Unnatural Amino Acids: Strategies, Designs, and Applications in Medicinal Chemistry and Drug Discovery.

Peptides can operate as therapeutic agents that sit within a privileged space between small molecules and larger biologics. Despite examples of their potential to regulate receptors and modulate disease pathways, the development of peptides with drug-like properties remains a challenge. In the quest to optimize physicochemical parameters and improve target selectivity, unnatural amino acids (UAAs) have emerged as critical tools in peptide- and peptidomimetic-based drugs.

Overcoming chemoresistance and radio resistance in prostate cancer: The emergent role of non-coding RNAs.

Prostate cancer (PCa) continues to be a major health concern worldwide, with its resistance to chemotherapy and radiation therapy presenting major hurdles in successful treatment. While patients with localized prostate cancer generally have a good survival rate, those with metastatic prostate cancer often face a grim prognosis, even with aggressive treatments using various methods. The high mortality rate in severe cases is largely due to the lack of treatment options that can offer lasting results, especially considering the significant genetic diversity found in tumors at the genomic level.

Resveratrol-Laden Nano-Systems in the Cancer Environment: Views and Reviews.

The genesis of cancer is a precisely organized process in which normal cells undergo genetic alterations that cause the cells to multiply abnormally, colonize, and metastasize to other organs such as the liver, lungs, colon, and brain. Potential drugs that could modify these carcinogenic pathways are the ones that will be used in clinical trials as anti-cancer drugs. Resveratrol (RES) is a polyphenolic natural antitoxin that has been utilized for the treatment of several diseases, owing to its ability to scavenge free radicals, control the expression and activity of antioxidant enzymes, and have effects on inflammation, cancer, aging, diabetes, and cardioprotection.

Nanotechnology-Based Drug Delivery Approaches of Mangiferin: Promises, Reality and Challenges in Cancer Chemotherapy.

Mangiferin (MGF), a xanthone derived from L., initially employed as a nutraceutical, is now being explored extensively for its anticancer potential. Scientists across the globe have explored this bioactive for managing a variety of cancers using validated in vitro and in vivo models.

Synthesis, biological evaluation and mechanistic studies of 4-(1,3-thiazol-2-yl)morpholine-benzimidazole hybrids as a new structural class of antimicrobials.

In spite of several attempts to develop newer pharmacophores as potential antimicrobial agents, the benzimidazole scaffold is still considered as one of the most sought after structural component towards the design of compounds that act against a wide spectrum of microbes. Herein, we report the design and synthesis of a new structural class of 4-(1,3-thiazol-2-yl)morpholine-benzimidazole hybrids as antimicrobial agents. The most potent analog, 6g shows IC of 1.

Synthetic amino acids-based short amphipathic peptides exhibit antifungal activity by targeting cell membrane disruption.

Availability of a limited number of antifungal drugs created a necessity to develop new antifungals with distinct mode of action. Investigation on a new series of peptides led us to identify Boc-His-Trp-His[1-(4-tert-butylphenyl)] (10g) as the most promising inhibitor exhibiting IC value of 4.4 µg/mL against Cryptococcus neoformans.

Design, synthesis, and applications of ring-functionalized histidines in peptide-based medicinal chemistry and drug discovery.

Modified and synthetic α-amino acids are known to show diverse applications. Histidine, which possesses numerous applications when subjected to synthetic modifications, is one such amino acid. The utility of modified histidines varies widely from remarkable biological activities to catalysis, and from nanotechnology to polymer chemistry.

Ring-Modified Histidine-Containing Cationic Short Peptides Exhibit Anticryptococcal Activity by Cellular Disruption.

Delineation of clinical complications secondary to fungal infections, such as cryptococcal meningitis, and the concurrent emergence of multidrug resistance in large population subsets necessitates the need for the development of new classes of antifungals. Herein, we report a series of ring-modified histidine-containing short cationic peptides exhibiting anticryptococcal activity via membrane lysis. The -1 position of histidine was benzylated, followed by iodination at the C-5 position via electrophilic iodination, and the dipeptides were obtained after coupling with tryptophan.

Anticryptococcal activity and mechanistic studies of short amphipathic peptides.

Cryptococcus neoformans, an opportunistic fungal pathogen, causes cryptococcosis in immunocompromised persons. A series of modified L-histidines-containing peptides are synthesized that exhibit promising activity against C. neoformans.

Synthetic amino acids-derived peptides target Cryptococcus neoformans by inducing cell membrane disruption.

We investigated synthetic amino acid-based approach to design short peptide-based antibiotics. Tautomerically restricted, amphiphilic 1-aryl-l-histidines along with hydrophobic tryptophan were utilized to synthesize the designed peptides. l-Trp-l-His(1-biphenyl)-NHBzl (12e, IC = 1.

Antifungal evaluation and mechanistic investigations of membrane active short synthetic peptides-based amphiphiles.

The quest for new class of peptide-based antibiotics has steered this research towards the design and synthesis of short sequences possessing modified amphiphilic histidine along with hydrophobic tryptophan residues. The new structural class of dipeptides Trp-His(1-Bn)-OMe/NHBn and tripeptides His(1-Bn)-Trp-His(1-Bn)-OMe/NHBn demonstrated promising antifungal and antibacterial activities with membrane lytic action. The illustration of desirable hydrophilic-lipophilic balance appeared in the dipeptide Trp-His[1-(3,5-di-tert-butylbenzyl)]-NHBn (13d) that produced the most promising antifungal activity with IC value of 2.

β-Carbolines as potential anticancer agents.

β-Carbolines are indole alkaloids having a tricyclic pyrido[3,4-b]indole ring in their structure. Since the isolation of first β-carboline from Peganum harmala in 1841, the isolation and synthesis of various β-carboline derivatives surged in the following centuries. β-Carboline derivatives due to their widespread availability from natural sources, structural flexibility, quick reactivity and interaction with varied anticancer targets such as DNA (intercalation, groove binding, etc.

Peptides as Potential Anticancer Agents.

Cancer consists of heterogeneous multiple cell subpopulation which at a later stage develop resistant phenotypes, which include resistance to pro-apoptotic stimuli and/or cytotoxic resistance to anticancer compounds. The property of cancerous cells to affect almost any part of the body categorizes cancer to many anatomic and molecular subtypes, each requiring a particular therapeutic intervention. As several modalities are hindered in a variety of cancers and as the cancer cells accrue varied types of oncogenic mutations during their progression the most likely benefit will be obtained by a combination of therapeutic agents that might address the diverse hallmarks of cancer.

Short Antimicrobial Peptides.

Background: After the era of serendipitous discovery of penicillin and outburst in the discovery and development of highly efficient antibiotics, a surge in resistance against the target specific drugs was observed, primarily due to a combination of selective pressure of antibiotics use and spontaneous mutations. As per the World Health Organization, antibiotic resistance is one of the greatest threats to the mankind.

Objective: Short antimicrobial peptides (SAMPs) can be considered as a viable therapeutic alternative to conventional antibiotics in tackling resistant microbes.

Synthesis, molecular docking and anti-diabetic evaluation of 2,4-thiazolidinedione based amide derivatives.

A series of thiazolidinedione based amide derivatives were designed, synthesized and docked against the PPARγ receptor target. 11 compounds from the series with good glide scores were selected for in vivo antidiabetic study based on streptozotocin induced diabetic rat model. It was observed that 4 compounds (6c, 6e, 6m &6n) showed significantly good antidiabetic activity in comparison to rosiglitazone and pioglitazone as reference drugs.