Carbohydrate derivatives fight against malaria parasite as anti-plasmodial agents.

Malaria, a prevalent fatal disease around the world is caused by Plasmodium sp. and is transmitted by the bite of female Anopheles mosquito. It is leading cause of death in this century among most infectious diseases.

Safe Polycationic Dendrimers as Potent Oral In Vivo Inhibitors of : A New Therapy to Take Down Tuberculosis.

The long-term treatment of tuberculosis (TB) sometimes leads to nonadherence to treatment, resulting in multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis. Inadequate bioavailability of the drug is the main factor for therapeutic failure, which leads to the development of drug-resistant cases. Therefore, there is an urgent need to design and develop novel antimycobacterial agents minimizing the period of treatment and reducing the propagation of resistance at the same time.

Glycosylated-imidazole aldoximes as reactivators of pesticides inhibited AChE: Synthesis and in-vitro reactivation study.

The present armamentarium of commercially available antidotes provides limited protection against the neurological effects of organophosphate exposure. Hence, there is an urgent need to design and develop molecules that can protect and reactivate inhibited-AChE in the central nervous system. Some natural compounds like glucose and certain amino acids (glutamate, the anion of glutamic acid) can easily cross the blood brain barrier although they are highly polar.

Novel Tetrahydroquinazolinamines as Selective Histamine 3 Receptor Antagonists for the Treatment of Obesity.

The histamine 3 receptor (H3R) is a presynaptic receptor, which modulates several neurotransmitters including histamine and various essential physiological processes, such as feeding, arousal, cognition, and pain. The H3R is considered as a drug target for the treatment of several central nervous system disorders. We have synthesized and identified a novel series of 4-aryl-6-methyl-5,6,7,8-tetrahydroquinazolinamines that act as selective H3R antagonists.

An Overview on Glyco-Macrocycles: Potential New Lead and their Future in Medicinal Chemistry.

Macrocycles cover a small segment of molecules with a vast range of biological activity in the chemotherapeutic world. Primarily, the natural sources derived from macrocyclic drug candidates with a wide range of biological activities are known. Further evolutions of the medicinal chemistry towards macrocycle-based chemotherapeutics involve the functionalization of the natural product by hemisynthesis.

Identification of dual role of piperazine-linked phenyl cyclopropyl methanone as positive allosteric modulator of 5-HT and negative allosteric modulator of 5-HT receptors.

Allosteric modulators of G-protein-coupled receptors have lately gained significant traction in drug discovery. Recent studies have shown that allosteric modulation of serotonin 2C receptor (5-HT) as a viable strategy for the treatment of various central nervous system (CNS) disorders. Considering the critical role of 5-HT in the modulation of appetite, a selective positive allosteric modulator (PAM) of 5-HT offers a new opportunity for anti-obesity therapeutic development.

Synthesis of isatin based N-alkylated 3-β-C-glycoconjugated-oxopropylidene oxindoles as potent antiplasmodial agents.

In an attempt to develop new antimalarial drugs, we have synthesized a new class of N-alkylated 3-glycoconjugated-oxopropylidene oxindoles starting from substituted isatins and glucopyranosyl propanone via a well-known cross-aldol reaction followed by dehydration. The newly synthesized compounds were screened for their in vitro antiplasmodial activity, and among all the compounds 9g, 9f, 9b, 8d, 9d, 9c, and 9e displayed potent activity with the IC values in the range of 0.1-0.

Metal- and Phenol-Free Synthesis of Biaryl Ethers: Access to Dibenzobistriazolo-1,4,7-oxadiazonines and Vancomycin-Like Glyco-Macrocycles as Antibacterial Agents.

An efficient synthesis of biaryl ethers, from electron-deficient aryl halides using NaH/DMSO under metal- and phenol-free conditions, has been achieved to access dibenzo-bistriazolo-1,4,7-oxadiazonines and vancomycin-like glyco-macrocycles. A 44-membered glyco-macrocycle showed promising activity against vancomycin-resistant Staphylococcus aureus (VRSA).

Synthesis and antiplasmodial activity of purine-based -nucleoside analogues.

A series of homologous -nucleoside mimics have been synthesized an efficient and facile synthetic protocol involving the conjugate addition of purine to sugar derived olefinic ester in good yields. The synthesized compounds were evaluated for their antiplasmodial activity against both the CQ-sensitive and resistant strains of . Interestingly, all the synthesized nucleoside analogs exhibited an IC of <5 μM, while compounds , , and showed promising antiplasmodial activity with an IC of 1.

