01771nas a2200217 4500008004100000022001400041245013700055210006900192260011000261300001600371490000700387520090800394100001701302700002301319700001801342700001801360700001501378700002101393700001701414856012201431 2013 eng d a1477-922600aNew chemodosimetric probe for the specific detection of Hg2+ in physiological condition and its utilisation for cell imaging studies0 aNew chemodosimetric probe for the specific detection of Hg2 in p aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL a15097-151050 v423 a

A dithiane derivative of BODIPY is synthesized. This new reagent could be used for the specific and instantaneous detection of Hg2+ in physiological condition. This dithiane reagent reacts specifically with Hg2+ to regenerate the parent BODIPY-aldehyde with consequential change in visually detectable optical responses and this provides the possibility of using this reagent as a colorimetric probe or as a fluorescent biomarker/imaging reagent. Further, non-covalent interactions could be utilized for formation of an inclusion complex with biologically benign beta-cyclodextrin for enhancing its solubility in aqueous environment and this included adduct could be used as a fluorescent marker and imaging reagent for Hg2+. Uptake of Hg2+ ions in live HeLa cells, exposed to a solution having Hg2+ ion concentration as low as 2 ppb, could also be detected by confocal laser microscopic studies.

1 aSaha, Sukdeb1 aAgarwalla, Hridesh1 aGupta, Hariom1 aBaidya, Mithu1 aSuresh, E.1 aGhosh, Sudip, K.1 aDas, Amitava uhttps://library.ncl.res.in/content/new-chemodosimetric-probe-specific-detection-hg2-physiological-condition-and-its-002505nas a2200205 4500008004100000022001400041245016500055210006900220260007100289300001600360490000700376520165600383100001802039700002802057700002102085700002302106700002302129700001702152856013002169 2013 eng d a0020-166900aRole of metal ion in specific recognition of pyrophosphate ion under physiological conditions and hydrolysis of the phosphoester linkage by alkaline phosphatase0 aRole of metal ion in specific recognition of pyrophosphate ion u a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a11034-110410 v523 a

Complexes synthesized from Zn(II), Cu(II), and Cd(II), using a dipicolyl amine derivative (L), showed unique specificity toward pyrophosphate ion (PPi or P4O74-) among all other common anionic analytes, including different biologically significant phosphate ion (PO43-, H2PO42-) or phosphate-ion-based nucleotides, such as AMP, ADP, ATP, and CTP. However, the relative affinities of PPi toward these three metal complexes were found to vary and follow the order K-a(L.Zn-PPi) > are given in units of (L.Cu-PPi)(a) >= K-a(L.Cd-PPi). Luminescence responses of the receptor L were substantial on binding to Zn2+ and Cd2+, while relatively a much smaller luminescence response was observed in the presence of Cu2+. Luminescence responses of L.M-PPi (M is Zn2+, Cd2+, and Cu2+) were further modified on binding to the PPi ion. This could be utilized for quantitative detection of PPi in physiological condition as well as for developing a real time ``turn-on'' (for L.Zn and L.Cu) and ``turn-off'' (for L.Cd) fluorescence assay for evaluating the enzymatic activity of alkaline phosphatase (ALP). Experimental results revealed how the subtle differences in the binding affinities between PPi and M in L.M (M is Zn2+, Cd2+, and Cu2+), could influence the cleavage of the phosphoester linkage in PPi by ALP. The DFT calculations further revealed that the hydrolytic cleavage of the metal ion coordinated phosphoester bond is kinetically faster than that for free PPi and thus, rationalized the observed difference in the cleavage of the phosphoester bond by an important mammalian enzyme such as ALP in the presence of different metal complexes.

1 aDas, Priyadip1 aChandar, Nellore, Bhanu1 aChourey, Shishir1 aAgarwalla, Hridesh1 aGanguly, Bishwajit1 aDas, Amitava uhttps://library.ncl.res.in/content/role-metal-ion-specific-recognition-pyrophosphate-ion-under-physiological-conditions-and-002517nas a2200193 4500008004100000245018100041210006900222260000800291300001600299490000800315520173800323100002302061700002202084700001902106700002602125700002302151700001702174856013202191 2014 eng d00aHydrogen bonding interaction between active methylene hydrogen atoms and an anion as a binding motif for anion recognition: experimental studies and theoretical rationalization0 aHydrogen bonding interaction between active methylene hydrogen a cMAR a2656–26660 v1183 a

