Friday, 16 June 2017

Kojic acid kháng Caco-2

Kojic acid kháng Caco-2

From Wikipedia, the free encyclopedia
Kojic acid
KojicAcid.svg
Names
IUPAC name
5-Hydroxy-2-(hydroxymethyl)-4H-pyran-4-one
Other names
Kojic acid, 5-Hydroxy-2-(hydroxymethyl)-4-pyrone, 2-Hydroxymethyl-5-hydroxy-γ-pyrone
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
DrugBank
ECHA InfoCard100.007.203
EC Number207-922-4
KEGG
PubChem CID
RTECS numberUQ0875000
UNII
Properties
C6H6O4
Molar mass142.11 g/mol
Appearancewhite
Melting point152 to 155 °C (306 to 311 °F; 425 to 428 K)
Slight
Acidity (pKa)9.40[1]
Hazards
R-phrases(outdated)R36/37/38
S-phrases(outdated)S22, S24/25
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
Kojic acid is a chelation agent produced by several species of fungi, especially Aspergillus oryzae, which has the Japanese common name koji.[2][3] Kojic acid is a by-product in the fermentation process of malting rice, for use in the manufacturing of sake, the Japanese rice wine.[2] It is a mild inhibitor of the formation of pigment in plant and animal tissues, and is used in food and cosmetics to preserve or change colors of substances.[4] It forms a bright red complex with ferric ions.

Biosynthesis[edit]

13C-Labeling studies have revealed at least two pathways to kojic acid. In the usual route, dehydratase enzymes convert glucose to kojic acid. Pentoses are also viable precursors in which case dihydroxyacetone is invoked as an intermediate.[2]

Applications[edit]

Kojic acid may be used on cut fruits to prevent oxidative browning, in seafood to preserve pink and red colors, and in cosmetics to lighten skin. As an example of the latter, it is used to treat skin diseases like melasma.[5] Kojic acid also has antibacterial and antifungal properties.[citation needed] The cocrystals of kojic acid with quercetin were found to have two times better cytotoxic activity to human cervical cancer cells (HeLa) and human colon cancer cells (Caco-2) in comparison with quercetin itself.[6]

Protective effects from radiation-induced damage[edit]

Kojic acid appears to possess marked protective (radioresistance) effects from radiation-induced damage. It increased the 30-day survival rate of mice after exposed to a lethal dose of gamma radiation and had significant radioprotective effects on the hematopoietic system, the immune system and DNA of mice exposed to a 4 Gy sublethal dose of radiation. Pretreatment with Kojic acid has been shown to protect Chinese hamster ovary cells against ionizing radiation-induced damage. Dogs pretreated with kojic acid after whole-body exposure to a lethal dose of 3 Gy gamma radiation had a 51-day survival rate of 66.7% versus the dogs in the 3 Gy irradiation only group, which all died within 16 days of postirradiation.[7]
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Chlorogenic acid (axit caffeoylquinic từ lá Vernonia condensata) kháng Caco-2

Ức chế hoạt tính reductase HMG-CoA và sự thấm mốc cholesterol 

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-695X2016000600738&lng=pt&nrm=iso

Chlorogenic acid (axit caffeoylquinic từ lá Vernonia condensata) kháng Caco-2

From Wikipedia, the free encyclopedia
Chlorogenic acid
Chlorogenic acid
Names
IUPAC name
(1S,3R,4R,5R)-3-{[(2E)-3-(3,4-dihydroxyphenyl)prop-2-enoyl]oxy}-1,4,5-trihydroxycyclohexanecarboxylic acid
Other names
3-(3,4-Dihydroxycinnamoyl)quinate
3-(3,4-Dihydroxycinnamoyl)quinic acid
3-Caffeoylquinate
3-Caffeoylquinic acid
3-CQA
3-O-Caffeoylquinic acid
Chlorogenate
Chlorogenic acid
Heriguard
3-trans-Caffeoylquinic acid
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard100.005.751
PubChem CID
RTECS numberGU8480000
UNII
Properties
C16H18O9
Molar mass354.31 g·mol−1
Density1.28 g/cm3
Melting point207 to 209 °C (405 to 408 °F; 480 to 482 K)
Hazards
Safety data sheetExternal MSDS
R-phrases(outdated)-
S-phrases(outdated)S24 S25 S28 S37 S45
NFPA 704
Flammability code 0: Will not burn. E.g., waterHealth code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentineReactivity (yellow): no hazard codeSpecial hazards (white): no codeNFPA 704 four-colored diamond
0
1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 verify (what is Yes ?)
Infobox references
Chlorogenic acid (CGA) is the ester of caffeic acid and (−)-quinic acid, functioning as an intermediate in lignin biosynthesis.[1] The term "chlorogenic acids" refers to a related polyphenol family of esters, including hydroxycinnamic acids (caffeic acid, ferulic acid and p-coumaric acid) with quinic acid.[2]
Despite the "chloro" of the name, chlorogenic acids contain no chlorine. Instead, the name comes from the Greek χλωρός (light green) and -γένος (a suffix meaning "giving rise to"), pertaining to the green color produced when chlorogenic acids are oxidized.

Chemical properties[edit]

Structurally, chlorogenic acid is the ester formed between caffeic acid and the 3-hydroxyl position of L-quinic acid.[3]Isomers of chlorogenic acid include the caffeoyl ester at other hydroxyl sites on the quinic acid ring: 4-O-caffeoylquinic acid (cryptochlorogenic acid or 4-CQA) and 5-O-caffeoylquinic acid (neochlorogenic acid or 5-CQA). The epimer at position 1 has not yet been reported.[2]
It should be noted that there is considerable ambiguity about the atom-numbering of chlorogenic acid.[4] The order of numbering of atoms on the quinic acid ring was reversed in 1976 following IUPAC guidelines, with the consequence that 3-CQA became 5-CQA, and 5-CQA became 3-CQA. This article uses the original numbering, which was exclusive prior to 1976, (chlorogenic acid being 3-CQA, while neochlorogenic acid is 5-CQA). Thereafter researchers and manufacturers have been divided, with both numbering systems in use. Even the 1976 IUPAC recommendations are not entirely satisfactory when applied to some of the less common chlorogenic acids.[5][unreliable source?]
Structures having more than one caffeic acid group are called isochlorogenic acids, and can be found in coffee.[6] There are several isomers, such as 3,4-dicaffeoylquinic acid and 3,5-dicaffeoylquinic acid[7] and cynarine (1,5-dicaffeoylquinic acid).
Chlorogenic acid UV–visible spectrum with a maximum of absorbance at 325 nm
Chlorogenic acid is freely soluble in ethanol and acetone.

Natural occurrences[edit]

Chlorogenic acid can be found in the bamboo Phyllostachys edulis.[8] as well as in many other plants.[9]
Chlorogenic acid can be found in the shoots of common heather (Calluna vulgaris).[10]

In food[edit]

Chlorogenic acid and the related compounds cryptochlorogenic acid, and neochlorogenic acid have been found in the leaves of Hibiscus sabdariffa.[11] Isomers of chlorogenic acid are found in potatoes.[12] Chlorogenic acid is present in the flesh of eggplants,[13] peaches,[14] prunes,[15] and green tea.[16]

Research[edit]

Taken as a dietary supplement or in coffee, chlorogenic acid has been shown in review articles to have a small reduction in blood pressure,[17][18] and remains under investigation for possible anti-inflammatory effects.[19] Chlorogenic acid has been studied as a possible chemical sensitizer involved in respiratory allergy to certain plant materials.[20]
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