- Angiogenesis process / tube formation: Anti-tube formation (IC50 = 28.3 μM for Isoliquiritin in vascular endothelial cells) [1]
- Monoamine neurotransmitters (5-HT and NE) in hippocampus, hypothalamus, and cortex [2]
- Oxidative stress pathway: reduces ROS and MDA, increases SOD and CAT activities [4]
- Mitochondrial apoptotic pathway: down-regulates Bax, caspase-3, cytochrome C; up-regulates Bcl-2 [4]
- Nrf2 signaling pathway: activates Nrf2, increases HO-1 and NQO1 expression [5]
- NF-κB signaling pathway: inhibits NF-κB p65, IKKβ, COX-2, iNOS, TNF-α, IL-1β, IL-8, ICAM-1, VCAM-1, E-selectin [5]
- p38 MAPK pathway: inhibits p38 MAPK and p-p38 MAPK expression [5]

Isoliquiritigenin (0-400 μg/mL) effectively inhibits the growth of plant pathogenic fungi [3]. Isoliquiritigenin (0-100 μg/mL, 4 hours) effectively inhibits P. litchii sporangia [3]. Isoliquiritigenin (20 μM, 24 hours) prevents ketone (400 μM) from disinfecting PC12 cells, decreases LDH release, boosts SOD and CAT activity, and lowers ROS and MDA levels [4].

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Isoliquiritin (1-100 μM) inhibited tube formation from vascular endothelial cells cultured in type I collagen gel with 2% FBS-DMEM in a concentration-dependent manner with an IC50 value of 28.3 μM (20-40). The potency of Isoliquiritin for anti-tube formation was 44-fold greater than that of licorice extract. [1]
The anti-tube formation effects of licorice-derived flavonoids showed potency in the order: isoliquiritigenin > Isoliquiritin > liquiritigenin >> isoliquiritin-apioside. Isoliquiritigenin had an IC50 of 7.39 μM (4.78-11.4) and liquiritigenin had an IC50 of 39.2 μM (17.1-90.1). [1]
Glycyrrhizin (1-100 μM) and glycyrrhetinic acid (1-10 μM) increased tube formation in a concentration-dependent manner. The increasing effect of glycyrrhetinic acid was 10-fold greater than that of glycyrrhizin. Isoliquiritin (0.42-42 μg/ml) significantly inhibited the glycyrrhizin (82 μg/ml)-induced increase in tube formation in a concentration-dependent fashion. The inhibitory effect of Isoliquiritin in the presence of glycyrrhizin was 0.28-fold weaker than that of Isoliquiritin alone. [1]
Isoliquiritin exhibited significant antifungal activity against Peronophthora litchi Chen with an EC50 of 27.33 mg/L (15.49-48.23) for mycelial growth inhibition. At 200 mg/L, it inhibited mycelial growth by 96.45%; at 400 mg/L, it completely inhibited mycelial growth. [3]
Isoliquiritin inhibited sporangia germination of P. litchi Chen in a concentration-dependent manner. At 70 mg/L and 100 mg/L, the inhibitory effects on sporangia germination were 70.89% and 82.5%, respectively. Treated sporangia showed deformed germ tubes with chunky, nodular swelling, distortion, multi-site germination, and multi-branching at the germ tube base. [3]
In PC12 cells, Isoliquiritin (20 μmol·L⁻¹) significantly prevented corticosterone (400 μmol·L⁻¹)-induced cell apoptosis. Cell viability increased to 72.7% of control compared to 51.8% in corticosterone-only treated group. LDH release decreased to 119.2% compared to 155.7% in corticosterone-only group. [4]
Isoliquiritin (20 μmol·L⁻¹) increased SOD and CAT activities (to 80.1% and 78.7% respectively) and decreased ROS and MDA levels (to 133.6% and 105.0% respectively) in corticosterone-treated PC12 cells. [4]
Isoliquiritin (20 μmol·L⁻¹) reduced corticosterone-induced intracellular calcium overload (from 303.1% to 172.3% of control) and prevented mitochondrial membrane potential dissipation (MMP decline rate reduced from 32.2% to 19.6%). [4]
Isoliquiritin down-regulated Bax, caspase-3, and cytochrome C protein expression, and up-regulated Bcl-2 protein expression in corticosterone-treated PC12 cells. [4]
In MGN rats, Isoliquiritin (10 mg/kg/day) increased renal mRNA expression levels of Nrf2, HO-1, and NQO1, and decreased Keap1 mRNA expression. Immunohistochemistry showed increased distribution of Nrf2, HO-1, NQO1 proteins and decreased Keap1 distribution in glomerular and tubular regions. [5]
Isoliquiritin decreased mRNA expression of NF-κB p65, IKKβ, TNF-α, IL-1β, IL-8, ICAM-1, VCAM-1, MCP-1, and E-selectin in MGN rat kidneys. Western blot analysis showed decreased nuclear NF-κB p65 and decreased p-IKKβ protein expression. [5]
Isoliquiritin reduced p38 MAPK and p-p38 MAPK protein expression levels in MGN rat kidneys as shown by immunohistochemistry and Western blotting. [5]

