrogen bonds with Asp124 acting like a carboxylic acid bioisostere. Additionally, thiosemicarbazone tautomer with oxidized sulfur (thione) seems to act as a spacer rather than zinc chelator, and the aromatic moieties are stabilized by pi-pi and cation-pi interactions with His189 and Lys221 residues. Our results addressed some thiosemicarbazone structural changes to increase its biological activity against NDM and highlight its scaffold as promising alternatives to treat bacterial resistance.Communicated by Ramaswamy H. Sarma.

Enhanced anticancer potency with reduced nephrotoxicity of newly synthesized platin-based complexes compared with cisplatin

As a platinum-containing anticancer drug, cisplatin is the keystone for treating many malignancies. Nephrotoxicity is the main dose-limiting toxicity, and several hydration therapies and supplementary strategies are utilized to reduce cisplatin-induced kidney damage, so the discovery and development of effective and safe antitumor drugs are still on the path of human health. Herein, a new four-coordinated Pt complex [Pt(TSC)Cl] using N(4)-phenyl-2-formylpyridine thiosemicarbazone (HTSC) was synthesized and characterized by single-crystal X-ray diffraction, ¹HNMR, FT-IR, LC/MS and CHN elemental analysis. The Pt(TSC)Cl complex revealed antiproliferative activity against A549, MCF-7 and Caco-2 cell lines with a low micromolar IC₅₀ (200–1.75 µM). Specifically, the Pt(TSC)Cl complex displayed more selectivity in Caco-2 cells (IC₅₀ = 2.3 µM) than cisplatin (IC₅₀ = 107 µM) after 48 h of treatment. Moreover, compared with cisplatin, a known nephrotoxic drug, the Pt(TSC)Cl complex exhibited lower nephrotoxicity against Hek293 normal cells. We also found that the Pt(TSC)Cl complex can effectively prevent cancer cell propagation in sub-G1 and S phases and induce apoptosis (more than 90%). Real time PCR and western analysis demonstrated that the expression pattern of apoptotic genes and proteins is according to the intrinsic apoptosis pathway through the Bax/Bcl-2-Casp9-Casp3/Casp7 axis. Collectively, our findings indicated that the Pt(TSC)Cl complex triggers apoptosis in Caco-2 cell lines, while low nephrotoxicity was shown and may be considered a useful anticancer drug candidate for colorectal cancers for further optimization and growth.

4-Arylthiosemicarbazide Derivatives as Toxoplasmic Aromatic Amino Acid Hydroxylase Inhibitors and Anti-inflammatory Agents

Approximately one-third of the human population is infected with the intracellular cosmopolitan protozoan Toxoplasma gondii (Tg), and a specific treatment for this parasite is still needed. Additionally, the increasing resistance of Tg to drugs has become a challenge for numerous research centers. The high selectivity of a compound toward the protozoan, along with low cytotoxicity toward the host cells, form the basis for further research, which aims at determining the molecular targets of the active compounds. Thiosemicarbazide derivatives are biologically active organic compounds. Previous studies on the initial preselection of 58 new 4-arylthiosemicarbazide derivatives in terms of their anti-Tg activity and selectivity made it possible to select two promising derivatives for further research. One of the important amino acids involved in the proliferation of Tg and the formation of parasitophorous vacuoles is tyrosine, which is converted by two unique aromatic amino acid hydroxylases to levodopa. Enzymatic studies with two derivatives (R: para-nitro and meta-iodo) and recombinant aromatic amino acid hydroxylase (AAHs) obtained in the E. coli expression system were performed, and the results indicated that toxoplasmic AAHs are a molecular target for 4-arylthiosemicarbazide derivatives. Moreover, the drug affinity responsive target stability assay also confirmed that the selected compounds bind to AAHs. Additionally, the anti-inflammatory activity of these derivatives was tested using THP1-Blue™ NF-κB reporter cells due to the similarity of the thiosemicarbazide scaffold to thiosemicarbazone, both of which are known NF-κB pathway inhibitors.

Imidazole-Thiosemicarbazide Derivatives as Potent Anti-Mycobacterium tuberculosis Compounds with Antibiofilm Activity

Mycobacterium tuberculosis (Mtb) is an intracellular pathogenic bacterium and the causative agent of tuberculosis. This disease is one of the most ancient and deadliest bacterial infections, as it poses major health, social and economic challenges at a global level, primarily in low- and middle-income countries. The lack of an effective vaccine, the long and expensive drug therapy, and the rapid spread of drug-resistant strains of Mtb have led to the re-emergence of tuberculosis as a global pandemic. Here, we assessed the in vitro activity of new imidazole-thiosemicarbazide derivatives (ITDs) against Mtb infection and their effects on mycobacterial biofilm formation. Cytotoxicity studies of the new compounds in cell lines and human monocyte-derived macrophages (MDMs) were performed. The anti-Mtb activity of ITDs was evaluated by determining minimal inhibitory concentrations of resazurin, time-kill curves, bacterial intracellular growth and the effect on biofilm formation. Mutation frequency and whole-genome sequencing of mutants that were resistant to ITDs were performed. The antimycobacterial potential of ITDs with the ability to penetrate Mtb-infected human macrophages and significantly inhibit the intracellular growth of tubercle bacilli and suppress Mtb biofilm formation was observed.

