@article {4969, title = {Vasodilator effects of organotransition-metal nitrosyl complexes, novel nitric oxide donors}, journal = {Journal of Cardiovascular Pharmacology}, volume = {35}, number = {1}, year = {2000}, note = {ISI Document Delivery No.: 270ABTimes Cited: 26Cited Reference Count: 14}, month = {Jan}, pages = {73-77}, type = {Article}, abstract = {Nitrovasodilators cause endothelium-independent relaxation of blood vessels by generating nitric oxide (NO). We examined the relaxation and depressor effects of two organotransition-metal nitrosyl complexes, CpCr(NO)(2)Cl and CpMo(NO)(2)Cl, relative to those of the prototypal nitrovasodilators, nitroglycerin, and sodium nitroprusside (SNP), in phenylephrine-preconstricted aortic rings and conscious, unrestrained rats. CpCr(NO)(2)Cl, CpMo(NO)(2)Cl, nitroglycerin and SNP caused dose-dependent relaxation of aortic rings at maximal responses (E-max) of -118 +/- 4, -113 +/- 4, -104 +/- 1, and -128 +/- 5\% and EC50 of 0.14 +/- 0.04, 22 +/- 4, 1.23 +/- 0.65, and 0.063 +/- 0.013 mu M, respectively. The dose-response curve of CpCr(NO)(2)Cl was displaced to the right by hemoglobin, as well as methylene blue, showing involvement of the NO/cGMP pathway. Unlike nitroglycerin, preexposure for 1 h to CpCr(NO)(2)Cl did not alter subsequent relaxation response to the compound, Intravenous bolus injections of CpCr(NO)(2)Cl, CpMo(NO)(2)Cl, nitroglycerin, and SNP caused dose-dependent decreases in MAP with E-max of -42 +/- 2, -51 +/- 8, -56 +/- 6, and -58 +/- 2 mm Hg and EC50 of 0.041 +/- 0.010, 13 +/- 4, 1.6 +/- 0.4, and 0.037 +/- 0.004 mu mol/kg, respectively. These results show that CpCr(NO)(2)Cl and CpMo(NO)(2)Cl are efficacious nitrovasodilators in vitro and in vivo.}, keywords = {BLOOD, cyanide, ISOLATED TAIL ARTERY, metal-nitrosyl complexes, nitric oxide, nitroglycerin, nitrovasodilator, pressure, RAT AORTA, relaxation, RELEASE, sodium nitroprusside (SNP), SODIUM-NITROPRUSSIDE}, isbn = {0160-2446}, url = {://000084512200009}, author = {Wang, Y. X. and Legzdins,Peter and Poon, J. S. and Pang, C. C. Y.} } @article {4224, title = {Reversible molecular capsules composed of two cavitands linked via an assortment of charged-hydrogen bonds and covalent bonds}, journal = {Journal of the American Chemical Society}, volume = {120}, number = {38}, year = {1998}, note = {ISI Document Delivery No.: 125EVTimes Cited: 42Cited Reference Count: 29}, month = {Sep}, pages = {9818-9826}, type = {Article}, abstract = {Six new cavitand bowls are reported (6, 7, 8, 9, 11, and 12), as are three bis-bowl compounds (4, 13, and 14). Eight new complexes (4.guest, 7C.guest, 8C.guest, 9C.guest, 14.guest, 15.guest, 15C.guest, and 16C.guest) that reversibly encapsulate small molecules are reported. Two or more charged-hydrogen bonds (CHBs) or covalent linkages between the bowls are required to form stable complexes. Guest exchange rates vary from milliseconds to days. Thermodynamically, these complexes display an enthalpy-entropy compensation. The relative stability of complex 3.pyrazine versus complex 3.chloroform is 170000 in nitrobenzene-d(5) at 298 It. Apparent stability constants in nitrobenzene-d(5) at 298 K yield 1.1 x 10(9) M-1 for complex 3.pyrazine. The absolute stability constant for complex 4.pyrazine in nitrobenzene-d(5) at 333 K is 3.5 x 10(6) M-1.}, keywords = {BINDING, carceplex, CHEMISTRY, ENCAPSULATION, HEMICARCERANDS, HOST-GUEST COMPLEXATION, ORGANIC-MOLECULES, RELEASE, TEMPLATION}, isbn = {0002-7863}, url = {://000076225200012}, author = {Chapman, R. G. and Sherman, J. C.} } @article {3322, title = {AN ASYMMETRIC CARCEPLEX AND NEW CRYSTAL-STRUCTURE YIELD INFORMATION REGARDING A 1-MILLION-FOLD TEMPLATE EFFECT}, journal = {Journal of Organic Chemistry}, volume = {60}, number = {5}, year = {1995}, note = {ISI Document Delivery No.: QL605Times Cited: 48Cited Reference Count: 50}, month = {Mar}, pages = {1207-1213}, type = {Article}, abstract = {We report the incorporation of methyl {\textquoteright}{\textquoteright}feet{\textquoteright}{\textquoteright} as pendant groups in cavitands and carceplexes and their use in the creation of an asymmetric carceplex and the facilitation of the determination of the crystal structure of a carceplex. From the asymmetric carceplex, we have determined a 19 kcal/mol energy barrier to rotation of the guest pyrazine about the host{\textquoteright}s pseudo-C-2 axes, which demonstrates a high degree of complementarity between the shell of the carceplex and the guest pyrazine. The crystal structure reveals the extensive conjugation of the aryl ethers into the aromatic rings of the host when pyrazine is the guest. This result helps explain why pyrazine is, to date, the best template for the reaction to form the carceplex and thus provides insight to the powerful template effect that is the hallmark of this carceplex reaction. Thus, the investigation of this template effect provides a sensitive probe into noncovalent interactions in general and may be useful in the understanding of recognition in both natural systems such as enzyme/substrate complexes and in non-natural systems such as designed self-assembling structures.