Facile Approach to Develop Peptide-Stabilized CdS/CdSe Quantum Dots for Cellular Imaging.

This study presents a mild, one-pot synthetic approach for the synthesis of multicolor, water soluble, photo luminescent CdS and CdSe quantum dots (QDs). To achieve this goal, cyclic peptides containing cysteine residues are rationally designed and synthesized. Among the peptides tested, those containing two cysteine residues exhibit superior stabilizing properties, ensuring the solubility and long-term stability of the QDs in aqueous solutions for several months.

High-throughput screening of small-molecules libraries identified antibacterials against clinically relevant multidrug-resistant A. baumannii and K. pneumoniae.

Background: The current pipeline for new antibiotics fails to fully address the significant threat posed by drug-resistant Gram-negative bacteria that have been identified by the World Health Organization (WHO) as a global health priority. New antibacterials acting through novel mechanisms of action are urgently needed. We aimed to identify new chemical entities (NCEs) with activity against Klebsiella pneumoniae and Acinetobacter baumannii that could be developed into a new treatment for drug-resistant infections.

Novel detection method to rapidly quantify toxic cucurbitacin in (bottle gourd).

Unlabelled: Bottle gourd () is widely used in India for its medicinal properties. Sometimes its consumption as a fruit or juice can lead to serious health issues due to the presence of toxic cucurbitacins (Cuc) like Cuc B at high concentration. In the present study, a molecularly imprinted polymer (MIP) based method was developed to quantify Cuc B in commercial bottle gourd juice.

Collaborative Virtual Screening Identifies a 2-Aryl-4-aminoquinazoline Series with Efficacy in an Model of Infection.

Probing multiple proprietary pharmaceutical libraries in parallel via virtual screening allowed rapid expansion of the structure-activity relationship (SAR) around hit compounds with moderate efficacy against , the causative agent of Chagas Disease. A potency-improving scaffold hop, followed by elaboration of the SAR via design guided by the output of the phenotypic virtual screening efforts, identified two promising hit compounds and , which were profiled further in pharmacokinetic studies and in an model of infection. Compound demonstrated clear reduction of parasitemia in the setting, confirming the interest in this series of 2-(pyridin-2-yl)quinazolines as potential anti-trypanosome treatments.

A quantitative and qualitative investigation of the impact of irradiation on the physico-chemical of pointed gourd during storage.

Unlabelled: Irradiation effect on the physico-chemical characteristics and shelf stability of pointed gourd was investigated in research. It was estimated that moisture content, total phenol and total carotenoids was significantly (p≤0.05) decreased while physiological loss in weight, total soluble solids, lutein and α-cryptoxanthin were increased during the completion of study.

Cyclic peptides nanospheres: A '2-in-1' self-assembled delivery system for targeting nucleus and cytoplasm.

Vascular endothelial growth factor (VEGF) is considered as one of the vital growth factors for angiogenesis, which is primarily responsible for the progress and maintenance of new vascular network in tumor. Numerous studies report that inhibition of VEGF-induced angiogenesis is a potent technique for cancer suppression. Recently, RNA interference, especially small interfering RNA (siRNA) signified a promising approach to suppress the gene expression.

Carbon nano-dot for cancer studies as dual nano-sensor for imaging intracellular temperature or pH variation.

Cellular temperature and pH govern many cellular physiologies, especially of cancer cells. Besides, attaining higher cellular temperature plays key role in therapeutic efficacy of hyperthermia treatment of cancer. This requires bio-compatible, non-toxic and sensitive probe with dual sensing ability to detect temperature and pH variations.

Targeting RECQL5 Functions, by a Small Molecule, Selectively Kills Breast Cancer o and .

Clinical and preclinical data reveal that RECQL5 protein overexpression in breast cancer was strongly correlated with poor prognosis, survival, and therapeutic resistance. In the current investigation, we report design, synthesis, and specificity of a small molecule, , which can preferentially kill RECQL5-expressing breast cancers but not RECQL5 knockout. Our stringent analysis showed that compound specifically sensitizes RECQL5-expressing cancers, while it did not have any effect on other members of DNA RECQL-helicases.

'BhAVI-23'-A spice-herb based dietary infusion possessing in-vitro anti-viral potential.

Background: Viruses cause many life threatening human diseases. Recently, COVID-19 pandemic has challenged the health care systems worldwide. As a disease preventive approach and to bring relief to the severity of the symptoms, a infusion termed as Bhabha Anti-Viral Infusion-23 ('BhAVI-23') was conceptualized and formulated which comprised of 23 selected spices and herbals.

Intussusception in children aged under two years in India: Retrospective surveillance at nineteen tertiary care hospitals.

Objective: Intussusception has been linked with rotavirus vaccine (RVV) as a rare adverse reaction. In view of limited background data on intussusception in India and in preparation for RVV introduction, a surveillance network was established to document the epidemiology of intussusception cases in Indian children.

