EVALUATION OF THE SYNTHESIS AND STRUCTURE OF NEW AZETIDIN-2-ONES OF FERULIC ACID.

AIM: To synthesize some new azetidin-2-ones of ferulic acid and to evaluate them from physicochemical and spectral point of view. MATERIAL AND METHODS: The synthesis was carried out in several steps: (i) obtaining the ferulic acid chloride; (ii) obtaining the ferulic acid hydrazide with hydrazine hydrate (98%); (iii) condensation of ferulic acid hydrazide with different benzaldehydes (2-hydroxy-/2-nitro-/4-chloro-/4- fluoro-/4-bromo-benzaldehyde) in order to obtain the corresponding hydrazones; (iv) cy- clization of ferulic acid hydrazones with chloroacethyl chloride in freshly distilled toluene medium and in the presence of triethylamine, resulting in the corresponding azetidin-2-ones. RESULTS: Six new azetidin-2-ones of ferulic acid were synthesized. They were characterized in terms of their physicochemical properties and their structure was confirmed by IR and 1H-NMR spectroscopy. CONCLUSIONS: Six new azetidin-2-ones of ferulic acid were synthesized, physicochemically characterized and validated spectrally. A

Synthesis and biological evaluation of new 1,3-thiazolidine-4-one derivatives of nitro-l-arginine methyl ester.

BACKGROUND: l-Arginine is a semi-essential aminoacid with important role in regulation of physiological processes in humans. It serves as precursor for the synthesis of proteins and is also substrate for different enzymes such as nitric oxide synthase. This amino-acid act as free radical scavenger, inhibits the activity of pro-oxidant enzymes and thus acts as an antioxidant and has also bactericidal effect against a broad spectrum of bacteria. RESULTS: New thiazolidine-4-one derivatives of nitro-l-arginine methyl ester (NO2-Arg-OMe) have been synthesized and biologically evaluated in terms of antioxidant and antibacterial/antifungal activity. The structures of the synthesized compounds were confirmed by (1)H, (13)C NMR, Mass and IR spectral data. The antioxidant potential was investigated using in vitro methods based on ferric/phosphomolybdenum reducing antioxidant power and DPPH/ABTS radical scavenging assay. The antibacterial effect was investigated against Gram positive (Staphylococcus aureus ATCC 25923, Sarcina lutea ATCC 9341) and Gram negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853) bacterial strains. The antifungal activity was also investigated against Candida spp. (Candida albicans ATCC 10231, Candida glabrata ATCC MYA 2950, Candida parapsilosis ATCC 22019). CONCLUSIONS: Synthesized compounds showed a good antioxidant activity in comparison with the NO2-Arg-OMe. The antimicrobial results support the selectivity of tested compounds especially on P. aeruginosa as bacterial strain and C. parapsilosis as fungal strain. The most proper compounds were 6g (R = 3-OCH3) and 6h (R = 2-OCH3) which showed a high free radical (DPPH, ABTS) scavenging ability and 6j (R = 2-NO2) that was the most active on both bacterial and fungal strains and also it showed the highest ABTS radical scavenging ability.Graphical abstract1: ethyl 3-aminopropionate hydrochloride, 2a-j: aromatic aldehydes, 3: thioglycolic acid, 4a-j: thiazolidine-propionic acid derivatives , 5: Nω-nitro-L-arginine methyl ester hydrochloride, 6a-j: thiazolidine-propionyl-nitro-L-arginine methyl ester derivatives.

New antimicrobial chitosan derivatives for wound dressing applications.

Chitosan is a non-toxic, biocompatible, biodegradable natural cationic polymer known for its low imunogenicity, antimicrobial, antioxidant effects and wound-healing activity. To improve its therapeutic potential, new chitosan-sulfonamide derivatives have been designed to develop new wound dressing biomaterials. The structural, morphological and physico-chemical properties of synthesized chitosan derivatives were analyzed by FT-IR, (1)H NMR spectroscopy, scanning electron microscopy, swelling ability and porosity. Antimicrobial, in vivo testing and biodegradation behavior have been also performed. The chitosan derivative membranes showed improved swelling and biodegradation rate, which are important characteristics required for the wound healing process. The antimicrobial assay evidenced that chitosan-based sulfadiazine, sulfadimethoxine and sulfamethoxazole derivatives were the most active. The MTT assay showed that some of chitosan derivatives are nontoxic. Furthermore, the in vivo study on burn wound model induced in Wistar rats demonstrated an improved healing effect and enhanced epithelialization of chitosan-sulfonamide derivatives compared to neat chitosan. The obtained results strongly recommend the use of some of the newly developed chitosan derivatives as antimicrobial wound dressing biomaterials.

Development and Characterization of Novel Films Based on Sulfonamide-Chitosan Derivatives for Potential Wound Dressing.

