A novel class of potent antiangiogenic and antioxidant pyrazoles: synthesis, bioactivity, docking and ADMET studies.

Angiogenesis is the hallmark of cancer progression driven by VEGF/VEGFR-2 signalling pathway, inhibition of which could be a solution to tackle the progression of tumour cells and thus arresting their growth. A novel class of pyrazoles was synthesized using arginine and dibromo ketones. Antiangiogenic activity was performed by yolk sac method.

Role of small molecules and nanoparticles in effective inhibition of microbial biofilms: A ray of hope in combating microbial resistance.

Microbial biofilms pose a severe threat to global health, as they are associated with deadly chronic infections and antibiotic resistance. To date, very few drugs are in clinical practice that specifically target microbial biofilms. Therefore, there is an urgent need for the development of novel therapeutic options targeting biofilm-related infections.

Conjugation as a Tool in Therapeutics: Role of Amino Acids/Peptides-Bioactive (Including Heterocycles) Hybrid Molecules in Treating Infectious Diseases.

Peptide-based drugs are gaining significant momentum in the modern drug discovery, which is witnessed by the approval of new drugs by the FDA in recent years. On the other hand, small molecules-based drugs are an integral part of drug development since the past several decades. Peptide-containing drugs are placed between small molecules and the biologics.

Microwave-Assisted Synthesis of Antimicrobial Peptides.

Antimicrobial peptides (AMPs) are emerging as one of the unsurpassed therapeutic tools to treat various devastating diseases that are affecting millions of lives. Conventional synthesis of peptides requires longer times, and hence automated microwave technology could be regarded as an alternative implement which offers advantages like less reaction times and higher yields. In this sense, we herein describe a methodology to prepare AMPs through solid-phase peptide synthesis under microwave conditions.

Peptides conjugated to silver nanoparticles in biomedicine - a "value-added" phenomenon.

Nanotechnology is gaining impetus in the present century and particularly the use of nanoparticles (NPs), whose properties are significantly different from the larger matter. These have found wider and potential applications in the fields of medicine, energy, cosmetics, environment and biomedicine. Among the NPs, silver nanoparticles (AgNPs) are of particular interest for scientists and technologists due to their unique physico-chemical and biological properties.

Short AntiMicrobial Peptides (SAMPs) as a class of extraordinary promising therapeutic agents.

The emergence of multidrug resistant bacteria has a direct impact on global public health because of the reduced potency of existing antibiotics against pathogens. Hence, there is a pressing need for new drugs with different modes of action that can kill microorganisms. Antimicrobial peptides (AMPs) can be regarded as an alternative tool for this purpose because they are proven to have therapeutic effects with broad-spectrum activities.

Highly chemoselective ligation of thiol- and amino-peptides on a bromomaleimide core.

Application of a bromomaleimide core allows for the incorporation of three different peptides. The key reactions of the process are the selective stapling of both thiol- and amino-peptides on two different sites of the core. The thiol-peptide attacks and replaces the bromide whereas the amino-peptide attaches to the ene-position of the core revealing differential and selective reactivity.

Chemical Platforms for Peptide Vaccine Constructs.

Knowledge of the sequences and structures of proteins from pathogenic microorganisms has been put to great use in the field of protein chemistry for the development of peptide-based vaccines. These vaccine constructs include chemically tailored, shorter peptidic fragments that can induce high immunogenicity, thus shunning the allergenic and nonimmunogenic part of the antigens. Based on this concept, several different chemistries have been pursued to obtain novel platforms onto which antigenic epitopes can be tethered, with the aim to achieve a higher antibody response.

An efficient solid-phase strategy for total synthesis of naturally occurring amphiphilic marine siderophores: amphibactin-T and moanachelin ala-B.

Microorganisms such as bacteria, fungi and some plants secrete an abundance of suites of low molecular weight, high-affinity iron(iii)-chelating acylated siderophores. The peptide composition of a suite of amphiphilic siderophores generated by a Vibrio species, isolated from oligotrophic open ocean water, contained the same iron(iii)-scavenging polar head group and is attached to a fatty acid. In the present study, we report the first total synthesis of the naturally obtainable marine siderophores amphibactin-T and moanachelin ala-B on solid-phase using standard Fmoc-chemistry.