Methods: Intussusception in children 2-23 months were documented at 19 nationally representative sentinel hospitals through a retrospective surveillance for 69 months (July 2010 to March 2016).

Ag(I)-Fesulphos-Catalyzed Enantioselective Synthesis of 3-Silylproline Derivatives.

An efficient catalytic asymmetric 1,3-dipolar cycloaddition of N-benzylidineiminoglycinate-derived azomethine ylides to β-silylmethylene malonates catalyzed by a Ag(I)-Fesulphos complex has been developed, affording fully substituted 3-silylproline derivatives with an all carbon quaternary center. The silylproline derivatives were obtained in moderate-to-good yields (up to 81%) in high diastereoselectivities and enantioselectivities (dr up to 95:5; er up to 96:4). Tamao-Fleming oxidation of selected 3-silylproline derivatives provided not only an efficient route but also the shortest route to 3-hydroxyproline derivatives, which are not accessible by direct 1,3-dipolar cycloadditions of azomethine ylide with frequently used arylidene/alkylidene malonates.

First Report on the Separation of Trivalent Lanthanides from Trivalent Actinides Using an Aqueous Soluble Multiple N-Donor Ligand, 2,6-bis(1 H-tetrazol-5-yl)pyridine: Extraction, Spectroscopic, Structural, and Computational Studies.

A terdentate multiple N donor ligand, 2,6-bis(1 H-tetrazol-5-yl)pyridine (HBTzP), was synthesized, and its complexation with trivalent americium, neodymium, and europium was studied using single-crystal X-ray diffraction, attenuated total reflectance-fourrier transform infrared spectroscopy, time-resolved fluorescence spectroscopy, UV-vis absorption spectrophotometry. Higher complexation strength of BTzP toward trivalent actinide over lanthanides as observed from UV-vis spectrophotometric study resulted in an effective separation of Am and Eu in liquid-liquid extraction studies employing N,N, N',N'-tetra- n-octyl diglycolamide in the presence of BTzP as the aqueous complexant. The selectivity of BTzP toward Am over Eu was further investigated by DFT computations, which indicated higher metal-ligand overlap in the Am complex as indicated from the metal-nitrogen bond order and frontier molecular orbital analysis of the BTzP complexes of Am and Eu.

Superparamagnetic graphene oxide-magnetite nanoparticle composites for uptake of actinide ions from mildly acidic feeds.

Super paramagnetic graphene oxide (GO) - FeO nanoparticle composites were prepared and characterized by conventional techniques such as XRD, SEM, EDX, FT-IR, Raman, XPS, DLS and zeta potential, etc. TEM studies have confirmed nanoparticle nature of the composites. The GO-magnetic nanoparticle composites can be dispersed in mildly acidic aqueous solutions and get concentrated in a small volume under application of an external magnetic field.

Organocatalytic decarboxylative aldol reaction of β-ketoacids with α-ketophosphonates en route to the enantioselective synthesis of tertiary α-hydroxyphosphonates.

The first example of an asymmetric organocatalyzed decarboxylative aldol reaction of β-ketoacids (aroylacetic acids) with α-ketophosphonates that produces a quaternary chiral centre has been developed. A quinidine based bifunctional urea derivative was identified as the preferred catalyst affording γ-aroyl tertiary α-hydroxyphosphonates in good yield and enantioselectivity. The P NMR spectroscopic study was performed to shed light on the reaction mechanism.

Tuning the Stability and the Reactivity of Substituted [3]Dendralenes for Quick Access to Diverse Copiously Functionalized Fused Polycycles with Step and Atom Economy.

This is the first comprehensive study that details the synthesis of stable acyclic trisubstituted [3]dendralenes and deciphers their structural requisite for a successful diene transmissive Diels-Alder (DTDA) reaction by employing two different dienophiles and eventually generating a small repository of complex molecules, thus exemplifying how substituted [3]dendralenes could be deployed in diversity-oriented synthesis with high selectivities. A balance of reactivity and stability was struck by prudent selection of the position and nature of functional groups on these [3]dendralenes. Upon tandem Diels-Alder reactions with several symmetrical as well as unsymmetrical dienophiles, these dendralenes afforded diversity-oriented quick access to many polycyclic complex motifs possessing several functional groups and multiple stereogenic centers.

Molecular Origin and Self-Assembly of Fluorescent Carbon Nanodots in Polar Solvents.

Despite numerous efforts, there are several fundamental ambiguities regarding the photoluminescence of carbon dots (CDs). Spectral shift measurements display characteristic of both π-π* and n-π* transitions for the main absorption or excitation band at ∼350 nm, contrary to common assignment of exclusive n-π* transition. Additionally, the generally perceived core-state transition at ∼250 nm, involving sp-networked carbogenic domains shielded from external environments, needs to be reassessed because it fails to explain the observed fluorescence quenching and spectral shift.

