|Source:||From the Aspergillus parasiticus.|
|Biological Activity or Inhibitors:||1. Kojic acid exhibits a competitive inhibition for the oxidation of chlorogenic acid and catechol by potato polyphenol oxidase (PPO) and of 4-methylcatechol and chlorogenic acid by apple PPO.
2. Kojic acid has significant tyrosinase inhibitory activity.
3. Kojic acid has been used as a food additive for preventing enzymatic browning of crustaceans and as a cosmetic agent for skin whitening.
4. Kojic acid exhibits concentration-dependent scavenging activity on DPPH possessing strong antioxidant activity, it can reduce the mortality induced by gamma irradiation.
|Solvent:||Chloroform, Dichloromethane, Ethyl Acetate, DMSO, Acetone, etc.|
|Storage:||Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months(2-8C).
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20C. Generally, these will be useable for up to two weeks. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.
Need more advice on solubility, usage and handling? Please email to: email@example.com
|After receiving:||The packaging of the product may have turned upside down during transportation, resulting in the natural compounds adhering to the neck or cap of the vial. take the vial out of its packaging and gently shake to let the compounds fall to the bottom of the vial. for liquid products, centrifuge at 200-500 RPM to gather the liquid at the bottom of the vial. try to avoid loss or contamination during handling.|
|1 mg||5 mg||10 mg||20 mg||25 mg|
|1 mM||7.0368 mL||35.184 mL||70.368 mL||140.736 mL||175.9201 mL|
|5 mM||1.4074 mL||7.0368 mL||14.0736 mL||28.1472 mL||35.184 mL|
|10 mM||0.7037 mL||3.5184 mL||7.0368 mL||14.0736 mL||17.592 mL|
|50 mM||0.1407 mL||0.7037 mL||1.4074 mL||2.8147 mL||3.5184 mL|
|100 mM||0.0704 mL||0.3518 mL||0.7037 mL||1.4074 mL||1.7592 mL|
Journal of Agricultural & Food Chemistry, 1991 , 39 (8) :1396-401.
|Inhibitory effect of kojic acid on some plant and crustacean polyphenol oxidases.[Reference: WebLink]|
|Kojic acid exhibited a competitive inhibition for the oxidation of chlorogenic acid and catechol by potato polyphenol oxidase (PPO) and of 4-methylcatechol and chlorogenic acid by apple PPO. This compound showed a mixed-type inhibition for white shrimp, grass prawn, and lobster PPO when DL-beta-3,4-dihydroxyphenylalanine (DL-dopa) and catechol were used as substrates but a mixed-type and a competitive inhibition for mushroom PPO when DL-dopa and L-tyrosine were used, respectively. Potato and apple PPOs were shown to have much higher affinities for Dopa than for chlorogenic acid, 4-methylcatechol, and catechol. These two PPOs also had a higher affinity for Dopa than the other four PPOs. Kojic acid is thus an effective inhibitor of PPO on the oxidation of Dopa.|
J Pharm Pharmacol. 1994 Dec;46(12):982-5.
|Kojic acid, a cosmetic skin whitening agent, is a slow-binding inhibitor of catecholase activity of tyrosinase.[Pubmed: 7714722]|
|It was found that Kojic acid, which is used in cosmetics for its excellent whitening effect, inhibits catecholase activity of tyrosinase in a non-classical manner. A decrease in the initial velocity to a steady-state inhibited velocity can be observed over a few minutes. This time-dependence, which is unaltered by prior incubation of the enzyme with the inhibitor, is consistent with a first-order transition. The kinetic data obtained correspond to those for a postulated mechanism that involves the rapid formation of an enzyme inhibitor complex that subsequently undergoes a relatively slow reversible reaction. Kinetic parameters characterizing this type of inhibition were evaluated by means of nonlinear regression of product accumulation curves.|
Toxicol Sci. 2004 Sep;81(1):43-9.
|Enhancement of hepatocarcinogenesis by kojic acid in rat two-stage models after initiation with N-bis(2-hydroxypropyl)nitrosamine or N-diethylnitrosamine.[Pubmed: 15201437]|
|Kojic acid (KA) has been used as a food additive for preventing enzymatic browning of crustaceans and as a cosmetic agent for skin whitening. In the present experiments, effects of KA on the induction of hepatic pre-neoplastic lesions in N-bis(2-hydroxypropyl)nitrosamine-initiated (experiment 1) and non-initiated (experiment 2) models, and its promoting influence in a medium-term liver bioassay (experiment 3) were investigated at dietary doses of up to 2% in male F344 rats. These results demonstrate tumor-promoting and possible hepatocarcinogenic activity of KA at 2%, but the carcinogenic potential is likely to be weak. This study also indicated that enhanced replication of hepatocytes related to toxic changes might be involved as an underlying mechanism.|
Arch Pharm Res. 2003 Jul;26(7):532-4.
|Gamma-pyrone derivatives, kojic acid methyl ethers from a marine-derived fungus Alternaria [correction of Altenaria] sp.[Pubmed: 12934644]|
|Kojic acid dimethyl ether (1), and the known Kojic acid monomethyl ether (2), Kojic acid (3) and phomaligol A (4) have been isolated from the organic extract of the broth of the marine-derived fungus Alternaria sp. collected from the surface of the marine green alga Ulva pertusa. The structures were assigned on the basis of comprehensive spectroscopic analyses. Each isolate was tested for its tyrosinase inhibitory activity. Kojic acid (3) was found to have significant tyrosinase inhibitory activity, but compounds 1, 2, and 4 were found to be inactive.|
Saudi Med J. 2009 Apr;30(4):490-3.
|Radioprotective effects of kojic acid against mortality induced by gamma irradiation in mice.[Pubmed: 19370273]|
|To evaluate the protective effects of Kojic acid on mortality induced by gamma irradiation in mice. The efficacy was compared with amifostine as a reference radioprotector.One hundred and twenty NMRI mice were divided into 6 groups with 20 mice in each group. At 30 days after treatment, the percentage of survival in each group was: control, 5%; 142 mg/kg, 5%; 175 mg/kg, 0%; 232 mg/kg, 30%; 350 mg/kg, 40%; and amifostine, 40% one hour treatment prior gamma irradiation. The survival rate was statistically increased in animals treated with Kojic acid (350 mg/kg), one hour prior irradiation, as compared with the irradiated control group. Kojic acid exhibited concentration-dependent scavenging activity on DPPH possessing strong antioxidant activity. CONCLUSION: Kojic acid with antioxidant activity reduced the mortality induced by gamma irradiation.|