Synthesis, antileishmanial activity and docking study of N′-substitutedbenzylidene-2-(6,7-dihydrothieno[3,2-c]pyridin-5(4H)-yl)acetohydrazides

Therapeutic Potential of Marine-Derived Cyclic Peptides as Antiparasitic Agents

Parasitic diseases still compromise human health. Some of the currently available therapeutic drugs have limitations considering their adverse effects, questionable efficacy, and long treatment, which have encouraged drug resistance. There is an urgent need to find new, safe, effective, and affordable antiparasitic drugs. Marine-derived cyclic peptides have been increasingly screened as candidates for developing new drugs. Therefore, in this review, a systematic analysis of the scientific literature was performed and 25 marine-derived cyclic peptides with antiparasitic activity (1-25) were found. Antimalarial activity is the most reported (51%), followed by antileishmanial (27%) and antitrypanosomal (20%) activities. Some compounds showed promising antiparasitic activity at the nM scale, being active against various parasites. The mechanisms of action and targets for some of the compounds have been investigated, revealing different strategies against parasites.

In vitro anti-Leishmania activity and molecular docking of spiro-acridine compounds as potential multitarget agents against Leishmania infantum

Leishmaniasis is an infectious disease with several limitations regarding treatment schemes. This work reports the anti-Leishmania activity of spiroacridine compounds against the promastigote (IC₅₀ = 1.1 to 6.0 µg / mL) and amastigote forms of the best compounds (EC₅₀ = 4.9 and 0.9 µg / mL) inLeishmania (L.) infantumand proposes an in-silico study with possible selective therapeutic targets for L. infantum. The substituted dimethyl-amine compound (AMTAC 11) showed the best leishmanicidal activity in vitro, and was found to interact with TryRandLdTopoI. comparisons with standard inhibitors were performed, and its main interactions were elucidated. Based on the biological assessment and the structure-activity relationship study, the spiroacridine compounds appear to be promisinganti-leishmaniachemotherapeutic agents to be explored.

Recent Advances in the Discovery of Novel Antiprotozoal Agents

Parasitic diseases have serious health, social, and economic impacts, especially in the tropical regions of the world. Diseases caused by protozoan parasites are responsible for considerable mortality and morbidity, affecting more than 500 million people worldwide. Globally, the burden of protozoan diseases is increasing and is been exacerbated because of a lack of effective medication due to the drug resistance and toxicity of current antiprotozoal agents. These limitations have prompted many researchers to search for new drugs against protozoan parasites. In this review, we have compiled the latest information (2012-2017) on the structures and pharmacological activities of newly developed organic compounds against five major protozoan diseases, giardiasis, leishmaniasis, malaria, trichomoniasis, and trypanosomiasis, with the aim of showing recent advances in the discovery of new antiprotozoal drugs.

Targeting pteridine reductase 1 and dihydrofolate reductase: the old is a new trend for leishmaniasis drug discovery

Leishmaniasis is one of the major neglected tropical diseases in the world and it is considered endemic in 88 countries. This disease is transmitted by a Leishmania spp. infected sandfly and it may lead to cutaneous or systemic manifestations. The preconized treatment has low efficacy and there are cases of resistance to some drugs. Therefore, the search for new efficient molecular targets that can lead to the preparation of new drugs must be pursued. This review aims to evaluate both Leishmania enzymes PTR1 and DHFR-TS as potential drug targets, highlight their inhibitors and to discuss critically the use of chemoinformatics to elucidate interactions and propose new molecules against these enzymes.

Synthesis, biological evaluations and computational studies of N-(3-(-2-(7-Chloroquinolin-2-yl)vinyl) benzylidene)anilines as fungal biofilm inhibitors

In the present investigation, new chloroquinoline derivatives bearing vinyl benzylidene aniline substituents at 2nd position were synthesized and screed for biofilm inhibitory, antifungal and antibacterial activity. The result of biofilm inhibition of C. albicans suggested that compounds 5j (IC₅₀ value = 51.2 μM) and 5a (IC₅₀ value = 66.2 μM) possess promising antibiofilm inhibition when compared with the standard antifungal drug fluconazole (IC₅₀ = 40.0 μM). Two compounds 5a (MIC = 94.2 μg/mL) and 5f (MIC = 98.8 μg/mL) also exhibited good antifungal activity comparable to standard drug fluconazole (MIC = 50.0 μg/mL). The antibacterial screening against four strains of bacteria viz. E. coli, P. aeruginosa, B. subtilis, and S. aureus suggested their potential antibacterial activity and especially all the compounds except 5g were found more active than the standard drug ciprofloxacin against B. subtilis. To further gain insights into the possible mechanism of these compounds in biofilm inhibition through the agglutinin like protein (Als), molecular docking and molecular dynamics simulation studies were carried out. Molecular modeling studies suggested the clear role in inhibition of this protein and the resulting biofilm inhibitory activity.

