A silylated chalcone based sensing probe was designed and synthesized for both simultaneous as well as discriminative detection of fluoride and cyanide ions. The probe showed chromogenic response after the addition of either fluoride or cyanide ion. However, addition of water caused discoloration of the probe solution in case of fluoride ion only while no such change was observed in case of cyanide ions. The probe was found to be selective for the colorimetric detection of F- and CN-ions as it did not generate any chromogenic response in presence of other analyte. For fluoride ions, the detection limit of sensor was calculated to be 0.075 mu M while in case of cyanide ions; the detection limit was determined to be 0.23 and 0.44 mu M in absence and in presence of water respectively. Practical utility of the proposed method was also demonstrated by testing the real water samples. A chalcone based single chromogenic probe was designed and developed which gave orange colour on exposure to both fluoride and cyanide ions. However, addition of water led to the discoloration of test solution containing fluoride ion only while no such effect was observed in the presence of cyanide ions. This event could be used for discriminative detection of fluoride and cyanide ions.image

Selective optical detection of highly toxic nerve agents and their mimics like diethyl cyanophosphate (DCNP) is of paramount importance for armed forces and first responders in order to decide the suitable medical countermeasures. The reported optical chemical sensors for DCNP suffered from poor selectivity due to their single point covalent interaction with analyte. To overcome this limitation, we herein, report a novel protocol utilizing a ditopic chemodosimeter which, in presence of tetrabutylammonium hydroxide (TBAOH), underwent dual interaction with reactive subunits of DCNP, viz., electrophilic phosphorus and cyanide, to induce unique changes in its fluorescence as well as colorimetric properties. Other interfering analytes could not trigger the similar optical response in the sensing probe due to the absence of electrophilic phosphorus and cyanide. A truth table was constructed to reveal that only DCNP but not other analytes could induce changes in both fluorescence as well as colorimetric properties of sensing probe. The linearity range of the proposed method was found to be 30-70 mu M while chromogenic limit of detection (LOD) was calculated to be 99 nM which are comparable to the reported methods. Thus, use of indigenously available 2-hydroxy-1-naphthaldehyde as sensing probe without requiring further chemical manipulation represented a significant improvement over the literature methods for DCNP sensing.

This paper reports a novel optical chemical sensing system for selective detection of diisopropylfluorophosphate (DFP), a simulant of fluorine-containing nerve agents (Sarin and Soman). Contrary to the reported methods involving only single sensing probe, this sensing system is comprised of two molecular sensing probes (1 and 2) having intrinsic affinities for reactive subunits of DFP (electrophilic phosphorus and fluoride ion). On exposure to DFP, two molecular probes react in tandem with electrophilic phosphorus and fluoride ion (by-product of the initial phosphorylation reaction) to induce a unique modulation in the optical properties of the sensing system which leads to selective detection of DFP in solution as interferents like phosphorus-containing compounds, acids, and anions were unable to induce similar optical modulation due to lack of both electrophilic phosphorus and fluorine in the same molecule. Calibration curve between the amount of DFP added and the absorption intensity revealed the colorimetric detection limit of the system to be 4.50 μM which was further lowered to 2.22 μM by making use of a self-immolative fluoride sensing probe 5.

