29106-49-8

Basic information

• Product Name: PROCYANIDIN B2
• Synonyms: PROCYANIDIN B2;4,8'-BI-[(+)-EPICATECHIN];EPICATECHIN(4BETA->8)EPICATECHIN;EPICATECHIN(4B-8)EPICATECHIN;CIS,CIS'-4,8'-BI(3,3',4',5,7-PENTAHYDROXYFLAVANE);4,8-Bi-2H-1-benzopyran-3,3,5,5,7,7-hexol, 2,2-bis(3,4-dihydroxyphenyl)-3,3,4,4-tetrahydro-, (2R,2R,3R,3R,4R)-;PROCYANIDIN B2(RG);PROCYANIDINDIMERB2
• CAS NO: 29106-49-8
• Molecular Formula: C₃₀H₂₆O₁₂
• Molecular Weight: 578.52
• Product Categories: Catechins & Tannins;chemical reagent;pharmaceutical intermediate;phytochemical;reference standards from Chinese medicinal herbs (TCM).;standardized herbal extract
• Mol File: 29106-49-8.mol
• Article Data: 23

Chemical Properties

• Melting Point: 197-198℃
• Boiling Point: 955.319 °C at 760 mmHg
• Flash Point: 531.558 °C
• Appearance: /
• Density: 1.705
• Storage Temp.: 2-8°C
• Solubility: DMSO (Slightly), Ethanol (Slightly), Methanol (Slightly)
• PKA: 9.29±0.60(Predicted)
• CAS DataBase Reference: PROCYANIDIN B2(CAS DataBase Reference)
• NIST Chemistry Reference: PROCYANIDIN B2(29106-49-8)
• EPA Substance Registry System: PROCYANIDIN B2(29106-49-8)

Safety Data

• Safety Statements: 22-24/25
• WGK Germany: 3
• Hazardous Substances Data: 29106-49-8(Hazardous Substances Data)

Usage

Uses

Different sources of media describe the Uses of 29106-49-8 differently. You can refer to the following data:
1. Procyanidin B2 is a selective protein kinase C inhibitor and was also found to promote hair epithelial cell growth and stimulate anagen induction. Procyanidin B2 extracted from apples have also shown anti-inflammatory activities.
2. Procyanidin B2 is a selective protein kinase C inhibitor and was also found to promote hair epithelial cell growth and stimulate anagen induction. Procyanidin B2 extracted from apples have also shown anti-inflammatory activities.

Synthetic route

3',4',5,7-tetra-O-benzyl-8-bromoepicatechin-4β,8-(3',4',5,7-tetra-O-benzylepicatechin) (442626-19-9) → procyanidin B2 (29106-49-8)

Conditions	Yield
With hydrogen; sodium hydrogencarbonate; triethylamine; palladium dihydroxide In methanol; water; ethyl acetate at 20℃; for 18h;	99%

5,7,3',4'-tetra-O-benzyl-(-)-epicatechin-(4β,8)-[5,7,3',4'-tetra-O-benzyl-(-)-epicatechin] (223387-28-8) → procyanidin B2 (29106-49-8)

Conditions	Yield
With hydrogen; palladium dihydroxide In tetrahydrofuran; methanol; water at 20℃; for 12h;	86%
With palladium hydroxide on carbon; hydrogen In water; ethyl acetate at 20℃; under 760.051 Torr; for 18h;	85%
With 20 % Pd(OH)2/C; hydrogen In water; ethyl acetate at 20℃; for 18h;	85%

4β-benzylthioepicatechin (37064-35-0) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0) → procyanidin B2 (29106-49-8)

Conditions	Yield
silver tetrafluoroborate In tetrahydrofuran at 0℃; for 1h; Condensation;	37%

procyanidin B2-3,3'-di-O-gallate (79907-44-1, 123051-12-7, 134054-57-2) → procyanidin B2 (29106-49-8)

Conditions	Yield
With tannase In water at 37℃; for 1h;

procyanidin B2-3,3'-di-O-gallate (79907-44-1, 123051-12-7, 134054-57-2) → procyanidin B2 (29106-49-8) + 3,4,5-trihydroxybenzoic acid (149-91-7)

Conditions	Yield
With tannase at 37℃; for 1h; 0.05 M acetate buffer (pH 5.0);

kandelin B-1 (96182-33-1) → procyanidin B2 (29106-49-8) + (2R,3R,4R,10R)-4-[(2R,3S,4S)-4-Benzylsulfanyl-2-(3,4-dihydroxy-phenyl)-3,5,7-trihydroxy-chroman-8-yl]-2,10-bis-(3,4-dihydroxy-phenyl)-3,5-dihydroxy-3,4,9,10-tetrahydro-2H-pyrano[2,3-f]chromen-8-one

