caa a22 4500 445869984 CHVBK 20180317145508.0 cr unu---uuuuu 170323e20111201xx s 000 0 eng 10.1007/s11101-010-9169-x doi (NATIONALLICENCE)springer-10.1007/s11101-010-9169-x Biosynthesis of saponins in the genus Medicago [Elektronische Daten] [Aldo Tava, Carla Scotti, Pinarosa Avato] Abstracts: Saponins from Medicago species are glycosidic compounds with an aglycone moiety formed through the enzymatic cyclization of 2,3-oxidosqualene by the β-amyrin cyclase. All the saponins from Medicago genus possess the triterpenic pentacyclic nucleus belonging to the class of β-amyrin. The so formed β-amyrin skeleton can be further modified by oxidative reactions, mediated by cytochromes belonging to the class of cytochrome P450, to give different saponin compounds, characterized by the presence of hydroxyl or carboxyl groups located in specific positions of the triterpenic skeleton. Based on the position and the oxidation degree of the substituents, it is possible to distinguish two groups of saponins (sapogenins) in Medicago spp: (1) sapogenins possessing an OH group on C-24 (soyasapogenols A, B and E) without any substituent at the C-28 atom, and (2) sapogenins possessing the COOH group at C-28 that are associated with different oxidation degrees (zero, OH, CHO, COOH) at C-23. These results seem to indicate that the oxidation at C-24 and the presence of the COOH group at C-28 are mutually exclusive. The subdivision in the aglycone moiety is reflected also in the sugar moiety, operated by glycosyltranferases, as the saponins of the two groups differ for the position and the nature of the sugar chains. Based on these findings, new considerations on the biosynthesis of saponins in the genus Medicago can be drawn and a biosynthetic scheme is proposed. Springer Science+Business Media B.V., 2010 Triterpenes nationallicence Sapogenins nationallicence Biosynthesis nationallicence Cytochrome P450 nationallicence Medicagenic acid nationallicence Tava Aldo CRA-FLC Centro di Ricerca per le Produzioni Foraggere e Lattiero Casearie, v.le Piacenza 29, 26900, Lodi, Italy aut Scotti Carla CRA-FLC Centro di Ricerca per le Produzioni Foraggere e Lattiero Casearie, v.le Piacenza 29, 26900, Lodi, Italy aut Avato Pinarosa Dipartimento Farmaco-Chimico, Università di Bari Aldo Moro, via Orabona 4, 70125, Bari, Italy aut Phytochemistry Reviews Springer Netherlands 10/4(2011-12-01), 459-469 1568-7767 10:4<459 2011 10 11101 https://doi.org/10.1007/s11101-010-9169-x text/html Onlinezugriff via DOI 1 review-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11101-010-9169-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tava Aldo CRA-FLC Centro di Ricerca per le Produzioni Foraggere e Lattiero Casearie, v.le Piacenza 29, 26900, Lodi, Italy aut NATIONALLICENCE 700 1- Scotti Carla CRA-FLC Centro di Ricerca per le Produzioni Foraggere e Lattiero Casearie, v.le Piacenza 29, 26900, Lodi, Italy aut NATIONALLICENCE 700 1- Avato Pinarosa Dipartimento Farmaco-Chimico, Università di Bari Aldo Moro, via Orabona 4, 70125, Bari, Italy aut NATIONALLICENCE 773 0- Phytochemistry Reviews Springer Netherlands 10/4(2011-12-01), 459-469 1568-7767 10:4<459 2011 10 11101 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer