Tikslas: Įvertinti chinoksalino darinių struktūros įtaką jų antimikrobiniam ir priešvėžiniam aktyvumui ir atrinkti perspektyviausius junginius tolimesniems tyrimams. Darbo uždaviniai: 1. Ištirti chinoksalino darinių antimikrobinį (priešgrybelinį ir antibakterinį) aktyvumą in vitro. 2. Ištirti chinoksalino darinių priešvėžinį aktyvumą in vitro. 3. Nustatyti chinoksalino darinių antimikrobinio ir priešvėžinio aktyvumo bei cheminės struktūros ryšio dėsningumus. 4. Įvertinti chinoksalino darinių toksiškumą ir farmakokinetines savybes in silico. 5. Remiantis gautais rezultatais, atrinkti perspektyviausius chinoksalino darinius. Tyrimo metodai. Antimikrobiniam aktyvumui nustatyti naudoti in vitro metodai: skiedimo standžioje ir skystoje terpėse bei difuzijos į agarą metodas. Priešvėžinis aktyvumas įvertintas tiriant ląstelių gyvybingumo slopinimą MTT metodu. Struktūros-aktyvumo ryšys įvertintas analizuojant eksperimentinius duomenis. Junginių toksiškumas ir farmakokinetinės savybės įvertintos in silico, remiantis kompiuterinės programos ACD/I-Lab duomenimis. Tyrimo rezultatai. Aktyviausi chinoksalino dariniai Bacillus ir Staphylococcus genties bakterijų augimą slopino 16 μM koncentracija, grybelio Candida albicans – 22 μM koncentracija. Aktyviausi chinoksalino dariniai žmogaus plaučių karcinomos A549 ir glioblastomos U87 ląsteles veikė 0,5-10 μM koncentracijomis. Nustatyti antimikrobinio poveikio struktūros ryšio dėsningumai: aktyviausi junginiai chinoksalino žiedo antroje padėtyje... [toliau žr. visą tekstą] / The Aim of the Research: To evaluate the structure influence on antimicrobial and anticancer activity of quinoxaline derivatives and identify the most promising compounds for the further development. Objectives: 1. To test antimicrobial (antibacterial and antifungal) activity of quinoxaline derivatives in vitro. 2. To test anticancer activity of quinoxaline derivatives in vitro. 3. To establish relationship between structure and antimicrobial, also anticancer activity. 4. To evaluate toxicity and pharmacokinetic properties of quinoxaline derivatives in silico. 5. To identify the most promising quinoxaline derivatives with reference to experimental results. Methods. Antimicrobial activity was tested in vitro using three different methods: serial dilution in agar, in liquid broth, and diffusion into agar. Anticancer activity was investigated by evaluating cell viability using MTT assay. Structure-activity relationship was evaluated from analysis of experimental data. Toxicity and pharmacokinetic properties were predicted by using ACD/I-Lab program. Results. The most promising quinoxaline derivatives inhibited growth of Bacillus and Staphylococcus genus bacteria with 16 μM concentration, fungus Candida albicans with 22 μM concentration. The most active quinoxaline derivatives were active against human lung carcinoma A549 and glioblastoma U87 cell lines with concentrations of 0.5-10 μM. Some principles of structure – antimicrobial activity relationship were established: the most... [to full text]

This study is focused on the use of visible light in photoinitiated cationic polymerization. Photoinitiated polymerization of oxiranes, vinyl ethers, and other vinyl monomers was achieved. In doing so, (2-(2,3 dihydrobenzo [b][1,4]dioxin-6-yl)-3-(2,3-dihydrobenzo[b]-[1,4]dioxin-7-yl)-5-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-8-(2,3-dihydrothieno[3,4-b][1,4]dioxin-7yl) quinoxaline) (DBQEd) and poly(2,3,5,8-tetra(thiophen-2-yl)quinoxaline) (TTQ), two dibenzo[a,c]phenazine derivatives / 10,13-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)dibenzo[a,c] phenazine (PHED) and 10,13-bis(4-hexylthiophen-2-yl)dibenzo[a,c]phenazine (PHEHT) were utilized as the photosensitizers for diaryliodonium salt photoinitiators. Novel dyes based on the dibenzo[a,c]phenazine and quinoxaline skeleton were shown to be efficient in carrying out the cationic photopolymerizations of a wide variety of epoxide, oxetane, and vinyl monomers at room temperature upon irradiation with long-wavelength UV and visible light. The polymerizations were initiated at room temperature in the presence of diphenyliodonium hexafluorophosphate (Ph2I+PF-6) and monitored by optical pyrometry (OP). The photopolymerization of an epoxide monomer via solar irradiation was also demonstrated.