520-36-5

Basic information

• Product Name: Apigenin
• Synonyms: Apigenin (30 mg);LY 080400;Pelargidenone;Apegenin;NSC 83244;UCCF 031;4',5,7-Trihydroxyflavone, 5,7-Dihydroxy-2-(4-hydroxyphenyl)-4H-chromen-4-one;Chinese Taxillus Herb
• CAS NO: 520-36-5
• Molecular Formula: C₁₅H₁₀O₅
• Molecular Weight: 270.24
• EINECS: 208-292-3
• Product Categories: chemical reagent;pharmaceutical intermediate;phytochemical;reference standards from Chinese medicinal herbs (TCM).;standardized herbal extract;natural product;Plant extract;pyridine series;Tri-substituted Flavones;Biochemistry;Flavonoids;Natural Plant Extract;Inhibitors;Protein Kinase;Signalling
• Mol File: 520-36-5.mol
• Article Data: 99

Chemical Properties

• Melting Point: >300 °C(lit.)
• Boiling Point: 333.35°C (rough estimate)
• Flash Point: 217 °C
• Appearance: yellow/powder
• Density: 1.2319 (rough estimate)
• Vapor Pressure: 6E-13mmHg at 25°C
• Refractive Index: 1.6000 (estimate)
• Storage Temp.: −20°C
• Solubility: DMSO: 27 mg/mL
• PKA: 6.53±0.40(Predicted)
• Stability: Stable for 1 year from date of purchase as supplied. Solutions in DMSO may be stored at -20°C for up to 1 month.
• Merck: 14,730
• BRN: 262620
• CAS DataBase Reference: Apigenin(CAS DataBase Reference)
• NIST Chemistry Reference: Apigenin(520-36-5)
• EPA Substance Registry System: Apigenin(520-36-5)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 26-36
• WGK Germany: 3
• RTECS: LK9276000
• F: 10
• Hazardous Substances Data: 520-36-5(Hazardous Substances Data)

Usage

Description

Apigenin is one of the most widespread flavonoids in plants and formally belongs to the flavone sub-class. Of all the flavonoids, apigenin is one of the most widely distributed in the plant kingdom, and one of the most studied phenolics. Apigenin is present principally as glycosylated in significant amount in vegetables (parsley, celery, onions) fruits (oranges), herbs (chamomile, thyme, oregano, basil), and plant-based beverages (tea, beer, and wine). Plants belonging to the Asteraceae, such as those belonging to Artemisia, Achillea, Matricaria, and Tanacetum genera, are the main sources of this compound.

Chemical Properties

Pale Yellow Crystalline Solid

Uses

Different sources of media describe the Uses of 520-36-5 differently. You can refer to the following data:
1. Apigenin is an active antioxidant, anti-inflammatory, anti-amyloidogenic, neuroprotective and cognitive enhancing substance with interesting potential in the treatment/prevention of Alzheimer's disease.
2. Apigenin has been shown to possess antibacterial, antiviral, antifungal, and antiparasitic activities. Although it can’t stop all types of bacteria on its own, it can be combined with other antibiotics to increase their effects.
3. Apigenin is a promising reagent for cancer therapy. Apigenin appears to have the potential to be developed either as a dietary supplement or as an adjuvant chemotherapeutic agent for cancer therapy.

Preparation

4-hydroxybenzaldehyde (1.22 g, 9.97 mmol, 1.0 equiv) was added to asolution of 50% KOH (aq.) (6.72 g, 59.82 mmol, 6.0 equiv) and ethanol (3 mL) andstirred for 10 min. Then compound 9 (2.02g, 9.97 mmol, 1.0 equiv) was added to the reaction mixture and heated to 60 °C and stirred for 4 h. After cooled toroom temperature, the mixture was poured into ice water and acidified withconcentrated hydrochloric acid to pH = 3. Then the suspension was filtrated, washed and the residue was dried toafford Apigenin(2.43 g, 90%) as a red solid.