Synthesis, 68Ga-radiolabeling, and preliminary in vivo assessment of a depsipeptide-derived compound as a potential PET/CT infection imaging agent.

Noninvasive imaging is a powerful tool for early diagnosis and monitoring of various disease processes, such as infections. An alarming shortage of infection-selective radiopharmaceuticals exists for overcoming the diagnostic limitations with unspecific tracers such as (67/68)Ga-citrate or (18)F-FDG. We report here TBIA101, an antimicrobial peptide derivative that was conjugated to DOTA and radiolabeled with (68)Ga for a subsequent in vitro assessment and in vivo infection imaging using Escherichia coli-bearing mice by targeting bacterial lipopolysaccharides with PET/CT.

6-(Bromomaleimido)hexanoic acid as a connector for the construction of multiple branched peptide platforms.

We report on a novel and user-friendly platform based on a bromomaleimide moiety to obtain branched peptides. The platform is stable for all SPPS conditions. The bromomaleimide core was conjugated to n-copies of thiol-peptide in-solution to obtain two/four/eight-armed dendrimers.

Immobilized coupling reagents: synthesis of amides/peptides.

The primary idea of using immobilized reagents in organic synthetic chemistry is to simplify the downstream process, product workup and isolation, and therefore avoiding time-consuming and expensive chromatographic separations, which are intrinsic to every synthetic process. Numerous polymer-bounded reagents are commercially available and applicable to almost all kinds of synthetic chemistry conversions. Herein, we have covered all known supported-coupling reagents and bases which have had a great impact in amide/peptide bond formation.

Microreactors for peptide synthesis: looking through the eyes of twenty first century !!!

The twenty first century has witnessed several advances in synthetic chemistry, among them microreactors. It is expected that these devices will have a considerable impact on synthetic organic chemistry since they offer a wide range of applications in various fields. Perhaps the synthesis of peptides deserves mention in this regard as these molecules are emerging as therapeutics and offer several advantages over the so-called small molecules.

Solid-phase peptide synthesis (SPPS), C-terminal vs. side-chain anchoring: a reality or a myth.

Here we review the strategies for the solid-phase synthesis of peptides starting from the side chain of the C-terminal amino acid. Furthermore, we provide experimental data to support that C-terminal and side-chain syntheses give similar results in terms of purity. However, the stability of the two bonds that anchor the peptide to the polymer may determine the overall yield and this should be considered for the large-scale production of peptides.

Ureas/thioureas of benzo[d]isothiazole analog conjugated glutamic acid: synthesis and biological evaluation.

A series of urea and thiourea derivatives of glutamic acid conjugated to 3-(1-piperazinyl)-1,2-benzisothiazole were synthesized, spectroscopically characterized, and evaluated for their in vitro antiglycation and urease inhibitory activities. Preliminary screening of the synthesized compounds 1-35 showed significant results. Amongst these, compounds 17-21 and 30-35 bearing fluoro and methoxy substituents, respectively, exhibited inhibitory potency greater than the reference standards.

Synthesis and SAR studies of urea and thiourea derivatives of gly/pro conjugated to piperazine analogue as potential AGE inhibitors.

Synthesis of a series of urea and thiourea derivatives of glycine and proline conjugated to 2,3-dichlorophenyl piperazine has been reported. The structures were confirmed by physical and spectroscopical measurements followed by characterization of antiglycation activity. All synthesized compounds were able to inhibit protein glycation, particularly halogen containing derivatives without preference of oxygen or sulphur at the urea function.

Structure-based rationale design and synthesis of aurantiamide acetate analogues - towards a new class of potent analgesic and anti-inflammatory agents.

A series of new aurantiamide acetate analogues were synthesized by modifying its N-terminal substitution and the amino acid residue. The structure of all these compounds was established on the basis of analytical and spectral studies. All the new derivatives were evaluated in vivo for their analgesic activity by tail flick method in mice and anti-inflammatory activity against carrageenan-induced oedema in albino rats at different doses (25, 50 and 100 mg/kg body weight).