New Ways to Treat Tuberculosis Using Dendrimers as Nanocarriers.

Tuberculosis (TB) is a contagious infection that usually attacks not only the lungs, but also brain and spine. More than twenty drugs have been developed for the treatment of TB, but most of them were developed some years ago. They are used in different combinations.

Synthesis and antiplasmodial activity of glyco-conjugate hybrids of phenylhydrazono-indolinones and glycosylated 1,2,3-triazolyl-methyl-indoline-2,3-diones.

A small library of 36 new glycohybrids of phenylhydrazono-indolinones was synthesized employing glycosylated 1,2,3-triazolyl-methyl-indoline-2,3-diones and different phenylhydrazines via acid catalyzed reaction. All the compounds were screened for their antiplasmodial activity in vitro. Compounds 6c, 7c, and 7b showed significant activity with the IC values 1.

Synthesis and antiplasmodial activity of novel indoleamide derivatives bearing sulfonamide and triazole pharmacophores.

Due to the recent reports of growing parasite resistance to artemisinins and other antimalarial drugs, development of new antimalarial chemotypes is an urgent priority. Here in, we report a novel series of adamantyl/cycloheptyl indoleamide derivatives bearing sulfonamide and triazole pharmacophores adopting different chemical modifications and evaluated them for antiplasmodial activity in vitro. Among all the indoleamides, compounds 22, 24, 26 and 30 with sulfonamide pharmacophore showed promising activity with IC of 1.

One-Pot Copper(I)-Catalyzed Ligand/Base-Free Tandem Cyclooxidative Synthesis of Quinazolinones.

A novel and efficient Cu(I)-catalyzed ligand- and base-free multipathway domino strategy has been developed for the synthesis of 2-substituted quinazolinones. The reaction utilizes 2-bromobenzamide and multiform substrates such as aldehydes, alcohols, and methyl arenes for a one-pot protocol, whereas TMSN3 is used as a nitrogen source. A wide range of substrate scope, functional group tolerance, and operational simplicity are synthetically useful features.

Crystal Structure of Mycobacterium tuberculosis H37Rv AldR (Rv2779c), a Regulator of the ald Gene: DNA BINDING AND IDENTIFICATION OF SMALL MOLECULE INHIBITORS.

Here we report the crystal structure of M. tuberculosis AldR (Rv2779c) showing that the N-terminal DNA-binding domains are swapped, forming a dimer, and four dimers are assembled into an octamer through crystal symmetry. The C-terminal domain is involved in oligomeric interactions that stabilize the oligomer, and it contains the effector-binding sites.

Identification of β-Amino alcohol grafted 1,4,5 trisubstituted 1,2,3-triazoles as potent antimalarial agents.

In a quest to discover new drugs, we have synthesized a series of novel β-amino alcohol grafted 1,2,3-triazoles and screened them for their in vitro antiplasmodial and in vivo antimalarial activity. Among them, compounds 16 and 25 showed potent activity against chloroquine-sensitive (Pf3D7) strain with IC50 of 0.87 and 0.

Identification of gallic acid based glycoconjugates as a novel tubulin polymerization inhibitors.

A novel class of gallic acid based glycoconjugates were designed and synthesized as potential anticancer agents. Among all the compounds screened, compound 2a showed potent anticancer activity against breast cancer cells. The latter resulted in tubulin polymerization inhibition and induced G2/M cell cycle arrest, generation of reactive oxygen species, mitochondrial depolarization and subsequent apoptosis in breast cancer cells.

Triazole analog 1-(1-benzyl-5-(4-chlorophenyl)-1H-1,2,3-triazol-4-yl)-2-(4-bromophenylamino)-1-(4-chlorophenyl)ethanol induces reactive oxygen species and autophagy-dependent apoptosis in both in vitro and in vivo breast cancer models.

Autophagy is considered as an important cell death mechanism that closely interacts with other common cell death programs like apoptosis. Critical role of autophagy in cell death makes it a promising, yet challenging therapeutic target for cancer. We identified a series of 1,2,3-triazole analogs having significant breast cancer inhibition property.

Homology modeling of NAD+-dependent DNA ligase of the Wolbachia endosymbiont of Brugia malayi and its drug target potential using dispiro-cycloalkanones.

