- MECHANISTIC STUDIES OF THE UROCANASE REACTION USING (1)H- AND (31)P-NMR SPECTROSCOPY AND THE SUBSTRATE ANALOGUE 2-METHYLUROCANATE
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The reaction of 2-methylurocanate with urocanase from Pseudomonas putida was monitored by (1)H-NMR spectroscopy at 500 MHz.The following conclusions were drawn: (i) 2-methylurocanate reacts 128 times more slowly with urocanase than does urocanate, (ii) no signals for the enol form of the produced 2-methylimidazolone propionate were detected, (iii) 2-methylimidazolone propionate is about 25 times more stable to hydrolysis than imidazolone propionate, (iv) the urocanase-catalysed exchange of the 5-proton of 2-methylurocanate with the solvent deuterium is 1.3 times faster than the overall reaction and (v) the non-enzymic exchange of the Me protons of 2-methylimidazolone propionate with solvent D takes place with a half life of 5.8 hr. By (1)H-NMR spectroscopy it was shown that the urocanase reaction is reversible.At 8o and pD 6.3 1.6percent of the total imidazolone propionate was converted into urocanate. Apart from the pyrophosphate ester group of NAD(1+) no phosphorylated groups could be detected in urocanase by (31)P-NMR spectroscopy.
- Gerlinger, Erich,Hull, William E.,Retey, Janos
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- The 2-position of imidazolium ionic liquids: Substitution and exchange
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(Chemical Equation Presented) The 2-position of imidazolium cations is known to be relatively acidic, leading to the useful Arduengo-type carbenes. At the same time, the acidity of this site can lead to undesired side reactions when using imidazolium-based ionic liquids as solvents. In this note, we describe the surprisingly facile deuterium exchange at this position and also the synthesis and exchange under modestly basic conditions (triethylamine) of a series of 2-methyl-substituted compounds.
- Handy, Scott T.,Okello, Maurice
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- 5-Substituted imidazole-4-acetic acid analogues: Synthesis, modeling, and pharmacological characterization of a series of novel γ-aminobutyric acidC receptor agonists
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A series of ring-substituted analogues of imidazole-4-acetic acid (IAA, 4), a partial agonist at both GABAA and GABAC receptors (GABA = γ-aminobutyric acid), have been synthesized. The synthesized compounds 8a-1 have been evaluated a
- Madsen, Christian,Jensen, Anders A.,Liljefors, Tommy,Kristiansen, Uffe,Nielsen, Birgitte,Hansen, Camilla P.,Larsen, Mogens,Ebert, Bjarke,Bang-Andersen, Benny,Krogsgaard-Larsen, Povl,Fr?lund, Bente
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p. 4147 - 4161
(2008/02/13)
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- Inhibitors of protein isoprenyl transferases
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Compounds having the formula or a pharmaceutically acceptable salt thereof wherein R1 is (a) hydrogen, (b) loweralkyl, (c) alkenyl, (d) alkoxy, (e) thioalkoxy, (f) halo, (g) haloalkyl, (h) aryl-L2—, and (i) heterocyclic-L2—; R2 is selected from (a) (b) —C(O)NH—CH(R14)—C(O)OR15, (c) (d) —C(O)NH—CH(R14)—C(O)NHSO2R16 (e) —C(O)NH—CH(R14)-tetrazolyl, (f) —C(O)NH-heterocyclic, and (g) —C(O)NH—CH(R14)—C(O)NR17R18; R3 is heterocyclic, aryl, substituted or unsubstituted cycloalkyl; R4 is hydrogen, lower alkyl, haloalkyl, halogen, aryl, arylakyl, heterocyclic, or (heterocyclic)alkyl; L1 is absent or is selected from (a) —L4—N(R5)—L5—, (b) —L4—O—L5—, (c) —L4—S(O)n—L5— (d) —L4-L6—C(W)—N(R5)—L5—, (e) —L4-L6—S(O)m—N(R5)—L5—, (f) —L4—N(R5)—C(W)—L7-L5—, (g) —L4—N(R5)—S(O)p—L7—L5—, (h) optionally substituted alkylene, (i) optionally substituted alkenylene, and (j) optionally substituted alkynylene are inhibitors of protein isoprenyl transferases. Also disclosed are protein isoprenyl transferase inhibiting compositions and a method of inhibiting protein isoprenyl transferases.