Conditions	Yield
With acetic acid; phenylmethanethiol In ethanol for 8h; Heating;

(-)-epicatechin-<4β->8>-(-)-epicatechin-<4β->8>-(-)-epicatechin-<4β->8>-(-)-epicatechin (86631-38-1) + phenylmethanethiol (100-53-8) → procyanidin B2 (29106-49-8) + 4β-benzylthioepicatechin (37064-35-0) + (2R,3R,4R)-2,3-cis-3,4-trans-3,5,7,3',4'-pentahydroxy-4-<(2R,3S,4S)-2,3-cis-3,4-trans-3,5,7,3',4'-pentahydroxy-4-benzylthioflavan-8-yl>flavan (68200-27-1) + procyanidin C1 (37064-30-5) + procyanidin C-1 4''-benzylthioether (103215-52-7) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
acetic acid In ethanol for 6h; Product distribution; Heating; other reaction time;

epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin (86631-39-2) + phenylmethanethiol (100-53-8) → procyanidin B2 (29106-49-8) + 4β-benzylthioepicatechin (37064-35-0) + (2R,3R,4R)-2,3-cis-3,4-trans-3,5,7,3',4'-pentahydroxy-4-<(2R,3S,4S)-2,3-cis-3,4-trans-3,5,7,3',4'-pentahydroxy-4-benzylthioflavan-8-yl>flavan (68200-27-1) + procyanidin C1 (37064-30-5) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
acetic acid In ethanol for 6h; Product distribution; Heating; other reaction time;

epicatechin (4β,8)5-hexamer (88847-05-6) + phenylmethanethiol (100-53-8) → procyanidin B2 (29106-49-8) + 4β-benzylthioepicatechin (37064-35-0) + (2R,3R,4R)-2,3-cis-3,4-trans-3,5,7,3',4'-pentahydroxy-4-<(2R,3S,4S)-2,3-cis-3,4-trans-3,5,7,3',4'-pentahydroxy-4-benzylthioflavan-8-yl>flavan (68200-27-1) + procyanidin C1 (37064-30-5) + epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin (86631-39-2) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
acetic acid In ethanol for 5h; Product distribution; Heating; other reaction time;

epicatechin-(4β-6)-epicatechin-(4β-8)-epecatechin + phenylmethanethiol (100-53-8) → procyanidin B2 (29106-49-8) + procyanidin B-5 4'-benzykthioether (78591-32-9, 82863-23-8)

Conditions	Yield
In ethanol; acetic acid for 8h; Heating; degradation;

aesculitannin E (114569-30-1, 114612-79-2, 114715-46-7) + phenylmethanethiol (100-53-8) → procyanidin B2 (29106-49-8) + proanthocyanidin A-2 4'-benzylthioether (50562-99-7, 114612-76-9, 140145-59-1) + 4β-benzylthioepicatechin (37064-35-0) + cinnamtannin B1 4''-benzylthioether (114586-49-1, 114613-61-5) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
With hydrogenchloride for 2h; Heating; partial thiolytic degradation;	A 7 mg B 30 mg C 15 mg D 284 mg E 10 mg

aesculitannin F (114569-30-1, 114612-79-2, 114715-46-7) + phenylmethanethiol (100-53-8) → procyanidin B2 (29106-49-8) + 4β-benzylthioepicatechin (37064-35-0) + C37H30O12S (50562-99-7, 114612-76-9, 140145-59-1) + C52H42O18S (114586-49-1, 114613-61-5) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
With hydrogenchloride for 2h; Heating; partial thiolytic degradation;	A 16 mg B 8 mg C 12 mg D 152 mg E 5 mg

(2R,3R,4R)-2,3-cis-3,4-trans-3,3',4',5,7-pentahydroxy-4-<(2R,3S,4S)-2,3-cis-3,4-trans-3,3',4',5,7-pentahydroxy-4-phenylthioflavan-8-yl>flavan → procyanidin B2 (29106-49-8)

Conditions	Yield
With W-2 Raney-Ni

(2R,3R,4S)-2,3-cis-3,4-trans-3',4',5,7-tetramethoxyflavan-3,4-diol (22970-70-3) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0) → procyanidin B2 (29106-49-8) + procyanidin B5 (12798-57-1)

