Synthesis of new xanthone analogues and their biological activity test—Cytotoxicity, topoisomerase II inhibition, and DNA cross-linking study

Chemical modifications of a natural xanthone and antimicrobial activity against multidrug resistant Staphylococcus aureus and cytotoxicity against human tumor cell lines

“…4,6 Xanthone compounds represent a class of these lichen substances, but they are widely distributed in nature, 2 and can also be isolated from higher plants and microorganisms. 7 In recent years, xanthones and xanthone derivatives have been reported to have significant pharmacological activities based on their diverse structures. [8][9][10][11][12][13][14][15][16][17][18][19][20] Their interesting structural scaffold and the significant biological activities have led many scientists to isolate, modify or synthesize different xanthones for the development of prospective new drug candidates.…”

“…[8][9][10][11][12][13][14][15][16][17][18][19][20] Their interesting structural scaffold and the significant biological activities have led many scientists to isolate, modify or synthesize different xanthones for the development of prospective new drug candidates. 7 Many xanthones bearing nitrogenated side chains connected to the phenolic core in different positions by C, O or N atoms have been synthesized during the last 10 years, and this group of molecules have showed interesting biological effects 14,18,[21][22][23][24][25] including antibacterial 26 and cytotoxic activities. 27,28 Based on this information and as a part of our efforts to enhance biological activities of lichen substances, we have decided to synthesize five series (dimethyl, diethyl, dipropyl, t-butylamine and piperidinyl) of (ω-aminoalkoxyl)-xanthone derivatives from lichexanthone (1), a naturally occurring xanthone isolated from the lichen Parmotrema lichexanthonicum, and evaluate their cytotoxic acitvity against human tumor cell lines and their antimicrobial activity against selected bacterial strains, including multidrug resistant Staphylococcus aureus, aiming to establish a relationship between side chains characteristics and biological activity.…”

Synthesis, Cytotoxicity and Topoisomerase II Inhibitory Activity of Benzonaphthofurandiones

“…Experiments were performed as described previously. 15 The test compounds were dissolved in DMSO at 20 mM as stock solution. The activity of DNA topoisomerase I (topo I) was determined by assessing the relaxation of supercoiled DNA pBR322.…”

“…DNA topoisomerase II (topo II) inhibitory activity of compounds was measured as follows. 15 The mixture of 100 ng of supercoiled pBR322 plasmid DNA and 1 units of human DNA topoisomerase IIα (Amersham, USA) was incubated without and with the prepared compounds in the assay buffer (10 mM Tris-HCl; pH 7.9) containing 50 mM NaCl, 5 mM MgCl 2 , 1 mM EDTA, 1 mM ATP, and 15 µg/mL bovine serum albumin) for 30 min at 30 °C. The reaction in a final volume of 20 µL was terminated by the addition of 3 µL of 7 mM EDTA.…”

“…The data were analyzed and calculated with LabWork 4.5 Software for the inhibition ratio. 15 The results of topoisomerase inhibition of the tested compounds are shown in Table 2. All the tested compounds showed clearly very low topo I inhibitory activity.…”