Anticancer Research

It induces apoptosis by targeting leptin/leptin receptor pathway and by targeting caspase-dependent extrinsic pathway aswell as STAT3 signaling pathway in lung adenocarcinoma and BT-474 breast cancercells, respectively. It shows antitumor activity against breastcancer MCF-7 cells and colon cancer HCT 116 cells and is a mediator of cancerchemoprevention and an inducer of autophagy. It can be used to treat colon canceras it induces apoptosis in colon cancer cells. It also increase melanogenesis in B16cells by activating the p38 MAPK pathway.

Purification Methods

The current method for the purification of apigenin is crude-solvent extraction method by using solvent in small quantity and also time saving. Apigenin that was isolated from Symphyotrichum novae-angliae was obtained in large quantity and directly from extract.

InChI:InChI=1/C15H10O5/c16-9-3-1-8(2-4-9)13-7-12(19)15-11(18)5-10(17)6-14(15)20-13/h1-7,16-18H

Synthetic route

2,4’,5,7-tetrahydroxyflavanone → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With hydrogenchloride In methanol; water	100%

5,7-Dihydroxy-2-(4-hydroxy-phenyl)-chroman-4-on (480-41-1) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With sulfuric acid; iodine In dimethyl sulfoxide at 100℃; for 1.5h;	95%
With pyridine; iodine for 4h; Heating;	93%
With pyridine; iodine at 95℃; for 5h;	66%

apigenin 7-O-glucoside (578-74-5) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With hydrogenchloride for 2h; Heating;	95%
Acid hydrolysis;
Acidic conditions;

2-chloro-1-(2,4,6-trihydroxyphenyl)ethan-1-one (110865-03-7) + 4-hydroxy-benzaldehyde (123-08-0) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
Stage #1: 2-chloro-1-(2,4,6-trihydroxyphenyl)ethan-1-one; 4-hydroxy-benzaldehyde With sodium hydroxide In ethanol; water Stage #2: With hydrogenchloride Further stages.;	92%
Stage #1: 4-hydroxy-benzaldehyde With potassium hydroxide In ethanol; water for 0.166667h; Inert atmosphere; Stage #2: 2-chloro-1-(2,4,6-trihydroxyphenyl)ethan-1-one In ethanol; water at 60℃; for 4h;	90%
With potassium hydroxide In ethanol at 20 - 60℃; for 6h;	83%

4',5,7-trimethoxyflavone (5631-70-9) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With pyridine hydrochloride at 180 - 190℃; for 6h; Inert atmosphere;	90%
With pyridine hydrochloride at 180℃; for 6h; Inert atmosphere;	90%
With boron tribromide In dichloromethane at 20℃; for 24h; Inert atmosphere;	90%
Stage #1: 4',5,7-trimethoxyflavone With aluminum (III) chloride In toluene at 80 - 140℃; Stage #2: With hydrogenchloride In water; toluene at 0℃; Reagent/catalyst; Solvent; Temperature; Time;	61.5%
With hydrogen iodide In acetic anhydride at 115 - 118℃; for 6h;	10 g

naringenin (480-41-1) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With iodine In pyridine at 90℃; for 8h;	86%
With flavone synthase I Product distribution;
With GLUTATHIONE; N-[tris(hydroxymethyl)methyl]glycine; flavone synthase II; NADPH; potassium hydroxide at 25℃; for 0.5h; pH=7.9; Enzymatic reaction;
With 2,3-dicyano-5,6-dichloro-p-benzoquinone

2',4',6',4-tetrahydroxydihydrochalcone (25515-46-2, 73692-50-9) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With oxygen at 20℃; under 760.051 Torr; for 0.866667h; Reagent/catalyst;	77%

1-[4-(tert-Butyl-dimethyl-silanyloxy)-phenyl]-3-(2,4,6-trihydroxy-phenyl)-propane-1,3-dione → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With sulfuric acid In acetic acid at 95 - 100℃; for 1h;	76%

apigenin-7-O-β-D-glucuronide (29741-09-1, 56317-11-4) → D-glucuronic acid (6556-12-3, 489-91-8, 528-16-5, 552-12-5, 577-46-8, 643-33-4, 2240-07-5, 6294-16-2, 10133-02-5, 18402-78-3, 18968-14-4, 21179-08-8, 23018-83-9, 33599-45-0, 33599-46-1, 46171-67-9, 46171-69-1, 46172-26-3, 70021-34-0, 71031-08-8, 104195-06-4, 106499-29-0, 124817-72-7) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With sulfuric acid for 5h;	A n/a B 68%
With sulfuric acid for 5h;

