Alfacalcidol

Gefahreninformationscode (GHS)

• Bildanzeige (GHS)

  

• Alarmwort

  Achtung

• Gefahrenhinweise

  H300：Lebensgefahr bei Verschlucken.

Alfacalcidol Chemische Eigenschaften,Einsatz,Produktion Methoden

• R-Sätze Betriebsanweisung:

  R26/27/28:Sehr giftig beim Einatmen, Verschlucken und Berührung mit der Haut.
  R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.

• S-Sätze Betriebsanweisung:

  S28:Bei Berührung mit der Haut sofort abwaschen mit viel . . . (vom Hersteller anzugeben).
  S36/37:Bei der Arbeit geeignete Schutzhandschuhe und Schutzkleidung tragen.
  S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn möglich, dieses Etikett vorzeigen).
  S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
  S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.

• Chemische Eigenschaften

  White Solid

• Originator

  One-Alpha ,Leo ,UK ,1978

• Verwenden

  A synthetic analog of Calcitiol (the hormonal form of vitamin D3), which shows identical potency with respect to stimulation of intestinal calcium absorption and bone mineral mobilization. Vitamin D source

• Definition

  ChEBI: A member of the class of D3 vitamins that is calciol in which the hydrogen at the 1alpha position is replaced by a hydroxy group. It is an active metabolite of cholecalciferol, which performs important functions in reg lation of the calcium balance and the bone metabolism.

• Manufacturing Process

  1. Preparation of 1,4-cyclized adduct of cholesta-1,5,7-trien-β-ol and 4- phenyl-1,2,4-triazoline-3,5-dione: a solution of 400 mg of cholesta-1,5-7- trien-3β-ol in 30 ml of tetrahydrofuran is cooled with ice, and 190 mg of 4- phenyl-1,2,4-triazoline-3,5-dione is added little by little to the solution under agitation. The mixture is agitated at room temperature for 1 hour and the solvent is distilled under reduced pressure. The residue is purified by chromatography using a column packed with silica gel. Fractions eluted with ether-hexane (7:3 v/v) are collected and recrystallization from ether gives 550 mg of a 1,4-cyclized adduct of cholesta-1,5,7-trien-3β-ol and 4-phenyl- 1,2,4-triazoline-3,5-dione having a melting point of 178°C to 182°C.
  2. Preparation of 1,4-cyclized adduct of cholesta-5,7-dien-3β-ol-1α-epoxide and 4-phenyl-1,2,4-triazoline-3,5-dione: 1.25 g of the 1,4-cyclized adduct of cholesta-1,5,7-trien-3β-ol and 4-phenyl-1,2,4-triazoline-3,5-dione is dissolved in 50 ml of chloroform, and 560 mg of m-chloroperbenzoic acid is added to the solution. The mixture is agitated for 20 hours at room temperature, and 200 mg of m-chloroperbenzoic acid is further added and the mixture is agitated again for 20 hours. The reaction mixture liquid is diluted with chloroform, washed with a 10% aqueous solution of potassium carbonate and dried with magnesium sulfate. Then, the solvent is distilled under reduced pressure. The residue is purified by silica gel chromatography, and first effluent fractions eluted with ether are collected, and recrystallization from methanol gives 680 g of a crystal melting at 172°C to 173°C. The second ether effluent fractions are collected, and recrystallization from methanol gives 400 mg of a 1,4-cyclized adduct of cholesta-5,7-dien-3β-ol-1α,2α-epoxide and 4-phenyl-1,2,4-triazoline-3,5-dione having a melting point of 152°C to 154°C.
  3. Preparation of cholesta-5,7-diene-1α,3β-diol: a solution of 500 mg of the 1,4-cyclized adduct of cholesta-5,7-dien-3β-ol-1α,2α-epoxide and 4-phenyl- 1,2,4-triazoline-3,5-dione in 40 ml of tetrahydrofuran is added dropwise under agitation to a solution of 600 mg of lithium aluminum hydride in 30 ml of THF. Then, the reaction mixture liquid is gently refluxed and boiled for 1 hour and cooled, and a saturated aqueous solution of sodium sulfate is added to the reaction mixture to decompose excessive lithium aluminum hydride. The organic solvent layer is separated and dried, and the solvent is distilled. The residue is purified by chromatography using a column packed with silica gel. Fractions eluted with ether-hexane (7:3 v/v) are collected, and recrystallization from the methanol gives 400 mg of cholesta-5,7-diene-1α,3β- diol.
  4. Preparation of 1α,3β-dihydroxyprovitamin D3: a solution of 25 mg of cholesta-5,7-diene-1α,3β-diol in 650 ml of ether is subjected to radiation of ultraviolet rays for 14 minutes in an argon gas atmosphere by passing it through a Vycor filter using a 200-W high pressure mercury lamp (Model 654A-36 manufactured by Hanobia). The solvent is distilled at room temperature under reduced pressure. This operation is repeated twice, and 50 mg of the so obtained crude product is fractionated by chromatography using a column packed with 20 g of Sephadex LH-20. The first effluent fractions eluted with chloroform-hexane (65:35 v/v) give 13.5 mg of oily 1α,3β- dihydroxyprovitamin D3. The composition exhibits a maximum ultraviolet absorption at 260 nm in an ether solution.
  5. Preparation of 1α-hydroxycholecalciferol: a solution of 13.5 mg of 1α,3β- dihydroxyprovitamin D3 in 200 mi of ether is allowed to stand still in the dark at room temperature in an argon gas atmosphere for 2 weeks. During this period, the position of the maximum ultraviolet absorption is shifted from 260 nm to 264 nm, and the absorption intensity becomes 1.6 times as high as the original intensity. The solvent is distilled at room temperature under reduced pressure, and the

• Therapeutic Function

  Calcium regulator, Vitamin

• Allgemeine Beschreibung

  Has biological properties similar to 1α-Hydroxyvitamin D₂ (Cat. No. 679100). Converted to active Calcitriol (1α,25-Dihydroxyvitamin D₃; Cat. No. 679101) in vivo. Inhibits the formation of nephrocalcinosis in streptozotocin-induced diabetic rats fed on low zinc diets.

• Clinical Use

  Vitamin D analogue:
  Increase serum calcium levels
  Suppression of PTH production

• Arzneimittelwechselwirkung

  Potentially hazardous interactions with other drugs
  Carbamazepine, fosphenytoin, phenytoin, phenobarbital and primidone may increase metabolism of alfacalcidol, necessitating larger doses than normal to produce the desired effect.

• Stoffwechsel

  Alfacalcidol is hydroxylated in the liver by the enzyme vitamin D 25-hydroxylase to form the active 1,25-dihydroxycolecalciferol (calcitriol). Calcitriol is inactivated in both the kidney and the intestine, through the formation of a number of intermediates including the formation of the 1,24,25-trihydroxy derivatives. Vitamin D compounds and their metabolites are excreted mainly in the bile and faeces with only small amounts appearing in urine; there is some enterohepatic recycling but it is considered to have a negligible contribution to vitamin D status.

Alfacalcidol Upstream-Materialien And Downstream Produkte

Alfacalcidol Anbieter Lieferant Produzent Hersteller Vertrieb Händler.

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