Medicinal applications of coumarins bearing azetidinone and thiazolidinone moieties

Coumarins (2H-chromen-2-ones), also known as benzopyran-2-ones, are a family of naturally occurring heterocyclic ring systems that contain a lactone moiety. Coumarins exhibit a wide range of well-studied pharmacological properties. Over the last few decades, as a result of advances in diverse oriented synthetic routes, physicochemical properties and numerous biological activities, coumarins have become globally studied molecules from various synthetic and medicinal chemists. Recently, several bioactive coumarins bearing azetidinone and thiazolidinone moieties have been found to display a range of therapeutic characteristics, including antimicrobial, anticancer, antidiabetic and anti-inflammatory properties. This review offers a brief description of the synthetic methodologies, known bioactivity and structure-activity relationships of coumarins bearing azetidinones and thiazolidinones.

N-acylhydrazones confer inhibitory efficacy against New Delhi metallo-β-lactamase-1

The expression of β-lactamases, especially metallo-β-lactamases (MβLs) in bacteria is one of the main causes of drug resistance. In this work, an effective N-acylhydrazone scaffold as MβL inhibitor was constructed and characterized. The biological activity assays indicated that the synthesized N-acylhydrazones 1-11 preferentially inhibited MβL NDM-1, and 1 was found to be the most effective inhibitor with an IC₅₀ of 1.2 µM. Analysis of IC₅₀ data revealed a structure-activity relationship, which is that the pyridine and hydroxylbenzene substituents at 2-position improved inhibition of the compounds on NDM-1. ITC and enzyme kinetics assays suggested that it reversibly and competitively inhibited NDM-1 (K_i = 0.29 ± 0.05 µM). The synthesized N-acylhydrazones showed synergistic antibacterial activities with meropenem, reduced 4-16-fold MIC of meropenem on NDM-1- producing E. coli BL21 (DE3), while 1 restored 4-fold activity of meropenem on K. pneumonia expressing NDM-1 (NDM-K. pneumoniae). The mice experiments suggested that 1 combined meropenem to fight against NDM-K. pneumoniae infection in the spleen and liver. Cytotoxicity assays showed that 1 and 2 have low cytotoxicity. This study offered a new framework for the development of NDM-1 inhibitors.

Synthesis of new 1,2,4-triazole-(thio)semicarbazide hybrid molecules: Their tyrosinase inhibitor activities and molecular docking analysis

Tyrosinase inhibition is very important in controlling melanin synthesis. If melanin synthesis is not controlled in metabolism, an unwanted increase in melanin synthesis occurs. As melanin plays a role in the formation of skin color, its unusual levels cause some skin disorders such as pregnancy scars, age spots, and especially skin cancer (melanoma). However, the tyrosinase activity is also related to Parkinson's disease and some neurodegenerative diseases. For all these reasons, the medicinal as well as the cosmetic industries focus on research on tyrosinase inhibitors for the treatment of skin disorders and some neurodegenerative diseases. In this study, 32 new 1,2,4-triazole-(thio)semicarbazide hybrid molecules (6a-p and 7a-p) were synthesized, starting from 4-amino-1-pentyl-3-phenyl-1H-1,2,4-triazole-5(4H)-one. These compounds were evaluated for their inhibitory activity against mushroom tyrosinase. The results indicated that 6h, 6m, 6n, and 6p exhibited the most effective inhibitory activity, with IC₅₀ values of 0.00162 ± 0.0109, 0.00166 ± 0.0217, 0.00165 ± 0.019, and 0.00197 ± 0.0063 μM, respectively, compared with kojic acid as the reference drug (IC₅₀  = 14.09 ± 0.02 μM). Also, molecular docking analyses were performed to suggest possible binding poses for the ligands. As a result, derivatives 6h, 6m, 6n, and 6p can be used as promising tyrosinase inhibitor candidates in the medicinal, cosmetics, or food industries.

Synthesis, antioxidant, antimicrobial and antiviral docking studies of ethyl 2-(2-(arylidene)hydrazinyl)thiazole-4-carboxylates

A series of ethyl 2-(2-(arylidene)hydrazinyl)thiazole-4-carboxylates (2a-r) was synthesized in two steps from thiosemicarbazones (1a-r), which were cyclized with ethyl bromopyruvate to ethyl 2-(2-(arylidene)hydrazinyl)thiazole-4-carboxylates (2a-r). The structures of compounds (2a-r) were established by FT-IR, ¹H- and ¹³C-NMR. The structure of compound 2a was confirmed by HRMS. The compounds (2a-r) were then evaluated for their antimicrobial and antioxidant assays. The antioxidant studies revealed, ethyl 2-(2-(4-hydroxy-3-methoxybenzylidene)hydrazinyl)thiazole-4-carboxylate (2g) and ethyl 2-(2-(1-phenylethylidene)hydrazinyl)thiazole-4-carboxylate (2h) as promising antioxidant agents with %FRSA: 84.46 ± 0.13 and 74.50 ± 0.37, TAC: 269.08 ± 0.92 and 269.11 ± 0.61 and TRP: 272.34 ± 0.87 and 231.11 ± 0.67 μg AAE/mg dry weight of compound. Beside bioactivities, density functional theory (DFT) methods were used to study the electronic structure and properties of synthesized compounds (2a-m). The potential of synthesized compounds for possible antiviral targets is also predicted through molecular docking methods. The compounds 2e and 2h showed good binding affinities and inhibition constants to be considered as therapeutic target for M^pro protein of SARS-CoV-2 (COVID-19). The present in-depth analysis of synthesized compounds will put them under the spot light for practical applications as antioxidants and the modification in structural motif may open the way for COVID-19 drug.

Synthesis and Biological Activity Evaluation of Polyfunctionalized Anthraquinonehydrazones

Background :

Anthraquinone derivatives, frequently occurring motifs in many various natural compounds, have attracted a great deal of interest as compounds with a wide spectrum of biological activities.

Introduction:

The hybrid pharmacophore approach has become an object of considerable interest due to the incorporation of a five- or six-membered heterocyclic rings in the structure of various natural compounds, especially anthraquinone derivatives.

Methods:

A series of polyfunctionalized anthraquinonehydrazones have been synthesized via the azo-coupling reaction between anthraquinone-based triazenes and methylene active compounds. The structures of synthesized compounds were confirmed by spectral data. Some of the synthesized compounds were screened for their in vitro anticancer activity according to US NCI protocols. The screening of antimicrobial and antifungal activities against Candida albicans and Lactobacillus sp. was carried out. The synthesized compounds were evaluated for their antioxidant (DPPH free radical scavenging assay) and herbicidal activity.

Results:

The synthesized 1-[N'-(5-oxo-2-thioxoimidazolidin-4-ylidene)-hydrazino]-anthraquinone 1.5 displayed a high level of antimitotic activity against tested human tumor cells with mean GI50/TGI values 4.06/78.52μM. The screening of antimicrobial and antifungal activities led to the identification of 1.8 and 1.9 with a moderate effect on Candida albicans and Lactobacillus sp. Antioxidant activity evaluation allowed the identification of 1-[N'-(3-methyl-5-oxo-1-phenyl-1,5- dihydropyrazol-4-ylidene)-hydrazino]-anthraquinone 1.8 with an IC50 value of 3.715 mM. The herbicidal activity screening led to compound identification 1.8 with growth inhibition of Agrostis stolonifera at 25 %.

Conclusion:

The obtained anthraquinonehydrazones constitute an interesting template for the design of new synthetic agents with polypharmacological activities.

Synthesis of a new 1,3,4-thiadiazole-substituted phenanthroimidazole derivative, its growth on glass/ITO as a thin film and analysis of some surface and optoelectronic properties

A novel phenanthroimidazole derivative with p-type conductivity was prepared and fabricated as a heterostructure, exhibiting a negative differential resistance and photodiode properties.

Diaryl-substituted thiosemicarbazone: A potent scaffold for the development of New Delhi metallo-β-lactamase-1 inhibitors

The superbug infection caused by New Delhi metallo-β-lactamase (NDM-1) has become an emerging public health threat. Inhibition of NDM-1 has proven challenging due to its shuttling between pathogenic bacteria. A potent scaffold, diaryl-substituted thiosemicarbazone, was constructed and assayed with metallo-β-lactamases (MβLs). The obtained twenty-six molecules specifically inhibited NDM-1 with IC₅₀ 0.038-34.7 µM range (except 1e, 2e, and 3d), and 1c is the most potent inhibitor (IC₅₀ = 0.038 µM). The structure-activity relationship of synthetic thiosemicarbazones revealed that the diaryl-substitutes, specifically 2-pyridine and 2-hydroxylbenzene improved inhibitory activities of the inhibitors. The thiosemicarbazones exhibited synergistic antimycobacterial actions against E. coli-NDM-1, resulted a 2-512-fold reduction in MIC of meropenem, while 1c restored 16-256-, 16-, and 2-fold activity of the antibiotic on clinical isolates ECs, K. pneumonia and P. aeruginosa harboring NDM-1, respectively. Also, mice experiments showed that 1c had a synergistic antibacterial ability with meropenem, reduced the bacterial load clinical isolate EC08 in the spleen and liver. This work provided a highly promising scaffold for the development of NDM-1 inhibitors.