Isoliquiritigenin (0.31-3.1 mg/kg, intraperitoneal injection, once a day for 5 days) prevents the growth of granuloma angiogenesis in mice [1]. 10–40 mg/kg of isoliquiritigenin administered intraperitoneally once day for five days. Similar antidepressant effects are seen in mouse FST and TST tests when isoliquiritigenin (10–40 mg/kg) is injected intraperitoneally [2]. In certain animal models, active BSA-induced membranous glomerulonephritis can be treated with isoliquiritin (10 mg/kg/day, sidewall), which possesses anti-inflammatory and antioxidant qualities [5].

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Isoliquiritin (0.31-3.1 mg/kg, i.p.) inhibited granuloma angiogenesis in adjuvant-induced chronic inflammation in mice with an ID50 of 1.46 mg/kg (0.824-2.58) for carmine content (an index of newly formed blood vessels). The potency of Isoliquiritin was 50-fold greater than that of licorice extract. Isoliquiritin also inhibited pouch fluid weight with an ID50 of 0.771 mg/kg (0.513-1.18), with potency 18-fold greater than licorice extract. [1]
Glycyrrhizin (20-80 mg/kg) inhibited carmine content but with less than 50% inhibition and weaker potency than licorice extract. [1]
In mouse forced swimming test (FST) and tail suspension test (TST), Isoliquiritin at doses of 10, 20, and 40 mg/kg (oral gavage, 30 min before test) significantly reduced immobility time. The 20 mg/kg dose showed the most significant activity among the three doses. Isoliquiritin had no central nervous system-stimulating effects as measured by locomotor activity (389.1±26.8 counts vs 408±26.1 for vehicle). [2]
Isoliquiritin (20 mg/kg) significantly increased 5-HT and NE concentrations in mouse hippocampus, hypothalamus, and cortex in both FST and TST models. It also significantly reduced the 5-HIAA/5-HT ratio in hippocampus, hypothalamus, and cortex, indicating slowed 5-HT metabolism. No significant changes in DA concentrations were observed. [2]
In detached leaf test for antifungal activity, Isoliquiritin at concentrations of 100-400 mg/L showed dose-dependent inhibitory effect against P. litchi Chen. At 400 mg/L, the inhibitory effect was 86.42%, similar to that of 25% metalaxyl-propamocarb WP diluted 500 times. [3]
In cationic bovine serum albumin (C-BSA)-induced membranous glomerulonephritis (MGN) rat model, Isoliquiritin (10 mg/kg/day orally for 4 weeks) significantly reduced kidney weights and somatic indices, reduced urinary protein, serum creatinine, BUN, adiponectin, total cholesterol, and serum triglycerides levels compared to MGN untreated rats. Histopathological analysis showed that Isoliquiritin attenuated severe pathological conditions to mild pathological changes in the mesangium and interstitium. [5]