Conditions	Yield
With hydrogenchloride Ambient temperature;

procyanidin C1 (37064-30-5) + phenylmethanethiol (100-53-8) → procyanidin B2 (29106-49-8) + 4β-benzylthioepicatechin (37064-35-0) + (2R,3R,4R)-2,3-cis-3,4-trans-3,5,7,3',4'-pentahydroxy-4-<(2R,3S,4S)-2,3-cis-3,4-trans-3,5,7,3',4'-pentahydroxy-4-benzylthioflavan-8-yl>flavan (68200-27-1) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
In ethanol at 94℃;

(-)-epicatechin-<4β->6>-(-)-epicatechin-<4β->8>-(-)-epicatechin (82801-35-2, 99297-47-9, 128779-44-2, 101469-10-7) + phenylmethanethiol (100-53-8) → procyanidin B2 (29106-49-8) + 4β-benzylthioepicatechin (37064-35-0) + epicatechin-(4β<*>6)-epicatechin-(4β<*>S)-benzylthioether (82863-23-8) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
In ethanol at 94℃;

(+)-epicatechin (35323-91-2) + tannin → procyanidin B2 (29106-49-8) + procyanidin B5 (12798-57-1)

Conditions	Yield
With hydrogenchloride In 1,4-dioxane; water at 25℃; for 48h;

tannin extract of roots of Fragaria vesca → procyanidin B2 (29106-49-8) + procyanidin B1 (20315-25-7) + procyanidin B5 (12798-57-1) + catechin (154-23-4)

Conditions	Yield
In ethanol; water at 27℃; for 108h; fermentation; Saccharomyces rouxii; Further byproducts given;

(2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0) + palm procyanidin polymer → procyanidin B2 (29106-49-8) + ent-epicatechin-(4α->8)-epicatechin (88314-64-1)

Conditions	Yield
With acetic acid In ethanol at 95℃; for 22h;

(2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0) + procyanidins from Phoenix canariensis → procyanidin B2 (29106-49-8) + ent-epicatechin-(4α->8)-epicatechin (88314-64-1)

Conditions	Yield
Multistep reaction;

tannin extract of roots of Fragaria vesca → procyanidin B2 (29106-49-8) + procyanidin B1 (20315-25-7) + procyanidin B5 (12798-57-1) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
In ethanol; water at 27℃; for 108h; fermentation; Saccharomyces rouxii; Further byproducts given;

[4,8']-2,3-cis-3,4-trans-2',3'-cis-octa-O-benzyl-3-O-acetyl-bi-(-)-epicatechin → procyanidin B2 (29106-49-8)

Conditions	Yield
Stage #1: [4,8']-2,3-cis-3,4-trans:2',3'-cis-octa-O-benzyl-3-O-acetyl-bi-(-)-epicatechin With potassium carbonate In methanol Stage #2: With hydrogen; palladium dihydroxide In tetrahydrofuran; methanol; water Further stages.;

3’,4’,5,7-tetra-O-benzyl-4β-(2-hydroxyethyloxy)epicatechin (223387-26-6) → procyanidin B2 (29106-49-8)

Conditions	Yield
Multi-step reaction with 3 steps 1: 99 percent / N-bromosuccinimide / CH2Cl2 / -78 - 20 °C 2: 43 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 3 h / 20 °C 3: 99 percent / H2; Et3N; NaHCO3 / Pd(OH)2/C / H2O; methanol; ethyl acetate / 18 h / 20 °C View Scheme

3’,4’,5,7-tetra-O-benzyl-4β-(2-hydroxyethyloxy)-8-bromoepicatechin (223387-42-6) → procyanidin B2 (29106-49-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: 43 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 3 h / 20 °C 2: 99 percent / H2; Et3N; NaHCO3 / Pd(OH)2/C / H2O; methanol; ethyl acetate / 18 h / 20 °C View Scheme

5,7,3',4'-tetra-O-benzylepicatechin (87292-49-7) → procyanidin B2 (29106-49-8)