Novel amalgamation of phthalazine-quinolines as biofilm inhibitors: One-pot synthesis, biological evaluation and in silico ADME prediction with favorable metabolic fate

A facile and highly efficient one-pot synthesis of phthalazine-quinoline derivatives is reported via four component reaction of phthalic anhydride, hydrazine hydrate, 5,5-dimethyl 1,3 cyclohexanedione and various quinoline aldehydes using PrxCoFe2-xO4 (x=0.1) nanoparticles as a catalyst. The synthesized compounds have been evaluated for anti-biofilm activity against Pseudomonas aeruginosa and Candida albicans. The compounds 12a (IC50=30.0μM) and 12f (IC50=34.5μM) had shown promising anti-biofilm activity against P. aeruginosa and C. albicans, respectively, when compared with standards without affecting the growth of cells (and thus behave as anti-quorum sensing agents). Compounds 12a (MIC=45.0μg/mL) and 12f (MIC=57.5μg/mL) showed significant potent antimicrobial activity against P. aeruginosa and C. albicans, respectively. Thus, the active derivatives were not only potent biofilm inhibitors but also efficient antimicrobial agents. In silico ADME and metabolic site prediction studies were also held out to set an effective lead candidate for the future antimicrobial drug discovery initiatives.

Antileishmanial activity of novel indolyl-coumarin hybrids: Design, synthesis, biological evaluation, molecular docking study and in silico ADME prediction

In present work we have designed and synthesized total twelve novel 3-(3-(1H-indol-3-yl)-3-phenylpropanoyl)-4-hydroxy-2H-chromen-2-one derivatives 13(a-l) using Ho(3+) doped CoFe2O4 nanoparticles as catalyst and evaluated for their potential antileishmanial and antioxidant activities. The compounds 13a, 13d and 13h were found to possess significant antileishmanial activity (IC50 value=95.50, 95.00 and 99.00μg/mL, respectively) when compared to the standard sodium stibogluconate (IC50=490.00 μg/mL). The compounds 13a (IC50=12.40 μg/mL), 13d (IC50=13.49 μg/mL), 13g (IC50=13.24 μg/mL) and 13l (IC50=13.74 μg/mL) had shown good antioxidant activity when compared with standards butylated hydroxy toluene (IC50=16.5 μg/mL) and ascorbic acid (IC50=12.8 μg/mL). After performing molecular docking studies, it was found that compounds 13a and 13d had potential to inhibit pteridine reductase 1 enzyme. In silico ADME pharmacokinetic parameters had shown promising results and none of the synthesized compounds had violated Lipinski's rule of five. Thus, suggesting that compounds from the present series can serve as important gateway for the design and development of new antileishmanial as well as antioxidant agent.

Efficient one-pot synthesis, molecular docking and in silico ADME prediction of bis-(4-hydroxycoumarin-3-yl) methane derivatives as antileishmanial agents

Bis-(4-hydroxycoumarin-3-yl) methane derivatives 3(a-l) were synthesized from 4-hydroxycoumarin and substituted aromatic aldehydes using succinimide-N-sulfonic acid as catalyst and evaluated for their in vitro antileishmanial activity against promastigotes form of Leishmania donovani. Compounds 3a (IC₅₀= 155 μg/mL), 3g (IC₅₀= 157.5 μg/mL) and 3l (IC₅₀= 150 μg/mL) were shown significant antileishmanial activity when compared with standard sodium stibogluconate (IC₅₀= 490 μg/mL). Also, synthesized compounds 3(a-l) did not show cytotoxicity against HeLa cell line upto tested concentrations. Further, molecular docking study against Adenine phosphoribosyltransferase of Leishmania donovani showed good binding interactions. ADME properties were analyzed and showed good oral drug candidate like properties. The synthesized compounds were also shown good drug likeness and drug score values when compared with drugs currently used in therapy. The present study has helped us in identifying a new lead that could be exploited as a potential antileishmanial agent.

1,2,3-Triazole derivatives as antitubercular agents: synthesis, biological evaluation and molecular docking study

A library of thirty one 1,2,3-triazole derivatives efficiently preparedviaclick chemistry and evaluated for their antitubercular, antioxidant, and cytotoxic activities.

Antileishmanial drug discovery: comprehensive review of the last 10 years

This review covers the current aspects of leishmaniasis including marketed drugs, new antileishmanial agents, and possible drug targets of antileishmanial agents.