Two new reagents, having similar spatial arrangements for hydrogen atoms of the active methylene functionalities, were synthesized and interactions of such reagents with different anionic analytes were studied using electronic spectroscopy as well as by using 1H and 31P NMR spectroscopic methods. Experimental studies revealed that these two reagents showed preference for binding to F– and OAc–. Detailed theoretical studies along with the above-mentioned spectroscopic studies were carried out to understand the contribution of the positively charged phosphonium ion, along with methylene functionality, in achieving the observed preference of these two receptors for binding to F– and OAc–. Observed differences in the binding affinities of these two reagents toward fluoride and acetate ions also reflected the role of acidity of such methylene hydrogen atoms in controlling the efficiencies of the hydrogen bonding in anion–Hmethylene interactions. Hydrogen bonding interactions at lower concentrations of these two anionic analytes and deprotonation equilibrium at higher concentration were observed with associated electronic spectral changes as well as visually detectable change in solution color, an observation that is generally common for other strong hydrogen bond donor functionalities like urea and thiourea. DFT calculations performed with the M06/6-31+G**//M05-2X/6-31G* level of theory showed that F– binds more strongly than OAc– with the reagent molecules. The deprotonation of methylene hydrogen atom of receptors with F– ion was observed computationally. The metal complex as reagent showed even stronger binding energies with these analytes, which corroborated the experimental results.

1 aAgarwalla, Hridesh1 aJana, Kalyanashis1 aMaity, Arunava1 aKesharwani, Manoj, K.1 aGanguly, Bishwajit1 aDas, Amitava uhttps://library.ncl.res.in/content/hydrogen-bonding-interaction-between-active-methylene-hydrogen-atoms-and-anion-binding-motif01196nas a2200205 4500008004100000022001400041245014800055210006900203260011000272300001400382490000700396520032900403100002300732700002300755700001900778700002100797700002500818700001700843856013000860 2014 eng d a1359-734500aNovel fluorescence probe for estimation of cysteine/histidine in human blood plasma and recognition of endogenous cysteine in live Hct116 cells0 aNovel fluorescence probe for estimation of cysteinehistidine in  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a9899-99020 v503 a

A new Cu(II)-complex is used as a ``Turn-On'' luminescence probe for specific detection of endogenous Cys in live Hct116 cells and Cys present in human blood plasma without any interference from other amino acids, especially GSH and Hcy. Difference in the mechanistic pathway for Cys and His recognition is discussed.

1 aReddy, Upendar, G.1 aAgarwalla, Hridesh1 aTaye, Nandaraj1 aGhorai, Suvankar1 aChattopadhyay, Samit1 aDas, Amitava uhttps://library.ncl.res.in/content/novel-fluorescence-probe-estimation-cysteinehistidine-human-blood-plasma-and-recognition-002568nas a2200193 4500008004100000022001400041245006000055210005900115260011000174300001600284490000600300520188500306100002202191700001702213700001802230700002302248700001702271856008602288 2014 eng d a2046-206900aOverview of the recent developments on Hg2+ recognition0 aOverview of the recent developments on Hg2 recognition aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUN a36140-361740 v43 a

Adverse influences of mercury on living organisms are well known. Despite efforts from various regulatory agencies, the build-up of Hg2+ concentration in the environment is of serious concern. This necessitates the search for new and efficient reagents for recognition and detection of Hg2+ in environmental samples as well as for application in diagnostics. Among various detection processes adopted for designing such reagents, generally methodologies that allow associated changes in spectra properties are preferred for the obvious ease in the detection process. Significant changes in the electronic spectral pattern in the visible region of the spectrum also induce detectable changes in solution colour for naked-eye detection and are useful for developing reagents for in-field sample analysis with yes-no type binary responses. However, reagents that allow detection of Hg2+ with associated fluorescence on response are useful for detection of Hg2+ in environmental samples, as well as for use as an imaging reagent, for detection of cellular uptake. High spin-orbit coupling constant for Hg2+ along with its high solvation energy in aqueous medium poses a challenge in developing efficient reagents with fluorescence on response that work in aqueous medium/physiological condition. To get around this problem, several methodologies, like conversion of rhodamine derivative spirolactam to strongly fluorescent xanthenes that form on binding to Hg2+, chemodosimetric reaction for generation of a new luminescent derivative, have been adopted. Apart from these, modified charge transfer processes on binding to Hg2+ have also been utilized for designing reagents for optical detection of Hg2+. Immobilization of such reagents on solid surfaces also led to the development of self-indicating Hg2+ ion scavengers. All such examples are discussed in the present review.

1 aMahato, Prasenjit1 aSaha, Sukdeb1 aDas, Priyadip1 aAgarwalla, Hridesh1 aDas, Amitava uhttps://library.ncl.res.in/content/overview-recent-developments-hg2-recognition-002667nas a2200217 4500008004100000022001400041245014800055210006900203260011000272300001400382490000600396520175400402100002302156700002702179700003002206700002502236700001902261700002302280700001702303856012902320 2015 eng d a2050-750X00aFluorescent probes for the detection of cyanide ions in aqueous medium: cellular uptake and assay for beta-glucosidase and hydroxynitrile lyase0 aFluorescent probes for the detection of cyanide ions in aqueous  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT a9148-91560 v33 a

