Betacarotene 7235-40-7 GlpBio

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Product Data Sheet

Product Name: Cat. No.: Chemical Name:

Betacarotene GC10582

1,3,3-trimethyl-2-[(1E,3E,5E,7E,9E,11E,13E,15E,17E)-3,7,12,16-tetramethyl-18-(2,6,6-trimethylcyclohexen-1-yl)octadeca-1,3,5,7,9,11,13,15,17-nonaenyl]cyclohexene

CHEMICAL PROPERTIES Cas No.: 7235-40-7 Molecular Formula: Molecular Weight: Storage: Solubility:

Chemical Structure:

C40H56 536.87 Powder

>9.6mg/mL in DMSO

Background

β-Carotene is a strongly colored red-orange pigment abundant in plants and fruits. It is an organic compound and chemically is classified as a hydrocarbon and specifically as a terpenoid (isoprenoid), reflecting its derivation from isoprene units. β-Carotene is biosynthesized from geranylgeranyl pyrophosphate. It is a member of the carotenes, which are tetraterpenes, synthesized biochemically from eight isoprene units and thus having 40 carbons. Among this general class of carotenes, β-carotene is distinguished by having beta-rings at both ends of the molecule. Absorption of β-carotene is enhanced if eaten with fats, as carotenes are fat soluble References:

[1]Li CJ, Averboukh L, Pardee AB. beta-Lapachone, a novel DNA topoisomerase I inhibitor with a mode of action different from camptothecin. J Biol Chem. 1993 Oct 25;268(30):22463-8.

[2]Li YZ, Li CJ, Pinto AV, Pardee AB. Release of mitochondrial cytochrome C in both apoptosis and necrosis induced by beta-lapachone in human carcinoma cells. Mol Med. 1999 Apr;5(4):232-9.

[3]Huang L, Pardee AB. beta-lapachone induces cell cycle arrest and apoptosis in human colon cancer cells. Mol Med. 1999 Nov;5(11):711-20.

Research Update

1. Effect of Hydrofluoric Acid Concentration and Etching Time on Bond Strength to Lithium Disilicate Glass Ceramic. Oper Dent. 2017 Nov/Dec;42(6):606-615. doi: 10.2341/16-215-L. Epub 2017 Jul 14. PMID:28708007 Abstract

The aim of this study was to evaluate the influence of different concentrations of hydrofluoric acid (HF) associated with varied etching times on the microshear bond strength (μSBS) of a resin cement to a lithium disilicate glass ceramic. Two hundred seventy-five ceramic blocks (IPS e.max Press [EMX], Ivoclar Vivadent), measuring 8 mm × 3 mm thickness, were randomly distributed into five groups according to the HF concentrations (n=50): 1%, 2.5%, 5%, 7.5%, and 10%.

2. Does acid etching morphologically and chemically affect lithium disilicate glass ceramic surfaces? J Appl Biomater Funct Mater. 2017 Jan 26;15(1):e93-e100. doi: 10.5301/jabfm.5000303. PMID:27647389 Abstract

BACKGROUND: This study evaluated the surface morphology, chemical composition and adhesiveness of lithium disilicate glass ceramic after acid etching with hydrofluoric acid or phosphoric acid.METHODS: Lithium disilicate glass ceramic specimens polished by 600-grit silicon carbide paper were subjected to one or a combination of these surface treatments: airborne particle abrasion with 50-μm alumina (AA), etching with 5% hydrofluoric acid (HF) or 36% phosphoric acid (Phos), and application of silane coupling agent (Si). 3. Fatigue failure load of feldspathic ceramic crowns after hydrofluoric acid etching at different concentrations. J Prosthet Dent. 2018 Feb;119(2):278-285. doi: 10.1016/j.prosdent.2017.03.021. Epub 2017 May 26. PMID:28552291 Abstract

STATEMENT OF PROBLEM: Hydrofluoric acid etching modifies the cementation surface of ceramic restorations, which is the same surface where failure is initiated. Information regarding the influence of hydrofluoric acid etching on the cyclic loads to failure of ceramic crowns is lacking.PURPOSE: The purpose of this in vitro study was to evaluate the influence of different hydrofluoric acid concentrations on the fatigue failure loads of feldspathic ceramic crowns.