35734-61-3Relevant articles and documents
Selective oxygenation of ionones and damascones by fungal peroxygenases
Aranda, Carmen,Babot, Esteban D.,Del R?o, José C.,Gutiérrez, Ana,Hofrichter, Martin,Kiebist, Jan,Mart?nez, Angel T.,Scheibner, Katrin,Ullrich, René
, p. 5375 - 5383 (2020/06/08)
Apocarotenoids are among the most highly valued fragrance constituents, being also appreciated as synthetic building blocks. This work shows the ability of unspecific peroxygenases (UPOs, EC1.11.2.1) from several fungi, some of them being described recently, to catalyze the oxyfunctionalization of α- and β-ionones and α- and β-damascones. Enzymatic reactions yielded oxygenated products such as hydroxy, oxo, carboxy, and epoxy derivatives that are interesting compounds for the flavor and fragrance and pharmaceutical industries. Although variable regioselectivity was observed depending on the substrate and enzyme, oxygenation was preferentially produced at the allylic position in the ring, being especially evident in the reaction with α-ionone, forming 3-hydroxy-α-ionone and/or 3-oxo-α-ionone. Noteworthy were the reactions with damascones, in the course of which some UPOs oxygenated the terminal position of the side chain, forming oxygenated derivatives (i.e., the corresponding alcohol, aldehyde, and carboxylic acid) at C-10, which were predominant in the Agrocybe aegerita UPO reactions, and first reported here.
Structural analysis of CYP101C1 from Novosphingobium aromaticivorans DSM12444
Ma, Ming,Bell, Stephen G.,Yang, Wen,Hao, Yiming,Rees, Nicholas H.,Bartlam, Mark,Zhou, Weihong,Wong, Luet-Lok,Rao, Zihe
experimental part, p. 88 - 99 (2011/12/15)
CYP101C1 from Novosphingobium aromaticivorans DSM12444 is a homologue of CYP101D1 and CYP101D2 enzymes from the same bacterium and CYP101A1 from Pseudomonas putida. CYP101C1 does not bind camphor but is capable of binding and hydroxylating ionone derivatives including α- and β-ionone and β-damascone. The activity of CYP101C1 was highest with β-damascone (kcat=86 s-1) but α-ionone oxidation was the most regioselective (98% at C3). The crystal structures of hexane-2,5-diol- and β-ionone-bound CYP101C1 have been solved; both have open conformations and the hexanediol-bound form has a clear access channel from the heme to the bulk solvent. The entrance of this channel is blocked when β-ionone binds to the enzyme. The heme moiety of CYP101C1 is in a significantly different environment compared to the other structurally characterised CYP101 enzymes. The likely ferredoxin binding site on the proximal face of CYP101C1 has a different topology but a similar overall positive charge compared to CYP101D1 and CYP101D2, all of which accept electrons from the ArR/Arx class I electron transfer system.Crystal clear: CYP101C1 oxidises ionone derivatives fast (kcat≤86 s-1) and with high regioselectivity (≤98%). Its crystal structure (shown) provides structural insights into how this enzyme differs from those that bind camphor from the same CYP family, and further information on how open conformations of CYP enzymes are involved in substrate entry and binding.
C13-norisoprenoid glucoconjugates from lulo (Solanum quitoense L.) leaves
Osorio, Coralia,Duque, Carmenza,Fujimoto, Yoshinori
, p. 1641 - 1645 (2007/10/03)
With the aid of multilayer coil countercurrent chromatography, subsequent acetylation, and liquid chromatographic purification of a glycosidic mixture obtained from lulo (Solanum quitoense L.) leaves, three C13-norisoprenoid glucoconjugates were isolated in pure form. Their structures were elucidated by NMR, MS, and CD analyses to be the novel (6R,9R)-13-hydroxy-3-oxo-α-ionol 9-O-β-D-glucopyranoside (4a), the uncommon (3S,5R,8R)-3,5-dihydroxy-6,7-megastigmadien-9-one 5-O-β-D-glucopyranoside (citroside A) (5a), and the known (6S,9R)-vomifoliol 9-O-β-D-glucopyranoside (6a). Enzymatic treatment of compound 5a showed the formation of 3-hydroxy- 7,8-didehydro-β-ionone (7), an important lulo peeling volatile, which in its turn after chemical reduction and heated acid catalyzed rearrangement generates β-damascenone (9) and 3-hydroxy-β-damascone (10).
