Detail of "938-55-6"

Reference

Benzodiazepine receptor ligand actions on GABA responses

Benzodiazepine receptor ligand actions on GABA responses. b-Carbolines, purines. Skerritt, John H.; MacDonald, Robert L. (Dep. Neurol., Univ. Michigan, Ann Arbor, MI 48109, USA). Eur. J. Pharmacol., 101(1-2), 135-41 (English) 1984. CODEN: EJPHAZ. ISSN: 0014-2999. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacology) Section cross-reference(s): 2 The effects of several b-carboline and purine ligands for benzodiazepine receptors were studied upon GABA [56-12-2] responses and upon diazepam [439-14-5] enhancement of GABA responses, using mouse spinal cord neurons in dissocd. cell culture. While the potent convulsant b-carboline methyl 6,7-dimethoxy-4-ethylcarboline-3-carboxylate [82499-00-1] reduced GABA responses, methyl carboline-3-carboxylate (bCCMe) [69954-48-9] and the corresponding ethyl ester (bCCEt) [74214-62-3] did not alter GABA responses. The propyl ester (bCCPr) [76808-18-9] enhanced GABA responses in a concn.-dependent fashion, while both bCCMe and bCCPr blocked diazepam enhancement of GABA responses. bCCPr may thus have partial agonist activity. Two purines with moderate benzodiazepine receptor affinity, 1-methylisoguanosine (MeIG) [70639-65-5] and 6-dimethylaminopurine (DMAP) [938-55-6], weakly enhanced GABA responses. MeIG also significantly antagonized diazepam enhancement of GABA responses. Inosine [58-63-9] and hypoxanthine [68-94-0] had no apparent actions upon GABA responses or upon diazepam enhancement of such responses. The results with b-carbolines are consistent with their behavioral profile in vivo and with neurochem. studies of their effects upon GABA-benzodiazepine receptor complexes. Furthermore, certain purines are also able to interact with these complexes.

Hydrogen bonding of adenine derivatives to tyrosine side chain

Hydrogen bonding of adenine derivatives to tyrosine side chain. Lancelot, G. (Cent. Biophys. Mol., Orleans, Fr.). Biophys. J., 17(3), 243-54 (English) 1977. CODEN: BIOJAU. DOCUMENT TYPE: Journal CA Section: 6 (General Biochemistry) Section cross-reference(s): 7 High-resoln. 1H NMR measurements provided evidence for the formation of H-bonded complexes between 9-ethyladenine and p-cresol used as a model of tyrosine side chain in CDCl3. The sum of the assocn. consts. corresponding to the 3 existing 1:1 complexes was calcd. as K = 6.3. With the use of N-methylated adenine derivs., the ratio of the 2 strongest equil. consts. K7/K1 was calcd. as 1.6. Theor. computations by the CNDO/2 method indicate that several H-bonded planar complexes can form between 9-methyladenine and p-cresol or PhOH. 938-55-6 and 443-72-1 are cas registry numbers of chemicals which are used as reagents here. The computed energy of the complexes with N6-dimethyladenine removes some ambiguity concerning the computed ratio of the assocn. consts. Comparison of the calcd. energies with free energies exptl. detd. in org. solvent shows that, despite the competition with CDCl3, which assocs. with both solute mols., the preferential order of assocn. is conserved. The small variations of charge d. of adenine C atoms when complexed with p-cresol or PhOH are in agreement with very small chem. shifts obsd. by 13C NMR. .