Synthesis of threo- and erythro-configured trihydroxy open chain lipophilic ketones as possible anti-mycobacterial agents

A series of threo- and erythro-configured open-chain trihydroxy ketones was synthesized starting from l- and d-ascorbic acid respectively as the starting material, through the use of Grignard reactions for the requisite CC bond formations. The lipophilic ketones were screened against Mycobacteriumtuberculosis for anti-proliferative activity. The lipophilic ketones with tetradecyl alkyl side chains were found to be moderately active against cell proliferation.     

Propargyl bromide as an excellent alpha-bromoacetone equivalent: convenient and new route to alpha-aroylacetones

[reaction: see text] A variety of alpha-aroylacetones 4a-g have been prepared in excellent yields following a new protocol wherein alpha-aminonitriles 1a-g as the aryl acyl anion equivalents readily react with propargyl bromide as the alpha-bromoacetone equivalent. The alkylated product undergoes one-pot unmasking of the keto functionality along with Markovnikov's hydration of the terminal alkyne with CuSO4 x 5H2O in aqueous methanol at 60 degrees C to furnish the desired target in excellent isolated yields.     

2-O-Benzylation in D-Gluconamide Derivative Under Basic Conditions with Complete Retention of Stereo-Integrity: Convenient Access to 2-O-benzyl-3,4:5,6- di-O-isopropylidene-D-glucitol and other Differently Protected D-glucitol Derivatives

A new and convenient synthesis of 2-O-benzyl-3, 4: 5, 6-di-O-isopropylidene-D-glucitol has been accomplished and has been generalized with the syntheses of differently protected D-glucitols at C-2 position. In the course of our new route to the differently protected D-glucitols at C-2 position, a new D-gluco configured building block, 1-morpholino-(3, 4: 5, 6-di-O-isopropylidene)-D-gluconamide has been achieved.     

Interaction of Folic Acid with Mn2+ Doped CdTe/ZnS Quantum Dots: In Situ Detection of Folic Acid

To utilize the nanomaterials as an effective carrier for the drug delivery applications, it is important to study the interaction between nanomaterials and drug or biomolecules. In this study GSH functionalized Mn²⁺-doped CdTe/ZnS QDs has been utilized as a model nanomaterial due to its high luminescence property. Folic acid (FA) gradually quenches the FL of GSH functionalized Mn²⁺???doped CdTe/ZnS QDs. The Stern-Volmer quenching constant (K_sv), binding constant (K_s) and effective quenching constant (Ka) for the FA-QDs system is calculated to be 1.32?×?10⁵ M^?1, 1.92?×?10⁵ and 0.27?×?10⁵ M^?1, respectively under optimized condition (Temp. 300 K, pH 8.0, incubation time 40 min.). The effects of temperature, pH, and incubation time on FA-QDs system have also been studied. Statistical analysis of the quenched FL intensity versus FA concentration revealed a linear range from 1?×?10^?7 to 5.0?×?10^?5 for FA detection. The LOD of the current nano-sensor for FA was calculated to be 0.2 μM. The effect of common interfering metal ions and other relevant biomolecules on the detection of FA (12.0 μM) have also been investigated. L-cysteine and glutathione displayed moderate effect on FA detection. Similarly, the common metal ions (Na⁺, K⁺, Ca²⁺ and Mg²⁺) produced minute interference while Zn²⁺ Cu²⁺ and Fe³⁺ exert moderate interference. Toxic metal ions (Hg²⁺ and Pb²⁺) produced severe interferences in FA detection.

Graphical abstract

GSH-Mn²⁺ CdTe/ZnS QDs based Fluorescence Nanosensor for Folic acid

     

Facile Green Synthesis of BCN Nanosheets as High‐Performance Electrode Material for Electrochemical Energy Storage

Two‐dimensional hexagonal boron carbon nitride (BCN) nanosheets (NSs) were synthesized by new approach in which a mixture of glucose and an adduct of boric acid (H₃BO₃) and urea (NH₂CONH₂) is heated at 900 °C. The method is green, scalable and gives a high yield of BCN NSs with average size of about 1 μm and thickness of about 13 nm. Structural characterization of the as‐synthesized material was carried out by several techniques, and its energy‐storage properties were evaluated electrochemically. The material showed excellent capacitive behaviour with a specific capacitance as high as 244 F g^?1 at a current density of 1 A g^?1. The material retains up to 96 % of its initial capacity after 3000 cycles at a current density of 5 A g^?1.     

Weinreb amide based building blocks for convenient access to 1,1-diarylethenes and isocombretastatin analogues

A successful strategy based on the synthetic equivalent containing Weinreb amide functionality for the convenient access to 1,1-diarylethenes in general and for the isocombretastatin analogues in particular has been developed from the commercially available glyoxalic acid. The convenience with which the structural variations can be made in assembling the aryl residues shows generality associated with the developed strategy. The intermediates also provide access to 1,2,2-triarylethanones, represented by the synthesis of advanced intermediate of tamoxifen.     

Umpolung strategy for the synthesis of 2-deoxy-C-aryl glycosides: a serendipitous,efficient route for C-furanoside analogues

[reaction: see text] 2-Deoxy-C-aryl glycosides are potential synthetic targets as they form a very vital moiety of several biologically active natural products. This paper describes a synthetic route using an umpolung strategy, which has not been explored till date. Our synthetic endeavor led to a versatile intermediate aryl ketone 10, which has paved the way for two important classes of C-glycosides, viz., C-alkyl furanosides 12 and methyl 2-deoxy-C-aryl pyranosides 14.     

Towards a synthesis of vigabatrin using glycal chemistry

Application of the Ferrier rearrangement led to a novel carbohydrate based synthetic route to 4-aminohexenoic acid viz. (R) and (S)-vigabatrin. The potential of D- glucose or D-galactose as the chiral starting materials for the synthesis of (R) and (S)- vigabatrin has been explored.