3,5-dihydroxyphenol (108-73-6) + ethyl (4-hydroxybenzoyl)acetate (77103-47-0) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
for 0.0633333h; microwave irradiation;	66%

C27H18O9S2 → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With potassium carbonate In methanol at 65℃; for 5h; Inert atmosphere;	66%

7-benzyloxy-5-hydroxy-2-(4-hydroxyphenyl)chroman-4-one (874202-29-6) → 7-O-benzylapigenin (20450-81-1) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
Stage #1: 7-benzyloxy-5-hydroxy-2-(4-hydroxyphenyl)chroman-4-one With pyridine; iodine for 4h; Heating / reflux; Stage #2: With hydrogenchloride In water	A 58% B 24%

4,6-bis(methoxymethyl)-2-(4-acetoxybenzoyloxy)acetophenone → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
Stage #1: 4,6-bis(methoxymethyl)-2-(4-acetoxybenzoyloxy)acetophenone With potassium hydroxide In pyridine at 50℃; for 0.333333h; Stage #2: With acetic acid In pyridine; water for 0.5h; Stage #3: With hydrogenchloride In methanol Reflux;	58%

4',5,7-trimethoxyflavone (5631-70-9) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + 5,7-dihydroxy-2-(4'-methoxyphenyl)-4H-1-benzopyran-4-one (480-44-4)

Conditions	Yield
With N-butyl-N-methylimidazolium heptachlorodialuminate In dichloromethane at 40℃; for 4h;	A 54% B 16%

apigenin 7-O-[β-D-glucuronopyranosyl-(1->2)]-O-β-D-glucuronopyranoside → D-Glucuronic acid (6556-12-3) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
Acid hydrolysis;	A n/a B 52%

5,7-dihydroxy-2-phenyl-chromen-4-one (480-40-0) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + 2-(3,4-Dihydroxy-phenyl)-5,7-dihydroxy-chromen-4-on (491-70-3) + luteolin 3'-monosulphate

Conditions	Yield
With Mucore ramannianus (ATCC 9628) In N,N-dimethyl-formamide for 336h; Microbiological reaction;	A 3% B 10.2% C 10.2%

5,7-Dihydroxy-2-(4-hydroxy-phenyl)-chroman-4-on (480-41-1) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + eriodictyol (4049-38-1)

Conditions	Yield
With plasmid pFusionF87V-carrying recombinant Escherichia coli BL21 (DE3) cells at 28℃; for 24h; Microbiological reaction;	A 3.7% B 5.2%

5,7-dihydroxy-2-phenyl-chromen-4-one (480-40-0) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With Aspergillus alliaceous (ATCC 10060) In N,N-dimethyl-formamide for 336h; Microbiological reaction;	4.1%

6-bromo-5-hydroxy-7,4'-dimethoxyflavone (35095-48-8) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With hydrogen iodide; acetic anhydride

dihydrokaempferol (724434-08-6) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With sulfuric acid

4'-O-methylapigenin 6-C-β-D-glucopyranoside (21089-34-9) → D-Glucose (2280-44-6) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With hydrogenchloride; water In acetic acid at 100℃; for 24h;
With iron(III) chloride at 100℃; for 6h;

FLAVONE (525-82-6) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With pyridine hydrochloride

5-hydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one (5128-44-9) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With pyridine hydrochloride at 170℃; for 2h; Product distribution; for identification of structure;

apigenin 7-p-coumarate (126661-94-7) → p-Coumaric Acid (7400-08-0) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With sodium hydroxide for 0.5h; Ambient temperature;

crotonoylcosmosiin (123656-62-2) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With hydrogenchloride In methanol for 5h; Heating;	6 mg

apigenin 7-(4-O-β-glucosyl-trans-p-coumarate) (126871-97-4) → D-Glucose (2280-44-6) + p-Coumaric Acid (7400-08-0) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With hydrogenchloride Heating;
With hydrogenchloride Heating;

