Biosynthesis of antioxidant lignans in Sesamum indicum seeds

• Published in: Phytochemistry (Oxford) Vol. 47; no. 4; pp. 583 - 591
• Main Authors: Kato, Massuo J., Chu, Alex, Davin, Laurence B., Lewis, Norman G.
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.02.1998; Elsevier
• Subjects: antioxidants; biochemical pathways; Biochemistry & Molecular Biology; Biological and medical sciences; biosynthesis; chemical constituents of plants; Fundamental and applied biological sciences. Psychology; General pharmacology; isotope labeling; Life Sciences & Biomedicine; lignans; Medical sciences; Metabolism; Metabolism. Physicochemical requirements; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Plant physiology and development; Plant Sciences; Science & Technology; secondary metabolites; seeds; Sesamum indicum; sesamolin; pinoresinol; antioxidants; seeds; biosynthesis; Sesamum indicum; Pedaliaceae; sesamin; piperitol; lignans; RATS; SYNTHASE; (+)-PINORESINOL; VITAMIN-E ACTIVITY; FORSYTHIA-INTERMEDIA; OIL; ALCOHOL; METHYLENEDIOXY BRIDGE; Molecular structure; Pharmacognosy; Biosynthesis; Metabolic pathway; Antioxidant; Oil plant(vegetal); Medicinal plant; Polyphenol; Dicotyledones; Seed; Angiospermae; Plant origin; Lignan; Spermatophyta
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/S0031-9422(97)00727-9

The biosynthesis of the sesame lignans, (+)-sesamin and (+)-sesamolin, was found to result from stereoselective coupling of E-coniferyl alcohol to give (+)-pinoresinol which was then subsequently metabolized Sesame lignans, whose biosynthetic pathway is the subject of this study, have well-established antioxidant and health protecting properties. Using a combination of radio- and stable-isotopically labelled precursor administration experiments, it was demonstrated that E-coniferyl alcohol undergoes stereoselective coupling to afford (+)-pinoresinol in Sesamum indicum seeds. Only this enantiomer, and not its (−)-antipode, is metabolized further in maturing seeds to afford (+)-piperitol, (+)-sesamin, and (+)-sesamolin. Introduction of the methylene dioxy bridges occurs sequentially with piperitol first being formed, this being subsequently modified to afford sesamin.