Novel aryloxy azolyl chalcones with potent activity against Mycobacterium tuberculosis H37Rv

Chalcones reloaded: an integration of network pharmacology and molecular docking for type 2 diabetes therapy

Chalcones have various biological effects, from immune boosting to anti-cancer and anti-diabetic. Structurally modified chalcones (SMC) are clinically relevant for diabetes and cardiometabolic complications. From the original research articles, a structurally proven and biologically outstanding 14 structurally modified chalcones were screened and inducted in this study. This study evaluated the effects of SMC towards diabetes via network pharmacology analysis. The network data shows compounds S2, S3, S5, S9 &S12 suit the diabetes target. Especially Compounds S5 and S9 have a higher binding affinity towards the targets of TNF, PI3K, MAPK1 and AKT1 active sites. Compound S9 [(E)-3-(4-(1H-imidazol-1-yl)phenyl)-1-(4-(2,4-difluorobenz-yloxy)phenyl)prop-2-en-1-one] have identified with stronger binding affinities towards the active sites of MAPK3 (PDB:4QTB) -10.5(Kcal/mol). To provide a more effective mechanism for demonstrating protein-ligand interaction, one of the molecular docking complex (ERK2 kinase-S5) was subjected to a molecular dynamic at 300K for 100 ns. In term of structural stability, structure compactness, residual flexibility and hydrogen bond interaction of the complex was evaluated Integrating network pharmacology, in silico virtual screening, and molecular docking analysis shows that structurally modified compounds are effective and may help identify lead compounds towards glycemic control.Communicated by Ramaswamy H. Sarma.

Design and fabrication of dysprosium impregnated polyvinyl alcohol hydrogels. Physiochemical, mechanical, bioimaging and in vitro evaluation

Tissue engineering has gained prominence during the past decade since it offers a key solution to defects associated with the tissue regeneration. The limited healing potential of the cartilage tissue damage has significant clinical implications. Herein, dysprosium (Dy3+) impregnated polyvinyl alcohol (PVA) hydrogels have been developed to enhance the therapeutic efficacy, enabling simultaneous diagnostic imaging and antibacterial drug delivery for potential applications in articular cartilage. Based on the favorable imaging features, Dy3+ impregnated PVA hydrogels with enhanced stability were formed through successive steps of repeated cycles of freezing at - 30 °C for 21 h, thawing at 25 °C for 4 h and lyophilization. The tensile and compression tests of the hydrogels respectively determined a maximum of 3.88 and 1.58 MPa, which reflected better compatibility towards cartilage. The hydrogels fetched a sustained drug release for a period of 12 h with an associated swelling ratio of 80%. The potential of the resultant hydrogels in image diagnosis has been deliberated through their blue and yellow emissions in the visible region. Further, the computed tomography (CT) and magnetic resonance imaging characteristics of the hydrogels respectively accomplished a maximum of 343 Hounsfiled units (HU) and relaxivity of 7.25 mM-1s-1. The cytocompatibility of the hydrogels is also determined through in vitro tests performed in Murine pro B cell line (BA/F3) and human Megakaryocyte cell line (Mo7e) cell lines.

Identification of nitrofuranylchalcone tethered benzoxazole-2-amines as potent inhibitors of drug resistant Mycobacterium tuberculosis demonstrating bactericidal efficacy

Ever increasing drug resistance has become an impeding threat that continues to hamper effective tackling of otherwise treatable tuberculosis (TB). Such dismal situation necessitates identification and exploration of multitarget acting newer chemotypes with bactericidal efficacy as a priority, that could efficiently hinder uncontrolled spread of TB. In this context, herein we present design, synthesis and bio-evaluation of chalcone tethered bezoxazole-2-amines as promising anti-TB chemotypes. Preliminary screening of 24 compounds revealed initial hits 3,4,5-trimethoxyphenyl and 5-nitrofuran-2-yl derivative exhibiting selective inhibition of Mycobacterium tuberculosis (Mtb) H37Rv. Further, structural optimization of hit compounds generated 12 analogues, amongst which 5-nitrofuran-2-yl derivatives displayed potent inhibition of not only drug-susceptible (DS) Mtb but also clinical isolates of drug-resistant (DR) Mtb strains equipotently. Moreover, cell viability test against Vero cells found these compounds with favourable selectivity. Time kill analysis led to the identification of the lead compound (E)-1-(4-((5-chlorobenzo[d]oxazol-2-yl)amino)phenyl)-3-(5-nitrofuran-2-yl)prop-2-en-1-one, that demonstrated bactericidal killing of Mtb bacilli. Together with acceptable microsomal stability, the lead compound of the series manifested all desirable traits of a promising antitubercular agent.