Synthesis and bioefficacy of fentanyl and its 8 new 1-substituted analogs (1-8) were earlier reported by us. Of these 8 compounds, N-(1-(2-phenoxyethyl)-4-piperidinyl)propionanilide (2), N-isopropyl-3-(4-( N-phenylpropionamido)piperidin-1-yl)propanamide (5), and N- t-butyl-3-(4-( N-phenylpropionamido)piperidin-1-yl) propanamide (6) were found to be more effective and less toxic compared to fentanyl. The present study reports the acute effect of fentanyl (0.50 Median Lethal Dose (LD50); intraperitoneal) and its 3 analogs (2, 5, and 6) on various biochemical and oxidative parameters in mice and various physiological parameters in rats. Blood alkaline phosphatase (1 hour and 7 days) and urea levels (1 hour) were significantly elevated by fentanyl, while alanine aminotransferase levels (1 hour) were increased by both fentanyl and analog 2 compared to the corresponding control. Increase in partial pressure of carbon dioxide and decrease in partial pressure of oxygen were also caused by fentanyl and analog 2 (1 hour). Analog 6 alone elevated malondialdehyde levels in the brain, liver, and kidney tissues (7 days). The LD50 of fentanyl and analogs 2, 5, and 6 were found to be 0.879, 87.88, 69.80, and 55.44 mg/kg, respectively, in rats. Significant decrease in heart rate, mean arterial pressure, respiratory rate (RR), and neuromuscular transmission was produced by fentanyl and analog 2, while analog 5 decreased the RR alone. The changes, particularly the respiratory depression, were found to be reversed by naloxone, a μ-receptor antagonist. Thereby, indicating involvement of μ-receptor mediated effects of the compounds. To conclude, all the analogs were found to be less toxic compared to fentanyl, suggesting their possible role in pain management.

In this paper, we report a method for the conversion of primary carbamates into thiols in the presence of phosphorus pentasulfide (P2S5) in refluxing toluene. Presently, no method exists in the literature for conversion of carbamates into thiols and, to the best of our knowledge, it is the first report for this type of conversion. This method presents an indirect route for the conversion of alcohols into thiols via their carbamate derivatives that may be useful in the total synthesis of compounds containing a thiol functionality.

In this paper we report an efficient and mild procedure for the conversion of organic thiocyanates to thiols in the presence of phosphorus pentasulfide (P2S5) in refluxing toluene. The method avoids the use of expensive and hazardous transition metals and harsh reducing agents, as required by reported methods, and provides an attractive alternative to the existing methods for the conversion of organic thiocyanates to thiols.

ChemInformVolume 47, Issue 26 Preparative Organic Chemistry ChemInform Abstract: Synthesis of Disulfanes from Organic Thiocyanates Mediated by Sodium in Silica Gel. Chandra Kant Maurya, Chandra Kant Maurya Def. Res. Dev. Establ., Gwalior 474 002, IndiaSearch for more papers by this authorAvik Mazumder, Avik Mazumder Def. Res. Dev. Establ., Gwalior 474 002, IndiaSearch for more papers by this authorAjeet Kumar, Ajeet Kumar Def. Res. Dev. Establ., Gwalior 474 002, IndiaSearch for more papers by this authorPradeep Kumar Gupta, Pradeep Kumar Gupta Def. Res. Dev. Establ., Gwalior 474 002, IndiaSearch for more papers by this author Chandra Kant Maurya, Chandra Kant Maurya Def. Res. Dev. Establ., Gwalior 474 002, IndiaSearch for more papers by this authorAvik Mazumder, Avik Mazumder Def. Res. Dev. Establ., Gwalior 474 002, IndiaSearch for more papers by this authorAjeet Kumar, Ajeet Kumar Def. Res. Dev. Establ., Gwalior 474 002, IndiaSearch for more papers by this authorPradeep Kumar Gupta, Pradeep Kumar Gupta Def. Res. Dev. Establ., Gwalior 474 002, IndiaSearch for more papers by this author First published: 15 June 2016 https://doi.org/10.1002/chin.201626084Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume47, Issue26June, 2016 RelatedInformation

We report an efficient procedure for the synthesis of symmetrical disulfanes from organic thiocyanates in the presence of sodium in silica gel at room temperature. By avoiding the use of foul-smelling thiols, the present protocol provides an attractive alternative to existing methods for the preparation of symmetrical disulfanes.

1,2-Diones are important organic intermediates and substrates for many organic reactions. In this Letter, we describe a newer method for the synthesis of 1,2-diones from corresponding 1,2-diols using inexpensive iron(III) nitrate nonahydrate under microwave irradiations. The new protocol is efficient, rapid and high yielding that has circumvented the handling and use of toxic and expensive reagents. Moreover, exclusion of any organic solvent and solid support made this method an attractive and useful alternative to the existing methods for the synthesis of 1,2-diones. The process has been extended for the synthesis of a variety of diones and effect of electronic and steric factors on the reaction profile has been discussed.

