Meral Yilmaz Cankiliç

The lichens Tephromela atra and Tephromela grumosa were studied in detail using various techniques, including morphological identification, biochemical taxonomy (chemotaxonomy), anatomical, and molecular characterization. The molecular characterization of Tephromela atra and Tephromela grumosa (Pers.) Hafelner & Cl. Roux was analyzed using internal transcribed spacer rDNA (ITS1) genes and the sequences obtained were compared with the ITS sequences of the other Tephromela species in GenBank (NCBI). The sequences were analyzed against reference sequences from the GenBank databases using the programs; BLAST, ClustalW, and MEGA11. The phylogenetic relationship was evaluated. The results show that some samples of Tephromela atra obtained in this study are closer to the same species isolated from Greece, while other samples are closer to other samples isolated from Italy and Austria. Moreover, the Tephromela grumosa isolated from Eskisehir Bozdag Mountain form a separate branch closer to the Tephromela grumosa samples isolated from Italy. Our study shows that lichens are an important source of biodiversity in Türkiye, which has a high species richness in Anatolia.

Lichens and their secondary metabolites are of particular interest as they can be used as an alternative to synthetic drugs in the treatment of various diseases. The present study was carried out to investigate in vitro antioxidant and antimicrobial activities of acetone, dichloromethane, petroleum ether, and methanol extracts of the lichen Tephromela atra and its major metabolites. α-alectoronic acid and α-collatolic acid were identified as bioactive substances in the lichen Tephromela atra . The antibacterial activity was investigated using the disk diffusion method and the minimum inhibitory concentrations were determined against eleven bacterial species, nine fungal species, and four yeast species using broth microdilution method. The antioxidant activity of the methanol extracts of Tephromela atra was measured by the free radical scavenging ability using the DPPH method. The extracts of α-alectoronic acid and α-collatolic acid showed significant inhibitory activity against most of the tested bacteria, especially the lowest MIC values of the two acids for Bacillus subtilis . Furthermore, the antioxidant activity was determined in vitro by measuring the radical scavenging capacity of the extracts on DPPH. The methanol extracts showed significant antioxidant activity and high DPPH scavenging activity at all concentrations. The results indicate that the extracts of Tephromela atra and the natural products obtained can be used as a source of antimicrobial and antioxidant agents in the pharmaceutical industry. HIGHLIGHTS: The present study determines the antibacterial and antifungal activities of the Tephromela atra , lichen extracts, and its isolated major constituents (α-alectoronic acid and α-collatolic acid), as well as evaluates the antioxidant capacity. Although there are some studies on α-alectoronic acid and α-collatolic acid, isolated in different lichens, there is no study on the biological activity and antioxidant capacity of lichen Tephromela atra . The MIC values of isolates were evaluated against a broad range of microorganisms including eleven species of bacteria, nine species of fungi, and four species of yeasts. α-Alectoronic and α-collatolic acid extracts showed significant inhibitory activity against most of the tested bacteria, especially the lowest MIC values of both acids for Bacillus subtilis. Our results provide a future perspective that Tephromela atra extracts and the isolated metabolites might be used as effective antimicrobial and antioxidant agents in pharmaceutical areas. Graphical

Cyanobacteria are a concern worldwide due to their blooms and the toxins they produce. The aim of this study is to reveal the cyanobacterial diversity of Tersakan Stream and toxin analysis. For these purpose, water samples were taken from Tersakan Stream in 2018 and cyanobacterial diversity was determined by culture-dependent and independent methods. PCR amplification of microcystin genes (McyB and McyE) and Microcystin-LR (L:Leucine, R: Arginine) (MC-LR) analysis in water sample was performed. While 10 different Cyanobacteria were identified by light microscopy examination and 16S rRNA + ITS sequence, less diversity was revealed by culture-independent methods. Sequences of the isolates were associated with Pseudanabaena lonchoides, Leptolyngbya sp, Toxifilum sp, Cylindrospermum moravicum, Nostoc sp, Oscillatoria sp, Synechocystis sp, Synechococcus sp, Cyanobacterium aponinum and Cyanobium sp. Culture-independent sequences were associated with Microcytis sp, Nostoc sp, Cyanobium sp, Dolichospermum sp, Anabaena sp, Leptolyngbya sp and Uncultured cyanobacterium. Microcystin analysis was performed by both molecular and analytical methods. PCR results of McyB and McyE genes supported the HPLC-DAD analysis result. 0.467 μg L-1 microcystin LR was detected in Tersakan Stream by HPLC-DAD analysis. Although the microcystin concentration is low, Tersakan Stream is an important area to be monitored with its eutrophic character and cyanobacterial diversity.

