Skullcapflavone II is a flavonoid found in skullcap that has anti~inflammatory and antibacterial effects. Skullcapflavone II regulates osteoclast differentiation, survival, and function. Skullcapflavone II has strong anti-bacterial effect against M. aurum and M. bovis BCG.

Physicochemical Properties

Molecular Formula	C19H18O8
Molecular Weight	374.34142
Exact Mass	374.1
CAS #	55084-08-7
PubChem CID	124211
Appearance	Light yellow to yellow solid powder
Density	1.4±0.1 g/cm3
Boiling Point	636.9±55.0 °C at 760 mmHg
Flash Point	230.9±25.0 °C
Vapour Pressure	0.0±1.9 mmHg at 25°C
Index of Refraction	1.613
LogP	1.58
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	8
Rotatable Bond Count	5
Heavy Atom Count	27
Complexity	564
Defined Atom Stereocenter Count	0
InChi Key	GMQFOKBGMKVUQZ-UHFFFAOYSA-N
InChi Code	InChI=1S/C19H18O8/c1-23-11-7-5-6-9(20)13(11)12-8-10(21)14-15(22)17(24-2)19(26-4)18(25-3)16(14)27-12/h5-8,20,22H,1-4H3
Chemical Name	5-hydroxy-2-(2-hydroxy-6-methoxyphenyl)-6,7,8-trimethoxychromen-4-one
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture and light.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	Due to their recognized redox sensitivity, Scutellaria baicalensis flavonoid II suppresses osteoclastogenesis via decreasing the activation of MAPK, Src, and cAMP response element binding protein (CREB). By scavenging ROS or activating nuclear factor-erythroid 2-related factor 2 (Nrf2), Scutellaria baicalensis flavonoid II lowers ROS. Its effects can be partially countered by either Nrf2 deficiency or concurrent hydrogen peroxide treatment [2].
ln Vivo	Skullcapflavone II is a possible bradykinin antagonist that, through inhibiting the TGF-β1/Smad signaling pathway, at least partially, lessens the main pathophysiology aspects of allergic asthma [3].
References	[1]. Flavonoids as Novel Efflux Pump Inhibitors and Antimicrobials Against Both Environmental and Pathogenic Intracellular Mycobacterial Species. Molecules. 2020;25(3):734. Published 2020 Feb 7. [2]. Skullcapflavone II inhibits osteoclastogenesis by regulating reactive oxygen species and attenuates the survival and resorption function of osteoclasts by modulating integrin signaling. FASEB J. 2019;33(2):2026-2036. [3]. Skullcapflavone II inhibits ovalbumin-induced airway inflammation in a mouse model of asthma [published correction appears in Int Immunopharmacol. 2013 Sep;17(1):154]. Int Immunopharmacol. 2012;12(4):666-674.
Additional Infomation	Scullcapflavone II is a tetramethoxyflavone that is flavone substituted by methoxy groups at positions 6, 7, 8 and 6' and hydroxy groups at positons 5 and 2' respectively. It has a role as a plant metabolite, an anti-asthmatic drug and an EC 1.6.5.2 [NAD(P)H dehydrogenase (quinone)] inhibitor. It is a tetramethoxyflavone and a dihydroxyflavone. It is functionally related to a flavone. Skullcapflavone II has been reported in Lagochilus leiacanthus, Scutellaria alpina, and other organisms with data available.

Solubility Data

Solubility (In Vitro)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Solubility (In Vivo)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples. Injection Formulations (e.g. IP/IV/IM/SC) Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] *Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline) Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline) Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline) Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil) Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Oral Formulations Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). Oral Formulation 3: Dissolved in PEG400 Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose Oral Formulation 6: Mixing with food powders Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.6714 mL	13.3568 mL	26.7137 mL
	5 mM	0.5343 mL	2.6714 mL	5.3427 mL
	10 mM	0.2671 mL	1.3357 mL	2.6714 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.