Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 132 )

2018 ( 246 )

2017 ( 246 )

2016 ( 340 )

Custom range...

Search Results: 1 - 10 of 192549 matches for " Petrovi? Slobodan D. "
All listed articles are free for downloading (OA Articles)
Page 1 /192549
Display every page Item
Microwaves in organic chemistry and organic chemical
Mijin Du?an ?.,PetroviSlobodan D.
Hemijska Industrija , 2005, DOI: 10.2298/hemind0510224m
Abstract: The usual way of applying heat to a chemical reaction is the use of a Bunsen burner, an oil or some other type of bath, or an electric heater. In inorganic chemistry, microwave technology has been used since the late 1970s while it has been implemented in organic chemistry since the mid-1980s. Microwave heating has been used in the food industry for almost fifty years. The shorter reaction times and expanded reaction range that is offered by microwave technology are suited to the increased demands in industry. For example, there is a requirement in the pharmaceutical industry for a higher number of a novel chemical entities to be produced, which requires chemists to employ a number of resources to reduce time for the production of compounds. Also, microwaves are used in the food industry, as well as in the pyrolysis of waste materials, sample preparation, the solvent extraction of natural products and the hydrolysis of proteins and peptides.
Confirmation of the reaction pathway for obtaining 1-(stearamidoethyl)-2-hepta-decyl-2-i midazoline
Ru?i? Nenad Lj.,PetroviSlobodan D.
Hemijska Industrija , 2002, DOI: 10.2298/hemind0202043r
Abstract: 2-lmidazolines are components of many products, used in industry and households. 1-(Stearamidoethyl)-2-heptadecyl-2-imidazoline is a surface active compound, which after quaternization with dimethyl sulfate, is used in lubricants, detergents, shampoos, softeners and cosmetics products. Due to its importance, it was essential to establish the exact reaction pathway for obtaining this compound. Diethylene triamine and stearic acid were used as the starting components. Using titrimetric analysis, and IR and 1H NMR spectros-copic analysis, as well as UV-Vis spectrophotometry it was established that the main intermediate was the 1,3-diamide bis(stearamidoethyl)amine. Earlier investigations conducted by some authors, using exclusively titrimetric analysis, showed that the main intermediate was the 1,2-diamide. In this paper it was proved that the assumption of these authors that salicylaldehiyde would react only with the primary and not the secondary amine groups was wrong. 1,2-Diamide is the main product of the hydrolysis of 1-(stearamido-ethyl)-2-heptadecyl-2-imidazoline. It was shown, in this paper that the reaction of diethylene triamine with stearic acid in xylene at the reflux temperature, yields the salt of 1-(stearamidoethyl)-2-heptadecyl-2-imidazoline and stearic acid.
Obtaining of the antioxidants by supercritical fluid extraction
Babovi? Nada V.,PetroviSlobodan D.
Hemijska Industrija , 2011, DOI: 10.2298/hemind100713064b
Abstract: One of the important trends in the food industry today is demand for natural antioxidants from plant material. Synthetic antioxidants such as butylated hydroxytoluene (BHT), and butylated hydroxyanisole (BHA) are now being replaced by the natural antioxidants because of theirs possible toxicity and as they may act as promoters of carcinogens. The natural antioxidants may show equivalent or higher antioxidant activity than the endogenous or the synthetic antioxidants. Thus, great effort is being devoted to the search for alternative and cheap sources of natural antioxidants, as well as to the development of efficient and selective extraction techniques. The supercritical fluid extraction (SFE) with carbon dioxide is considered to be the most suitable method for producing natural antioxidants for the use in food industry. The supercritical extract does not contain residual organic solvents as in conventional extraction processes, which makes these products suitable for use in food, cosmetic and pharmaceutical industry. The recovery of antioxidants from plant sources involves many problematic aspects: choice of an adequate source (in terms of availability, cost, difference in phenolic content with variety and season); selection of the optimal recovery