An Insight into the Synthesis and SAR of 2,4-Thiazolidinediones (2,4-TZD) as Multifunctional Scaffold: A Review

2,4-Thiazolidinedione (2,4-TZD) is a versatile pharmacophore, a privileged scaffold, and a remarkable sulphur-containing heterocyclic compound with diverse pharmacological activities. The multifarious biological activities, due to different mechanisms of action, low cost, and easy availability of 2,4-TZD impressed medicinal chemists to integrate this moiety to develop various lead compounds with diverse therapeutic actions. This resulted in the swift development in the last decade for generating different new potential molecules bearing 2,4-TZD. In this review, the authors attempt to shape and present the latest investigations (2012 onwards) going on in generating promising 2,4-TZD containing lead compounds. The data has been collected and analyzed to develop the structure-activity relationship (SAR). The SAR and active pharmacophores of various leads accountable for antidiabetic, anticancer, antimicrobial, and antioxidant activities have also been illustrated. This review also highlighted some of the important chemical synthetic routes for the preparation of various 2,4-TZD derivatives. This review will definitely serve as a useful source of structural information to medicinal chemists and may be utilized for the strategic design of potent 2,4-TZD derivatives in the future.

Design, synthesis and biological evaluation of novel thiosemicarbazone-indole derivatives targeting prostate cancer cells

To discover novel anticancer agents with potent and low toxicity, we designed and synthesized a range of new thiosemicarbazone-indole analogues based on lead compound 4 we reported previously. Most compounds displayed moderate to high anticancer activities against five tested tumor cells (PC3, EC109, DU-145, MGC803, MCF-7). Specifically, the represented compound 16f possessed strong antiproliferative potency and high selectivity toward PC3 cells with the IC₅₀ value of 0.054 μM, compared with normal WPMY-1 cells with the IC₅₀ value of 19.470 μM. Preliminary mechanism research indicated that compound 16f could significantly suppress prostate cancer cells (PC3, DU-145) growth and colony formation in a dose-dependent manner. Besides, derivative 16f induced G1/S cycle arrest and apoptosis, which may be related to ROS accumulation due to the activation of MAPK signaling pathway. Furthermore, molecule 16f could effectively inhibit tumor growth through a xenograft model bearing PC3 cells and had no evident toxicity in vivo. Overall, based on the biological activity evaluation, analogue 16f can be viewed as a potential lead compound for further development of novel anti-prostate cancer drug.

The Efficacy of Composite Essential Oils against Aflatoxigenic Fungus Aspergillus flavus in Maize

The efficacy of eleven essential oils (EOs) against Aspergillus flavus NRRL 3357 was investigated. The highest antifungal activity against this aflatoxigenic fungus was exhibited by cinnamon, oregano and lemongrass, which showed low minimum inhibitory concentration (MIC) values under vapor conditions. Interactions of the three EOs were evaluated by the fractional inhibition concentration index (FICI), and the composite essential oils (CEO) showed synergistic inhibitory activities. Chemical analysis of the composite essential oils of cinnamon, oregano, and lemongrass (COL-CEO) revealed that (Z)-citral (33.44%), (E)-citral (32.88%) and carvacrol (19.84%) were the dominant components, followed by limonene (4.29%) and cinnamaldehyde (3.76%). COL-CEO not only inhibited fungal growth but also decreased aflatoxin B1 production by A. flavus. Downregulation of the relative expression of aflatoxin genes in the aflatoxin biosynthetic pathway by COL-CEO revealed its anti-aflatoxigenic mechanism. COL-CEO could also affect the colonization of A. flavus on maize grains. Therefore, COL-CEO may be considered as a potential natural antifungal agent, which could be used for the storage of maize and other grains.

Investigation of thiosemicarbazide free or within chitosan nanoparticles in a murine model of vulvovaginal candidiasis

Vulvovaginal candidiasis is a serious health problem affecting numerous women around the world. Its treatment is based on antifungals which may not provide an effective cure because of the resistance presented by its etiological pathogens Candida spp. Candida albicans is the most prevalent species related to vulvovaginal candidiasis. Here, we evaluated the in vivo antifungal potential of thiosemicarbazide and thiosemicarbazide encapsulated within chitosan nanoparticles in a murine model of vulvovaginal candidiasis. The results demonstrated the antifungal capacity of free or nanoencapsulated thiosemicarbazide within chitosan to reduce the fungal load in the vaginal tissue of infected mice. In addition, histological analyses indicated the absence or a mild to moderate infection in thiosemicarbazide-treated groups. Statistical tests confirmed the existence of significant differences between the treated and the control groups. Therefore, our results suggest a potential application of thiosemicarbazide and encapsulated thiosemicarbazide as an alternative vulvovaginal candidiasis therapy.

Neopapillarine, an Unusual Coumarino-Alkaloid from the Root Extract of Neocryptodiscus papillaris with Cytotoxic Activity on Renal Cancer Cells

Several simple and prenylated coumarin derivatives were isolated from the dichloromethane extract of the root of Neocryptodiscus papillaris based on moderate cytotoxic activity of the extract in COLO205, KM12 and MCF7 cancer cells. While the major prenylated furanocoumarin derivatives and osthol isolated from the dichloromethane extract were responsible for the activity in the colon and breast cancer cell lines, the 4′-acylated osthol derivatives including a novel coumarino-alkaloid; neopapillarine) demonstrated selective cytotoxic activity in A498 and UO31 renal cancer cell lines.

