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Abstract

AbstractTen major metabolites of rapamycin (M2, M3, M8, M9, M10, M11, M13, M14, M15, and M16) were isolated from pooled bile of intravenously dosed rats. Metabolites were extracted from the bile with ethyl acetate prior to isolation by HPLC using a Supelcosil SPLC-18, μm, 10 × 250 mm column. The mobile phase was a methanol/ammonium acetate linear gradient system. The isolated metabolites were characterized by negative ion FAB MS, ion-spray MS and ion-spray MS/MS analyses.Metabolite M2 is oxygenated in the southern portion of rapamycin and the macrolide ring is opened. M3 is a structural isomer of rapamycin where the lactone ring is opened. M10 is oxygenated in the southern portion of rapamycin and the macrolide ring is intact. M13 is a monohydroxylation and demethylation metabolite and both biotransformations occurred at the southern portion. M8, M9, and M11 are monohydroxylation and demethylation metabolites. M14 and M15 are di-hydroxylation metabolites. M16 is mainly a dihydroxylation metabolite.†This work was presented at the Fourth International ISSX Meeting, Seattle, WA, August 1995.

I. Flores has written a number of books on computers encompassing a broad spectrum of topics from logical design and system architecture to software and programming. This book on data structure and management examines the subject of data management in computer systems and gives a comprehensive treatment of the many facets of data; their encoding schemes, their representations in computer storage, the access and maintenance techniques for data structures and the related system-control operations to carry out data access and maintenance. The book starts from the fundamentals of data and data structures and places special emphasis on the reality of business data processing. The basic notions are then developed into thorough treatment of data management functions in both hardware and software, primarily in the context of IBM/ 360 type of systems. Despite the complexity of the subject matter, the material in the book is organized in a reasonably simplified manner to facilitate comprehension. The book can be used by students who major in computer systems and is also a good reference for practitioners in the data processing profession. For those readers who are information specialists but not involved in programming or managing computer systems, the book is a valuable text to gain understanding of the problems of data management.