procedure (in terms of yield, simplicity, industrial application, cost); chemical analysis of extracts (for optimization purposes a fast colorimetric method is more preferable than a chromatographic one); evaluation of the antioxidant power (preferably by the different assay methods). The paper presents information about different operational methods for SFE of bioactive compounds from natural sources. It also includes the various reports on the antioxidant activity of the supercritical extracts from Lamiaceae herbs, in comparison with the activity of the synthetic antioxidants and the extracts from Lamiaceae herbs obtained by the conventional methods.
Enalapril: Synthesis and properties
Mijin Du?an ?.,Stankovi? Milena,PetroviSlobodan D.
Hemijska Industrija , 2004, DOI: 10.2298/hemind0408355m
Abstract: Enalapril was originally synthesized by Merck Sharp and Dohme and is an angiotensin converting enzyme inhibitor. Thus, enalapril is used in the treatment of mild to severe hypertension. Enalapril is chemically (S)-1-[N-[1-(et-hoxycarbonyl)-3-phenylpropyl]-L-alanyl]-L-prolin and although the first synthesis was published in 1980, it can be obtained using different synthetic pathways. This paper describes the synthesis as well as the properties and stability of enalapril.
Ibuprofen: Synthesis, production and properties
Mijin Du?an ?.,Stankovi? Milena,PetroviSlobodan D.
Hemijska Industrija , 2003, DOI: 10.2298/hemind0305199m
Abstract: Since its introduction in 1969, ibuprofen has become one of the most common painkillers in the world. Ibuprofen in an NSAID (non-steroidal anti-inflammatory drug) and like other drugs of its class it possesses analgetic, antipyretic and anti-inflammatory properties. While ibuprofen is a relatively simple molecule, there is still sufficient structural complexity to ensure that a large number of different synthetic approaches are possible. Since the introduction of pharmaceutical products containing ibuprofen, industrial and academic scientists have developed many potential production processes. This paper describes the history, synthesis and production, as well as the properties and stability of ibuprofen.
The characteristics of novel dosage forms
Mili?-A?krabi? Jela,PetroviSlobodan D.
Hemijska Industrija , 2003, DOI: 10.2298/hemind0310424m
Abstract: The objective of pharmaceutical-technological development is to find a procedure of transforming an active substance (a drug) into a drug dosage form which is not only acceptable for application, but also enables the active substance to be released following administration, pursuant to therapy objectives. The aim is that the concentration of the active substance in the action location rapidly reaches a therapeutic level and maintains an approximately constant level in the course of a particular time, according to the established therapeutic goal. The primary objective is to present the active ingredient (drug) in the form and concentration/quantity that enables the corresponding therapeutic response, i.e. to control the site and rate of medicinal substance release from the drug, as well as the rate at which it reaches the membranes and surfaces to which it is absorbed, while applying a common method of administration. The procedures used to achieve this goal are becoming highly complex and demanding and are aiming at sophisticated drug delivery systems and functional packaging material. Development from the existing drug molecule, through the conventional drug dosage form, to a new system of drug "delivery" (novel delivery system), can improve the drug (active substance) characteristics significantly in view of compliance (acceptability by the patient), safety and efficiency. The paper presents an overview of the most important examples of pharmaceutical forms with controlled release and advanced drug "carriers".
Intellectual property and regulation of functional foods
Jovanovi? Slobodanka,PetroviSlobodan D.,Sikora Sonja
Industrija , 2012,