Objective: In this study, the number of bacteriae in the air at five different regions in Eskişehir (Turkey) according to the settle plate method and some meteorological factors such as temperature and relative humidity were collected and analyzed statistically. The data were used to predict the amount of bacteriae using machine learning algorithms. Material and Methods: Air samples were taken from specified sampling points using the settle plate method. The random forest method, multivariate adaptive regression splines, support vector machine and ordinary least squares models were employed to analyze a qualified data set collected through 5 different monitoring locations in Eskişehir city, Turkey. All analyses were conducted using RStudio Software (version 1.2.1335). Results: The results revealed that all variables including weather characteristics and particulate matters were found statistically significant on the amount of the bacteria. Among modeling methods, the random forest model overperformed the others in terms of root mean square. Conclusion: Results might be useful for researchers studying bacterial density. These findings may provide policy-makers with crucial information for a better climate and health policy development, which helps address the conflict between development and air pollution, may be applicable in Turkey and other countries as well.

New N-(naphthalen-1-yl)propanamide was synthesized and studied for their antimicrobial activity. The final compounds were procured by reacting N-(naphthalen-1-yl)propanamide with some 2-mercapto aryl or dithiocarbamate salt derivatives. Their structures were determined by ¹H-NMR and ¹³C-NMR spectroscopy and LC-MS/MS spectral data. The synthesized compounds were investigated for their antimicrobial activities against 10 bacteria and 10 fungi species. All compounds showed notable activity. Especially, compounds 2-[(5-methyl-1,3,4-thiadiazol-2-yl)thio]-N-(naphthalen-1-yl)propanamide (2a), 2-(benzothiazol-2-ylthio)-N-(naphthalen-1-yl)propenamide (2b), 2-[(1-methyl-1H-imidazol-2-yl)thio]-N-(naphthalen-1-yl)propanamide (2c), and N-(naphthalen-1-yl)-2-[(5-nitro-1H-benzimidazol-2-yl)thio]propanamide (2e) exhibited antifungal activity against at least one fungus at the half potency of ketoconazole. Also, 2-[(1-methyl-1H-imidazol-2-yl)thio]-N-(naphthalen-1-yl)propanamide (2c), N-(naphthalen-1-yl)-2-[(5-nitro-1H-benzimidazol-2-yl)thio]propanamide (2e) and 2-[(4-methyl-4H-1,2,4-triazol-3-yl)thio]-N-(naphthalen-1-yl)propanamide (2f) showed anti-gram-positive bacterial activity at the half potency of chloramphenicol. Only one compound, 2-(benzothiazol-2-ylthio)-N-(naphthalen-1-yl)propanamide (2b) displayed anti-gram-negative bacterial activity against Yersinia enterocolitica (Y53).

Background: In this study, 2-(substituted-sulfanyl)-N,N-dicyclohexylacetamide derivatives (2a-2g) and 2-(dicyclohexylamino)-2-oxoethyl-1-substituted carbodithioate derivatives (2h-2m) were synthesized and screened for their antimicrobial activity. Methods: Newly synthesized compounds were screened against two gram negative bacteria (S. typhimurium and E.coli), three gram positive bacteria (S. aureus, B. cereus and L. monocytogenes), four Candida species, four Aspergillus spp. and three Penicillium spp. Among them (2a-2m), compounds 2i (2-(dicyclohexylamino)-2-oxoethyl-thiomorpholine-4-carbodithioate) and 2k (2- (dicyclohexylamino)-2-oxoethyl-4-(4-methoxyphenyl)piperazine-1-carbodithioate) were detected to have higher inhibitory effect than other compounds. Results and Conclusion: Minumum inhibitor concentrations (MICs) of the compounds were determined between the range of 97.5-390 µg/mL. Additionally, parameters determined that some physicochemical and toxic properties were predicted using computational methods.

Background: In this work, 2-[[5-(4-aminophenyl)-4-(4-substituted phenyl)-4H-1,2,4- triazol-3-yl]thio]-1-(4-substituted phenyl)ethan-1-one derivatives (1-15) and 2-[[5-(4-aminophenyl)- 4-(4-substituted phenyl)-4H-1,2,4-triazol-3-yl]thio]-N-(4-substituted phenyl)acetamide derivatives (15-30) were synthesized using 4-aminobenzohydrazide as starting material. Methods: These compounds were screened to determine their antimicrobial activities against Grampositive bacteria B. cereus, S. aureus, E. faecalis, L. monocytogenes; Gram-negative bacteria E. coli, P. aeruginosa, K. pneumoniae, S. typhimurium, yeasts C. parapsilosis, C. albicans, C. glabrata, C. krusei; molds A. niger, A. flavus, A. parasiticus, A. fumigatus, Rhizopus sp., A. alternate, S. rolfsii and a mycobacteria M. tuberculosis. Results and Conclusion: Compounds 2, 6, 7, 8 have displayed antituberculotic potential as much as standard drug, rifampicin. Also, compounds have exhibited moderate antibacterial and antifungal activities, contrary to expectations.

In this work, six 2-[(1/4-methylimidazol/triazol/tetrazol- 2/3/5-yl)thio]-N-(4-substituted thiazol-2-yl) acetamide derivatives (2a-f) were synthesized. The antimicrobial activities of these substances were examined against some foodborne Gram positive and Gram negative test bacteria, Candida albicans, Candida glabrata, Candida krusei, and Candida parapsilosis yeasts, and some Aspergillus and Penicillium filamentous fungi species. The substances were shown considerable antimicrobial effect to tested pathogenic microorganisms.