Conditions	Yield
Multi-step reaction with 4 steps 1.1: DDQ / CH2Cl2 / 3 h / 20 °C 1.2: 63 percent / DMAP / CH2Cl2 / 0.33 h 2.1: 99 percent / N-bromosuccinimide / CH2Cl2 / -78 - 20 °C 3.1: 43 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 3 h / 20 °C 4.1: 99 percent / H2; Et3N; NaHCO3 / Pd(OH)2/C / H2O; methanol; ethyl acetate / 18 h / 20 °C View Scheme
Multi-step reaction with 2 steps 1: 43 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 3 h / 20 °C 2: 99 percent / H2; Et3N; NaHCO3 / Pd(OH)2/C / H2O; methanol; ethyl acetate / 18 h / 20 °C View Scheme
Multi-step reaction with 2 steps 1: TMSOTf / CH2Cl2 / 0.08 h / -78 °C 2: 86 percent / hydrogen / Pd(OH)2/C / tetrahydrofuran; methanol; H2O / 12 h / 20 °C View Scheme
Multi-step reaction with 3 steps 1: 52 percent / DDQ / CH2Cl2 / 20 °C 2: 53 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 20 °C 3: H2 / 20 percent Pd(OH)2/C / tetrahydrofuran; methanol; H2O / 750.06 Torr View Scheme
Multi-step reaction with 2 steps 1: 53 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 20 °C 2: H2 / 20 percent Pd(OH)2/C / tetrahydrofuran; methanol; H2O / 750.06 Torr View Scheme

(2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0) → procyanidin B2 (29106-49-8)

Conditions	Yield
Multi-step reaction with 5 steps 1.1: 82 percent / K2CO3 / dimethylformamide / 0 - 20 °C 2.1: DDQ / CH2Cl2 / 3 h / 20 °C 2.2: 63 percent / DMAP / CH2Cl2 / 0.33 h 3.1: 99 percent / N-bromosuccinimide / CH2Cl2 / -78 - 20 °C 4.1: 43 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 3 h / 20 °C 5.1: 99 percent / H2; Et3N; NaHCO3 / Pd(OH)2/C / H2O; methanol; ethyl acetate / 18 h / 20 °C View Scheme
Multi-step reaction with 3 steps 1: 82 percent / K2CO3 / dimethylformamide / 0 - 20 °C 2: 43 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 3 h / 20 °C 3: 99 percent / H2; Et3N; NaHCO3 / Pd(OH)2/C / H2O; methanol; ethyl acetate / 18 h / 20 °C View Scheme

(2R,3S,4S)-5,7,3',4'-tetrabenzyloxy-4-(2"-ethoxyethoxy)flavan-3-ol (478796-20-2) → procyanidin B2 (29106-49-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: TMSOTf / CH2Cl2 / 0.08 h / -78 °C 2: 86 percent / hydrogen / Pd(OH)2/C / tetrahydrofuran; methanol; H2O / 12 h / 20 °C View Scheme

5,7,3',4'-tetra-O-benzyl-(+)-catechin (20728-73-8) → procyanidin B2 (29106-49-8)

Conditions	Yield
Multi-step reaction with 5 steps 1: 90 percent / Dess-Martin periodinane; H2O / CH2Cl2 / 20 °C 2: 81 percent / L-Selectride; LiBr / tetrahydrofuran / -78 °C 3: 52 percent / DDQ / CH2Cl2 / 20 °C 4: 53 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 20 °C 5: H2 / 20 percent Pd(OH)2/C / tetrahydrofuran; methanol; H2O / 750.06 Torr View Scheme
Multi-step reaction with 4 steps 1: 90 percent / Dess-Martin periodinane; H2O / CH2Cl2 / 20 °C 2: 81 percent / L-Selectride; LiBr / tetrahydrofuran / -78 °C 3: 53 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 20 °C 4: H2 / 20 percent Pd(OH)2/C / tetrahydrofuran; methanol; H2O / 750.06 Torr View Scheme

(+)-(2R)-5,7-bis(benzyloxy)-2-[3,4-bis(benzyloxy)phenyl]chroman-3-one (87292-54-4) → procyanidin B2 (29106-49-8)

Conditions	Yield
Multi-step reaction with 4 steps 1: 81 percent / L-Selectride; LiBr / tetrahydrofuran / -78 °C 2: 52 percent / DDQ / CH2Cl2 / 20 °C 3: 53 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 20 °C 4: H2 / 20 percent Pd(OH)2/C / tetrahydrofuran; methanol; H2O / 750.06 Torr View Scheme
Multi-step reaction with 3 steps 1: 81 percent / L-Selectride; LiBr / tetrahydrofuran / -78 °C 2: 53 percent / TiCl4 / CH2Cl2; tetrahydrofuran / 20 °C 3: H2 / 20 percent Pd(OH)2/C / tetrahydrofuran; methanol; H2O / 750.06 Torr View Scheme

procyanidin B2 (29106-49-8) + dimethyl sulfate (77-78-1) → 5,7,3',4'-tetra-O-methylepicatechin-4β,8-(5,7,3',4'-tetra-O-methylepicatechin) (37064-32-7)

