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Leucocyanidin

Leucocyanidin
Names
IUPAC name
(2R,3S,4S)-Flavan-3,3′,4,4′,5,7-hexol
Systematic IUPAC name
(2R,3S,4S)-2-(3,4-Dihydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-3,4,5,7-tetrol
Other names
Leucocianidol
Leucocianidolum
Leucocyanidol
Leukocyanidine
Procyanidol
Resivit
Leucoanthocyanidol
Vitamin P faktor
3,4-Cyanidiol
(2R,3S,4S)-3,4,5,7,4-pentahydroxyflavan
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
UNII
  • InChI=1S/C15H14O7/c16-7-4-10(19)12-11(5-7)22-15(14(21)13(12)20)6-1-2-8(17)9(18)3-6/h1-5,13-21H/t13-,14-,15+/m0/s1 checkY
    Key: SBZWTSHAFILOTE-SOUVJXGZSA-N checkY
  • C1=CC(=C(C=C1[C@@H]2[C@H]([C@H](C3=C(C=C(C=C3O2)O)O)O)O)O)O
Properties
C15H14O7
Molar mass 306.26 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Leucocyanidin is a colorless chemical compound that is a member of the class of natural products known as leucoanthocyanidins.

Chemistry

(+)-Leucocyanidin can be synthesized from (+)-dihydroquercetin by reduction with sodium borohydride.[1]

Molar equivalents of synthetic (2R,3S,4R or S)-leucocyanidin and (+)-catechin condense with exceptional rapidity at pH 5 under ambient conditions to give the all-trans-[4,8]- and [4,6]-bi-[(+)-catechins] (procyanidins B3, B6) the all-trans-[4,8:4,8]- and [4,8:4,6]-tri-[(+)-catechins] (procyanidin C2 and isomer).[2]

Metabolism

Leucocyanidin oxygenase uses leucocyanidin, 2-oxoglutarate, and O2 to produce cis-dihydroquercetin, trans-dihydroquercetin (taxifolin), succinate, CO2, and H2O.

Leucoanthocyanidin reductase (LAR or leucocyanidin reductase LCR) uses (2R,3S)-catechin, NADP+, and H2O to produce 2,3-trans-3,4-cis-leucocyanidin, NADPH, and H+. Its gene expression has been studied in developing grape berries and grapevine leaves.[3] Its activity has also been measured in leaves, flowers, and seeds of the legumes Medicago sativa, Lotus japonicus, Lotus uliginosus, Hedysarum sulfurescens, and Robinia pseudoacacia.[4]

The C-4 stereochemistry of leucocyanidin substrates affects anthocyanidin synthase (ANS) products. This enzyme is an iron(II) and 2-oxoglutarate (2OG) dependent oxygenase.[5]

Occurrence

Leucoyanidin can be found in these plants:[6]

References

  1. ^ Heller, Werner; Britsch, Lothar; Forkmann, Gert; Grisebach, Hans (1985-02-01). "Leucoanthocyanidins as intermediates in anthocyanidin biosynthesis in flowers of Matthiola incana R. Br". Planta. 163 (2): 191–196. doi:10.1007/BF00393505. ISSN 0032-0935. PMID 24249337.
  2. ^ Synthesis of condensed tannins. Part 9. The condensation sequence of leucocyanidin with (+)-catechin and with the resultant procyanidins. Jan. A. Delcour, Daneel Ferreira and David G. Roux, J. Chem. Soc., Perkin Trans. 1, 1983, pages 1711-1717, doi:10.1039/P19830001711
  3. ^ Bogs, Jochen; Downey, Mark O.; Harvey, John S.; Ashton, Anthony R.; Tanner, Gregory J.; Robinson, Simon P. (2005-10-01). "Proanthocyanidin Synthesis and Expression of Genes Encoding Leucoanthocyanidin Reductase and Anthocyanidin Reductase in Developing Grape Berries and Grapevine Leaves". Plant Physiology. 139 (2): 652–663. doi:10.1104/pp.105.064238. ISSN 0032-0889. PMC 1255985. PMID 16169968.
  4. ^ Skadhauge, B.; Gruber, M. Y.; Thomsen, K. K.; Wettstein, D. V. (1997-04-01). "Leucocyanidin reductase activity and accumulation of proanthocyanidins in developing legume tissues". American Journal of Botany. 84 (4): 494. doi:10.2307/2446026. ISSN 0002-9122. JSTOR 2446026. (subscription required)
  5. ^ The C-4 stereochemistry of leucocyanidin substrates for anthocyanidin synthase affects product selectivity TURNBULL Jonathan J.; NAGLE Michael J.; SEIBEL Jürgen F.; WELFORD Richard W. D.; GRANT Guy H.; SCHOFIELD Christopher J. 2003
  6. ^ "Liber Herbarum II: DK: Leucocyanidin/ UK: Leucocyanidin/ D: Leucocyanidin". www.liberherbarum.com. Retrieved 2017-12-03.
Quelle: https://en.wikipedia.org/wiki/Leucocyanidin