Lymphatic filarial nematodes maintain a mutualistic relationship with the endosymbiont Wolbachia. Depletion of Wolbachia produces profound defects in nematode development, fertility, and viability and thus has great promise as a novel approach for treating filarial diseases. NAD(+)-dependent DNA ligase is an essential enzyme of DNA replication, repair, and recombination.

Biochemical and functional characterizations of tyrosine phosphatases from pathogenic and nonpathogenic mycobacteria: indication of phenyl cyclopropyl methyl-/phenyl butenyl azoles as tyrosine phosphatase inhibitors.

Tyrosine phosphorylation is one of the most common means of posttranslational modifications which can generate novel recognition motifs for protein interactions and thereafter affecting cellular localization, protein stability, and enzyme activity. Mycobacterium tuberculosis (Mtb) possesses a wide range of signal transduction systems, including two protein tyrosine phosphatases (PtpA and PtpB). Since functional diversities between protein tyrosine phosphatases (PTPases) are illustrated by regulatory domains and subunits, we have characterized the nature of tyrosine phosphatases from slow-grower pathogenic species Mtb and from fast-grower nonpathogenic species Mycobacterium smegmatis (MS).

Identification of novel phenyl butenonyl C-glycosides with ureidyl and sulfonamidyl moieties as antimalarial agents.

A new series of C-linked phenyl butenonyl glycosides bearing ureidyl(thioureidyl) and sulfonamidyl moieties in the phenyl rings were designed, synthesized, and evaluated for their in vitro antimalarial activities against Plasmodium falciparum 3D7 (CQ sensitive) and K1 (CQ resistant) strains. Among all the compounds screened the C-linked phenyl butenonyl glycosides bearing sulfonamidyl moiety (5a) and ureidyl moiety in the phenyl ring (7d and 8c) showed promising antimalarial activities against both 3D7 and K1 strains with IC50 values in micromolar range and low cytotoxicity offering new HITS for further exploration.

Identification of 1-[4-Benzyloxyphenyl)-but-3-enyl]-1H-azoles as New Class of Antitubercular and Antimicrobial Agents.

A series of 1-[(4-benzyloxyphenyl)-but-3-enyl]-1H-azoles has been identified as potent antitubercular agents against Mycobacterium tuberculosis. Synthesis of compounds involved acid catalyzed ring-opening of cyclopropyl ring of phenyl cyclopropyl methanols followed by nucleophilic attack of the azoles on the carbocation intermediates. Several of the compounds 26, 34, and 36 exhibited significant antitubercular activities with MIC value as low as 1.

Synthesis and anticancer activity of γ-(triazolyl ethylidene)butenolides and polyfunctional pyrrolinones.

A series of novel γ-(triazolyl ethylidene)butenolides (4-23) were prepared from commercially available l-ascorbic acid in good yields. These butenolides on reaction with ethanolic ammonia/amines led to formation of respective 5-hydroxy pyrrolinones (24-33). The two of these pyrrolinones on dehydration with p-toluenesulfonic acid, were transformed into γ-(triazolyl ethylidene)pyrrolinones (34, 35).

A strategy for the synthesis of anthraquinone-based aryl-C-glycosides.

An efficient and simple strategy for the synthesis of a diverse range of anthraquinone-based aryl-C-glycosides has been developed. It involves the sequential Diels-Alder reaction and oxidative aromatization with the preformed glycosyl diene and dienophiles. The glycosyl dienes were obtained from simple sugars by tandem one-pot substitution and elimination reaction.

Diversity oriented synthesis of pyran based polyfunctional stereogenic macrocyles and their conformational studies.

A new approach to synthesize a homologous series of 14-, 15-, and 16-membered drug-like, macrocyclic glycoconjugates involving TBAHS promoted azide-propenone intramolecular cycloaddition in designed C-glycopyranosyl butenones from a simple sugar d-glucose and d-mannose is reported.

One pot efficient diversity oriented synthesis of polyfunctional styryl thiazolopyrimidines and their bio-evaluation as antimalarial and anti-HIV agents.

An efficient one pot synthesis of a series of pluripotent (E)-1-(3-methyl-5-aryl-7-styryl-5H-thiazolo[3,2-a]pyrimidin-6-yl)-3-arylprop-2-en-1-ones is reported. It involves reaction of 5-acetyl-6-methyl-4-aryl-dihydropyrimidine-2-thiones, propargyl bromide and aromatic aldehydes in presence of ethanolic KOH. The newly synthesized compounds were evaluated for antimalarial activity against Plasmodium falciparum and as HIV-RT inhibitors.