2-hydroxynaringenin (64325-11-7) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With hydrogenchloride In acetic acid for 1h; Heating; Yield given;
With hydrogenchloride; acetic acid at 100℃; for 1.5h; Yield given;

nivyaside (84563-91-7) → D-Glucose (2280-44-6) + cyclohexanetetrol-(1r,2t,3t,4c) (20089-18-3, 907575-48-8) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
With Kiliani's mixture for 6h; Heating;	A n/a B n/a C 36 mg

apigenin 5-O-α-L-rhamnopyranosyl-(1'''->2'')-6''-O-acetyl-β-D-glucopyranoside (125300-52-9) → 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5)

Conditions	Yield
sulfuric acid In ethanol; water for 6h; Heating;

chlorosulfuric acid 2,2,2-trichloroethyl ester (764-09-0) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → C21H13Cl9O14S3

Conditions	Yield
With dmap; triethylamine In tetrahydrofuran at 20℃;	95%

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → 2-(3,4-Dihydroxy-phenyl)-5,7-dihydroxy-chromen-4-on (491-70-3)

Conditions	Yield
With C9H8IO4Pol In dimethyl sulfoxide at 25℃; for 2h;	95%
With cytochromes P450 in human liver microsomes Kinetics; Enzymatic reaction;

2-iodo-propane (75-30-9) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → 5-hydroxy-7-isopropoxy-2-(4-isopropoxyphenyl)-4H-chromen-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 30h; Inert atmosphere;	95%

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → C15H8F2O9S2

Conditions	Yield
With fluorosulfonyl fluoride In acetonitrile at 20℃; for 3h; Sealed tube;	95%

diazomethane (186581-53-3, 908094-01-9) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → 5-hydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one (5128-44-9)

Conditions	Yield
In methanol; diethyl ether at 20℃; for 0.5h;	94%
With ethanol
In methanol at 20℃; for 1h;

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + acetic anhydride (108-24-7) → apigenin triacetate (3316-46-9)

Conditions	Yield
With pyridine at 70℃; for 6h;	94%
With pyridine at 140℃; for 8h; Temperature;	90.8%
With pyridine Reflux;	87.2%

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + chloroacetic acid ethyl ester (105-39-5) → diethyl 2,2'-((2-(4-(2-ethoxy-2-oxoethoxy)phenyl)-4-oxo-4H-chromene-5,7-diyl)bis(oxy))diacetate

Conditions	Yield
Stage #1: 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 0.75h; Stage #2: chloroacetic acid ethyl ester In N,N-dimethyl-formamide at 20℃; for 24h;	94%

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → 6,8-dibromo-5,7,4'-trihydroxyflavone (1006032-73-0)

Conditions	Yield
With N-Bromosuccinimide In trifluoroacetic acid at 20℃; for 5h;	93%
With N-Bromosuccinimide In acetone at 22℃; for 0.716667h;

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → 5,7-Dihydroxy-2-(4-hydroxy-phenyl)-chroman-4-on (480-41-1)

Conditions	Yield
With palladium 10% on activated carbon; hydrogen at 20℃;	91%
With palladium 10% on activated carbon; hydrogen	25%

europium(III) oxide + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + water (7732-18-5) → C45H27EuO15*2H2O

Conditions	Yield
With dihydrogen peroxide; nitric acid; triethylamine In ethanol at 20℃; for 20h; pH=8; Reagent/catalyst; Darkness;	90.93%

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + benzoyl chloride (98-88-4) → 5,7,4'-tribenzoyloxyflavone

Conditions	Yield
With pyridine hydrochloride at 140 - 200℃; for 9h;	89%
With potassium hydroxide

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + tert-butyldimethylsilyl chloride (18162-48-6) → 7,4'-di-O-(tert-butyldimethylsilyl)apigenin

Conditions	Yield
With 1,8-diazabicyclo[5.4.0]undec-7-ene In dichloromethane at 20℃; for 5h;	89%