The antifungal activity of Isoliquiritin against P. litchi Chen was tested using the agar dilution method. PDA medium was poured into sterilized Petri dishes and measured amounts of Isoliquiritin were added to give desired concentrations (0, 1, 5, 10, 50, 100, 200, and 400 mg/L). A 6 mm diameter disc of inocula was cut from the periphery of an actively growing culture and placed at the center of each fresh Petri plate. Culture plates were incubated at 25±1°C for 5 days. The percentage of inhibition of mycelial growth was calculated as (dc-dt)/dc × 100, where dc was the mean colony diameter for control and dt was the mean colony diameter for treatment. [3]
Relative electric conductivity was measured to assess cell membrane permeability of P. litchi Chen. Fungal cells were centrifuged at 4000g for 10 min, washed twice with sterilized water, and resuspended in sterilized water. Isoliquiritin at 40 and 80 mg/L was added and electric conductivity was measured using a conductivity meter at 2, 4, 6, 8, and 10 hours. [3]
Reducing sugar content was analyzed by the DNS colorimetric method. After incubation with Isoliquiritin at 40 and 80 mg/L for 3, 6, 12, 18, and 24 hours, samples were centrifuged at 4000g for 10 min. Supernatant (2 mL) was mixed with 1.5 mL DNS reagent, heated in boiling water for 5 min, cooled, and absorbance measured at 520 nm. Reducing sugar concentration was calculated based on a standard curve with D-glucose. [3]
NF-κB p65 DNA binding activity was estimated using a kit in nuclear extracts of kidney tissue from MGN rats. [5]

Primary cultured vascular endothelial cells from rat thoracic aorta were used. EC (2.6±0.1×10⁴ cells/well) were cultured in 10% FBS-DMEM (0.5 mL) at 37°C for 20-24 hours on a collagen gel prepared by solidifying 0.3 mL of 0.15% type I collagen solution. The EC-cultured medium was aspirated and the same volume of collagen solution was overlaid and solidified. EC were cultured with 2% FBS-DMEM in the presence or absence of drugs for 4 days. The medium was changed every other day. Tube formation was measured by photographing 4 randomly selected fields from each dish at ×36 magnification on day 4. Total tubular length was measured using Graphic Software. [1]
PC12 cells were cultured in RPMI-1640 containing 10% heat-inactivated FBS, 100 U/mL penicillin, and 100 μg/mL streptomycin in 5% CO₂ at 37°C. For cytoprotective studies, cells were divided into control, corticosterone (400 μmol·L⁻¹), and corticosterone plus Isoliquiritin groups. Isoliquiritin was applied 3 hours prior to corticosterone treatment. Cell viability was measured by MTT assay. PC12 cells (2×10⁴ cells/well) in 96-well plates were treated for 24 hours, then 10 μL MTT (5 mg/mL) was added. After 4 hours at 37°C, medium was removed and 100 μL DMSO was added to dissolve formazan crystals. Absorbance was measured at 570 nm. [4]
LDH release was measured using an assay kit. PC12 cells (1×10⁵ cells/well) in 24-well plates were treated, and LDH release was calculated as (LDH activity in medium/total LDH activity) × 100%. [4]
Hoechst 33342 and PI double staining was performed. Cells were incubated with 5 mg/mL Hoechst 33342 for 10 min, washed twice with PBS, incubated with 1 μg/mL PI for 10 min, and visualized by inverted fluorescence microscopy. [4]
Annexin V and PI double staining for apoptosis detection: Cells were harvested, washed with PBS, incubated with Annexin V working solution containing PI (1 μg/mL final concentration) for 15 min at room temperature in the dark, and apoptosis rates were determined by flow cytometry. [4]
Intracellular calcium level was measured using Fura-3/AM (final concentration 5 μmol·L⁻¹). Cells were incubated with Fura-3/AM for 30 min at 37°C, washed twice, incubated for an additional 30 min, and fluorescence intensity was determined by flow cytometry. [4]
Mitochondrial membrane potential was measured using JC-1. Cells (1×10⁶ cells/mL) were incubated with JC-1 (final concentration 2 mmol·L⁻¹) for 30 min in the dark, washed twice, and MMP was determined by flow cytometry. [4]
Intracellular ROS level was measured using DCFH-DA (final concentration 10 mmol·L⁻¹). Cells were incubated for 30 min at 37°C in darkness, washed three times with PBS, and fluorescence intensity was measured by flow cytometry. [4]
Western blot analysis: Cells were lysed with RIPA lysis buffer containing 1% PMSF, centrifuged at 12,000 rpm for 15 min at 4°C, and supernatants collected. Protein (50 μg) was separated by electrophoresis on 12% SDS-PAGE gels, transferred onto PVDF membranes, blocked with 5% non-fat milk, incubated with primary antibodies overnight at 4°C, then with fluorescent secondary antibodies for 2 hours at room temperature, and scanned by fluorescent scanner. [4]
SOD and CAT activities and MDA levels were measured using commercial assay kits. Cells were washed with ice-cold PBS, homogenized, centrifuged at 1000 rpm for 10 min at 4°C, and the precipitation was analyzed. [4]
For RT-PCR analysis, total RNA was extracted using TRIzol reagent, quantified, and reverse transcription performed using cDNA synthesis kit. RT-PCR was carried out in triplicates using SYBR GREEN PCR master mix. Relative quantitation of mRNA expression was performed by 2⁻ΔΔCT method. β-actin was used as housekeeping gene. [5]
Immunohistochemistry: Kidney sections were deparaffinized, rehydrated, and antigen retrieved with 10 mM citrate buffer (pH 6.0). Sections were blocked with BSA, incubated with primary antibody (1:100 dilution in 5% BSA), washed with PBS, incubated with biotinylated secondary antibody for 1 hour, then with DAB, counterstained with hematoxylin, and images captured. [5]