Coumarin sulfonamide derivatives: An emerging class of therapeutic agents

Coumarin sulfonamide is a heterocyclic pharmacophore and an important structural motif which is a core and integral part of different therapeutic scaffolds and analogues. Coumarin sulfonamides are privileged and pivotal templates which have a broad spectrum of applications in the fields of medicine, pharmacology and pharmaceutics. Coumarin sulfonamide exhibited versatile and myriad biomedical activities such as anti-bacterial, antiviral, antifungal, anti-inflammatory and anti-cancer. This review article focuses on the structural features of coumarin sulfonamide derivatives in the treatment of different lethal diseases on the basis of structure-activity relationships (SAR). The plethora of research cited in this review article summarizes and discusses the various substitutions around the coumarin sulfonamide nucleus which have provided a wide spectrum of biological activities and therapeutic potential that has proved attractive to many researchers looking to exploit the coumarin sulfonamide skeleton for drug discovery and the development of novel therapeutic agents.

Fullerol C60(OH)24 Nanoparticles Affect Secondary Metabolite Profile of Important Foodborne Mycotoxigenic Fungi In Vitro

Despite the efforts to control mycotoxin contamination worldwide, extensive contamination has been reported to occur in food and feed. The contamination is even more intense due to climate changes and different stressors. This study examined the impact of fullerol C₆₀(OH)₂₄ nanoparticles (FNP) (at 0, 1, 10, 100, and 1000 ng mL^-1) on the secondary metabolite profile of the most relevant foodborne mycotoxigenic fungi from genera Aspergillus, Fusarium, Alternaria and Penicillium, during growth in vitro. Fungi were grown in liquid RPMI 1640 media for 72 h at 29 °C, and metabolites were investigated by the LC-MS/MS dilute and shoot multimycotoxin method. Exposure to FNP showed great potential in decreasing the concentrations of 35 secondary metabolites; the decreases were dependent on FNP concentration and fungal genus. These results are a relevant guide for future examination of fungi-FNP interactions in environmental conditions. The aim is to establish the exact mechanism of FNP action and determine the impact such interactions have on food and feed safety.

Molecular Hybrids of N-Phthaloylglycyl Hydrazide and Hydrazinecarbothioamide with Anti-inflammatory and Anti-oxidant Activities

BACKGROUND

Oxidative stress due to high levels of reactive organic species is the cause of the progression of inflammation in various diseases. The molecules possessing both anti-inflammatory and antioxidant activity can be the promising key to treat inflammatory diseases. Phthalimide and hydrazinecarbothioamide are anti-inflammatory and anti-oxidant pharmacophores.

OBJECTIVE

Molecular hybrids possessing above two pharmacophores were designed. A series of N-phenyl substituted 2-(2-(1,3-dioxoisoindolin-2-yl)acetyl)-N-phenylhydrazine-1-carbothioamide (CGS compounds) was synthesized and evaluated for biological activities.

METHODS

N-phthaloylglycyl hydrazide was reacted with unsubstituted/substituted phenyl isothiocyanates to yield CGS compounds. Synthesized compounds were evaluated for in vivo anti-inflammatory activity in carrageenan rat paw edema model, and in vitro anti-oxidant activity by DPPH assay. Levels of TNF-α and oxidative stress at the site of inflammation were measured. The genetic algorithm-PLS regression based QSAR model correlating the effect of N-phenyl substituent on the anti-inflammatory activity was developed. Further, the interaction of the active compound in the TNF-α binding pocket was studied by in silico docking.

RESULTS

Compound containing the 2-OCH3, 4-NO2 (CGS-5); 4-CF3 (CGS-9); 4-NO2 (CGS-3) showed significant anti-inflammatory activity (percentage inhibition of paw edema after 3 hour = 58.24, 50.38, 40.05, respectively) and potent anti-oxidant activity (IC50 =0.045, 0.998, 0.285 μg/ml, respectively). Reduced levels of TNF- α and increased levels of GSH were observed for the above three compounds. Descriptors for QSAR model identified by GA-PLS were WPSA1, Weta1unity, WDunity, SC3, VC5, MlogP, and WTPT3. The identified model was highly predictive, and value of root mean square error of prediction for internal (leave one out) and external validation was: 1.579, 1.325.

CONCLUSION

Molecular hybrids of phthalimide and hydrazinecarbothioamide were synthesized. Some of the compounds possessed promising anti-inflammatory and anti-oxidant activities.

Identification and molecular modeling of new quinolin-2-one thiosemicarbazide scaffold with antimicrobial urease inhibitory activity

A new series of 6-substituted quinolin-2-one thiosemicarbazides 6a-j has been synthesized. The structure of the target compounds was proved by different spectroscopic and elemental analyses. All the designed final compounds were evaluated for their in vitro activity against the urease-producing R. mucilaginosa and Proteus mirabilis bacteria as fungal and bacterial pathogens, respectively. Moreover, all compounds were in vitro tested as potential urease inhibitors using the cup-plate diffusion method. Compounds 6a and 6b were the most active with (IC₅₀ = 0.58 ± 0.15 and 0.43 ± 0.09 µM), respectively, in comparison with lead compound I (IC₅₀ = 1.13 ± 0.00 µM). Also, the designed compounds were docked into urease proteins (ID: 3LA4 and ID: 4UBP) using Open Eye^® software to understand correctly about ligand-receptor interactions. The docking results revealed that the designed compounds can interact with the active site of the enzyme through multiple strong hydrogen bonds. Moreover, rapid overlay of chemical structures' analysis was described to understand the 3D QSAR of synthesized compounds as urease inhibitors. The results emphasize the importance of polar thiosemicarbazide directly linked to 6-substituted quinolone moieties as promising antimicrobial urease inhibitors.