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + Hexanoyl chloride (142-61-0) → 5,7,4'-tri-O-hexanoyl apigenin (1145669-46-0)

Conditions	Yield
With dmap; triethylamine In N,N-dimethyl-formamide for 8h; Cooling with ice;	88%
With dmap; triethylamine In N,N-dimethyl-formamide at 20℃; for 4.5h; Cooling with ice;	87%
With dmap; triethylamine In N,N-dimethyl-formamide

methyl 6-bromohexanoate (14273-90-6) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → methyl 6-((5-hydroxy-2-(4-hydroxyphenyl)-4-oxo-4H-chromen-7-yl)oxy)hexanoate

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 70℃; for 6h; Inert atmosphere;	87%
With potassium carbonate In N,N-dimethyl-formamide at 80℃; for 6h;	20%

4-chloro-3,5-dinitrobenzotrifluoride (393-75-9) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → 7-(2,6-dinitro-4-(trifluoromethyl)phenoxy)-5-hydroxy-2-(4-hydroxyphenyl)-4H-chromen-4-one

Conditions	Yield
With potassium tert-butylate In N,N-dimethyl-formamide at 20℃;	84%

formaldehyd (50-00-0) + furan-2-ylmethanamine (617-89-0) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → C36H31N3O8

Conditions	Yield
In dimethyl sulfoxide at 100℃; for 12h;	84%

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → 5,7-dihydroxy-2-(4-hydroxyphenyl-3,5-D2)-4H-1-benzopyran-4-one-3,6,8-D3 (263711-74-6)

Conditions	Yield
With boron trifluoride; [D3]phosphoric acid In water-d2 at 55℃; for 96h; deuteration;	83%
Multi-step reaction with 3 steps 1: D2O / acetone 2: 1-butyl-3-methylimidazolium chloride; DCl; D2O / 0.33 h / 120 °C / 3750.38 Torr / microwave irradiation 3: H2O View Scheme

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + diethyl chlorophosphate (814-49-3) → C27H37O14P3

Conditions	Yield
With dmap; triethylamine In tetrahydrofuran at 20℃; for 24.5h; Inert atmosphere; Cooling with ice;	83%
With dmap; triethylamine In tetrahydrofuran at 70℃; for 3.5h; Cooling with ice; Inert atmosphere;

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + acetic anhydride (108-24-7) → 7,4'-diacetoxy-5-hydroxyflavone (857-79-4)

Conditions	Yield
	82%
With pyridine
With pyridine at 20℃; for 24h;

2-iodo-propane (75-30-9) + 5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → 5,7-diisopropoxy-2-(4-isopropoxyphenyl)-4H-benzopyran-4-one

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide for 24h; Inert atmosphere;	82%
With potassium carbonate In N,N-dimethyl-formamide at 60℃; for 24h; Inert atmosphere;	78%
With potassium carbonate In N,N-dimethyl-formamide	73%

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) → C15H9O8S(1-)*K(1+) (120562-19-8) + C15H8O11S2(2-)*2K(1+) (116097-08-6)

Conditions	Yield
With potassium acetate; tetra(n-butyl)ammonium hydrogensulfate; dicyclohexyl-carbodiimide In pyridine at 4℃; for 72h; Yields of byproduct given;	A n/a B 81%
With potassium acetate; tetra(n-butyl)ammonium hydrogensulfate; dicyclohexyl-carbodiimide In pyridine at 4℃; for 72h; Yields of byproduct given;	A 28% B n/a

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + diazomethyl-trimethyl-silane (18107-18-1) → 5-hydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one (5128-44-9)

Conditions	Yield
In methanol; hexane; dichloromethane at 20℃; for 12h;	81%

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + dimethyl sulfate (77-78-1) → 5-hydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one (5128-44-9)

Conditions	Yield
With potassium hydroxide In water; acetone at 20℃; for 4h;	80%
With potassium hydroxide
With sodium hydroxide
With potassium carbonate regioselective reaction;
With potassium carbonate In acetone at 65℃;