A chemodosimteric reagent (1) for the efficient detection of cyanide species (CN- and/or HCN) in aq. medium as well as under physiological conditions has been described. Selective reaction of the cyanide species with this reagent in the presence of all common interfering anions, amino acids and glutathione (GSH) led to the generation of the corresponding cyanohydrin derivative. The formation of the cyanohydrin derivative of the probe is associated with a visually detectable change in solution fluorescence in aq. buffer medium with 1.9 mu M NaCN, the threshold limit set by WHO for the safe drinking water and this makes this fluorogenic sensor an ideal candidate for in-field applications. An apparent switch on the luminescence response, ultralow detection limit, low response time, cell membrane permeability and insignificant toxicity are key features of a probe molecule, which gives it a distinct edge over previously reported chemodosimetric reagents for the detection of cyanide species (CN- or HCN) in an aqueous environment. This methodology could be used for developing a generalized and efficient fluorescence-based assay for crucial enzymes like beta-glucosidase and hydroxynitrile lyase. Furthermore, spectrally-resolved fluorescence microscopy measurements on single-cells revealed that this sensor molecule could also be used for imaging the cellular uptake of cyanide species from aq. solution contaminated with NaCN. Our results confirmed that statistical analysis of integrated intensity and transition energy obtained from the emission spectra collected over various microscopic sub-cellular regions can potentially be used to discriminate the effects of local cellular environments and that due to cyanide detection.

1 aAgarwalla, Hridesh1 aGangopadhyay, Monalisa1 aSharma, Dharmendar, Kumar1 aBasu, Santanu, Kumar1 aJadhav, Sameer1 aChowdhury, Arindam1 aDas, Amitava uhttps://library.ncl.res.in/content/fluorescent-probes-detection-cyanide-ions-aqueous-medium-cellular-uptake-and-assay-beta-001122nas a2200193 4500008004100000022001400041245013800055210006900193260011000262300001400372490000700386520030900393100001900702700001500721700002300736700002500759700001700784856012700801 2015 eng d a1359-734500aTuning of multiple luminescence outputs and white-light emission from a single gelator molecule through an ESIPT coupled AIEE process0 aTuning of multiple luminescence outputs and whitelight emission  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcDEC a2130-21330 v513 a

A unique example of an ESIPT coupled AIEE process, associated with a single molecule (1), is utilized for generating multiple luminescent colors (blue-green-white-yellow). The J-aggregated state of 1 forms a luminescent gel in THF and this luminescent property is retained even in the solid state.

1 aMaity, Arunava1 aAli, Firoj1 aAgarwalla, Hridesh1 aAnothumakkool, Bihag1 aDas, Amitava uhttps://library.ncl.res.in/content/tuning-multiple-luminescence-outputs-and-white-light-emission-single-gelator-molecule-001412nas a2200217 4500008004100000245008700041210006900128260000800197300001400205490000600219520069900225100002300924700001500947700001800962700002100980700001701001700001801018700002701036700001701063856011401080 2016 eng d00aFluorescent probe for bisulfite ions: its application to two-photon tissue imaging0 aFluorescent probe for bisulfite ions its application to twophoto cDEC a7888-78940 v43 aA benzoxazinone based fluorescent probe for the specific and efficient detection of bisulfite ions in aqueous medium is described. The probe formed a bisulfite/sulphite adduct with an associated turn-on fluorescence response in the red wavelength region. No interference was observed in the detection process from all possible competing anions and molecules, including cyanide ion, cysteine, homocysteine and glutathione. In addition, the probe showed a fast response time, low detection limit, and cell membrane permeability. Furthermore, the probe was two-photon excitable, enabling imaging of endogenous bisulfite ions in HeLa cells as well as in deep tissues from different organs of mouse.1 aAgarwalla, Hridesh1 aPal, Suman1 aPaul, Anirban1 aJun, Yong, Woong1 aBae, Juryang1 aAhn, Kyo, Han1 aSrivastava, Divesh, N.1 aDas, Amitava uhttps://library.ncl.res.in/content/fluorescent-probe-bisulfite-ions-its-application-two-photon-tissue-imaging00951nas a2200205 4500008004100000245014100041210006900182260000800251300001400259490000700273520017900280100002300459700002300482700001500505700002800520700002300548700002700571700001700598856013000615 2018 eng d00aFluorescent chemodosimeter for quantification of Cystathionine-y-synthase activity in plant extracts and imaging of endogenous biothiols0 aFluorescent chemodosimeter for quantification of Cystathionineys cAUG a9079-90820 v543 a

A new reagent for quantification of CgS in plant extracts using a generalized methodology suitable for recognition of homocysteine (Hcy) with luminescence ON response.

1 aAgarwalla, Hridesh1 aHoskere, Anila, A.1 aAli, Firoj1 aPradhan, Swaraj, Rashmi1 aGanguly, Bishwajit1 aPramanik, Sumit, kumar1 aDas, Amitava uhttps://library.ncl.res.in/content/fluorescent-chemodosimeter-quantification-cystathionine-y-synthase-activity-plant-extracts