Conditions	Yield
With potassium carbonate In various solvent(s) at 60℃; for 4h; Methylation;	41%

diazomethane (186581-53-3, 908094-01-9) + procyanidin B2 (29106-49-8) → 5,7,3',4'-tetra-O-methylepicatechin-4β,8-(5,7,3',4'-tetra-O-methylepicatechin) (37064-32-7)

Conditions	Yield
In methanol; diethyl ether at -15℃; for 48h;
at -15℃; for 48h;
Stage #1: procyanidin B2 With hydrogen; palladium dihydroxide In tetrahydrofuran; methanol under 750.075 Torr; for 0.666667h; Hydrogenolysis; Stage #2: diazomethane In diethyl ether at 20℃; for 0.133333h; Methylation; Further stages.;	4.8 mg

procyanidin B2 (29106-49-8) → (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
With hydrogenchloride for 0.5h; heating on a boiling water bath;
Multi-step reaction with 2 steps 1: ethanol / 1 h / boiling water bath 2: Raney nickel / ethanol / 2 h / Ambient temperature View Scheme

procyanidin B2 (29106-49-8) → (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0) + catechin (154-23-4)

Conditions	Yield
phosphoric acid In water; acetonitrile at 25 - 40℃; Rate constant; acid catalysis at different pH-values;

procyanidin B2 (29106-49-8) → (-)-epicatechin-(2β→O→7,4β→8)-(-)-catechin (111466-29-6) + (2R,3R:8S,9R,10R)-3,5,9-Trihydroxy-2,8-bis-(3,4-dihydroxyphenyl)-10-(2,4,6-trihydroxyphenyl)-2,3-cis-8,9-trans-9,10-cis-3,4,9,10-tetrahydro-2H,8H-pyrano<2,3-h>chromene (130999-36-9) + (2R,3R:8S,9S,10R)-3,5,9-Trihydroxy-2,10-bis-(3,4-dihydroxyphenyl)-8-(2,4,6-trihydroxyphenyl)-2,3-cis-8,9-cis-9,10-trans-3,4,9,10-tetrahydro-2H,8H-pyrano<2,3-h>chromene (131065-08-2) + (2S,3R:8S,9S,10R)-3,5,9-Trihydroxy-2,10-bis-(3,4-dihydroxyphenyl)-8-(2,4,6-trihydroxyphenyl)-2,3-trans-8,9-cis-9,10-trans-3,4,9,10-tetrahydro-2H,8H-pyrano<2,3-h>chromene (131065-09-3)

Conditions	Yield
With sodium hydrogencarbonate at 40℃; for 6.5h; Product distribution; Mechanism;	A 17 mg B 6 mg C 29 mg D 15 mg
With sodium hydrogencarbonate at 40℃; for 6.5h;	A 17 mg B 6 mg C 29 mg D 15 mg

procyanidin B2 (29106-49-8) → aesculitannin C (114569-29-8)

Conditions	Yield
With dihydrogen peroxide; sodium hydrogencarbonate In ethanol for 12h; Ambient temperature;	32 mg

procyanidin B2 (29106-49-8) + acetic anhydride (108-24-7) → epicatechin-(4β->8)-epicatechin decaacetate (21179-21-5)

Conditions	Yield
With pyridine
In pyridine for 24h; Ambient temperature;
With pyridine Yield given;

procyanidin B2 (29106-49-8) + mercaptoacetic acid (68-11-1) → [(2R,3S)-2-(3,4-Dihydroxy-phenyl)-3,5,7-trihydroxy-chroman-4-ylsulfanyl]-acetic acid + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
In ethanol for 1h; boiling water bath;

procyanidin B2 (29106-49-8) + phenylmethanethiol (100-53-8) → 4β-benzylthioepicatechin (37064-35-0) + (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol (490-46-0)

Conditions	Yield
With acetic acid In ethanol Heating; Yield given. Yields of byproduct given;