Synthesis, Characterization, Antibacterial and Antioxidant Potency of NSubstituted- 2-Sulfanylidene-1,3-Thiazolidin-4-one Derivatives and QSAR Study

BACKGROUND

Rhodanine is known for its potential and important role in the medicinal chemistry since its derivatives exhibit a wide range of pharmacological activities such as antibacterial, antifungal, antidiabetic, antitubercular, anti-HIV, antiparasitic, antioxidant, anticancer, antiproliferative and anthelmintic agents.

OBJECTIVES

Since N-substituted rhodanine synthons are rarely commercially available, it is desirable to develop a straightforward synthetic approach for the synthesis of these key building blocks. The objective was to synthesize a series of rhodanine derivatives and to investigate their antimicrobial and antioxidant activity. Also, in order to obtain an insight into their structure-activity relationship, QSAR studies on the antioxidant activity were performed.

METHODS

1H and 13C FTNMR spectra were recorded on Bruker Avance 600 MHz NMR Spectrometer, mass analysis was carried out on ESI+ mode by LC-MS/MS API 2000. 2,2-Diphenyl-1- picrylhydrazyl radical scavenging activity (% DPPH) was determined in dimethylsulfoxide (DMSO) as a solvent. The antibacterial activity was assessed against Bacillus subtilis, Staphylococcus aureus (Gram positive) and Escherichia coli, Pseudomonas aeruginosa (Gram negative) bacteria in terms of the minimum inhibitory concentrations (MICs) by a modified broth microdilution method.

RESULTS

A series of N-substituted-2-sulfanylidene-1,3-thiazolidin-4-ones were synthesized and characterized by 1H NMR, 13C NMR, FTIR, GC MS, LCMS/MS and C,H,N,S elemental analysis. Most of the synthesized compounds showed moderate to excellent antibacterial activity (MIC values from 125 μg/ml to 15.62 μg/mL) and DPPH scavenging activity (from 3.60% to 94.40%). Compound 2-thioxo-3- (4-(trifluoromethyl)-phenyl)thiazolidin-4-one showed the most potent activity against Escherichia coli (3.125 μg/mL), equivalent to antibiotic Amikacin sulphate and against Staphylococcus aureus (0.097 μg/ml), 100 times superior then antibiotic Amikacin sulphate. It has also shown a potent antioxidant activity (95% DPPH scavenging). Two best QSAR models, obtained by GETAWAY descriptor R7p+, Balabans molecular connectivity topological index and Narumi harmonic topological index (HNar), suggest that the enhanced antioxidant activity is related to the presence of pairs of atoms higher polarizability at the topological distance 7, substituted benzene ring and longer saturated aliphatic chain in N-substituents.

CONCLUSION

A series of novel N-substituted-2-thioxothiazolidin-4-one derivatives were designed, synthesized, characterized and evaluated for their antibacterial and antioxidant activity in vitro. Majority of the compounds showed excellent antibacterial activity compared to ampicillin and few of them have an excellent activity as compared to Chloramphenicol standard antibacterial drug. The QSAR study has clarified the importance of presenting a pairs of atoms higher polarizability, such as Cl and S at the specific distance, as well as the substituted benzene ring and a long saturated aliphatic chain in N-substituents for the enhanced antioxidant activity of 2-sulfanylidene-1,3- thiazolidin-4-one derivatives.

Angiotensin-I-Converting Enzyme Inhibitory Activity of Coumarins from Angelica decursiva

The bioactivity of ten traditional Korean Angelica species were screened by angiotensin-converting enzyme (ACE) assay in vitro. Among the crude extracts, the methanol extract of Angelica decursiva whole plants exhibited potent inhibitory effects against ACE. In addition, the ACE inhibitory activity of coumarins 1–5, 8–18 was evaluated, along with two phenolic acids (6, 7) obtained from A. decursiva. Among profound coumarins, 11–18 were determined to manifest marked inhibitory activity against ACE with IC₅₀ values of 4.68–20.04 µM. Compounds 12, 13, and 15 displayed competitive inhibition against ACE. Molecular docking studies confirmed that coumarins inhibited ACE via many hydrogen bond and hydrophobic interactions with catalytic residues and zinc ion of C- and N-domain ACE that blocked the catalytic activity of ACE. The results derived from these computational and in vitro experiments give additional scientific support to the anecdotal use of A. decursiva in traditional medicine to treat cardiovascular diseases such as hypertension.

