Shiva Hemmati

Biosynthesis of lignans in plant species of the section Linum

Pinoresinol-lariciresinol reductase and justicidin B 7-hydroxylase

• Broschiertes Buch

Produktbeschreibung

A cDNA encoding a pinoresinol lariciresinol reductase PLR (PLR-Lp1) from a cell culture of Linum. perenne was cloned. Hairy root lines were transformed with an ihpRNAi construct to suppress PLR-Lp1 gene expression. As a second enzyme of the proposed pathway, Justicidin B 7-hydroxylase (JusB7H) was characterized from a microsomal fraction prepared from a L. perenne H suspension culture. The enzyme catalyzes the last step in the biosynthesis of Diphyllin by introducing a hydroxyl group in position 7 of Jus B. Enantiomeric purity in lignan biosynthesis is determined during the first steps, but on different levels. Seeds of Linum usitatissimum contain almost 99% (+)- and 1% (-)-Seco-diglucoside. A recombinant PLR (PLR-Lu1) from L. usitatissimum seeds converts only (-)-pinoresinol (Pino) to (+)-Seco. A second cDNA PLR-Lu2 from the leaves of L. usitatissimum was isolated. The recombinant protein converts only (+)-Pino to (-)-Seco. Therefore, the enantiomeric composition of lignans in the organs of L. usitatissimum is determined by the relative action of two PLRs with opposite enantiospecificity rather than a single enzyme with low enantiospecificity.

Produktdetails

• Verlag: LAP Lambert Academic Publishing
• Seitenzahl: 156
• Englisch
• Abmessung: 220mm x 150mm x 8mm
• Gewicht: 224g
• ISBN-13: 9783659228209
• ISBN-10: 3659228206
• Artikelnr.: 36643153

Autorenporträt

Dr. Shiva Hemmati had obtained her PhD in Natural sciences in 2007 from Germany. Since then she has worked in the field of biochemistry in USA. She is now employed as an assistant professor in the school of pharmacy, Shiraz University of Medical Sciences.