AIEE activated Pyrene-Dansyl coupled FRET probe for discriminating detection of lethal Cu2+ and CN-: Bio-Imaging, DNA binding studies and prompt prognosis of Menke's disease

In present work a pyrene-dansyl dyad functionalized chemoreceptor, DPNS is unveiled towards ultrasensitive chromo-fluorogenic detection of heavy and transition metal ions (HTMs) like Cu2+ and pernicious CN-. It demonstrated distinct chromogenic responses; colorless to faint yellow (Cu2+), intense yellow (CN-) from contaminant aqueous sources. Cu2+ instigated alteration in DPNS fluorescence from feeble emission to sparkling green with LOD: 37.75 × 10-9 M, cyan emission for CN- having LOD 61.51 × 10-8M. In particular, chemical scaffold of DPNS consists of -C = N, O = S = O donor entitities that escalates overall polarity thereby providing an excellent binding pocket for simultaneous Cu2+ and CN- recognition with distinct photophysical signaling. Impressively, presence of two fluorophoric moieties triggers FRET, CHEF phenomenon. The conceivable host:guest interactive pathway is manifested by LMCT- FRET-PET-CHEF, C = N isomerization for Cu2+ and ICT-H-bonding for CN-. An exquisite experimental and theoretical corroboration further strengthened the recognition phenomenon. In addition owing to pyrene excimer formation, DPNS exhibits AIEE with increasing water fraction. Notably, DPNS could successfully undergo intracellular tracking of Cu2+ in Tecoma Stans, Peperomia Pellucida. DPNS•••Cu2+ adduct displayed significant intercalative DNA binding activity rationalized by spectral investigation, competitive EB binding, viscosity study. The overall findings, excellent properties endows DPNS a potential contender towards discriminative detection of Cu2+ and CN- like toxic industrial contaminants.

A Carbohydrate-based Synthetic Approach to Diverse Structurally and Stereochemically Complex Chiral Polyheterocycles

Chiral polyheterocycles are one of the most frequently encountered scaffolds in natural products and in current drugs repertoire. A carbohydrate-based diversity oriented synthetic (DOS) approach has been employed for gaining access to many structurally diverse and stereochemically complex rigid polyheterocyclic molecules with multiple chiral hydroxyl groups to enhance aqueous solubility. Inexpensive chiral pool of D-Glucose has been judiciously exploited to get access of complex chiral polyheterocyclic structures using inexpensive, common achiral reagents and domino-Knoevenagel hetero-Diels-Alder (DKHDA) reaction as one of the key synthetic tools. Stereochemistry of newly generated stereocenters of polycyclic structures are unambiguously determined through NMR and X-ray crystallographic study. A chemoinformatic comparison (PCA and PMI) with 40 branded blockbuster drugs showed that newly generated polyheterocycles have good three-dimensional scaffold diversity and most of these pass the Lipinski filter of drug-likeness.

A simple urea-based multianalyte and multichannel chemosensor for the selective detection of F−, Hg2+ and Cu2+ in solution and cells and the extraction of Hg2+ and Cu2+ from real water sources: a logic gate mimic ensemble

Herein, a hydrazine-based chromogenic, fluorogenic and electrochemical chemosensor BCC [1,5-bis(4-cyanophenyl) carbonohydrazide] was reported.

Nanomolar-level selective dual channel sensing of Cu2+and CN−from an aqueous medium by an opto-electronic chemoreceptor

A novel chromogenic and fluorogenic chemoreceptor exhibiting a proclivity towards Cu²⁺and CN⁻, with applications in bioimaging and molecular electronics, was developed.

257 IN VITRO YAK EMBRYO PRODUCTION THROUGH CONVENTIONAL AND OVUM PICKUP METHODS

Yak is one of the most important economically useful animals for highlanders. The decline in the yak population demands effective measures for conservation and multiplication of elite germplasm. In vitro production of embryos and their cryopreservation and transfer to suitable recipients for production of elite calves may contribute to fulfill the objectives. The work was conducted at the National Research Center on Yak over a period of 3 years. The ovaries of slaughtered animals were used for collecting oocytes through aspiration of follicles followed by slicing of ovaries in the conventional method. Trials were conducted using 7 cyclic parous yaks for ultrasound-guided ovum pickup (OPU) at Nyukmadung farm (2700 m above mean sea level). The technique followed was similar to that in buffaloes with slight modification. Categories of oocytes classified A (2–3 layers of cumulus) and B (at least one layer of cumulus) obtained through the processes were subjected to in vitro maturation using standardized maturation medium (TCM-199 + 10% follicular fluid + sodium pyruvate + l-glutamine + 10% heat inactivated oestrus cow serum + pFSH + 17β oestradiol). The frozen-thawed yak sperm were capacitated using the swing-up method before their incubation with matured oocytes using BO medium. Oocytes matured for 24 h were washed 5 to 6 times with BO medium and then co-incubated with in vitro capacitated spermatozoa (0.1 to 0.25 million) for fertilization (8–10 oocytes per group) in 100-µL droplets of BO medium under mineral oil in 35-mm Petri dishes and placed in a CO2 incubator (5% CO2, 90% RH) at 38.5°C for 16 to 18 h. The presumed zygotes were washed several times in mCR2aa (modified Charles Rosenkrans) washing medium and then cultured in culture medium for 7 days on original beds of granulosa cells. The rates of maturation and fertilization of oocytes collected by conventional and OPU technique were comparable (Table 1). This may be attributed to greater numbers of good quality oocytes recovered in the conventional method. Embryos developed up to the stage of compact morula and blastocysts (24.66% through conventional and 22.73% through OPU) were cryopreserved using the vitrification method for further study. Thirteen embryos were transferred non-surgically to one each of 13 yak recipients; 5 became pregnant and only 1 recipient transferred with a cryopreserved-thawed embryo, developed through OPU, delivered one male calf, leading to the first successful production of an IVF yak calf in the world. The present findings are suggestive of using the OPU technique for in vitro embryo production, though resulting in lower numbers of transferable embryos (Table 1), because availability of ovaries for conventional IVF is a major constraint in yak. Table 1.Comparative in vitro yak embryo production rate with recovery of oocytes by conventional or ovum pickup (OPU) method