Synthesis and biological evaluation of purine-pyrazole hybrids incorporating thiazole, thiazolidinone or rhodanine moiety as 15-LOX inhibitors endowed with anticancer and antioxidant potential

Novel purine-pyrazole hybrids combining thiazoles, thiazolidinones and rhodanines, were designed and tested as 15-LOX inhibitors, potential anticancer and antioxidant agents. All tested compounds were found to be potent 15-LOX inhibitors with IC₅₀ ranging from 1.76 to 6.12 µM. The prepared compounds were evaluated in vitro against five cancer cell lines: A549 (lung), Caco-2 (colon), PC3 (prostate), MCF-7 (breast) and HepG-2 (liver). Compounds 7b and 8b displayed broad spectrum anticancer activity against the five tested cell lines (IC₅₀ = 18.5-95.39 µM). While, compound 7h demonstrated moderate anticancer activity against lung A549 and colon Caco-2 cell lines. Antioxidant screening revealed that six compounds (5a, 5b, 6b, 7b, 7h and 8b) with IC₅₀ ranging from 0.93 to 14.43 µg/ml were found to be more potent scavengers of 2,2- diphenyl-1-picrylhydrazyl (DPPH) than the reference ascorbic acid with IC₅₀ value of 15.34 µg/ml. Compounds 7b, 7h and 8b, when evaluated for their antioxidant activity, where found to be potent DPPH scavengers. Moreover, compound 7b displayed twice the potency of ascorbic acid as NO scavenger. Docking study was performed to elucidate the possible binding mode of the most active compounds with the active site of 15-LOX enzyme. Collectively, the purine-pyrazole hybrids having thiazoline or thizolidinone moieties (7b, 7h and 8b) constitute a promising scaffold in designing more potent 15-LOX inhibitors with anticancer and antioxidant potential.

Chemical Diversity of Codium bursa (Olivi) C. Agardh Headspace Compounds, Volatiles, Fatty Acids and Insight into Its Antifungal Activity

The focus of present study is on Codium bursa collected from the Adriatic Sea. C. bursa volatiles were identified by gas chromatography and mass spectrometry (GC-FID; GC-MS) after headspace solid-phase microextraction (HS-SPME), hydrodistillation (HD), and supercritical CO₂ extraction (SC-CO₂). The headspace composition of dried (HS-D) and fresh (HS-F) C. bursa was remarkably different. Dimethyl sulfide, the major HS-F compound was present in HS-D only as a minor constituent and heptadecane percentage was raised in HS-D. The distillate of fresh C. bursa contained heptadecane and docosane among the major compounds. After air-drying, a significantly different composition of the volatile oil was obtained with (E)-phytol as the predominant compound. It was also found in SC-CO₂ extract of freeze-dried C. bursa (FD-CB) as the major constituent. Loliolide (3.51%) was only identified in SC-CO₂ extract. Fatty acids were determined from FD-CB after derivatisation as methyl esters by GC-FID. The most dominant acids were palmitic (25.4%), oleic (36.5%), linoleic (11.6%), and stearic (9.0%). FD-CB H₂O extract exhibited better antifungal effects against Fusarium spp., while dimethyl sulfoxide (DMSO) extract was better for the inhibition of Penicillium expansum, Aspergillus flavus, and Rhizophus spp. The extracts showed relatively good antifungal activity, especially against P. expansum (for DMSO extract MIC₅₀ was at 50 µg/mL).

Environmentally Friendly Approach to Knoevenagel Condensation of Rhodanine in Choline Chloride: Urea Deep Eutectic Solvent and QSAR Studies on Their Antioxidant Activity

A series of rhodanine derivatives was synthesized in the Knoevenagel condensation of rhodanine and different aldehydes using choline chloride:urea (1:2) deep eutectic solvent. This environmentally friendly and catalyst free approach was very effective in the condensation of rhodanine with commercially available aldehydes, as well as the ones synthesized in our laboratory. All rhodanine derivatives were subjected to 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activity investigation and quantitative structure-activity relationship (QSAR) studies were performed to elucidate their structure-activity relationship. The best multiple linear QSAR model demonstrate a stability in the internal validation and Y-randomization (R² = 0.81; F = 24.225; Q²loo = 0.72; R²Yscr = 0.148). Sphericity of the molecule, ratio of symmetric atoms enhanced atomic mass along the principle axes in regard to total number of atoms in molecule, and 3D distribution of the atoms higher electronegativity (O, N, and S) in molecules are important characteristic for antioxidant ability of rhodanine derivatives. Molecular docking studies were carried out in order to explain in silico antioxidant studies, a specific protein tyrosine kinase (2HCK). The binding interactions of the most active compound have shown strong hydrogen bonding and van der Waals interactions with the target protein.

Retracted: Novel spiro-thiazolidin-4-one and thioether derivatives of benzylidene flavanones: New leads in cancer and microbial chemotherapy

The above article from Archiv der Pharmazie, published online on 12 March 2018 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor-in-Chief, Prof. Holger Stark, and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. The retraction has been agreed due to errors in the spectroscopic data of the investigated new compounds.