Animal/Disease Models: Forced swim test (FST) and Mice in the tail suspension test (TST) [2] Doses: 10, 20 and 40 mg/kg
Route of Administration: po (oral gavage)
Experimental Results: diminished immobility time in mice FST and TST. Increases 5-HT and NE levels in the hippocampus, hypothalamus and cortex and decreases the 5-HIAA/5-HT ratio.

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Male ddY mice (6-7 weeks old) were used for adjuvant-induced pouch granuloma angiogenesis. Freund's complete adjuvant emulsion was prepared with 2 mg heat-killed M. tuberculosis per mL of Freund's incomplete adjuvant. Three mL of air was injected subcutaneously into the dorsum under ether anesthesia. After 24 hours, 0.5 mL of FCA emulsion containing 0.1% croton oil was injected into the air pouch under ether anesthesia. Isoliquiritin (0.31-1.3 mg/kg), licorice extract (12.5-100 mg/kg), and glycyrrhizin (20-80 mg/kg) were suspended in saline containing 1% Avicel and injected intraperitoneally into mice 2 hours after FCA injection and then subsequently once a day for 4-5 days. On day 5 after FCA injection, mice were injected with 10% carmine solution containing 5% gelatin into the tail vein. Cadavers were cooled below 4°C for several hours. Granuloma tissues and pouch fluid were isolated and weighed. Carmine content was measured at 490 nm. [1]
Male Swiss mice (weighing 22-25 g) were used for forced swimming test and tail suspension test. Isoliquiritin at doses of 10, 20, and 40 mg/kg was dissolved in deionized water and administered via gastric intubation (0.1 mL/10 g of mouse) 30 minutes before test session. Fluoxetine (20 mg/kg) was used as positive control. For FST, mice were forced to swim individually for 6 minutes in a glass cylinder (20 cm × 14 cm) containing fresh water up to 10 cm height at 25±1°C. Immobility duration was recorded during the final 4 minutes. For TST, each mouse was individually suspended by its tail using a clamp (2 cm from the end) for 6 minutes in a box (25×25×30 cm). Immobility duration was recorded during the 6-minute test period. Locomotor activity was measured by an activity-monitoring system. Four mice were placed in four cylinders (15 cm diameter, 25 cm high) 30 minutes after drug administration, and total locomotor activity was automatically recorded for 5 minutes. [2]
For neurotransmitter analysis, mice were sacrificed by decapitation after activity tests, brains were rapidly removed, and hippocampus, hypothalamus, and cortex were dissected on an ice-cold plate and stored at -80°C. Brain regions were weighed and homogenized by ultrasonication in ice-cold 0.02 M perchloric acid containing internal standard (DHBA at 1.0 μM). Homogenates were centrifuged at 14,000 rpm at 4°C, and supernatant was filtered through 0.45 μm membrane filter. Neurotransmitter concentrations were determined by HPLC-ECD. [2]
For antifungal detached leaf test, tender leaves of Litchi chinensis of similar shape, size, and age were washed with distilled water and dried at room temperature. Isoliquiritin was dissolved in distilled water with 0.1% Tween-80 to obtain 0, 100, 150, 200, 250, 300, 350, 400 mg/L concentrations. Twenty-five percent metalaxyl-propamocarb WP diluted 500 times was used as positive control. Ten leaves per treatment were immersed into drug-containing solution for 10 min and dried at room temperature. Treated leaves were placed on wet filter paper in Petri dishes. Sporangia suspension (5×10⁵ cfu/mL) was sprayed on the back of leaves, and leaves were incubated at 25±1°C for 72 hours. Disease index and antifungal effect were calculated. [3]
Adult male Sprague-Dawley rats (225±20 g) were used for membranous glomerulonephritis model. MGN was induced by daily intravenous injection of cationic C-BSA for 4 weeks with gradual dose increase from day 1 to day 7: 1 mg, 1 mg, 1 mg, 1.5 mg, 1.5 mg, 2 mg, 2 mg, followed by constant dose of 2.5 mg for next 3 weeks. MGN condition was confirmed by 24-hour proteinuria. Isoliquiritin (10 mg/kg/day) and TPCA-1 (IKKβ inhibitor, 10 mg/kg/day) were dissolved in distilled water and DMSO respectively, and administered orally for 28 consecutive days. Rats were divided into 4 groups: normal control, MGN control, MGN + Isoliquiritin, and MGN + TPCA-1 (6 animals per group). Before experimental completion, rats were placed in metabolic cages to collect urine for analysis. After experimental period, animals were sacrificed, blood was collected by cardiac puncture, and kidneys were collected, weighed, and stored at -80°C for analyses. Kidneys were fixed in 10% neutral formalin buffer for histological studies. [5]

Isoliquiritin alone at concentrations within 1-50 μmol·L⁻¹ showed no significant changes on PC12 cell viability. At 100 μmol·L⁻¹, slight damage on cell survival rate was observed. [4]
No significant changes in body weights were observed in MGN rats treated with Isoliquiritin (10 mg/kg/day) compared to control rats, indicating no systemic toxicity. [5]

[1]. Inhibitory effect of isoliquiritin, a compound in licorice root, on angiogenesis in vivo and tube formation in vitro. Biol Pharm Bull. 1995 Oct;18(10):1382-6.

[2]. Antidepressant-like effects of liquiritin and isoliquiritin from Glycyrrhiza uralensis in the forced swimming test and tail suspension test in mice. Prog Neuropsychopharmacol Biol Psychiatry. 2008 Jul 1;32(5):1179-84.

[3]. Antifungal Activity of Isoliquiritin and Its Inhibitory Effect against Peronophythora litchi Chen through a Membrane Damage Mechanism. Molecules. 2016 Feb 19;21(2):237.

[4]. Protective effect of isoliquiritin against corticosterone-induced neurotoxicity in PC12 cells. Food Funct. 2017 Mar 22;8(3):1235-1244.

[5]. Renoprotective Effects Of Isoliquiritin Against Cationic Bovine Serum Albumin-Induced Membranous Glomerulonephritis In Experimental Rat Model Through Its Anti-Oxidative And Anti-Inflammatory Properties. Drug Des Devel Ther. 2019 Oct 30;13:3735-3751.