5,7-dihydroxy-2-(4-hydroxyphenyl)-4H-1-benzopyran-4-one (520-36-5) + methyl iodide (74-88-4) → 5,7-dihydroxy-2-(4'-methoxyphenyl)-4H-1-benzopyran-4-one (480-44-4)

Conditions	Yield
With potassium carbonate In N,N-dimethyl-formamide at 20℃; for 18h; Inert atmosphere; regiospecific reaction;	79%
With potassium carbonate In N,N-dimethyl-formamide for 2h;

Upstream product

• 35095-48-8 6-bromo-5-hydroxy-7,4'-dimethoxyflavone 
• 525-82-6 FLAVONE 
• 29741-09-1 apigenin-7-O-β-D-glucuronide 
• 108-73-6 3,5-dihydroxyphenol 
• 77103-47-0 ethyl (4-hydroxybenzoyl)acetate 
• 480-40-0 5,7-dihydroxy-2-phenyl-chromen-4-one 
• 25515-46-2 2',4',6',4-tetrahydroxydihydrochalcone 
• 90-24-4 2-hydroxy-4,6-dimethoxyacetophenone 
• 94805-88-6 acetylembinin 
• 134810-54-1 4-iodo-1,3,5-trihydroxybenzene 
• 119738-57-7 apigenin 7-O-[β-D-glucuronopyranosyl-(1->2)]-O-β-D-glucuronopyranoside 
• 480-41-1 5,7-Dihydroxy-2-(4-hydroxy-phenyl)-chroman-4-on 
• 480-41-1 (+)-Naringenin 
• 480-44-4 5,7-dihydroxy-2-(4'-methoxyphenyl)-4H-1-benzopyran-4-one 

Downstream Products

• 108-73-6 3,5-dihydroxyphenol 
• 99-93-4 4-Hydroxyacetophenone 
• 72357-31-4 4',5,7-trihydroxy-8-prenylflavone 
• 890661-83-3 3'-nitroapigenin 
• 480-41-1 5,7-Dihydroxy-2-(4-hydroxy-phenyl)-chroman-4-on 
• 1006032-73-0 6,8-dibromo-5,7,4'-trihydroxyflavone 
• 4323-80-2 5,7-dihydroxy-2-(4-hydroxyphenyl)-6,8-dimethoxy-4H-chromen-4-one 
• 99-96-7 4-hydroxy-benzoic acid 
• 120562-19-8 C₁₅H₉O₈S^(1-)*K⁽¹⁺⁾ 
• 116097-08-6 C₁₅H₈O₁₁S₂^(2-)*2K⁽¹⁺⁾ 
• 480-44-4 5,7-dihydroxy-2-(4'-methoxyphenyl)-4H-1-benzopyran-4-one 
• 5128-44-9 5-hydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one 
• 5631-70-9 4',5,7-trimethoxyflavone 
• 130999-30-3 apigen-4'7-diyl-di(2,3,4,6-tetra-O-acetyl-β-D-galactopyranoside) 

Relevant articles and documents

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Regioselective ortho-Hydroxylations of Flavonoids by Yeast

Natural flavonoids, such as naringenin, hesperetin, chrysin, apigenin, luteolin, quercetin, epicatechin, and biochanin A, were subjected to microbiological transformations by Rhodotorula glutinis. Yeast was able to regioselectively C-8 hydroxylate hesperetin, luteolin, and chrysin. Naringenin was transformed to 8- and 6-hydroxyderivatives. Quercetin, epicatechin, and biochanin A did not undergo biotransformation. A metabolic pathway for the degradation of chrysin has been elucidated. The metabolism of chrysin proceeds via an initial C-8 hydroxylation to norwogonin, followed by A-ring cleavage to 4-hydroxy-6-phenyl-2H-pyran-2-one.

Secondary metabolites of an Algerian Phlomis bovei and their antioxidant activities

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FLAVONOID GLYCOSIDES OF ARTEMISIA MONOSPERMA AND A. HERBA-ALBA

Ten flavonoid glycosides were isolated and identified from Artemisia monosperma: vicenin-2, lucenin-2, acacetin 7-glucoside, acacetin 7-rutinoside, the 3-glucosides and 3-rutinosides of quercetin and patuletin, and the 5-glucosides of quercetin and isorhamnetin.From Artemisia herba-alba eight flavonoid glycosides were isolated and identified: isovitexin, vicenin-2, schaftoside, isoschaftoside and the 3-glucosides and 3-rutinosides of quercetin and patuletin.Key Word Index - Artemisia monosperma; A herba-alba; Compositae; flavone and flavonol glycosides.