REFERENCE TO RETRACTION

S. Mukhtar, M. A. Alsharif, M. I. Alahmdi, H. Parveen, A. U. Khan, Arch. Pharm. Chem. Life Sci. 2018;1-12. DOI: 10.1002/ardp.201700397.

Drug likeness prediction of 5-hydroxy-substituted coumarins with high affinity to 5-HT1A and 5-HT2A receptors

One of the latest trends is search for the new anti-psychotic drugs among coumarin derivatives with piperazine moiety. Their therapeutic potential can be hampered by poor physico-chemical parameters as low brain penetration or limited transport in the body fluid. Herein, we predicted the drug likeness of six coumarins with high affinity towards 5-HT_1A and 5-HT_2A receptors. Subsequent experimental determination of their binding constants to human serum albumin (HSA) revealed the binding with a moderate strength (logK=4.8-5.8) at the Sudlow's site 1, which represents a possibility of temporary storage of tested coumarins on HSA. Computational mapping of the binding of coumarins - HSA complexes showed that the coumarin rings of all tested compounds were similarly located within the hydrophobic binding pocket of HSA, while the rest of molecules (composed with alkyl chains, piperazine and benzene rings) decided about the difference in binding modes by the hydrogen bonding interactions. The proton dissociation constants (pK_a) of the compounds were also determined by UV-vis spectrophotometric titrations to obtain the distribution of the species in the different protonation states at physiological pH of 7.4. A good agreement of the computationally-determined free enthalpy values of the ligand - HSA complexes with the values determined by experimental fluorescence quenching data could be a promising prospect for proposed theoretical strategy.

In vitro antioxidant activity of thiazolidinone derivatives of 1,3-thiazole and 1,3,4-thiadiazole

The initial steps in preclinical drug developing research concern the synthesis of new compounds for specific therapeutic use which needs to be confirmed by in vitro and then in vivo testing. Nine thiazolidinone derivatives (numerically labeled 1-9) classified as follows: 1,3-thiazole-based compounds (1 and 2); 1,3,4-thiadiazole based compounds (3 and 4); substituted 5-benzylideno-2-adamantylthiazol[3,2-b][1,2,4]triazol-6(5H)ones (5-8); and an ethylaminothiazole-based chalcone (9), were tested for antioxidant activity (AOA) by using three in vitro assays: DPPH (1,1-diphenyl-2-picrylhydrazyl scavenging capacity test); FRAP (ferric reducing antioxidant power test); and TBARS (thiobarbituric acid reactive substances test). Compounds 1-4 and 9 in particular are newly synthesized compounds. Also, traditional antioxidants Vitamins E and C and α-lipoic acid (α-LA) were tested. The results of DPPH testing: Vitamin C 94.35%, Vitamin E 2.99% and α-LA 1.57%; compounds: 4 33.98%; 2 18.73%; 1 15.62%; 5 6.59%; 3 4.99%; 6-9 demonstrated almost no AOA. The results of TBARS testing (% of LPO inhibition): Vitamin C 62.32%; Vitamin E 36.29%; α-LA 51.36%; compounds: 1 62.11%; 5 66.71%; 9 60.93%; 4, 6 and 7 demonstrated ∼50%; 3 and 8 displayed ∼38%; 2 23.51%. By FRAP method, Vitamins E and C showed equal AOA, ∼100%, unlike α-LA (no AOA), and AOA of the tested compounds (expressed as a fraction of the AOA of Vitamin C) were: 2 and 4-75%; 8, 3 and 1-45%; 5-7 and 9-27%. Different red-ox reaction principles between these assays dictate different AOA outcomes for a single compound. Vitamin C appeared to be the superior antioxidant out of the traditional antioxidants; and compound 4 was superior to other tested thiazolidinone derivatives. Vitamin C appeared to be the superior antioxidant out of the traditional antioxidants; and compound 4 was superior to other tested thiazolidinone derivatives. Phenyl-functionalized benzylidene, amino-carbonyl functional domains and chelating ligand properties of the thiazolidinone derivatives correlated with AOA.

Novel Trifluoromethylcoumarinyl Urea Derivatives: Synthesis, Characterization, Fluorescence, and Bioactivity

A series of novel trifluoromethylcoumarinyl urea derivatives were designed, synthesized, and characterized by ¹H-NMR, ¹³C-NMR, and HR-ESI-MS. The fluorescence spectra of the target compounds were recorded. The spectra show that most of the title compounds glow green with λ_max^em of 500-517 nm, while compounds 5r, 5s, 5u, and 5l (compounds named by authors) glow violet with λ_max^em of 381-443 nm. Moreover, the herbicidal and antifungal activities of the synthesized compounds were evaluated for their potential use as pesticides. The results indicate that compound 5f against the caulis of Amaranthusretroflexus and compounds 5j and 5l against the taproot of Digitariasanguinalis are equivalent to the commercial herbicide Acetochlor. Nine of the title compounds are more antifungal than commercial fungicide Carbendazim against Botrytis cinerea.