Abstract: A new generation of fluorescent ion indicators for measuring cytosolic concentrations of calcium. These new indicators emit in the red portion of the visible spectrum and are ratiometric. The ratiometry consists of shifting in the emission upon binding calcium when exciting with an argon laser at 488 nm. These indicators also show marked increases in red fluorescence when excited with visible light at longer wavelengths. Like all calcium indicators, they comprise the usual chelating portion based on BAPTA (Bis Amino Phenyl Tetraacetic Acid) and a fluorophore portion, either a seminaphthofluorescein/seminaphthorhodamine or dinaphthofluorescein, which enable ratiometry. Unlike other naphthofluoresceins, the pKa has been adjusted on the naphtho moiety to make it suitable for biological calcium measurements. The invention relates to the structures of the indicators and to the method of synthesizing these indicators.

Abstract: A new class of visible wavelength fluorescent calcium indicators with the BAPTA-like portion rendered zwitterionic by introduction of amine and carboxylic groups. “Fluo” compounds generally function with no extra ionized groups. The modified BAPTA moiety confers new properties while retaining ion selectivity and pH insensitivity. The dyes demonstrate reduced cell leakage and improved ability to study calcium near the cell membrane and preserve the fluorescent properties of “fluo” dyes. The modifications include (a) piperazinoacetic acid XIII for the leakage resistance (FLUO-LR), (b) dodecylpiperazine XIII for a near membrane indicator (FLUO-MOMO, FLUO-NOMO amphipathic “fluo” indicators which bind to cellular membranes and respond to calcium near the membrane), and (c) a propionic acid XII for general leakage resistance -FLUO-LOJO, FLUO-KOJO “fluo” indicators with an extra charge that enables them to resist leakage).

Abstract: The invention discloses fluorescent chelator compounds that are especially useful to monitor and measure cytosolic concentrations of alkali metal cations such as Na.sup.+, K.sup.+, and Li.sup.+. The new compounds are comprised of: (1) crown ethers (that may or may not have substituent groups attached to the core carbons, but will always contain at least one core nitrogen) that are linked via the core nitrogen(s) to at least one (2) fluorophore that contains an additional heteroaromatic liganding center. In the currently preferred dye, SBFI, the core compound is crown ether 1,7-diaza-4,10,13-trioxacyclopentadecane and the heteroaromatic fluorophores are benzofurans that are linked to isophthalate groups. Selectivities for Na.sup.+ over K.sup.+ of about 20 are observed, resulting in effective dissociation constants for Na.sup.+ of about 20 mM against a background of 120 mM K.sup.+. Increasing ?Na.sup.

Abstract: The present invention discloses several new calcium indicator dyes which are retained in the cytosol or which bind to cellular membranes and report calcium levels near the membrane. These indicators are analogs of a previously described tetracarboxylate calcium indicator fura-2 and indo-1 where the 5' methyl of the BAPTA moiety is replaced with a derivative of propionic acid in the form of --CH.sub.2 CH.sub.2 CON--(CH2).sub.n --N(X.sub.1)X.sub.2, where n is 4. The propionic acid derivative provides a flexible means for introducing additional functionality to the calcium indicator without greatly impacting the fluorescence and ion chelating properties of the parental indicator. When X.sub.1 is CH.sub.2 COOH and X.sub.2 is part of a ring system like piperazine, a fluorescent calcium indicator, Fura-PE3, is obtained which resists compartmentalization and leakage out of the cytosol.

Abstract: The invention discloses fluorescent chelator compounds that are especially useful to monitor and measure cytosolic concentrations of alkali metal cations such as Na.sup.+, K.sup.+, and Li.sup.+. The new compounds are comprised of: (1) crown ethers (that may or may not have substituent groups attached to the core carbons, but will always contain at least one core nitrogen) that are linked via the core nitrogen(s) to at least one (2) fluorophore that contains an additional heteroaromatic liganding center. In the currently preferred dye, SBFI, the core compound is crown ether 1,7-diaza-4,10,13-trioxacyclopentadecane and the heteroaromatic fluorophores are benzofurans that are linked to isophthalate groups. Selectivities for Na.sup.+ over K.sup.+ of about 20 are observed, resulting in effective dissociation constants for Na.sup.+ of about 20 mM against a background of 120 mM K.sup.+. Increasing [Na.sup.

Abstract: The present invention discloses a new class of calcium specific fluorescent indicator dyes having visible excitation and emission wavelengths. The new fluorescent indicator dyes combine at least one tricyclic chromophore with a tetracarboxylate parent CA.sup.2+ chelating compound having the octacoordinate pattern of liganding groups characteristic of BAPTA to give a rhodamine-like or fluorescein-like fluorophore. Binding of calcium.sup.2+ increases the fluorescence of the new compounds by up to 40-fold. The calcium.sup.2+ dissociation constants are in the range 0.37-2.3 microM, so that the new indicators give better resolution of high [CA.sup.2+ ] levels than were previously obtainable with predecessor compounds such as quin-2 or fluo-2. The visible excitation wavelengths of the new compounds are more convenient for fluorescent microscopy and flow cytometry than the UV required by previous indicators.

Abstract: The present invention discloses a group of calcium chelating compounds which have a descreased affinity for calcium following illumination. These new compounds contain a photolabile nitrobenzyl derivative coupled to a tetracarboxylate Ca.sup.2+ chelating parent compound having the octacoordinate chelating groups characteristic of EGTA or BAPTA. In a first form, the new compounds are comprised of a BAPTA-like chelator coupled to a single 2-nitrobenzyl derivative, which in turn is a photochemical precursor of a 2-nitrosobenzophenone. In a second form, the new compounds are comprised of a BAPTA-like chelator coupled to two 2-nitrobenzyl derivatives, themselves photochemical prcursors of the related 2-nitrosobenzophenones.The present invention also discloses a novel method for preparing 1-hydroxy- or 1-alkoxy-1-(2-nitroaryl)-1-aryl methanes. Methanes of this type are critical to the preparation of, or actually constitute, the photolabile Ca.sup.2+ chelating compounds disclosed and claimed herein.