The Medicinal Chemistry of Chalcones as Anti-Mycobacterium tuberculosis Agents

Abstract:

Tuberculosis (TB), a highly fatal infectious disease, is caused by Mycobacterium tuberculosis (Mtb) that has inflicted mankind for several centuries. In 2019, the staggering number of new cases reached 10 million resulting in 1.2 million deaths. The emergence of multidrug-resistance-Mycobacterium tuberculosis (MDR-TB) and extensively drug-resistant-Mycobacterium tuberculosis (XDR-TB) is a global concern that requires the search for novel, effective, and safer short-term therapies. Nowadays, among the few alternatives available to treat resistant-Mtb strains, the majority have limitations, which include drug-drug interactions, long-term treatment, and chronic induced toxicities. Therefore, it is mandatory to develop new anti-Mtb agents to achieve health policy goals to mitigate the disease by 2035. Among the several bioactive anti-Mtb compounds, chalcones have been described as the privileged scaffold useful for drug design. Overall, this review explores and analyzes 37 chalcones that exhibited anti-Mtb activity described in the literature up to April 2021 with minimum inhibitory concentration (MIC90) values inferior to 20 µM and selective index superior to 10. In addition, the correlation of some properties for most active compounds was evaluated, and the main targets for these compounds were discussed.

First-in-class pyrido[2,3-d]pyrimidine-2,4(1H,3H)-diones against leishmaniasis and tuberculosis: Rationale, in vitro, ex vivo studies and mechanistic insights

Pyrido[2,3-d]pyrimidine-2,4(1H,3H)-diones were synthesized, for the first time, from indole chalcones and 6-aminouracil, and their ability to inhibit leishmaniasis and tuberculosis (Tb) infections was evaluated. The in vitro antileishmanial activity against promastigotes of Leishmania donovani revealed exceptional activities of compounds 3, 12 and 13, with IC₅₀ values ranging from 10.23 ± 1.50 to 15.58 ± 1.67 µg/ml, which is better than the IC₅₀ value of the standard drug pentostam of 500 μg/ml. The selectivity of the compounds towards Leishmania parasites was evaluated via ex vivo studies in Swiss albino mice. The efficiency of these compounds against Tb infection was then evaluated using the in vitro anti-Tb microplate Alamar Blue assay. Five compounds, 3, 7, 8, 9 and 12, showed MIC₁₀₀ values against the Mycobacterium tuberculosis H₃₇ Rv strain at 25 µg/ml, and compound 20 yielded an MIC₁₀₀ value of 50 µg/ml. Molecular modelling of these compounds highlighted interactions with binding sites of dihydrofolate reductase, pteridine reductase and thymidylate kinase, thus establishing the rationale of their pharmacological activity against both pathogens, which is consistent with the in vitro results. From the above results, it is clear that compounds 3 and 12 are promising lead candidates for Leishmania and Mycobacterium infections and may be promising for coinfections.

Antimycobacterial and anti-inflammatory activities of thiourea derivatives focusing on treatment approaches for severe pulmonary tuberculosis

Tuberculosis (TB) remains a serious public health problem and one of the main concern is the emergence of multidrug-resistant and extensively resistant TB. Hyper-reactive patients develop inflammatory necrotic lung lesions that aggravate the pathology and facilitate transmission of mycobacteria. Treatment of severe TB is a major clinical challenge that has few effective solutions and patients face a poor prognosis, years of treatment and different adverse drug reactions. In this work, fifteen novel and thirty-one unusual thiourea derivatives were synthesized and evaluated in vitro for their antimycobacterial and anti-inflammatory potential and, in silico for ADMET parameters and for structure-activity relationship (SAR). Thioureas derivatives 10, 15, 16, 28 and 29 that had shown low cytotoxicity and high activities were selected for further investigation, after SAR study. These five thioureas derivatives inhibited Mtb H37Rv growth in bacterial culture and in infected macrophages, highlighting thiourea derivative 28 (MIC₅₀ 2.0 ± 1.1 and 2.3 ± 1.1 µM, respectively). Moreover, these compounds were active against the hypervirulent clinical Mtb strain M299, in bacterial culture, especially 16, 28 and 29, and in extracellular clumps, highlighting 29, with MIC₅₀ 5.6 ± 1.2 µM. Regarding inflammation, they inhibited NO through the suppression of iNOS expression, and also inhibited the production of TNF-α and IL-1β. In silico studies were carried out suggesting that these five compounds could be administered by oral route and have low toxicological effects when compared to rifampicin. In conclusion, our data show that, at least, thiourea derivatives 16, 28 and 29 are promising antimycobacterial and anti-inflammatory agents, and candidates for further prospective studies aiming new anti-TB drugs, that can be used on a dual approach for the treatment of severe TB cases associated with exacerbated inflammation.

