Dissolution Enthalpies and Entropies of Potassium Fluoride in N,N-Dimethylacetamide, Diethanolamine, Sulfolane, Pyridine at 300-367 K

Dimerisation of trifluoropropenenitrile (I) in the presence of potassium fluoride and tertiary amines afforded a mixture of stereoisomeric perfluoro-4-methyl-pentenedinitriles (II), higher-boiling compounds, and 2,3,3,3-tetrafluoropropanenitrile (III) which arises by proton transfer from the solvent molecule. Under optimum conditions, product II was obtained in about 50% yield. Reaction of the nitrile I with methyl trifluoropropenoate (IV) gave, besides the dimers II and V, the product of addition of the nitrile I to the propenoate, IV, i.e. methyl 4-cyanoperfluoro-2-pentenoate (VI), and the addition product of the propenoate IV to the nitrile I, i.e. methyl 4-cyanoperfluoro-2-methyl-3-butenoate (VII). The relative reactivity if I and IV is discussed. The ratio of stereoisomers in II, V, VI and VII indicates that the magnitude of the steric substituent effect, operating in the reaction mechanism, decreases in the order -CFCF3.(COOCH3) > -CFCF3(CN) > -COOCH3 > -CN.

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The effect of equal fluoride concentrations in silver diamine fluoride and potassium fluoride on demineralized dentin during pH‐cycling: chemical data

European Journal Of Oral Sciences ◽

10.1111/eos.12789 ◽

2021 ◽

Author(s):

Marwa Alhothali ◽

Rob Exterkate ◽

Maxim Lagerweij ◽

Mark Buijs ◽

Cor Loveren ◽

...

Keyword(s):

Potassium Fluoride ◽

Chemical Data ◽

Silver Diamine Fluoride ◽

Ph Cycling ◽

Demineralized Dentin

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Application of Commercially Available Anhydrous Potassium Fluoride for a Convenient Synthesis of Ketene Dithioacetals

Journal of Chemical Research ◽

10.1177/174751989902300819 ◽

1999 ◽

Vol 23 (8) ◽

pp. 492-493

Author(s):

Sabir H. Mashraqui ◽

Harini Hariharasubrahmanian

Keyword(s):

Carbon Disulfide ◽

Alkylating Agent ◽

Potassium Fluoride ◽

Solid Support ◽

Ambient Conditions ◽

Ketene Dithioacetals ◽

Convenient Synthesis ◽

Active Methylene Compounds ◽

Active Methylene

Commercially available anhydrous KF without activation or solid support promotes condensation between active methylene compounds, carbon disulfide and an alkylating agent in dry DMF to allow the preparation of a variety of ketene dithioacetals in fair to good yields under ambient conditions.

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Low Dose of Fluoride in the Culture Medium of Cordyceps militaris Promotes Its Growth and Enhances Bioactives with Antioxidant and Anticancer Properties

Journal of Fungi ◽

10.3390/jof7050342 ◽

2021 ◽

Vol 7 (5) ◽

pp. 342

Author(s):

Xiaoshuai Li ◽

Jia Wang ◽

Huayue Zhang ◽

Long Xiao ◽

Zhongfang Lei ◽

...

Keyword(s):

Low Dose ◽

Radical Scavenging ◽

Potassium Fluoride ◽

Cordyceps Militaris ◽

Carotenoid Content ◽

Market Demand ◽

Fruiting Bodies ◽

Human Osteosarcoma Cells ◽

Wide Range ◽

Bioactive Ingredients

Cordyceps militaris possesses several compounds with medicinal properties, and is commonly used in traditional Chinese functional food and medicine for a variety of health benefits. Because of its rare occurrence in nature, the market demand for artificial C. militaris is on the rise. Furthermore, efforts to increase its bioactive ingredients have also been considered in research. In this study, we aimed to investigate the effect of fluoride on the growth and enrichment of bioactive compounds in C. militaris. A wide range of potassium fluoride concentrations (0, 0.001, 0.01, 0.1, and 1 mM) were added to the culture media as a source of fluoride during the cultivation of C. militaris fruiting bodies. The contents of fluorine and bioactive substances of the fruiting bodies in normal (NM) and fluorine-supplemented (FM) media were measured and compared. C. militaris raised in the growth medium supplemented with 0.01 mM potassium fluoride led to a 44.86% (1.55 ± 0.14 g/bottle) increase in biomass and a 23.43% (3161.38 ± 35.71 µg/g) increase in total carotenoid content in the fruiting bodies. Furthermore, a remarkable increase in superoxide dismutase-like activity (84.75 U/mg) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (IC50 = 2.59 mg/mL) was recorded. In human cancer cell-based assays, C. militaris raised in FM caused stronger cytotoxicity, apoptosis, and cell cycle arrest in human osteosarcoma cells. These results demonstrated that a low dose of fluoride could stimulate the growth of C. militaris fruiting bodies and enhance the production of bioactive ingredients that possess useful antioxidant and anticancer activities.

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