25739-41-7

Basic information

• Product Name: velutin
• Synonyms: velutin;2-(3-Methoxy-4-hydroxyphenyl)-7-methoxy-5-hydroxy-4H-1-benzopyran-4-one;4',5-Dihydroxy-3',7-dimethoxyflavone;5-Hydroxy-2-(4-hydroxy-3-methoxyphenyl)-7-methoxy-4H-1-benzopyran-4-one;7,3'- Di-O- methylluteolin
• CAS NO: 25739-41-7
• Molecular Formula: C₁₇H₁₄O₆
• Molecular Weight: 314.28946
• Mol File: 25739-41-7.mol
• Article Data: 8

Chemical Properties

• Melting Point: 298 °C
• Boiling Point: 567.5°C at 760 mmHg
• Flash Point: 213.1°C
• Appearance: /
• Density: 1.402g/cm³
• Vapor Pressure: 1.76E-13mmHg at 25°C
• Refractive Index: 1.645
• PKA: 6.33±0.40(Predicted)
• CAS DataBase Reference: velutin(CAS DataBase Reference)
• NIST Chemistry Reference: velutin(25739-41-7)
• EPA Substance Registry System: velutin(25739-41-7)

Safety Data

• Hazardous Substances Data: 25739-41-7(Hazardous Substances Data)

Usage

Uses

Velutin is a flavone isolated from the aerial parts of Leucas stelligera.

InChI:InChI=1/C17H14O6/c1-21-10-6-12(19)17-13(20)8-14(23-16(17)7-10)9-3-4-11(18)15(5-9)22-2/h3-8,18-19H,1-2H3

Synthetic route

5-(benzyloxy)-2-(4-(benzyloxy)-3-methoxyphenyl)-7-methoxy-4H-chromen-4-one → velutin (25739-41-7)

Conditions	Yield
With palladium on activated charcoal; hydrogen In tetrahydrofuran; methanol at 20℃; for 12h;	79%

(-)-5-hydroxy-2-(4-hydroxy-3-methoxy-phenyl)-7-methoxy-chroman-4-one (41877-53-6, 54352-60-2, 66568-98-7) → velutin (25739-41-7)

Conditions	Yield
With iodine; potassium acetate; acetic acid

7,4′-dihydroxy-5,3′-dimethoxyflavone (62346-14-9) → chrysoeriol (491-71-4) + 5,7-dihydroxy-3',4'-dimethoxy flavone (4712-12-3) + velutin (25739-41-7) + 2-(3,4-dimethoxy-phenyl)-7-hydroxy-5-methoxy-chromen-4-one (10544-05-5) + 2-(4-hydroxy-3-methoxyphenyl)-5,7-dimethoxy-4H-benzopyran-4-one (1239-68-5)

Conditions	Yield
at 300℃; for 0.0333333h; Mechanism; transmethylation reaction;	A n/a B 2.0 % Chromat. C 4.7 % Chromat. D n/a E 14.1 % Chromat.

2-(3,4-Dihydroxy-phenyl)-5,7-dihydroxy-chromen-4-on (491-70-3) → diosmetin (520-34-3) + chrysoeriol (491-71-4) + velutin (25739-41-7) + pilloin (32174-62-2)

Conditions	Yield
With O-methyl transferase from cell-free extract of Citrus mitis; <(14)CH3>-S-adenosyl-L-methionine; 2-hydroxyethanethiol In water; dimethyl sulfoxide at 35℃; for 0.5h; Product distribution; pH 7.5 buffer;

2-(4-hydroxy-3-methoxyphenyl)-5,7-dimethoxy-4H-benzopyran-4-one (1239-68-5) → 7,4′-dihydroxy-5,3′-dimethoxyflavone (62346-14-9) + velutin (25739-41-7) + 5-hydroxy-3',4',7-trimethoxyflavone (29080-58-8) + 2-(3,4-dimethoxyphenyl)-5,7-dimethoxy-4H-chromen-4-one (855-97-0)

Conditions	Yield
at 300℃; for 0.0333333h; Mechanism; transmethylation reaction;	A 2.7 % Chromat. B 10.5 % Chromat. C 6.2 % Chromat. D 18.5 % Chromat.