Upstream product

• 86631-38-1 (-)-epicatechin-<4β->8>-(-)-epicatechin-<4β->8>-(-)-epicatechin-<4β->8>-(-)-epicatechin 
• 100-53-8 phenylmethanethiol 
• 86631-39-2 epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin-(4β->8)-epicatechin 
• 88847-05-6 epicatechin (4β,8)5-hexamer 
• 114569-30-1 aesculitannin E 
• 114569-30-1 aesculitannin F 
• 22970-70-3 (2R,3R,4S)-2,3-cis-3,4-trans-3',4',5,7-tetramethoxyflavan-3,4-diol 
• 490-46-0 (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol 
• 37064-30-5 procyanidin C₁ 
• 82801-35-2 (-)-epicatechin-<4β->6>-(-)-epicatechin-<4β->8>-(-)-epicatechin 
• 37064-35-0 4β-benzylthioepicatechin 
• 61540-96-3 C₁₅H₁₃O₆⁽¹⁺⁾ 
• 79907-44-1 procyanidin B₂-3,3'-di-O-gallate 
• 154-23-4 catechin 

Downstream Products

• 37064-32-7 5,7,3',4'-tetra-O-methylepicatechin-4β,8-(5,7,3',4'-tetra-O-methylepicatechin) 
• 490-46-0 (2R,3R)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1[2H]-benzopyran-3,5,7-triol 
• 37064-35-0 4β-benzylthioepicatechin 
• 154-23-4 catechin 
• 213007-61-5 (-)-epicatechin benzylthioether 
• 41743-41-3 procyanidin A2 
• 21179-21-5 epicatechin-(4β->8)-epicatechin decaacetate 
• 114569-29-8 aesculitannin C 
• 111466-29-6 (-)-epicatechin-(2β→O→7,4β→8)-(-)-catechin 
• 130999-36-9 (2R,3R:8S,9R,10R)-3,5,9-Trihydroxy-2,8-bis-(3,4-dihydroxyphenyl)-10-(2,4,6-trihydroxyphenyl)-2,3-cis-8,9-trans-9,10-cis-3,4,9,10-tetrahydro-2H,8H-pyrano<2,3-h>chromene 
• 131065-08-2 (2R,3R:8S,9S,10R)-3,5,9-Trihydroxy-2,10-bis-(3,4-dihydroxyphenyl)-8-(2,4,6-trihydroxyphenyl)-2,3-cis-8,9-cis-9,10-trans-3,4,9,10-tetrahydro-2H,8H-pyrano<2,3-h>chromene 
• 131065-09-3 (2S,3R:8S,9S,10R)-3,5,9-Trihydroxy-2,10-bis-(3,4-dihydroxyphenyl)-8-(2,4,6-trihydroxyphenyl)-2,3-trans-8,9-cis-9,10-trans-3,4,9,10-tetrahydro-2H,8H-pyrano<2,3-h>chromene 

Relevant articles and documents

Synthesis of procyanidin B1, B2, and B4 and their anti-inflammatory activity: The effect of 4-alkoxy group of catechin and/or epicatechin electrophiles for condensation

Abstract: Procyanidin B1, B2, and B3 were synthesized based on a Yb(OTf)3 catalyzed equimolar condensation using methoxy and/or 4-(2-ethoxyethoxy) drivatives as electrophiles. The anti-inflammatory effect of synthetic procyanidin B1, B2, and B4 on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation of mouse ears was examined. Procyanidin B1, B2, B 4 suppressed TPA-induced inflammation of mouse ears by 48%, 34%, and 29%, respectively, at a dose of 200 μg. Their activities are stronger than those of indomethacin and glycyrrhetinic acid, the normally used antiinflammatory agent.

Total synthesis of 14C-labeled procyanidin B2

During the last decades, many in vitro and in vivo studies have shown the beneficial effects on health of procyanidins. However, their absorption and metabolism is still not fully understood and some aspects are still controversial. In order to have a clearer picture of the metabolism of procyanidins, the use of labelled compounds is essential. In this context, the enantioselective synthesis of 14C-radiolabelled procyanidin B2 was developed in our laboratories. It was achieved in fourteen 'hot' steps, involving as key steps the Sharpless dihydroxylation of an elaborated alkene, a stereoselective intramolecular cyclization to benzylated (+)-catechin and the condensation of two (-)-epicatechin units. 11 mCi of protected procyanidin B2 were obtained from 524 mCi of potassium [14C]cyanide. Copyright

First total synthesis of14C-labeled procyanidin B2 - A milestone toward understanding cocoa polyphenol metabolism

The idea that foods consumed for pure pleasure could provide health benefits received much recognition in the recent years. Among these foods, cocoa and dark chocolate are particularly rich in procyanidins, one of the major dietary families of polyphenols. We developed the first asymmetric total synthesis of procyanidin B2 and applied it to the preparation of a regioselectively radiolabeled 14C-analogue, which will be used to strengthen our knowledge on the metabolism of procyanidins. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.