First Dual Responsive "Turn-On" and "Ratiometric" AIEgen Probe for Selective Detection of Hydrazine Both in Solution and the Vapour Phase.

A new dual responsive "turn-on" and "ratiometric" aggregation-induced emission luminogen (AIEgen) 3-formyl-5-(piperidin-1-yl)biphenyl-4-carbonitrile 6 a (FPBC 6 a) for selective detection of hydrazine in solution as well as in vapour phase is described. At a low concentration of 2.5 µm, the probe FPBC 6 a is non-fluorescent (turn-off) but remarkably lights up (turn-on with blue emission) in the presence of hydrazine solution (0.25-25 µm). Interestingly, at higher concentrations, the nanoaggregates of FPBC 6 a (>25 µm, 99 % HEPES in DMSO) displayed ratiometric response in the presence of hydrazine with a remarkable hypsochromic shift from the green (500-550 nm) to blue regions (440-480 nm). Furthermore, a real application of FPBC 6 a was successfully demonstrated through the detection and visualization of hydrazine in live cervical cancer cells as well as using portable test strips.

A Tetraphenylethene-Naphthyridine-Based AIEgen TPEN with Dual Mechanochromic and Chemosensing Properties.

Synthesis of new tetraphenylethene (TPE) conjugates via an innocuous route led to the revelation of a unique TPE-based aggregation-induced emissive fluorogen 3 (TPEN), which showed an interesting mechanochromic property when the emission was changed from blue to green upon grinding and green to blue upon fuming. The mechanochromic property of TPEN has been explored to prepare ink-free rewritable paper for security documentation. A detailed photophysical investigation of the TPE-naphthyridine scaffold led to the discovery of its high sensitivity to silver ions (Ag+) over other metal ions with a detection limit of 0.25 µM in an aqueous system. The stoichiometry of the complex of TPEN and silver ion was established to be 2:1 (TPEN:Ag+) on the basis of photophysical studies, mass analysis, and high-resolution mass spectrometry analysis.

New visible light excitable donor-acceptor 7-hydroxy-coumarins as blue fluorescent probes for selective staining of vacuoles in yeasts and L. donovani.

In order to address the existing limitations of the commercially available fluorescent probe CMAC (7-amino-4-chloromethylcoumarin), a new series of highly fluorescent donor-acceptor 7-hydroxy-coumarin derivatives was prepared and these derivatives were used as vacuole specific fluorescent probes for live cell imaging of unicellular parasitic protozoa L. donovani promastigotes and yeast cells S. pombe and S. cerevisiae. The synthesized 7-hydroxy-coumarins exhibited interesting photophysical properties and have advantages such as excitation in the visible region, good water solubility, photo-stability, good quantum yield and low cytotoxicity.

3-Piperidylethoxypterocarpan: A potential bone anabolic agent that improves bone quality and restores trabecular micro-architecture in ovariectomized osteopenic rats.

A series of new 6H-benzofuro[3, 2-c]chromenes (BFC, pterocarpans) with structure-activity relationships were investigated for their potential use in osteoporosis treatment. One of the BFCs 3-piperidylethoxypterocarpan 20 promotes osteoblast differentiation and mineralization at a dose as low as 1 pM via activation of ER/P38MAPK/BMP-2 pathway. When evaluated for in-vivo osteogenic activity in female Sprague-Dawley rats, BFC 20 increased bone mineral density and new bone formation, compared with control at 1.0 and 10.0 mg/kg/body weight by oral gavage for 30 days. The compound was devoid of any uterotrophic effect and led to the new bone formation in adult ovariectomized osteopenic rats. BFC 20 compound also inhibited bone resorption by reducing Ovx induced increase in urinary CTx, thus exhibiting both bone anabolic and anti-catabolic action. Finally, BFC 20 treatment to Ovx rats led to improved trabecular microarchitectural restoration and exhibited therapeutic potential as a dual acting anti-osteoporotic agent for the management of osteoporosis.

Lymphoepithelial cyst of the pancreas: a rare case report and review of literature.

UNLABELLED: Lymphoepithelial cysts are rare pancreatic lesions of undetermined pathogenesis. The literature on this entity is limited to case reports or small series. We describe a case of 66 year male, incidentally diagnosed as lymphoepithelial cyst of pancreas that was managed by enucleation. This is the first case report of lymphoepithelial cyst from India. An extensive Medline search was carried out for lymphoepithelial cyst of pancreas. Till date less than 100 cases were identified in available literature. All these cases (including our case) were analyzed. This entity has uniform and distinctive clinicopathological features. About half of the reported cases were asymptomatic with most of the lesions diagnosed incidentally. Majority of patients presents with non-specific symptoms making preoperative diagnosis difficult. Lymphoepithelial cyst of the pancreas is a rare benign lesion, which is difficult to diagnose preoperatively. High index of suspicion and preoperative fine needle aspiration cytology may help in making diagnosis and avoiding surgery in asymptomatic patients. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12262-010-0152-y) contains supplementary material, which is available to authorized users.