Synthesis and structure-activity relationship of new chalcone linked 5-phenyl-3-isoxazolecarboxylic acid methyl esters potentially active against drug resistant Mycobacterium tuberculosis

In search of novel therapeutic agents active against emerging drug-resistant Mycobacterium tuberculosis and to counter the long treatment protocol of existing drugs, herein we present synthesis and biological evaluation of a new series of 5-phenyl-3-isoxazolecarboxylic acid methyl ester-chalcone hybrids. Among 35 synthesized compounds, 32 analogues displayed potent in-vitro activity against Mycobacterium tuberculosis H37Rv with MIC 0.12-16 μg/mL. Cell viability test against Vero cells indicated 29 compounds to be non-cytotoxic (CC₅₀ > 20 μg/mL & SI > 10). Most potent compounds with MIC 0.12 μg/mL (7 b, 7j, 7 ab) exhibited selectivity index (SI) in excess of 320. Further studies on activity against drug-resistant Mycobacterium tuberculosis revealed 7j as the most potent compound with MIC 0.03-0.5 μg/mL. Time-kill kinetic study suggested compound 7j displaying concentration-dependent bactericidal killing activity with relatively comparable potency to that of current first-line anti-TB drugs. Taken together, 7j presents a novel hit with potential to be translated into a potent antimycobacterial.

Recent advances of imidazole-containing derivatives as anti-tubercular agents

Tuberculosis still remains one of the most common, communicable, and leading deadliest diseases known to mankind throughout the world. Drug-resistance in Mycobacterium tuberculosis which threatens to worsen the global tuberculosis epidemic has caused great concern in recent years. To overcome the resistance, the development of new drugs with novel mechanisms of actions is of great importance. Imidazole-containing derivatives endow with various biological properties, and some of them demonstrated excellent anti-tubercular activity. As the most emblematic example, 4-nitroimidazole delamanid has already received approval for treatment of multidrug-resistant tuberculosis infected patients. Thus, imidazole-containing derivatives have caused great interests in discovery of new anti-tubercular agents. Numerous of imidazole-containing derivatives were synthesized and screened for their in vitro and in vivo anti-mycobacterial activities against both drug-sensitive and drug-resistant Mycobacterium tuberculosis pathogens. This review aims to outline the recent advances of imidazole-containing derivatives as anti-tubercular agents, and summarize the structure-activity relationship of these derivatives. The enriched structure-activity relationship may pave the way for the further rational development of imidazole-containing derivatives as anti-tubercular agents.

A macrocyclic silver polycarbene complex based on 1,2,4-triazole units: synthesis and postsynthetic modification

A method for the synthesis of a new rectangular 1,2,4-triazole-containing macrocycle via photochemical [2 + 2] cycloaddition with a metal–carbene template was developed.

Azide-alkyne cycloaddition en route to 4-aminoquinoline-ferrocenylchalcone conjugates: synthesis and anti-TB evaluation

AIM

Tuberculosis is responsible for 9.6 million infections and 1.5 million deaths in 2015. The development of multidrug-resistant and extensively drug-resistant strains has impeded the development of effective antitubercular therapy. Results/methodology: The present manuscript describes the synthesis of a series of 4-aminoquinoline-ferrocenylchalcone conjugates via Cu-promoted Huisgen's azide-alkyne cycloaddition reaction and evaluation of their antitubercular activities against mc²6230 strain of Mycobacterium tuberculosis. The conjugate 11j proved to be the most potent of the synthesized conjugates with a minimum inhibitory concentration (MIC₉₉) value of 30 μM and proved to be noncytotoxic against HeLa cells.

CONCLUSION

The synthesized conjugates can act as starting point for the development of new antitubercular agents. Synthesis and antitubercular evaluation of 1H-1,2,3-triazole-tethered 4-aminoquinoline-ferrocenylchalcone conjugates. [Formula: see text].

Antitubercular activity of ZnO nanoparticles prepared by solution combustion synthesis using lemon juice as bio-fuel

In this study, we report the synthesis, structural and morphological characteristics of zinc oxide (ZnO) nanoparticles using solution combustion synthesis method where lemon juice was used as the fuel. In vitro anti-tubercular activity of the synthesized ZnO nanoparticles and their biocompatibility studies, both in vitro and in vivo were carried out. The synthesized nanoparticles showed inhibition of Mycobacterium tuberculosis H37Ra strain at concentrations as low as 12.5μg/mL. In vitro cytotoxicity study performed with normal mammalian cells (L929, 3T3-L1) showed that ZnO nanoparticles are non-toxic with a Selectivity Index (SI) >10. Cytotoxicity performed on two human cancer cell lines DU-145 and Calu-6 indicated the anti-cancer activity of ZnO nanoparticles at varied concentrations. Results of blood hemolysis indicated the biocompatibility of ZnO nanoparticles. Furthermore, in vivo toxicity studies of ZnO nanoparticles conducted on Swiss albino mice (for 14days as per the OECD 423 guidelines) showed no evident toxicity.

Design, synthesis and anticancer activity of novel hybrid compounds between benzofuran and N-aryl piperazine

A series of novel hybrid compounds between benzofuran and N-aryl piperazine have been designed and prepared. These derivatives were evaluated for their in vitro anti-tumor activity against a panel of human tumor cell lines by MTT assay. The results demonstrated that amide derivatives were more bioactive than sulfonamide compounds in general, and that chloro or trifluoromethyl substituent was vital for modulating cytotoxic activity. In particular, compound 13 was found to be the most potent compound against 4 strains human tumor cell lines, and exhibited cytotoxic activity selectively against Hela (0.03μM).