Cimetna kiselina i njeni derivati

Cinnamic acid (3-phenylpropenoic or phenylacrylic acid) and its derivatives occur naturally in a number of plants. Th ey are precursors in the biosynthetic pathways of many alkaloids, aromatic amino acids, phenylpropanoids, styrenes, stilbenes, coumarins, lignins and fl avonoids, and are present in various essential oils, gums and balsams. Cinnamic acid derivatives are used in large quantities in the food, cosmetic and pharmaceutical industries. In addition, they possess a variety of pharmacological activities: antimicrobial, antitubercular, antioxidative, antimicrobial, antimalarial, antiviral, antidiabetic, hepatoprotective, antidepressant, anxiolytic, hypolipemic, anti-infl ammatory and cytostatic activities. Several drugs with cinnamic acid motifs are used in modern therapy (panobinostat, belinostat, cinanserin, tranilast, ozagrel and entacapone)

Lijekovi s fluorom

Naturally occurring organofluorine compounds are extremely rare. On the other hand, there are almost million of synthetic organofluorine compounds and their number is growing rapidly. Due to their unique physicochemical and biological characteristics, they are widely used as pharmaceuticals, materials and agrochemicals. Strategic incorporation of fluorine in drug-candidate became a common strategy in drug design and development. Organofluorine compounds have increased lipophilicity, membrane permeability, thermal and metabolic stability, and enhanced binding affinity to the targeted macromolecules compared to their nonfluorinated analogs. About 20 % of the currently marketed drugs contain fluorine. Organofluorine drugs are particularly popular among inhalation anesthetics, glucocorticoids, anticancer drugs, neuroleptics and antidepressants. Many blockbuster pharmaceuticals such as fluoxetine, rosuvastatin, atorvastatin, celecoxib, sitagliptin etc. contain fluorine. 18F-radiolabeled 2-fl uoro-2-deoxyglucose, florbetapir, florbetaben, flutemetamol and fluorodopa are used in positron emission tomography (PET) as medical diagnostics of neurodegenerative diseases and cancer. Inorganic compound sodium fluoride is used for the prevention of tooth decay. The fluoride enhances the strength of teeth by the formation of fluorapatite, a naturally occurring component of tooth enamel. Sodium fluoride, hexafluorosilicic acid and sodium hexafluorosilicate are commonly used for water fluoridation, while sodium and tin(II) fluoride are components of toothpaste

Reactions of the aldehyde carbonyl group with nitrosobenzenes. Kinetic studies leading to a new synthetic route to the N-phenylhydroxamic acids

Five N-phenylhydroxamic acids were synthesized in high yields start ing from substituted nitrosobenzenes and formaIdehyde, in water acidic medium under the specific acid catalysis conditions as well as under the general acid-catalysis conditions for the reaction of nitrosobenzenes with formaIdehyde

Reactions with N-(1-benzotriazolylcarbonyl)-amino acids. IV. The use of N-(1-benzotriazolylcarbonyl)-amino acid derivates in peptide synthesis

The use of the 1-benzotriazolylearbonyl-(Bte)-group as an N-protecting and N-activating group in the synthesis of peptides was investigated. Removal of the Btc group from N-Btc-amino acids, their esters and amides under acidic conditions is possible, but has no advantages over removal of benzyloxyearbonyl-(Z)-group. N-Btc-amino acid esters react with Z-amino acids or Z-dipeptides yielding Z-dipeptide and Z-tripeptide esters, respcetively. This process is aceompanied with separation of benzotriazole and C02. Advantages and disadvantages of this method of peptide bond formation are discussed

Reaktionen mit N-(1- Benzotriazolylcarbonyl)-aminosauren.III Synthese von Aminosaure-estern

N-(l-Benzotriazolylcarbonyl)-aminosauren· (Ia-f) reagieren mit Alkoholen unter Abspaltung von Benzotriazol und Kohlendioxid zu den entsprechenden Aminosaure-Estern. (Ila-i). Die Reaktion verlauft bei Raumtemperatur und wird durch Zugabe von Triethylamin beschleunigt