Isolation of Vitamin D3 Metabolites from Solanum malacoxylon Leaf Extracts Incubated with Ruminal Fluid

R. L. Boland; M. I. Skliar; A. W. Norman

doi:10.1055/s-2006-962662

Planta Medica, Table of Contents

Planta Med 1987; 53(2): 161-164
DOI: 10.1055/s-2006-962662

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Isolation of Vitamin D₃ Metabolites from Solanum malacoxylon Leaf Extracts Incubated with Ruminal Fluid

R. L. Boland¹ , M. I. Skliar¹ , A. W. Norman²

¹Departamento de Biologia, Universidad Nacional del Sur, 8000 Bahia Blanca, Argentina.
²Department of Biochemistry, University of California, Riverside, California 92521, U.S.A.

Abstract

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Abstract

Two fractions which elute similarly as 1,25(OH)₂D₃ and 1,24,25(OH)₃D₃ were isolated by TLC, Sephadex LH-20 chromatog-raphy and HPLC from Solanum malacoxylon leaf extracts preincubated in vitro with ruminal fluid. Both fractions effectively competed with [³ H]-1,25(OH)₂D₃ for binding to the chick intestinal 1,25(OH)₂D₃ receptor. Only significant amounts of the fraction which coelutes with 1,25(OH)₂D₃ were detected in leaf extracts incubated with purified β-glucosidase. Incubation of [³ H]-1,25(OH)₂D₃ with ruminai fluid resulted in the formation of a metabolite with similar mobility as 1,24,25(OH)₃D₃ in TLC plates. The results suggest that 1,25(OH)₂D₃-glycoside present in S. malacoxylon is converted to 1,25 (OH)₂D₃ and a more polar metabolite, possibly 1,24,25(OH)₃D₃, by the action of rumen microbes.

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