Methotrexate is an organic compound with the chemical formula C20H22N8O5. It is mainly used as an anti-folate anti-tumor drug. By inhibiting dihydrofolate reductase, it can hinder the synthesis of tumor cells and inhibit the growth and reproduction of tumor cells.
Appearance: yellow crystalline powder.
Solubility: Soluble in dilute alkali, acid or alkali metal carbonate solution, slightly soluble in dilute hydrochloric acid, almost insoluble in water, ethanol, chloroform, ether.
Methotrexate is an antifolic acid antitumor drug, which has an inhibitory effect on many animal tumors. Experiments have shown that this drug works by competitive inhibition of dihydrofolate reductase. Dihydrofolate reductase is an important enzyme in DNA synthesis, especially in the conversion of folate to tetrahydrofolate and the methylation of deoxyuracil nucleoside to thymine nucleoside. This drug selectively acts on the DNA synthesis phase (that is, S phase), and is a cycle-specific drug. Recently, it has been suggested that this product has a second action point, that is, the G1/S transition phase, it can also inhibit the synthesis of interleukin-2 and inhibit the chemotactic effect of neutrophils, so it has immunosuppressive and anti-inflammatory effects. In large doses, it also has direct toxic effects on non-proliferating cells, especially hepatocytes, and CF is commonly used as an antidote in clinic.
The structure of methotrexate (MTX) is similar to folic acid, and the hydroxy group at 4 and the hydrogen at 10 NH are amino and CH3 respectively in MTX. MTX binds to dihydrofolate reductase, blocking the reduction of folate and dihydrofolate to activated tetrahydrofolate, thus inhibiting intracellular one-carbon transfer, affecting purine synthesis and deoxyuracil nucleotide conversion to deoxythymine nucleotide, and blocking DNA and RNA synthesis. MTX, at concentrations of 10-8mol/L in plasma, can effectively block the incorporation of deoxyuracil nucleotides into DNA via deoxythymine nucleotides, while inhibiting purine synthesis at concentrations of 10-7mol/L. The binding of MTX to dihydrofolate reductase is reversible but firm. The amount of dihydrofolate is 1000 times higher than MTX to resist MTX binding. In vitro, MTX can induce the differentiation of human chorionic epithelial cancer cells and increase the production of chorionic gonadotropin when the concentration is lower than that which completely inhibits DNA synthesis. MTX is a cell cycle specific drug, which mainly acts on S phase cells, has some effect on G1 phase, and has a delaying effect on G1/S.
Tá go leor monarchana ardchaighdeáin againn le comhar domhain, ar féidir leo táirgí ardchaighdeáin agus praghsanna iomaíocha a sholáthar duit. Agus is féidir linn lascainí a thabhairt freisin le haghaidh ceannach mórchóir. Tá an t-am seachadta thart ar 3-20 lá tar éis an íocaíocht a dhaingniú.
1. An bhfuil tú ag monarcha nó ag cuideachta thrádála?
Is cuideachta muid a chomhtháthaíonn tionscal agus trádáil, a sholáthraíonn seirbhís aon-stad. D'fhéadfaí glacadh le OEM.
2. An soláthraíonn tú samplaí? An bhfuil sé saor in aisce nó breise?
Samplaí saor in aisce. Ní mór táille lasta an tsampla a íoc le do thaobh.
3. An bhfuil aon deimhnithe agat a bhaineann le rialú cáilíochta?
Deimhniú ISO 9001:2008 chun cáilíocht a chinntiú.
4. Cad ba cheart dom a sholáthar chun luachan a fháil?
Cuireann Pls in iúl dúinn an cineál táirge atá uait, cainníocht a ordú, seoladh agus ceanglais shonracha. Déanfar an luachan le haghaidh do thagairt in am.
5. Cén cineál modh íocaíochta is fearr leat? Cén cineál téarmaí a nglactar leo?
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