Sodium metal stabilized in silica gel (Na_SG) has been reported as a powerful reducing agent. Being less pyrophoric than free metal, it has been used to carry out a variety of organic transformations including desulfonation, Birch reduction, Bouveault–Blanc Ester Reduction, etc. In this Letter, we describe a newer method involving its use for decarbamoylation of primary carbamates to the corresponding alcohols/phenols. In comparison with the reported methods, the present method requires milder reaction conditions and proceeds at room temperature. The reaction worked in solvents like THF and acetonitrile, the later giving better results in terms of reaction profiles. The process has been extended for decarbamoylation of a variety of carbamates.

Fentanyl [N-(1-phenethyl-4-piperidinyl)propionanilide] is a potent opioid analgesic agent, but a has narrow therapeutic index. We reported earlier on the synthesis and bioefficacy of fentanyl and its 1-substituted analogs (1-4) in mice. Here we report the synthesis and biological evaluation of four additional analogs, viz. N-isopropyl-3-(4-(N-phenylpropionamido)piperidin-1-yl)propanamide (5), N-t-butyl-3-(4-(N-phenylpropionamido)piperidin-1-yl)propanamide (6), isopropyl 2-[4-(N-phenylpropionamido)piperidin-1-yl]propionate (7) and t-butyl 2-[4-(N-phenylpropionamido)piperidin-1-yl]propionate (8). The median lethal dose (LD50) determined by intravenous, intraperitoneal and oral routes suggests these analogs to be comparatively less toxic than fentanyl. On the basis of observational assessment on spontaneous activities of the central, peripheral, and autonomic nervous systems, all the analogs were found to be similar to fentanyl. Naloxone hydrochloride abolished the neurotoxic effects of these analogs, thereby ascertaining their opioid receptor-mediated effects. All the analogs displayed significant analgesic effects, measured by formalin-induced hind paw licking and tail immersion tests at their respective median effective dose (ED50). They also exhibited 8-12 fold increase in therapeutic index over fentanyl. However, 5 and 6 alone produced lower ED50 (20.5 and 21.0 µg/kg, respectively) and higher potency ratio (1.37 and 1.33, respectively) compared to fentanyl. They could thus be considered for further studies on pain management.

Fentanyl [ N -(1-phenethyl-4-piperidinyl)propionanilide] is a popular narcotic analgesic agent that is clinically used worldwide. However, fentanyl and its several analogs have caused abuse and fatalities in humans due to overdosing and narrow therapeutic index. The present study reports the synthesis and comparative bioefficacy of fentanyl and its four analogs, viz., N -(1-propyl-4-piperidinyl)propionanilide ( 1 ), N -(1-(2-phenoxyethyl)-4-piperidinyl)propionanilide ( 2 ), N -(1-(3-phenoxypropyl)-4-piperidinyl)propionanilide ( 3 ) and N -(1-(2-cyanoethyl)-4-piperidinyl)propionanilide ( 4 ), where the phenethyl chain of fentanyl was replaced by different functional groups, viz., alkyl, ethereal, and nitrile moieties. The median lethal dose (LD 50 ) of the compounds was determined by three different routes and all the analogs were found to be safer than fentanyl. Observational assessment on spontaneous activities of the central nervous system, peripheral nervous system, and autonomic nervous system revealed that all the analogs were similar to fentanyl. Further, the neurotoxic effects of all the analogs were reversed by naloxone hydrochloride (opioid antagonist), confirming that their effects were mediated through opioid receptors. Antinociceptive activity was displayed by all the compounds and their median effective dose (ED 50 ) and analgesic potency ratio were more or less similar to fentanyl. The lowest ED 50 (23.7) and the highest potency ratio (1.18) was observed in the case of 2 . However, the maximum therapeutic index was afforded by 4 . The study indicates the promising role of some new opioid analgesics.