4'-hydroxy-7,3'-dimethoxyflavone-5-O-β-D(+)glucopyranoside → D-glucose (50-99-7) + velutin (25739-41-7)

Conditions	Yield
With hydrogenchloride for 6h; Heating;

2-(4-Hydroxy-3-methoxy-phenyl)-7-methoxy-5-((2R,3S,4S,5S,6R)-3,4,5-trihydroxy-6-methyl-tetrahydro-pyran-2-yloxy)-chromen-4-one → 6-deoxy-α-D-mannopyranose (28161-49-1) + velutin (25739-41-7)

Conditions	Yield
With hydrogenchloride In ethanol for 6h; Product distribution; Heating; study of the acid hydrolysis reaction;

5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-β-D-xylopyranosyl-(2a→1b)-2a-O-β-D-xylopyranosyl-(2b→1c)-2b-O-β-D-xylopyranosyl-2c-octadecanoate (1449692-19-6) → D-xylose (58-86-6) + velutin (25739-41-7) + stearic acid (57-11-4)

Conditions	Yield
Stage #1: 5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-β-D-xylopyranosyl-(2a→1b)-2a-O-β-D-xylopyranosyl-(2b→1c)-2b-O-β-D-xylopyranosyl-2c-octadecanoate With hydrogenchloride In ethanol; water at 70 - 80℃; Stage #2: With hydrogenchloride In ethanol; water

5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-β-D-xylopyranosyl-(2a→1b)-2a-O-β-D-xylopyranosyl-(2b→1c)-2b-O-β-D-xylopyranosyl-2c-octadecanoate (1449692-19-6) → velutin (25739-41-7)

Conditions	Yield
With hydrogenchloride In ethanol; water at 70 - 80℃; for 0.5h;

5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-α-D-xylopyranosyl-(2a→1b)-2a-O-α-D-xylopyranosyl-(2b→1c)-2b-O-α-D-xylopyranosyl-(2c→1d)-2c-O-α-D-xylopyranosyl-2d-octadecanoate (1449692-20-9) → D-xylose (58-86-6) + velutin (25739-41-7) + stearic acid (57-11-4)

Conditions	Yield
Stage #1: 5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-α-D-xylopyranosyl-(2a→1b)-2a-O-α-D-xylopyranosyl-(2b→1c)-2b-O-α-D-xylopyranosyl-(2c→1d)-2c-O-α-D-xylopyranosyl-2d-octadecanoate With hydrogenchloride In ethanol; water at 70 - 80℃; Stage #2: With hydrogenchloride In ethanol; water

5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-α-D-xylopyranosyl-(2a→1b)-2a-O-α-D-xylopyranosyl-(2b→1c)-2b-O-α-D-xylopyranosyl-(2c→1d)-2c-O-α-D-xylopyranosyl-2d-octadecanoate (1449692-20-9) → velutin (25739-41-7)

Conditions	Yield
With hydrogenchloride In ethanol; water at 70 - 80℃; for 0.5h;

5-(3-chlorobenzyloxy)-2-(3,4-dimethoxyphenyl)-7-methoxy-4H-chromen-4-one + C24H20O6 → 2-((2-benzyl-4,5-dimethoxy)phenyl)-5-hydroxy-7-methoxy-4H-benzopyran-4-one + 2-((3-benzyl-4-hydroxy-5-methoxy)phenyl)-5-hydroxy-7-methoxy-4H-benzopyran-4-one + 2-((2-benzyl-4-hydroxy-5-methoxy)phenyl)-5-hydroxy-7-methoxy-4H-benzopyran-4-one + C24H19ClO6 + C24H19ClO6 + C25H21ClO6 + velutin (25739-41-7) + 5-hydroxy-3',4',7-trimethoxyflavone (29080-58-8)