Abstract: Today, there exist scientific evidences that functional foods have favorable physiological and psychological effects as well as additional functions in relation to health, apart from the basic nutritional effects, thus offering the potential of enhance health or reduced the risk of diseases. Since interest in this category of foods has increased, new products have appeared as well as the need to introduce and set up standards and guidelines for the development and promotion of such foods. Technological development in this area and involvement of great multinationals in research investment and development of new products have reinforced the importance of the intellectual property rights, especially of patent protections and trademarks.
Modern catalysis in the synthesis of some pharmaceuticals and fine chemicals
PetroviSlobodan D.,Mi?i?-Vukovi? Milica M.,Mijin Du?an ?.
Hemijska Industrija , 2002, DOI: 10.2298/hemind0201010p
Abstract: Catalysis in the synthesis of Pharmaceuticals and line chemicals nowadays becomes more and more important. Synthesis that minimizes wastes is important from the economical aspect, as well as from the environmental aspect. "Green chemistry" or "green technology" is an effort to protect the environment by increasing the efficiency of the overall synthetic processes in the chemical industry by minimizing or eliminating wasteful by-products. Modern catalytic methods in the synthesis of some Pharmaceuticals and fine chemicals are discussed such as phase-transfer catalysis, biocatalysis asymmetric catalysis and, generally, solid-phase chemistry.
Properties and synthesis of milrinone
Mirkovi? Jelena M.,Mijin Du?an ?.,PetroviSlobodan D.
Hemijska Industrija , 2013, DOI: 10.2298/hemind120410057m
Abstract: Milrinone, 1,6-dihydro-2-methyl-6-oxo-[3,4’-bipyridine]-5-carbonitrile, is a positive inotropic cardiotonic agent with vasodilator properties that acts as selective phosphodiesterase 3 inhibitor in cardiac and vascular smooth muscle. Trade names of milrinone are Primacor, Corotrop, Corotrope, and Milrila. Milrinone, an amrinone derivative, is 20 to 50 times more active than amrinone and possesses reduced propensity to side effects. The use of milrinone has created controversy in the medical as the result of increased mortality rate among patients that received high amounts of milrinone in oral form. Reaserch show that it can be benifitial for patients with severe congestive heart failure when used as short-time intravenous therapy. Milrinone properties, stability, as well as mechanism of action and synthesis under laboratory and industry conditions have been described in this paper. For industrial purposes milrinone is synthesized by condensation of cyanoacetamide with 4-(dimethylamino)-3-(4-pyridinyl)-3-buten-2-one and 4-ethoxy-3-(4-pyridinyl)-3-buten-2-one in presence of a base, or by the reaction of 1-(4-pyridinyl)- 2-propanone with ethoxymethylenmalononitrile or 4-alkoxy-3-(4-pyridinyl)-3-buten-2-one with malononitrile without the use of external base. The starting compound for these syntheses is 4-picoline. Alternative synthesis of milrinone starts from 2-methyl-3-(4-pyridylidiene)-1,1,5-tricyano-1,4-pentadiene-5-carboxamide and 2-methyl-6-oxo-1,6-dihydro-3,4’-bipyridine-5-carboxamide. Lastly, methods for milrinone synthesis in laboratory, injection preparation and purification have been summarized.
Acetylsalicylic acid: Incoming 150 years of the first synthesis
Mijin Du?an ?.,Stankovi? Milena,PetroviSlobodan D.,Blagojevi? Milorad
Hemijska Industrija , 2002, DOI: 10.2298/hemind0210401m
Abstract: Acetylsalicylic acid is one of the most fascinating and versatile drugs known to medicine, as well as one of the oldest. Acetylsalicylic acid is a drug which is safe, with analgetic, antirheumatic, anti-inflammatory antiplatelet and antithrombotic action. It may be applied not only in clinical practice, but also as prevention. The first known use of an acetylsalicylic acid-like preparation can be traced to ancient Greece. In 1853 Charles Gerhardt published the first synthesis of acetylsalicylic acid. Felix Hoffmann, a chemist for Friedrich Bayer, a German dye company obtained a patent on acetylsalicylic acid some 40 years later. Bayer coined the name Aspirin for the new product. The 20 in century was the century in which many researchers in many companies tried to improve the synthesis of acetylsalicylic acid not only in terms of yield but also purity. This paper describes the history, use, mechanism of action, synthesis and production as well as the purification and stability of acetylsalicylic acid.
Page 1 /192549
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.