Steroidal hydrazones as antimicrobial agents: biological evaluation and molecular docking studies.

Most of pharmaceutical agents display several or even many biological activities. It is obvious that testing even one compound for thousands of biological activities is a practically not reasonable task. Therefore, computer-aided prediction is the method of choice for the selection of the most promising bioassays for particular compounds. Using PASS Online software, we determined the probable antimicrobial activity of the 31 steroid derivatives. Experimental testing of the antimicrobial activity of the tested compounds by microdilution method confirmed the computational predictions. Furthermore, P. aeruginosa and C. albicans biofilm formation was investigated. Compound 11 showed a biofilm reduction by 42.26% at the MIC of the tested compound. The percentages are lower than ketoconazole, but very close to its activity.

Caffeic and 3-(3,4-dihydroxyphenyl)glyceric acid derivatives as antimicrobial agent: biological evaluation and molecular docking studies.

Herein we report the evaluation of the antimicrobial activity of some previously synthesized 3-(3,4-dihydroxyphenyl)glyceric acid in benzylated and in free 3,4 hydroxy groups in catechol moiety along with some caffeic and 3-(3,4-dihydroxyphenyl)glyceric acid amides using the microdilution method. The evaluation revealed that compounds showed in general moderate to low activity with MIC in range of 0.36-4.5 mg/mL. Compounds were also studied against three resistant bacteria strains MRSA (Methicillin-resistant Staphylococcus aureus), E. coli and P. aeruginosa. Seven out of ten compounds were more potent than reference drugs ampicillin and streptomycin against MRSA, while against another two resistant strains seven compounds showed low activity and the rest were inactive. Antifungal activity of the tested compounds was much better than antibacterial, with MIC in the range of 0.019-3.0 mg/mL. Compounds #7 and 15 showed good activity against all fungi tested, being more potent than ketoconazole and in some case even better than bifonazole used as reference drugs. Docking studies revealed that the most active compound #7 binds to the haem group of the enzyme in the same way as ketoconazole.

[Development of technology for the substance of poly[3-(3,4-dihydroxyphenyl) glyceric acid] from Symphytum asperum].

Comfrey (Symphytum L.) is used to treat bone fractures, tendon injuries, ulcer lesions of gastrointestinal tract. It promotes wound healing, accelerates exudates resorption in lungs and reduces joints' inflammation. In Georgian folk medicine, herbal remedies from comfrey are used to accelerate regeneration processes. Comfrey contains hepatotoxic and carcinogenic pyrrolizidine alkaloids, besides the main active ingredient is poly [3 - (3,4-dihydroxyphenyl) glyceric acid] (PDPGA). The aim of present work was to develop a technology for the substance - poly [3-(3,4dihydroxyphenyl) glyceric acid] (PDPGA) from comfrey stems, free of toxic pyrrolizidine alkaloids. During the investigation the optimal conditions for extraction and purification have been established: on the first stage pyrrolizidine alkaloids were removed from plant material by supercritical extraction; then the crude polysaccharides' fraction was obtained by water extraction (raw materials/extragent ratio was 1:15 at 90oC, the procedure was carried twice for 60 and 90 minutes). The isolation of the final product - PDPGA from crude polysaccharides' fraction was carried out by ultrafiltration on membrane filters. Based on the results of the investigation the technological scheme for the substance has been developed.

Composition of intracellular soluble proteins in Mycobacterium "rubrum" and its mutants.

The composition of intracellular soluble proteins in a parental strain of Mycobacterium "rubrum" and its mutants was studied by polyacrylamide gel gradient electrophoresis. The composition of the protein fractions of the parental and the mutant strains was similar, they differed in one protein only. The presence of a 60 kDa protein should be stressed since its increased amount may be connected with a different intensity of the production of pigments in the strains studied.

[Kinetics of growth and development of Mycobacterium rubrum under conditions of periodic culturing]. / Kinetika rosta i razvitiia Mycobacterium rubrum pri periodicheskom kul'tivirovanii.

The kinetics of growth, development, carotenogenesis and changes in the composition of the reaction medium were studied in the course of Mycobacterium rubrum batch cultivation in synthetic and complex media. The culture growth was found to be composed of five phases in the synthetic medium and of four phases in the complex medium. When the culture was grown in the synthetic medium, the phenomenon of distinct diauxy was recorded by changes in the specific growth rate as well as the economic and metabolic coefficients. These growth changes were shown to be associated with the fact that the culture started to assimilate sucrose instead of glucose at the subsequent growth phases, and carbotenogenesis was found to be uncoupled with the period of active biomass and protein synthesis.