}, keywords = {4 PORTALS, CAPTURE, CAVITANDS, CONSTRICTIVE BINDING, DERIVATIVES, HEMICARCERAND, HOST-GUEST COMPLEXATION, RELEASE}, isbn = {0022-3263}, url = {://A1995QL60500025}, author = {Fraser, J. R. and Borecka, B. and Trotter, J. and Sherman, J. C.} } @article {3322, title = {AN ASYMMETRIC CARCEPLEX AND NEW CRYSTAL-STRUCTURE YIELD INFORMATION REGARDING A 1-MILLION-FOLD TEMPLATE EFFECT}, journal = {Journal of Organic Chemistry}, volume = {60}, number = {5}, year = {1995}, note = {ISI Document Delivery No.: QL605Times Cited: 48Cited Reference Count: 50}, month = {Mar}, pages = {1207-1213}, type = {Article}, abstract = {We report the incorporation of methyl {\textquoteright}{\textquoteright}feet{\textquoteright}{\textquoteright} as pendant groups in cavitands and carceplexes and their use in the creation of an asymmetric carceplex and the facilitation of the determination of the crystal structure of a carceplex. From the asymmetric carceplex, we have determined a 19 kcal/mol energy barrier to rotation of the guest pyrazine about the host{\textquoteright}s pseudo-C-2 axes, which demonstrates a high degree of complementarity between the shell of the carceplex and the guest pyrazine. The crystal structure reveals the extensive conjugation of the aryl ethers into the aromatic rings of the host when pyrazine is the guest. This result helps explain why pyrazine is, to date, the best template for the reaction to form the carceplex and thus provides insight to the powerful template effect that is the hallmark of this carceplex reaction. Thus, the investigation of this template effect provides a sensitive probe into noncovalent interactions in general and may be useful in the understanding of recognition in both natural systems such as enzyme/substrate complexes and in non-natural systems such as designed self-assembling structures.}, keywords = {4 PORTALS, CAPTURE, CAVITANDS, CONSTRICTIVE BINDING, DERIVATIVES, HEMICARCERAND, HOST-GUEST COMPLEXATION, RELEASE}, isbn = {0022-3263}, url = {://A1995QL60500025}, author = {Fraser, J. R. and Borecka, B. and Trotter, J. and Sherman, J. C.} } @article {3278, title = {TEMPLATION EFFECTS ON FORMATION OF A HEMICARCEPLEX}, journal = {Supramolecular Chemistry}, volume = {5}, number = {1}, year = {1995}, note = {ISI Document Delivery No.: RX096Times Cited: 15Cited Reference Count: 36}, pages = {31-37}, type = {Article}, abstract = {We have shown previously that the reaction to form carceplex 3 . guest has dramatic templation requirements where the best template molecule studied is one million times more effective at bridging the two bowl-shaped precursors than the poorest template. Here, we investigate the template requirements for the formation of hemicarceplex 4 . guest which is similar to carceplex 3 . guest in cavity size and shape. The two compounds differ in that 4 . guest lacks one of the four inter-bowl methylene bridges and thus has a portal and reduced symmetry relative to carceplex 3 . guest (C-2v vs D-4h). Thus, the template requirements for hemicarceplex 4 . guest are more stringent because the two howls can, in principle, misalign. We have found that despite these differences, the same template effect holds. We conclude that the same forces are at play in each reaction. These forces include 1) favorable van der Waals interactions between the template molecule and the forming cavity of the carceplex or hemicarceplex 2) unfavorable steric strain being imparted to the complex and 3) hydrogen bonds between the bowls. We also demonstrate the utility of matrix-assisted laser desorption ionization (MALDI) as a mild mass spectrometric technique for non-volatile organic compounds and complexes.}, keywords = {4 PORTALS, BINDING, CAPTURE, CARCERANDS, CONSTRICTIVE, HOST-GUEST COMPLEXATION, LASER DESORPTION IONIZATION, MASS-SPECTROMETRY, POLYMERS, RECOGNITION, RELEASE}, isbn = {1061-0278}, url = {://A1995RX09600007}, author = {Chopra, N. and Sherman, J. C.} }