Document Detail


Hydrolysis and acyl migration of a catechol monoester of L-dopa: L-3-(3-hydroxy-4-pivaloyloxyphenyl)alanine.
MedLine Citation:
PMID:  2231333     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Hydrolysis and acyl migration studies on L-3-(3-hydroxy-4-pivaloyloxyphenyl)alanine (1, NB-355), which produced long-lasting plasma L-dopa levels after oral dosing, have been conducted. Compound 1 exists as pure 4-O-pivaloyl-L-dopa in the solid state, but it converts rapidly to a mixture of the 3- and 4-O-isomers in solution. The rate of acyl migration increased with increases in pH and temperature, and the content of the 4-O-isomer in the equilibrium state was 53-59%. The hydrolysis rate of 1 to L-dopa (6) also increased with increases in pH and temperature, and accelerated steeply at neutral and alkaline pH. The rapid hydrolysis at neutral pH was not observed with O-pivaloyl-L-tyrosine (3), di-O-pivaloyl-L-dopa (4), or L-dopa methyl ester (5). Because of this chemical lability, 1 was hydrolyzed in rat plasma far faster than the other tested catechol esters. However, in rat intestinal homogenate at pH 6.0, 1 was hydrolyzed at the slowest rate among the tested esters, predominantly by a diisofluorophosphate (DFP)-sensitive esterase. Thus, 1 showed a unique in vitro profile on hydrolysis and acyl migration due to the existence of a neighboring hydroxyl group. The stability of 1 in the intestine might be essential for the long-lasting plasma L-dopa profile after oral dosing of 1.
Authors:
M Ihara; S Nakajima; A Hisaka; Y Tsuchiya; Y Sakuma; H Suzuki; K Kitani; M Yano
Related Documents :
6955803 - Central cardiovascular and thermal effects of prostaglandin d2 in rats.
10898753 - Mechanism of the alcohol cyclic pattern: role of the hypothalamic-pituitary-thyroid axis.
9780083 - A novel model of primary and secondary hyperalgesia after mild thermal injury in the rat.
Publication Detail:
Type:  In Vitro; Journal Article    
Journal Detail:
Title:  Journal of pharmaceutical sciences     Volume:  79     ISSN:  0022-3549     ISO Abbreviation:  J Pharm Sci     Publication Date:  1990 Aug 
Date Detail:
Created Date:  1990-12-06     Completed Date:  1990-12-06     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  2985195R     Medline TA:  J Pharm Sci     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  703-8     Citation Subset:  IM    
Affiliation:
Central Research Laboratories, Banyu Pharmaceutical Company, Ltd., Tokyo, Japan.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Acylation
Animals
Buffers
Chemical Phenomena
Chemistry
Hydrogen-Ion Concentration
Hydrolysis
Intestines / metabolism
Kinetics
Levodopa / analogs & derivatives*,  blood,  metabolism*
Magnetic Resonance Spectroscopy
Male
Pancreas / metabolism
Rats
Rats, Inbred Strains
Solutions
Temperature
Chemical
Reg. No./Substance:
0/Buffers; 0/Levodopa; 0/Solutions; 122551-95-5/L-3-(3-hydroxy-4-pivaloyloxyphenyl)alanine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Mechanism of nasal absorption of drugs. III: Nasal absorption of leucine enkephalin.
Next Document:  A study of the electrokinetic and stability properties of nitrofurantoin suspensions. II: Flocculati...