Taner Karaoglu

Antiviral and Antimicrobial Profiles of Selected Isoquinoline Alkaloids from Fumaria and Corydalis Species

In the current study, 33 isoquinoline alkaloids belonging to protopine-, benzylisoquinoline-, benzophenanthridine-, spirobenzylisoquinoline-, phthalideisoquinoline-, aporphine-, protoberberine-, cularine-, and isoquinolone-types as well as 7 derivatives of them obtained from some Fumaria and Corydalis species growing in Turkey have been evaluated for their in vitro antiviral and antimicrobial activities. Both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza (PI-3) were employed for antiviral assessment of the compounds using Madine- Darby bovine kidney and Vero cell lines and their maximum non-toxic concentrations (MNTC) and cytopathogenic effects (CPE) were determined using acyclovir and oseltamivir as the references. Antibacterial and antifungal activities of the alkaloids were tested against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumannii, Staphylococcus aureus, Bacillus subtilis, and Candida albicans by the microdilution method and compared to ampicilline, ofloxacine, and ketocanazole as the references. The alkaloids did not present any notable antibacterial effect, while they had significant antifungal activity at 8 μg/ml concentration. On the other hand, the alkaloids were found to have selective inhibition against the PI-3 virus ranging between 0.5 and 64 μg/ml as minimum and maximum CPE inhibitory concentrations, whereas they were completely inactive towards HSV.

In vitro biological activity screening of Lycopodium complanatum L. ssp. chamaecyparissus (A. Br.) Döll

This article reports the results of selected biological activities, including anticholinesterase, antioxidant, antibacterial, antifungal and antiviral properties, of the petroleum ether, chloroform and methanol extracts as well as the alkaloid fraction of Lycopodium complanatum L. ssp. chamaecyparissus (A. Br.) Döll (LCC, Lycopodiaceae) growing in Turkey. Anticholinesterase effect of the extracts was tested against both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) at concentrations of 0.2 and 1 mg mL−1 using microplate-reader assay based on Ellman method. Antioxidant activity of the LCC extracts was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging method at 0.2 mg mL−1 using microplate-reader assay. Both DNA virus Herpes simplex (HSV) and RNA virus Parainfluenza (PI-3) were employed for antiviral assessment of LCC exracts using Madin-Darby Bovine Kidney and Vero cell lines. Antibacterial and antifungal activities of the extracts were screened against the bacteria: Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Acinobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, Bacillus subtilis as well as the fungi: Candida albicans and C. parapsilosis. Only the petroleum ether extract of LCC possessed remarkable activity against both AChE and BChE at 1 mg mL−1 (76.5 and 69.6%, respectively), whereas LCC extracts showed low free radical-scavenging activity. All of the extracts were found to be more effective against the ATCC strains than isolated ones, particularly S. aureus, while the extracts had moderate antifungal activity. On the other hand, we found that only the petroleum ether extract was active against HSV. In addition, we also analysed the content of the alkaloid fraction of the plant by capillary gas chromatography-mass spectrometry (GC-MS) and identified lycopodine as the major alkaloid (60.8%).

Evaluation of Antiviral and Antimicrobial Activities of Ribes Species Growing in Turkey

Abstract Leaves and branches extracts of eight Ribes species were evaluated for antiviral, antibacterial, antifungal and antimycobacterial activities. Antiviral activities of the extracts were evaluated against Bovine Herpes Virus Type-1 (BHV-1) (Cooper strain). Generally, the extracts showed cytotoxic effect. The lyophilized water extract of R. multiflorum branches showed antiviral activity with minimum and maximum CPE values 15.62 and 31.25 μg/mL, respectively. Antibacterial and antifungal activities of the extracts were screened against gram-negative bacteria (Klebsiella pneumonia, Escherichia coli), gram-positive bacteria (Staphylococcus aureus, Enterococcus faecalis) and fungi (Candida albicans and C. parapsilosis). The extracts showed antibacterial activity against gram-positive bacteria, especially against Staphylococcus aureus. However, no antifungal activity was detected. Lyophilized water extracts of leaves and branches of Ribes species were assessed for antimycobacterial activity against clinical isolate of Mycobacterium tuberculosis and M. tuberculosis H37Rv ATCC 27294. The extracts showed a stronger effect against M. tuberculosis H37Rv ATCC 27294 than clinical isolate of M. tuberculosis. To the best of our knowledge, this study is the first investigation of antiviral and antimycobacterial activities of Ribes species growing in Turkey.

Electrochemical Investigation and DNA-Binding Studies of Valacyclovir-Copper(II) Complex

The synthesis and the electrochemical characterization of copper(II) complex containing one molecule of antiviral drug, valacyclovir (VAL), is reported. In addition to characterization, the electrochemical properties of the copper(II) complex of VAL ([Cu(VAL)Cl2]) were investigated by cyclic voltammetry (CV) using glassy carbon electrode. The redox properties of the metal complex was reversible and exhibited diffusion controlled process depending on pH. The dependence of intensities of currents and potentials on pH, concentration, scan rate, and nature of the buffer was investigated. The oxidation/reduction mechanism was proposed and discussed. Also, the interaction of copper complex of VAL- with calf thymus double-stranded DNA was studied spectrophotometrically (UV-vis) and electrochemically by using CV at glassy carbon working electrode. Additionally, the cytotoxicity activity of complex has been investigated against the bovine herpes virus type I.

In vitro antiviral assessment against DNA and RNA viruses as well as antibacterial and antifungal profiles of selected Turkish species of the Salvia genus

The present study was undertaken to evaluate antibacterial, antifungal, and antiviral properties of the chloroform and methanol extracts from the aerial parts of fourteen Turkish Salvia species (Lamiaceae) including S. albimaculata Hedge & Hub., S. aucheri var canescens Boiss. et Heldr., S. candidissima ssp. occidentalis Vahl., S. ceratophylla L., S. cryptantha Montbret et Aucher ex. Benth., S. cyanescens Boiss. et Bal., S. frigida Boiss., S. forskahlei L., S. halophila Hedge, S. microstegia Boiss. & Bal., S. multicaulis Vahl., S. sclarea L., S. syriaca L., and S. verticillata L. ssp. amasiaca (Freyn, & Bornm.) against Escherichia coli, Pseudomonas aeruginosa, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacer baumannii, Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis, and Candida albicans by microdilution method. Both Herpes simplex (DNA) and Parainfluenza-3 viruses (RNA) were used for the determination of antiviral activity of the abovementioned Salvia extracts by using Madin-Darby bovine kidney (MDBK) and Vero cell lines. The methanol extracts were found to be quite active against S. aureus and E. faecalis (2 and 4µg/mL, respectively), while the chloroform extracts were more active against S. aureus, B. subtilis, and E. faecalis (1, 2, and 2µg/mL, respectively). All of the extracts displayed the antifungal activity having the MIC value at 8µg/mL. Maximum cytopathogenic effect (CPE) concentrations as the indicator of antiviral activities of the extracts were determined and the chloroform extracts belonging to S. albimaculata, S. cyanescens, and S. microstegia (1–64µg/mL) along with the methanol extracts of S. ceratophylla, S. halophila, and S. sclarea (16–32µg/mL) showed reasonable antiviral effect. The cytotoxicity of the extracts was also expressed as the maximum non-toxic concentrations (MNTC), ranging between 16–128µg/mL.