Conditions	Yield
With methanesulfonic acid In chloroform for 1h; Reflux; Microwave irradiation;

...Expand

3-methoxy-4-(phenylmethoxy)benzaldehyde (2426-87-1) → velutin (25739-41-7)

Conditions	Yield
Multi-step reaction with 3 steps 1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 1 h / 0 °C 2: copper(l) iodide / N,N-dimethyl acetamide / 16 h / 130 °C 3: palladium on activated charcoal; hydrogen / methanol; tetrahydrofuran / 12 h / 20 °C View Scheme

vanillin (121-33-5) → velutin (25739-41-7)

Conditions	Yield
Multi-step reaction with 4 steps 1: potassium carbonate / methanol / 2 h / 0 - 70 °C 2: sodium hydride / N,N-dimethyl-formamide; mineral oil / 1 h / 0 °C 3: copper(l) iodide / N,N-dimethyl acetamide / 16 h / 130 °C 4: palladium on activated charcoal; hydrogen / methanol; tetrahydrofuran / 12 h / 20 °C View Scheme

(E)-3-((4-benzyloxy)-3-methoxyphenyl)-1-(2-(benzyloxy)-6-hydroxy-4-methoxyphenyl)prop-2-en-1-one → velutin (25739-41-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: copper(l) iodide / N,N-dimethyl acetamide / 16 h / 130 °C 2: palladium on activated charcoal; hydrogen / methanol; tetrahydrofuran / 12 h / 20 °C View Scheme

2,6-dihydroxy-4-methoxy-acetophenone (7507-89-3) → velutin (25739-41-7)

Conditions	Yield
Multi-step reaction with 4 steps 1: potassium carbonate / N,N-dimethyl-formamide / 0 - 70 °C 2: sodium hydride / N,N-dimethyl-formamide; mineral oil / 1 h / 0 °C 3: copper(l) iodide / N,N-dimethyl acetamide / 16 h / 130 °C 4: palladium on activated charcoal; hydrogen / methanol; tetrahydrofuran / 12 h / 20 °C View Scheme

2,4,6-trihydroxyacetophenone (480-66-0) → velutin (25739-41-7)

Conditions	Yield
Multi-step reaction with 5 steps 1: potassium carbonate / acetone / 10 °C 2: potassium carbonate / N,N-dimethyl-formamide / 0 - 70 °C 3: sodium hydride / N,N-dimethyl-formamide; mineral oil / 1 h / 0 °C 4: copper(l) iodide / N,N-dimethyl acetamide / 16 h / 130 °C 5: palladium on activated charcoal; hydrogen / methanol; tetrahydrofuran / 12 h / 20 °C View Scheme

2'-(benzyloxy)-6'-hydroxy-4'-methoxyacetophenone (10299-59-9) → velutin (25739-41-7)

Conditions	Yield
Multi-step reaction with 3 steps 1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 1 h / 0 °C 2: copper(l) iodide / N,N-dimethyl acetamide / 16 h / 130 °C 3: palladium on activated charcoal; hydrogen / methanol; tetrahydrofuran / 12 h / 20 °C View Scheme

diazomethane (186581-53-3, 908094-01-9) + velutin (25739-41-7) → 2-(3,4-dimethoxyphenyl)-5,7-dimethoxy-4H-chromen-4-one (855-97-0)

Conditions	Yield
With diethyl ether; ethyl acetate

velutin (25739-41-7) + acetic anhydride (108-24-7) → 5-acetoxy-2-(4-acetoxy-3-methoxy-phenyl)-7-methoxy-chromen-4-one (88428-84-6)

Conditions	Yield
With sodium acetate
In pyridine
With pyridine

velutin (25739-41-7) + dimethyl sulfate (77-78-1) → 2-(3,4-dimethoxyphenyl)-5,7-dimethoxy-4H-chromen-4-one (855-97-0)

