Autocatalytic hydrolysis

A drum of 30% solution in water exploded an hour after filling at 50°C, despite having a vent. Calorimetry demonstrated an exothermic, autocatalytic hydrolysis to ammoniacal potassium bicarbonate. In theory, a pressure exceeding 30 bar is obtainable. Aqueous solutions are unstable even at room temperature. Similar hydrolysis may account for an explosive product with Gold(III) chloride. 

The stomach secretes pepsinogens, which are inactive proteolytic enzymes, and protons - the high concentration of which initiates hydrolysis of the pepsinogens to form active pepsins, which then continue their own activation, via an autocatalytic, hydrolysis (Appendix 4.1). 

Domain I is the N-terminal portion of the protein. The autocatalytic hydrolysis of this domain leads to the activation of the enzyme, and consequent dissociation of the 30K subunit (Yoshizawa et al., 1995). 

Experiments on RVX hydrolysis with an equimolar amount of water were performed as follows. A mixture of 74 pi of RVX and 5.6 pi of water was exposed at room temperature for 3.5 months without stirring. An ash-gray thiek uniform material formed after hydrolysis and completely dissolved in 5 ml acetonitrile. The solution was diluted 100 times with acetonitrile and analyzed by GC-EIMS (sample D). An aliquot of this sample was mixed with an equal volume of bis-trimethylsilyltrifluoroacetamide (BSTFA), and the mixture was heated at 70°C for 30 min and then analyzed by GC-EIMS (sample E). The autocatalytic hydrolysis of RVX was almost complete by the end of the experiment, since the RVX content in the sample was no more than 0.01%. Qualitatively, the reaction mixture in the latter case was much poorer than in the hydrolysis with... 

In this chapter, we presented the principal products of RVX hydrolysis with excess water in an acid medium. It has been shown that after the 3 months exposure, close to 1% of the initial amount of RVX in the solution could be detected. According to data on RVX hydrolysis with an equimolar amount of water, the autocatalytic hydrolysis of RVX was almost completed after 3 months, since the RVX content in the sample was no more than 0.01%. Moreover, the reaction mixture was much poorer than in the case of hydrolysis with excess water. Isobutyl MPA, which catalyzes RVX degradation, was detected as the major component of the reaction mixture. Yang et al (1996) found 2-(diethyl amino)ethanethiol as the second major component of the mixture, but in our experiment it was almost completely converted into bis[2-(diethylamino)ethyl]disulfide. 

Figure 8. (A) Autocatalytic hydrolysis of oleic anhydride in the presence of 1.9 mM Carbobenzoxy-Phe-His-Leu-OH and Ci e-ONp in 0.02 mM borate buffer pH 8.5. Here the progress of the concentration of formed oleate/oleic acid is reported as a function of time. (B) The simultaneous initial velocity of the hydrolysis of Cl 6-0 Np is measured.

Allow for incorporating basic moieties in the PPI which can affect autocatalytic hydrolysis of the entire system, which in turn accelerates the absorption rate... 

Figure 5.3 Schematic description of the progress of autocatalytic hydrolysis of LAjGA polymers...

Tsuji, H. (2002) Autocatalytic hydrolysis of amorphous-made polylactides effects of L-lactide content, tacticity, and enantiomeric polymer blending. Polymer, 43,1789-1796. 

R. CAPOZZA. Yes, maybe it was one of the copolymers. I think you will find that hydrolysis of an es"ber follows autocatalytic hydrolysis. A. SCHINDLER. I comple bely agree with this statement and I believe its validily was amply demonstrated by all our in vitro and in vivo... 

Solution for early stage degradation by autocatalytic hydrolysis... 

In the literature. Equations [2.26] and [2.30] are often used to determine if a polymer degrades by autocatalytic hydrolysis reaction. In a degradation experiment, Af is measured as a function of time. Using the measured data, 1 / M and (1 / M are plotted against time t. If 1/M versus time forms a sttaight Une, then it is concluded that the hydrolysis is non-catalytic and can be calculated from the gradient of the... 

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