Study of the relationship between geometric isomerism and biologically active properties of compounds

The results of the research in the field of studying the relationship of the geometric structure of organic compounds with their biological activity are presented. It has been shown that the stereospecific structure of organic and inorganic molecules can have a direct effect on the biologically active properties of substances. Among the known types of stereoisomerism (geometric and optical), this work summarizes the effect of various types of geometric isomerism on the bioactivity of compounds. In addition, the results of the authors’ own research are presented. In particular, the results of studying the antimicrobial and antifungal activity of hydroxyalkyl monoesters of norbornedicarboxylic acid depending on their stereoisomeric forms in relation to various pathogenic microorganisms are shown. The studies were carried out by the serial dilution method. As nutrient media, we used MPA pH 7,2–7,4 for bacteria and Sabouraud’s medium for fungi. The incubation time in a thermostat for bacteria was 18–24 hours at 37ºC, for fungi 1–10 days at 28ºC. It has been noted that the endo-isomers of the synthesized compounds have a higher antimicrobial and antifungal activity against grampositive (Staphylococcus aureus), gramnegative (Escherichia coli, Pseudomonas aeruginosa) bacteria, as well as yeast-like fungi of the genus Candida. Based on the obtained test reports, the synthesized compounds have been recommended for use as local antiseptic preparations.

STUDY OF BIOLOGICAL ACTIVITY OF RACEMIC AND OPTICALLY ACTIVE ESTERS OF NAPHTHENIC AND FATTY ACIDS BASED ON UNSATURATED OXYESTERS

Petrochemical products based on petroleum naphthenic acids have special properties. Esters of naphthenic acids possess practically valuable organic compounds. The aim of this work is the development of effective methods for the preparation of aromatic esters based on naphthenic and individual fatty acids which is a very promising direction in the medicine practice. The synthesis of unsaturated racemic and chiral oxyethers was carried out on the basis of the interaction of chloromethylpropargyl (allyl) esters with carbonyl compounds with the participation of metallic zinc. Also, to study the biological activity, racemic and optically active esters were synthesized based on naphthenic acids and unsaturated racemic and chiral oxyesters. As test cultures used: gram-positive (Staphylo-coccus aureus-Staphylococcus aureus), gram-negative (Pseudomonas aeruginosa – Pseu-domonas aeruginosa, Escherichia coli) bacteria, as well as yeast-like fungi of the genus Candida - Candida albicans. Analysis of the biological activity of the synthesized compounds showed that optically active bicyclo [2.2.1] hept-5-ene-2-methylol monoesters have higher antimicrobial and antifungal activity compared to their racemic analogs and drugs used in medicine.

Pollen Analysis, Chemical Composition and Antibacterial Activity of Anatolian Chestnut Propolis Collected From Yıgılca Region

The purpose of this study is to examine the antimicrobial and antifungal activity of propolis samples of Yıgılca honey bee against Gram-positive and Gram-negative bacteria and yeast-like fungi. For this purpose the pollen and chemical components analyses of propolis sample was performed. The Liquid Chromatography-Mass Spectrometry (LC-MS/MS) method was used to identify the compounds of the propolis samples. According to the results of pollen analysis Fagaceae family were the dominant. As a result of LC-MS/MS method the main components of propolis was pinostrobin, gallic acid, and with Syringic acid. The antimicrobial activity of the propolis samples were tested against 7 Gram (+), 4 Gram (–) and 1 acid-resistant bacteria, and 3 yeast-like fungi. First, the activity of the propolis sample against these microorganisms was determined by the agar well diffusion method, then their zones were measured. The macrodilution method was used to determine the minimum inhibitory concentration (MIC) for the antimicrobial activity tests. The results of MIC values were found between 74 and 4746 µL for the tested microorganisms. It was found that Mycobacterium smegmatis was the most susceptible bacteria (74 µL), Lactobacillus acidophilus (149 µL) Staphylococcus aureus and Saccharomyces cerevisiae with a MIC concentration of 299 µL. We are opinion that, considering the biological effects of the propolis extract of Yıgılca honey bee, may be potentially used as an alternative therapeutic treatment thanks to its high antimicrobial and antifungal activity on different microorganisms, but its high in vitro activity needs to be confirmed by further research in vivo.