Conditions	Yield
With potassium carbonate

Upstream product

• 41877-53-6 (-)-5-hydroxy-2-(4-hydroxy-3-methoxy-phenyl)-7-methoxy-chroman-4-one 
• 62346-14-9 7,4′-dihydroxy-5,3′-dimethoxyflavone 
• 491-70-3 2-(3,4-Dihydroxy-phenyl)-5,7-dihydroxy-chromen-4-on 
• 1449692-19-6 5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-β-D-xylopyranosyl-(2a→1b)-2a-O-β-D-xylopyranosyl-(2b→1c)-2b-O-β-D-xylopyranosyl-2c-octadecanoate 
• 1449692-20-9 5,4'-dihydroxy-7,3'-dimethoxyflavone-4'-O-α-D-xylopyranosyl-(2a→1b)-2a-O-α-D-xylopyranosyl-(2b→1c)-2b-O-α-D-xylopyranosyl-(2c→1d)-2c-O-α-D-xylopyranosyl-2d-octadecanoate 
• 65490-09-7 2'-hydroxy-4',6'-bis(methoxymethoxy)acetophenone 
• 115623-29-5 2-benzyloxy-4,6-bis(methoxymethyloxy)acetophenone 
• 39548-86-2 1‐(2‐(benzyloxy)‐4,6‐dihydroxyphenyl)ethan‐1‐one 
• 10299-59-9 1‐(2‐(benzyloxy)‐6‐hydroxy‐4‐methoxyphenyl)ethan‐1‐one 
• 480-66-0 2,4,6-trihydroxyacetophenone 
• 7507-89-3 2,6-dihydroxy-4-methoxy-acetophenone 
• 121-33-5 vanillin 
• 2426-87-1 3-methoxy-4-(phenylmethoxy)benzaldehyde 
• 1239-68-5 2‐(4‐hydroxy‐3‐methoxyphenyl)‐5,7‐dimethoxy‐4H‐chromen‐4‐one 

Downstream Products

• 855-97-0 2-(3,4-dimethoxyphenyl)-5,7-dimethoxy-4H-chromen-4-one 
• 88428-84-6 5-acetoxy-2-(4-acetoxy-3-methoxy-phenyl)-7-methoxy-chromen-4-one 

Relevant articles and documents

Anti‐melanogenic properties of velutin and its analogs?

Velutin, one of the flavones contained in natural plants, has various beneficial activities, such as skin whitening, as well as anti‐inflammatory, anti‐allergic, antioxidant, and antimicrobial activities. However, the relationship between the structure of velutin and its anti‐melanogenesis activity is not yet investigated. In this study, we obtained 12 velutin derivatives substituted at C5, C7, C3′, and C4′ of the flavone backbone with hydrogen, hydroxyl, and methoxy functionalities by chemical synthesis, to perform SAR analysis of velutin structural analogues. The SAR study revealed that the substitution of functional groups at C5, C7, C3′, and C4′ of the flavone backbone affects biological activities related to melanin synthesis. The coexistence of hydroxyl and methoxy at the C5 and C7 position is essential for inhibiting tyrosinase activity. However, 1,2‐diol compounds substituted at C3′ and C4′ of flavone backbone induce apoptosis of melanoma cells. Further, substitution at C3′ and C4′ with methoxy or hydrogen is essential for inhibiting melanogenesis. Thus, this study would be helpful for the development of natural‐derived functional materials to regulate melanin synthesis.

Acidic rearrangement of benzyl group in flavone benzyl ethers and its regioselectivity

Abstract The benzyl-substituted flavone compounds are rare in nature, while some of which have interesting biological activities. The total synthesis of benzyl-substituted flavone derivatives via the acidic rearrangement of benzyl groups in flavone benzyl ethers, and the complicated regioselectivity of the rearrangement were reported. The regioselectivity was proposed to be determined by the steric hindrance as well as the ease of electrophilic substitution reaction for benzyl cations at different positions of corresponding debenzylated flavone compounds.

A Flavone Glycoside from Seeds of Cassia spectabilis DC

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