procyanidin B2
{{chembox
| verifiedrevid = 423484890
| Name = Procyanidin B2
| Reference =
| ImageFile = Structure_of_Procyanidin_B2.png
| ImageName = Chemical structure of procyanidin B2
| ImageSize = 200px
| IUPACName = [(2R,3R,4R)-Flavan-3,3′,4′,5,7-pentol]-(4→8)-[(2R,3R)-flavan-3,3′,4′,5,7-pentol]
| SystematicName = (2R,2′R,3R,3′R,4R)-2,2′-Bis(3,4-dihydroxyphenyl)-3,3′,4,4′-tetrahydro-2H,2′H-[4,8′-bi-1-benzopyran]-3,3′,5,5′,7,7′-hexol
| OtherNames = Procyanidin-B2
(−)-Epicatechin-(4β→8)-(−)-epicatechin
|Section1={{Chembox Identifiers
| CASNo = 29106-49-8
| CASNoOther =
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = L88HKE854X
| PubChem = 122738
| ChEBI = 75632
| SMILES = O[C@@H]1Cc2c(O)cc(O)c([C@@H]3[C@@H](O)[C@H](Oc4cc(O)cc(O)c34)c3ccc(O)c(O)c3)c2O[C@@H]1c1ccc(O)c(O)c1
| ChemSpiderID = 109417
| StdInChI = 1S/C30H26O12/c31-13-7-20(37)24-23(8-13)41-29(12-2-4-16(33)19(36)6-12)27(40)26(24)25-21(38)10-17(34)14-9-22(39)28(42-30(14)25)11-1-3-15(32)18(35)5-11/h1-8,10,22,26-29,31-40H,9H2/t22-,26-,27-,28-,29-/m1/s1
| StdInChIKey = XFZJEEAOWLFHDH-NFJBMHMQSA-N
}}
|Section2={{Chembox Properties
| Formula = C30H26O12
| MolarMass = 578.52 g/mol
| Appearance=
| Density=
| MeltingPtC=
| BoilingPt=
| Solubility=
}}
|Section3={{Chembox Hazards
| MainHazards=
| FlashPt=
| AutoignitionPt =
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}}
Procyanidin B2 is a B type proanthocyanidin. Its structure is (−)-Epicatechin-(4β→8)-(−)-epicatechin.
Procyanidin B2 can be found in Cinchona pubescens (Chinchona: in the rind, bark, and cortex), in Cinnamomum verum (Ceylon cinnamon: in the rind, bark, and cortex), in Crataegus monogyna (Common hawthorn: in the flower and blossom), in Uncaria guianensis (Cat's claw: in the root), in Vitis vinifera (Common grape vine: in the leaf),[http://www.liberherbarum.com/Minor/UK/IN2972.htm Proanthocyanidin-B2 on liberherbarum.com] in Litchi chinensis (litchi: in the pericarp),[http://cat.inist.fr/?aModele=afficheN&cpsidt=18403041 Immunomodulatory and anticancer activities of flavonoids extracted from litchi (Litchi chinensis Sonn.) pericarp. Mouming Zhao; Bao Yang; Jinshui Wang; Yang Liu; Limei Yu; Yueming Jiang, 2007] in the apple,[http://www.fuzing.com/vli/0020916c1226/Apple-Polyphenols.70HPLC.-Apple-Proanthocyanidins-Apple-Proanthocyanidin-B2-.-M.-F.-Molecular-FormulaC30H26O12. Proanthocyanidin-B2 on fuzing.com] and in Ecdysanthera utilis.{{cite journal|doi=10.1021/np010414l | volume=65 | issue=4 | title=Immunomodulatory Proanthocyanidins from Ecdysanthera u tilis | year=2002 | journal=Journal of Natural Products | pages=505–508 | vauthors=Lin LC | pmid=11975489}}
Procyanidin B2 can be converted into procyanidin A2 by radical oxidation using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals under neutral conditions.{{cite journal | doi = 10.1016/S0040-4039(99)02097-3 | volume=41 | title=Conversion of procyanidin B-type (catechin dimer) to A-type: evidence for abstraction of C-2 hydrogen in catechin during radical oxidation | year=2000 | journal=Tetrahedron Letters | pages=485–488 | vauthors=Kondo K| issue=4 }}
Procyanidin B2 has been shown to inhibit the formation of the advanced glycation end-products pentosidine, carboxymethyllysine (CML), and methylglyoxal (MGO).{{cite journal |vauthors=Peng X, Ma J, Chao J, Sun Z, Chang RC, Tse I, Li ET, Chen F, Wang M | title=Beneficial effects of cinnamon proanthocyanidins on the formation of specific advanced glycation endproducts and methylglyoxal-induced impairment on glucose consumption| journal= Journal of Agricultural and Food Chemistry | volume=58 | issue=11 | year=2010 | pages=6692–6696 | pmid=20476737 | doi=10.1021/jf100538t}}