A thermodynamic study of the hydrolysis of L-glutamine to (L-glutamate + ammonia) and of L-asparagine to (L -aspartate + ammonia)

Heat-capacity measurements and thermodynamic functions of crystalline adenine; revised thermodynamic properties of aqueous adenine

“…73-24-5, C 5 H 5 N 5 , molar mass M ¼ 0:1351267 kg Á mol À1 ) was obtained from Fisher Scientific. Water analysis of the sample was done by a Karl-Fisher titration procedure previously described [3]. The mass fraction of water in the sample was found to be (0:00178 AE 0:00007).…”

Thermochemistry of adenosine

“…58-61-7, C 10 H 13 N 5 O 4 , molar mass M = 0.267242 kg · mol −1 ) was obtained from Sigma Chemical Co. † Karl-Fischer analysis of the sample of adenosine was done by using a previously described procedure. (3) The mass fraction of water w in the sample was found to be (0.00040 ± 0.00005). The uncertainty given here and elsewhere in this paper unless indicated otherwise is equal to two estimated standard †Certain commercial equipment, instruments, or materials are identified in this paper to specify the experimental procedures adequately.…”

“…The following gradient of these two mobile phases was formed: volume fraction φ(I) = 0.95 and φ(II) = 0.05 at time t = 0; φ(I) = 0.90 and φ(II) = 0.10 at t = 10 min; φ(I) = 0.80 and φII) = 0.20 at t = 20 min. The flow rate was 0.01 cm 3 · s −1 . Using this method, the retention time of adenosine was 6.8 min.…”

“…The gradient was: φ(I) = 0.85 and φ(II) = 0.15 at t = 0; φ(I) = 0.50 and φ(II) = 0.50 at t = 15 min; φ(I) = 0.50 and φ(II) = 0.50 at t = 40 min. The flow rate was 0.0133 cm 3 · s −1 . Using this second method, the retention times of adenosine and of adenine were, respectively, 24.3 min and 20.4 min.…”

“…(13) A sample of adenosine having a mass m = 4.7794 g was loaded into the calorimeter (internal volume V = 10.48 cm 3 ) and then sealed with helium gas ( p = 3.73 kPa) at T = 296 K.…”