Isoliquiritin is a monosaccharide derivative with the structure trans-chalcone, substituted with hydroxyl groups at the 2' and 4' positions and with a β-D-glucopyranoside at the 4' position. It possesses antitumor activity and is also a plant metabolite. Isoliquiritin belongs to the chalcone, resorcinol, β-D-glucoside, and monosaccharide derivative classes. Its function is related to trans-chalcone. Isoliquiritin has been reported to be found in licorice (Glycyrrhiza uralensis), licorice root (Glycyrrhiza aspera), and other organisms with relevant data. See also: Glycyrrhiza glabra (partial).

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Isoliquiritin is a licorice-derived flavonoid. Its anti-angiogenic effect depends on anti-tube formation. The combined effect of a mixture of glycyrrhizin (82 μg/mL) and Isoliquiritin (4.2 μg/mL) at a concentration ratio similar to their yield ratio in licorice extract (0.8-1.6% for isoliquiritin) corresponded to the effect of 100 μg/mL licorice extract. The anti-angiogenic mode of Isoliquiritin was associated with inhibitory action on tube formation. [1]
The antidepressant-like mechanism of Isoliquiritin may be related to increased 5-HT and NE in the CNS. Isoliquiritin and liquiritin are glycosides of isoliquiritigenin and liquiritigenin respectively, and their antidepressant mechanism may also be related to monoamine oxidase inhibition. [2]
Isoliquiritin exhibits broad-spectrum antifungal activity against phytopathogenic fungi including P. litchii Chen, P. capsici Leonian, S. sclerotiorum, and C. herbarum. The antifungal mechanism involves membrane disruption causing cytoplasm leakage, mycelial distortion, increased cell membrane permeability, and reduced reducing sugar contents. [3]
Isoliquiritin exerts neuroprotective effects against corticosterone-induced neurotoxicity in PC12 cells through antioxidant action (reducing ROS and MDA, increasing SOD and CAT), inhibition of intracellular calcium overload, and inhibition of mitochondrial apoptotic pathway (down-regulating Bax, caspase-3, cytochrome C; up-regulating Bcl-2). [4]
Isoliquiritin has renoprotective effects in C-BSA induced membranous glomerulonephritis through activation of Nrf2 signaling pathway (increasing Nrf2, HO-1, NQO1; decreasing Keap1) and inhibition of NF-κB signaling pathway (decreasing NF-κB p65, IKKβ, COX-2, iNOS, TNF-α, IL-1β, IL-8, ICAM-1, VCAM-1, E-selectin, MCP-1) and p38 MAPK pathway. [5]

C21H22O9

418.3940

418.126

5041-81-6

5318591

Yellow to green solid

1.5±0.1 g/cm3

743.5±60.0 °C at 760 mmHg

185-186ºC

263.3±26.4 °C

0.0±2.6 mmHg at 25°C

1.707

0.76

6

9

6

30

589

5

O1[C@]([H])([C@@]([H])([C@]([H])([C@@]([H])([C@@]1([H])C([H])([H])O[H])O[H])O[H])O[H])OC1C([H])=C([H])C(/C(/[H])=C(\[H])/C(C2C([H])=C([H])C(=C([H])C=2O[H])O[H])=O)=C([H])C=1[H]

YNWXJFQOCHMPCK-LXGDFETPSA-N

InChI=1S/C21H22O9/c22-10-17-18(26)19(27)20(28)21(30-17)29-13-5-1-11(2-6-13)3-8-15(24)14-7-4-12(23)9-16(14)25/h1-9,17-23,25-28H,10H2/b8-3+/t17-,18-,19+,20-,21-/m1/s1

(E)-1-(2,4-dihydroxyphenyl)-3-[4-[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyphenyl]prop-2-en-1-one

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~125 mg/mL (~298.76 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (4.97 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.08 mg/mL (4.97 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
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.

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 (Please use freshly prepared in vivo formulations for optimal results.)