It has been established that intense physical exercise is associated with an increase in free radical production.Our body has defense system to combat the deleterious effect.But, when the body's natural defense system against free radicals are overwhelmed, oxidative stress increases.In the present investigation, we studied the effect of vitamin supplementation (composed of 400 IU of vitamin E and 500 mg ascorbic acid for 2 months) on oxidative and enzymatic exercise stress markers during endurance training activity in 50 trained elite Indian cyclists attending national camp at Sports Authority of India, Netaji Subas National Institute of Sports (SAI-NSNIS), Patiala, India.Serum concentrations of ascorbic acid, alpha tocopherol, malondialdehyde (MDA), superoxide dismutase (SOD) and catalase were measured before supplementation and after completion of 2 months of antioxidant supplementation.Antioxidant supplementation led to significant increase in serum alpha-tocopherol and ascorbic acid from pre-supplementation to postsupplementation stage.Serum MDA concentration and SOD activity decreased significantly after 2 months of antioxidant treatment.There was increase in serum catalase activity after supplementation compared to before supplementation.The results of the present study suggest that antioxidant supplementation may strengthen the antioxidant defense system, thus reducing the oxidative stress produced after endurance training in elite Indian cyclists.

The influence of exercise on free-radical chemistry is not well understood. It is yet to be confirmed whether an adequate biochemical defence system exists in the human body to provide protection from oxy-centred radicals generated by exercise. Fifty trained elite cyclists undertaking exhaustive endurance training were compared with a control group of 50 sedentary workers. Serum malondialdehyde (MDA), uric acid, superoxide dismutase (SOD), catalase, vitamin E, vitamin C and susceptibility to oxidative stress were assessed. Exhaustive exercise resulted in significantly (p < 0.05) higher concentrations of serum MDA, vitamin E and vitamin C, significantly (p < 0.001) higher SOD activity, but less significantly (p < 0.01) higher concentrations of uric acid and significantly (p < 0.05) lower catalase activity in elite cyclists than in the controls. Alterations in the activities of erythrocyte scavenger enzymes (SOD) and higher level of non-enzymatic defences in trained subjects may not be sufficient to counteract the increase in reactive oxygen species produced by endurance training.

Fentanyl is a very potent synthetic narcotic analgesic. Because of its strong sedative properties, it has become an analogue of illicit drugs such as heroin. Its unambiguous detection and identification in environmental samples can be regarded as strong evidence of its illicit preparation. In this paper we report application of single-drop microextraction (SDME) for analysis of water samples spiked with fentanyl. Experimental conditions which affect the performance of SDME, for example the nature of the extracting solvent, sample stirring speed, extraction time, ionic strength, and solution pH, were optimized. The method was found to be linear in the concentration range 0.10-10 ng mL(-1). The limits of quantitation and detection of the method were 100 pg mL(-1) and <75 pg mL(-1), respectively. This technique is superior to other sample-preparation techniques because of the simple experimental set-up, short analysis time, high sensitivity, and minimum use of organic solvent.

Experiments have been conducted on various configurations of Coriolis mass flowmeters, such as U-tube, S-tube, L-tube, and stair shaped tubes, with water as the working fluid. The sensitivity of the flowmeter has been measured for a wide range of parameters like position of sensors, geometry, material properties, etc. The results of this study indicate that the measured phase shift is proportional to the mass flow rate. The slope ratio (theoretical to measured) is observed to be constant for the range of parameters studies for U-tube flowmeters. Sensor positions for maximum sensitivity have been identified for S-tube and L-tube configurations.

The results for the phonon dispersion curves along the major symmetry directions, second order elastic constants (SOEC) and zero point energy are obtained on the basis of modified scheme, centered around an empirical Morse potential for some fcc metals. This exponential potential is less parametric, which incorporates the exchange and correlation effects due to electrons in a simple and effective manner. These above computed results are compared with experimental findings with remarkable success.

Dynamic performance simulations of a high-load, high-speed ball bearing for turbine-engine applications are considered using the available Dynamics of Rolling Element Bearings (DREB) computer program. It is shown that the key element in the bearing design is the traction behavior at the ball/race interface for the prescribed materials. With a given traction model, the geometry of the bearing may be designed to ensure acceptable ball/cage collision forces and to ensure the general stability of the cage.

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