Chemical Composition of Apiaceae Family Essential Oils from Different Plants and in-vitro Antimicrobial Activities on Probiotic Microorganisms

Coriander, fennel, caraway and anise species which have major characteristic specialities of Apiaceae family, have antimicrobial activities on pathogene microorganisms. Probiotic microorganisms have fundamental effects on human body and extermination of probiotics causes many diseases. In this study, it was aimed to determine investigate probiotic resistance against natural antimicrobial agents (as essential oils) compare to pathogenes in previous studies. Analysis of essential oils (Eos) from were analyzed by GC-FID and GC/MS, analysis of Eos antimicrobial and antifungal activity from were analyzed by Microdilution test (as described in CLSI). Linalool (%74.927), (E)-anethole (%68.239), carvone (%61.087) and (E)-anethole (%95.577) were found as major compounds of EOs respectively. All essential oils have antimicrobial activities on probiotic microorganisms.

Ultraviolet Radiation and Salinity-Induced Physiological Changes and Scytonemin Induction in Cyanobacteria Isolated from Diverse Habitats

A novel series of transition metal (II) complexes (5a-h) were conveniently synthesized via reaction of important transition metals (Co, Cu, Zn, Ni) with (E)-N-(4-methylbenzylidene)-2-((Z)-(4-methylbenzylidene)amino)benzamide Schiff base (3) which was previously synthesized by reacting 2- aminobenzohydrazide (1) with 4-methylbenzaldehyde (2). The synthesized metal complexes' structure was elucidated by IR, NMR, mass, and elemental analysis. Additionally, we also evaluated the antioxidant, antimicrobial and antifungal activity of the synthesized metal complexes. The bioassay of the novel transition metal complexes envisioned that compounds5eand5c showed better antimicrobial activity than the free ligand, and compounds5g and 5a showed good activity against most bacterial strains. On the other hand, hydrated metal complexes 5b, 5d, 5f, and 5h showed moderate to good antimicrobial activity. In comparison with ascorbic acid, most of the metal complexes showed moderate to good antioxidant activity. The current bioassay was investigated and proved that the compounds 5e and 5c as antimicrobial agents act on highly resistant strains of microbes.

Plants of the Family Asteraceae: Evaluation of Biological Properties and Identification of Phenolic Compounds

The present study focused on the biological analysis of five plants: Achillea millefolium, Arnica montana, Calendula officinalis, Chamaemelum nobile and Taraxacum officinale. The results indicated that A. montana extracts showed the highest content of phenolic compounds. Regarding the biological properties, A. millefolium had outstanding antioxidant activity, while C. officinalis had the highest rate of antimicrobial and antifungal activity. The anti-inflammatory and cytotoxic activities reflected that C. nobile showed the highest effect. In enzyme assays, C. nobile and C. officinalis extracts showed the highest inhibitory effects on acetylcholinesterase and butyrylcholinesterase enzymes. Overall, this study provides scientific evidence for the evaluation of the potential of medicinal plant extracts for the development of new products.

Synergistic Activity of New Diclofenac and Essential Oils Combinations against Different Candida spp.

According to recent studies, Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) have shown a good antimicrobial and antifungal activity. Their association with essential oils (EOs) could be useful for the treatment of infections caused by Candida spp. The aim of this studyis to evaluate the synergistic antifungal activity of new combinations between Diclofenac Sodium Salt (DSS), a widely used NSAID, with EOs of Mentha x piperita, Pelargonium graveolens and Melaleuca alternifolia. The in-vitroantifungal activity was determined on different Candida strains. The determination of the chemical composition of EOs was carried out by gaschromatography-massspectrometry (GC-MS). Susceptibility testing of planktonic cells was performed by using the broth microdilution assay and checkerboard methods. Minimum Inhibitory Concentrations (MIC) of DSS was in a range from 1.02 to 2.05 mg/mL reaching a MIC value of 0.05 mg/mL when combined with Pelargonium graveolens (FICI= 0.23–0.35) or Menthapiperita (FICI= 0.22–0.30) EOs. These preliminary results show thatthe combination of the EOs with DSS improves the antifungal activity on all the tested Candida strains.