Organocatalyzed enantioselective Michael addition/cyclization cascade reaction of 3-isothiocyanato oxindoles with arylidene malonates.

An organocatalyzed Michael addition-cyclization reaction between 3-isothiocyanatooxindoles and arylidene malonates has been developed for the synthesis of highly functionalized 3,2'-pyrrolidinyl spirooxindole derivatives. The reaction was catalyzed by a quinine derived tertiary amino-thiourea based bifunctional catalyst or its pseudo-enantiomeric quinidine derived catalyst providing both the enantiomers of the desired product. The products were obtained in high yields and with excellent diastereo- (up to 99 : 1 dr) and enantioselectivities (up to >99% ee).

Origin of Excitation Dependent Fluorescence in Carbon Nanodots.

The fascinating aspect of excitation dependent fluorescence in carbon nanodots has led to several hypotheses, starting from particle size distribution to the presence of different emissive states and even to sluggish solvent relaxation around nanodot. In this contribution we provide definitive evidence for the involvement of discrete multiple electronic states for the excitation dependent emission in carbon nanodots. The presence of different types of aggregates even at very dilute solutions used in ensemble fluorescence spectroscopy, where fluorescence intensity shows linear dependence with absorbance, is the origin of these multiple electronic states.

"On Water" Organocatalyzed [4 + 2] Cycloaddition of Enones and Nitro Dienes for the Enantioselective Synthesis of Densely Substituted Cyclohexanones.

An "on water" hydroquinine-based primary amine-benzoic acid organocatalyst system was found to be best suited to produce 3,4,5-trisubstituted cyclohexanones with a nitro group in the 4-position from enones and nitro dienes under ambient conditions in good yield, with good diastereoselectivity, and with excellent enantioselectivity. An appreciable rate enhancement by water was observed compared to organic solvents. Mechanistic analysis of the reaction suggests that it followed an endo [4 + 2] cycloaddition with enamine of enone as diene and nitro diene as dienophile.

Synthesis and extraction studies with a rationally designed diamide ligand selective to actinide(iv) pertinent to the plutonium uranium redox extraction process.

A new class of conformationally constrained oxa-bridged tricyclo-dicarboxamide (OTDA) ligand was rationally designed for the selective extraction of tetravalent actinides pertinent to the Plutonium Uranium Redox EXtraction (PUREX) process. Two of the designed diamide ligands were synthesized and extraction studies were performed for Pu(iv) from HNO3 medium. The mechanism of extraction was investigated by studying various parameters such as feed HNO3, NaNO3 and OTDA concentrations.

Design, synthesis and extraction studies of a new class of conformationally constrained (N,N,N',N'-tetraalkyl)7-oxabicyclo[2.2.1]heptane-2,3-dicarboxamides.

A new class of conformationally constrained 7-oxabicyclo[2.2.1]heptane-2,3-dicarboxamides (OBDA) of three secondary amines was synthesized, and their extraction behavior for trivalent and tetravalent actinides in HNO3 medium was studied.

Dialkylmethyl-2-(N,N-diisobutyl)acetamidoammonium iodide as a ruthenium selective ligand from nitric acid medium.

A new class of quaternary ammonium iodide based ligands with 2-(N,N-diisobutyl)acetamide as an alkyl appendage have been designed, synthesized and tested for their ability to extract ruthenium selectively from nitric acid medium. The 2-(N,N-diisobutyl)acetamido ammonium iodide with two propyl and a methyl substituents showed best results for the recovery of ruthenium. The optimized concentration of the solvent was found to be 0.

A remarkable enhancement in Am³⁺/Eu³⁺ selectivity by an ionic liquid based solvent containing bis-1,2,4-triazinyl pyridine derivatives: DFT validation of experimental results.

Mutual separation of trivalent actinide (An(3+)) and lanthanide (Ln(3+)) using several soft (N) donor ligands (bis(5,6-dialkyl-1,2,4-triazinyl)pyridine (R-BTP)) is attempted for the first time in room temperature ionic liquid (RTIL) medium. The results indicate a spectacular enhancement in the selectivity as compared to that in molecular diluents with a separation factor (S.F.

A facile synthesis of 5,5-dideutero-4-dimethyl(phenyl)silyl-6-undecyl-tetrahydropyran-2-one as a deuterium labeled synthon for (-)-tetrahydrolipstatin and (+)-δ-hexadecanolide.

Deuterium-labeled biologically active compounds are gaining importance because they can be utilized as tracers or surrogate compounds to understand the mechanism of action, absorption, distribution, metabolism, and excretion. Deuterated drug molecules (heavy drugs) become novel as well as popular because of better stability and bioavailability compared with their hydrogen analogs. Labeling of organic molecules with deuterium at specific positions is thus gaining popularity.