The objective of this study was to develop new films based on chitosan functionalized with sulfonamide drugs (sulfametoxydiazine, sulfadiazine, sulfadimetho-xine, sulfamethoxazol, sulfamerazine, sulfizoxazol) in order to enhance the biological effects of chitosan. The morphology and physical properties of functionalized chitosan films as well the antioxidant effects of sulfonamide-chitosan derivatives were investigated. The chitosan-derivative films showed a rough surface and hydrophilic properties, which are very important features for their use as a wound dressing. The film based on chitosan-sulfisoxazol (CS-S6) showed the highest swelling ratio (197%) and the highest biodegradation rate (63.04%) in comparison to chitosan film for which the swelling ratio was 190% and biodegradation rate was only 10%. Referring to the antioxidant effects the most active was chitosan-sulfamerazine (CS-S5) which was 8.3 times more active than chitosan related to DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging ability. This compound showed also a good ferric reducing power and improved total antioxidant capacity.

HYPOGLYCEMIA INDUCED BY ANTIDIABETIC SULFONYLUREAS.

Diabetes mellitus is a major health problem due to its increasing prevalence and life-threatening complications. Antidiabetic sulfonylureas represent the first-line drugs in type 2 diabetes even though the most common associated risk is pharmacologically-induced hypoglycemia. In the development of this side effect are involved several factors including the pharmacokinetic and pharmacodynamic profile of the drug, patient age and behavior, hepatic or renal dysfunctions, or other drugs associated with a high risk of interactions. If all these are controlled, the risk-benefit balance can be equal to other oral antidiabetic drugs.

Synthesis and biological evaluation of new 1,3-thiazolidine-4-one derivatives of 2-(4-isobutylphenyl)propionic acid.

New thiazolidine-4-one derivatives of 2-(4-isobutylphenyl)propionic acid (ibuprofen) have been synthesized as potential anti-inflammatory drugs. The structure of the new compounds was proved using spectral methods (FR-IR, 1H-NMR, 13C-NMR, MS). The in vitro antioxidant potential of the synthesized compounds was evaluated according to the total antioxidant activity, the DPPH and ABTS radical scavenging assays. Reactive oxygen species (ROS) and free radicals are considered to be involved in many pathological events like diabetes mellitus, neurodegenerative diseases, cancer, infections and more recently, in inflammation. It is known that overproduction of free radicals may initiate and amplify the inflammatory process via upregulation of genes involved in the production of proinflammatory cytokines and adhesion molecules. The chemical modulation of acyl hydrazones of ibuprofen 3a-l through cyclization to the corresponding thiazolidine-4-ones 4a-n led to increased antioxidant potential, as all thiazolidine-4-ones were more active than their parent acyl hydrazones and also ibuprofen. The most active compounds are the thiazolidine-4-ones 4e, m, which showed the highest DPPH radical scavenging ability, their activity being comparable with vitamin E.

Development and optimization of the synthesis of new thiazolidin-4-one derivatives of ibuprofen.

UNLABELLED: Ibuprofen, an important nonsteroidal anti-inflammatory agent, is one of the most prescribed drugs for the treatment of pain and inflammation from various rheumatic diseases, but some side effects can occur on long-term use. AIM: The method for synthesis optimization of new derivatives of Ibuprofen with thiazolidin-4-one moiety, with improved pharmacological and toxicological profile. MATERIAL AND METHODS: To optimize the derivatization method of free carboxyl group of Ibuprofen (2-(4-isobutylphenyl)propionic acid) the reaction conditions were varied (reagent ratio, catalyst, reaction medium). RESULTS: The most favorable method was proved to be the reaction between ibuprofen hydrazone and mercaptoacetic acid, in excess, at 80-85 degrees C, for 6 h with 96% conversion rate. CONCLUSIONS: The synthesis of 2-phenyl-3-[2-(4-(isobutyl)phenyl)-2-methyl]acetamido-thiazolidin-4-one derivative was optimized in view of applying it as a general procedure for the synthesis of other derivatives with related structure. The chemical structure and molecular weight of the synthesized compound were confirmed by spectral methods (IR, 1H NMR, 13C NMR, HR-MS).

New hydrazones of ferulic acid: synthesis, characterization and biological activity.

UNLABELLED: The ferulic acid (4-hydroxy-3-methoxy-cinnamic acid) is a phenolic compound with important antioxidant effects and which nowadays is being extensively studied for his potential indications in inflammatory and neurodegenerative diseases, hypertension, atherosclerosis, etc. AIM: The synthesis of new ferulic acid compounds with potential antioxidant activity. MATERIAL AND METHODS: The synthesis of the designed compounds was performed in several steps: (i) the obtaining of ferulic acid chloride by reacting of ferulic acid with thionyl chloride; (ii) the reaction between the ferulic acid chloride and hydrazine hydrate 98% to obtain the ferulic acid hydrazide; (iii) the condensation of ferrulic acid hydrazide with various benzaldehydes (2-hydroxy/3-hydroxy/4-hydroxy/2-nitro/3-nitro/4-nitro/2-methoxi/ 4-chloro/4-fluoro/4-bromo-benzaldehyde) resulting the correspond- ing hydrazones. RESULTS: The structure of the synthesized compounds was confirmed by FT-IR spectroscopy and the evaluation of antioxidant potential was achieved by determining the total antioxidant capacity and reducing power. CONCLUSIONS: In this study new hydrazones of ferulic acid have been synthesized, physic-chemical and spectral characterized. The evaluation of antioxidant potential using in vitro methods showed the favorable influence of the structural modulation on the antioxidant effects of ferulic acid.