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- Highly potent geminal bisphosphonates. From pamidronate disodium (Aredia) to zoledronic acid (Zometa)
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Bisphosphonates (BPs) are pyrophosphate analogues in which the oxygen in P-O-P has been replaced by a carbon, resulting in a metabolically stable P-C-P structure. Pamidronate (1b, Novartis), a second-generation BP, was the starting point for extensive SAR studies. Small changes of the structure of pamidronate lead to marked improvements of the inhibition of osteoclastic resorption potency. Alendronate (1c, MSD), with an extra methylene group in the N-alkyl chain, and olpadronate (1h, Gador), the N,N-dimethyl analogue, are about 10 times more potent than pamidronate. Extending one of the N-methyl groups of olpadronate to a pentyl substituent leads to ibandronate (1k, Roche, Boehringer-Mannheim), which is the most potent close analogue of pamidronate. Even slightly better antiresorptive potency is achieved with derivatives having a phenyl group linked via a short aliphatic tether of three to four atoms to nitrogen, the second substituent being preferentially a methyl group (e.g., 4g, 4j, 5d, or 5r). The most potent BPs are found in the series containing a heteroaromatic moiety (with at least one nitrogen atom), which is linked via a single methylene group to the geminal bisphosphonate unit. Zoledronic acid (6i), the most potent derivative, has an ED50 of 0.07 mg/kg in the TPTX in vivo assay after sc administration. It not only shows by far the highest therapeutic ratio when comparing resorption inhibition with undesired inhibition of bone mineralization but also exhibits superior renal tolerability. Zoledronic acid (6i) has thus been selected for clinical development under the registered trade name Zometa. The results of the clinical trials indicate that low doses are both efficacious and safe for the treatment of tumor-induced hypercalcemia, Paget's disease of bone, osteolytic metastases, and postmenopausal osteoporosis.
- Widler, Leo,Jaeggi, Knut A.,Glatt, Markus,Müller, Klaus,Bachmann, Rolf,Bisping, Michael,Born, Anne-Ruth,Cortesi, Reto,Guiglia, Gabriela,Jeker, Heidi,Klein, Rémy,Ramseier, Ueli,Schmid, Johann,Schreiber, Gerard,Seltenmeyer, Yves,Green, Jonathan R.
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p. 3721 - 3738
(2007/10/03)
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- BENZOFURAN DERIVATIVES
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The invention provides compounds of the general formula (I) STR1 and physiologically acceptable salts, solvates or non-toxic metabolically labile esters thereof where R 1 represents a halogen atom; Ar represents the group STR2 R 3 represents a C-linked tetrazolyl group; R 4 and R 5, which may be the same or different, each independently represent a hydrogen atom or a halogen atom or a C. sub.1-6 alkyl group; andHet represents an N-linked imidazolyl group optionally substituted at the 2-position.The compounds may be used in the treatment or prophylaxis of hypertension and diseases associated with cognitive disorders.
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- Imidazo[1,5-d]-as-triazine-4(3H)-ones and thiones
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There is provided substituted imidazo[1,5-d]-as-triazine-4(3H)-ones and substituted imidazo[1,5-d]-as-triazin-4(3H)-thiones useful as inhibitors of the enzyme cyclic-AMP phosphodiesterase and as broad spectrum herbicides.
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- Method for the control of undesired plant species using imidazo-as-triazinones and triazine-thiones
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This disclosure describes herbicidal methods for the pre- and postemergence control of undesired mono- and dicotyledonous plants using substituted imidazo[1,5-d]-as-triazin-4(3H)-ones and substituted imidazo[1,5-d]-as-triazine-4(3H)-thiones.
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- Imidazo[1,5-d]-as-triazines
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There are provided novel substituted imidazo-[1,5-d]-as-triazines useful as hypotensive agents as well as exhibiting herbicidal activity.
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- SUBSTITUTED 3-(4-IMIDAZOLYLMETHYLENE)CARBAZIC AND THIOCARBAZIC ACID ESTERS
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There are provided substituted 3-(4-imidazolyl-methylene)carbazic acid esters and 3-(4-imidazolylmethylene)dithiocarbazic acid esters useful as intermediates for the preparation of compounds which inhibit the enzyme cyclic-AMP phosphodiesterase
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- IMIDAZO [1,5-d]-AS-TRIAZINE-4(3H)-ONES AND THIONES
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There is provided substituted imidazo[1,5-d]-as-triazine-4(3H)-ones and substituted imidazo[1,5-d]-as-triazin-4(3H)-thiones useful as inhibitors of the enzyme cyclic-AMP phosphodiesterase and as broad spectrum herbicides
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