A NEW GLYCOSYLATED FLAVONOID, 7-O-α-L-RHAMNOPYRANOSYL-4'-O-RUTINOSYLAPIGENIN, IN THE EXUDATE FROM GERMINATING SEEDS OF Sesbania rostrata

The title apigenin triglycoside was isolated (4 mg/6000 seeds) by reversephase column chromatography as the major u.v.-absorbing compound in the exudate of germinating seeds of Sesbania rostrata.The structure was assigned on the basis of u.v. spectra, f.a.b.-mass-spectral and 2D-n.m.r. data.The triglycoside was released continuously from the germinating seeds, but at a decreasing rate during the first two weeks.

Studies on Bignoniaceae: Newbouldiosides D-F, Minor Phenylethanoid Glycosides from Newbouldia laevis, and New Flavonoids from Markhamia zanzibarica and Spathodea campanulata

Continued examination of the stem bark of Newbouldia laevis afforded three minor phenylethanoid glycosides, designated as newbouldiosides D-F. Their structures were elucidated by spectroscopic methods as β-(3,4-dihydroxyphenyl)ethyl 5-O-syringoyl-β-D-apiofuranosyloxy-(1 → 2)-O-[ α-L-rhamnopyranosyl-(1 → 3)]-6-O-E-sinapoyl-β-D-glucopyranoside, β-(3,4-dihydroxyphenyl)ethyl β-D-apiofuranosyloxy-(1 → 2)-O-[ α-L-rhamnopyranosyl-(1 → 3)]-6-O-E-sinapoyl-β-D-glucopyranoside, and β-(3,4-dihydroxyphenyl)ethyl β-D-apiofuranosyloxy-(1 → 2)-O-α-L-rhamnopyranosyl-(1 → 2)-6-O-E-sinapoyl-β-D-glucopyranoside, respectively. These metabolites are the first members possessing a sinapoyl structural element. In addition, the series of naturally occurring flavonoids is extended by the identification of 3′,4′,5,7-tetrahydroxy-5′-methoxyflavanone and apigenin-5-O-α-L-rhamnopyranosyl-7-O-β-D-glucopyranoside obtained from leaf extracts of Markhamia zanzibarica and aromadendrin-7-O-(2″-O-formyl)-β-D-glucopyranoside isolated from Spathodea campanulata. The latter compound is the first example of a flavonoid possessing a formylated glucosyl moiety.

Discovery of Novel Apigenin-Piperazine Hybrids as Potent and Selective Poly (ADP-Ribose) Polymerase-1 (PARP-1) Inhibitors for the Treatment of Cancer

Poly (ADP-ribose) polymerase-1 (PARP-1) is a potential target for the discovery of chemosensitizers and anticancer drugs. Amentoflavone (AMF) is reported to be a selective PARP-1 inhibitor. Here, structural modifications and trimming of AMF have led to a series of AMF derivatives (9a-h) and apigenin-piperazine/piperidine hybrids (14a-p, 15a-p, 17a-h, and 19a-f), respectively. Among these compounds, 15l exhibited a potent PARP-1 inhibitory effect (IC50 = 14.7 nM) and possessed high selectivity to PARP-1 over PARP-2 (61.2-fold). Molecular dynamics simulation and the cellular thermal shift assay revealed that 15l directly bound to the PARP-1 structure. In in vitro and in vivo studies, 15l showed a potent chemotherapy sensitizing effect against A549 cells and a selective cytotoxic effect toward SK-OV-3 cells through PARP-1 inhibition. 15l·2HCl also displayed good ADME characteristics, pharmacokinetic parameters, and a desirable safety margin. These findings demonstrated that 15l·2HCl may serve as a lead compound for chemosensitizers and the (BRCA-1)-deficient cancer therapy.