New derivatives of aryl-propionic acid. Synthesis and biological evaluation.

AIM: To design new derivatives of aryl-propionic acid with potential antibacterial and antioxidant activity. MATERIAL AND METHODS: New hydrazone of ibuprofen (2-(4-isobutylphenyl)propionic acid) have been synthesized by reaction of ethyl ester of ibuprofen with hydrazine hydrate and then condensation of corresponding hydrazide with various aromatic aldehydes. RESULTS: The synthesized compounds were screened for their antibacterial activity against Gram positive (Staphylococcus aureus ATCC 25923, Sarcinalutea ATCC 9341, Bacillus cereus ATCC 14579, Bacillus subtilis) and Gram negative bacterial strains (Escherichia coli ATCC 25922). Some of them were found to have good antibacterial activity. The antioxidant activity of these compounds was also tested using the total antiox idant capacity test. CONCLUSIONS: The chemical modulations performed on ibuprofen structure have a good influence on the biological activity of the synthesized compounds.

Importance of sulfonamide moiety in current and future therapy.

Sulfonamides and their different derivatives are extensively used in therapy due to their pharmacological properties. Sulfa drugs were amongst the oldest synthesized antimicrobial agents and are still widely used today to treat different microbial infections. Clinical treatment with sulfonamides has regained confidence with the use of a combination of sulfamethoxazole and trimethoprim to treat urinary tract bacterial infections. Today, they are widely used as antimicrobial agents, chiefly because of their low cost, low toxicity and excellent activity against bacterial diseases. Over the course of time, the application of sulfonamides has been extended from their use as antimicrobial agents to anticancer agents, antiglaucoma agents, inhibitors of gamma-secretase, cyclooxgenase-2 and lipoxygenase, anticonvulsivant agents, hypoglycemic agents.

Chitosan/hyaluronic acid polyelectrolyte complex hydrogels in the management of burn wounds.

AIM: This paper is a short review on the state-of-the-art of the use of polyelectrolyte complexes containing polysaccharides for wound and burn healing and treatment using the chitosan/hyaluronic acid polyelectrolyte complex (PEC) hydrogel. RESULTS AND CONCLUSIONS: PEC is suitable for wound healing because a wet treatment can be realized and both components of PEC contribute by their properties to the enhanced antimicrobial activity, promote wound healing and prevent wound damage during treatment.

Synthesis and evaluation of antioxidant activity of some new benzylidene-thiazolidine-xanthine derivatives.

UNLABELLED: The International Diabetes Federation reported that 246 million adults worldwide had diabetes mellitus and the prevalence of this syndrome was expected to increase continuously. AIM: To design new compound with potential antidiabetic and antioxidant activity. MATERIAL AND METHODS: New benzylidene-thiazolidine derivatives (BT2a-2e) were obtained by condensation of xanthine-thiazolidine-4-one (TZ-4-one) with aromatic aldehydes. The synthesized compounds were characterized by spectral method (IR, 1H-NMR, 13C-NMR) and their antioxidant potential has been also evaluated. RESULTS: The synthesized compounds have important antioxidant effects as compared to xanthine-thiazolidine derivatives. The most active compounds were those obtained by condensation with 4-dimethylaminobenzaldehyde (BT2c) and 4-nitro-benzaldehyde (BT2e). CONCLUSIONS: The chemical modulations performed on the structure of TZD-4-one have a good influence on their antioxidant potential.

[Incretin modulators, a new perspective in diabetes mellitus treatment]. / Modulatorii incretinelor, o noua perspectiva în tratamentul diabetului zaharat.

AIM: The study was designed to present the modern therapy used for the treatment of type 2 diabetes mellitus (T2DM). MATERIAL AND METHODS: Diabetes mellitus and the pharmacological and the pharmacokinetic characteristics of the incretins and of the incretin modulators are presented. RESULTS: Diabetes mellitus is a chronic metabolic disorder, which is considered to be a major health issue all over the world. World Health Organization indicates that world-wide almost 3 million deaths per year are caused by diabetes and 1,5 million new cases are diagnosed annually, T2DM representing approximately 90-95% of the diagnosed cases. This form of diabetes mellitus is characterized by several path physiological defects including insulin resistance at peripheral target tissues, excess hepatic glucose production and progressive pancreatic beta cell dysfunction. The newest direction in the treatment of T2DM mellitus is the incretin modulators. The incretins (GLP-1--glucagon-like-peptide-1 and GIP--glucose-dependent insulin tropic peptide), are natural hormones that contribute to glucose homeostasis by acting on the pancreas, gastrointestinal tract, muscle and brain tissue. After secretion, GLP-1 and GIP are immediately metabolized by dipeptidyl peptidase IV enzyme (DPP IV), which limits their therapeutic use. CONCLUSIONS: In order to achieve optimal glycemic control, by using the therapeutic effects of incretins, research has been directed to the development of synthetic analogues of GLP-1 resistant to DPP IV enzyme inactivation and DPP IV inhibitors.