The goal of this research were to consider these book xanthones and find out the quintessential well-known descriptor for cytotoxic activity to greatly help the development of more energetic anticancer agents. The synthesized xanthone compounds were the property of Yuanita (Laboratory of Organic Chemistry of the Faculty of Mathematics and Natural Sciences, Gadjah Mada University) and are listed in Table 1. Colorectal cancer WiDR cells and normal Vero cells were obtained from the Laboratory of Parasitology, Faculty of Medicine, Gadjah Mada University. Cells were cultured in RPMI 1640 (for WiDR) and M199 (for Vero) (Sigma-Aldrich Co., St Louis, MO, USA) supplemented with 0.1 mg/mL streptomycin (Thermo Fisher Scientific, Waltham, MA, USA) and maintained in an incubator with 5% CO2 at 37°C. Only confluent cells were used for the experiment. This study received ethics approval from the Medical and Health Research Committee Faculty of Medicine, Gadjah Mada University, and Dr Sardjito General Hospital, number KE/FK/399/EC/2016. The data set for the QSAR analysis was obtained from the cytotoxic activity test results. The in vitro cytotoxic activities of xanthones were expressed as the inhibitory concentration fifty% (IC50) values that were converted to log 1/IC50 and used as dependent variables in the QSAR analysis. A pc which have an enthusiastic Intel ® Pentium ® 2117U 1.80 Ghz Central processing unit, 4.00 GB RAM, five hundred GB hard drive, and you will a glass 8 ® os’s was applied. All the quantum-mechanical calculations off xanthones was executed by using Hyperchem 8 ® , and you may QSAR studies was did utilising the BuildQSAR program. 21 Planning of receptor protein and you can docking validation approach is did that with ligne de chat pour les célibataires locaux YASARA ( and planning of one’s ligand are performed with the Chemdraw Ultra a dozen.0.dos and s. New molecular docking process is actually performed making use of the Plant life/Protein–Ligand Ant System. twenty two Meanwhile, the Pymol system (pymol.org) was used observe the brand new hydrogen securities when you look at the amino acid deposits within ligand and you can receptors. 23 The in vitro cytotoxic activities were evaluated by using the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) method as described earlier 24 with modifications. Cells were seeded at 1?10 4 cells/well in 96-well plates and incubated for 24 h. They were then treated with 100 ?L of medium (as untreated control) or 100 ?L of varying concentrations of individual compounds (500, 250, 125, 62.5, , , 7.813, and 3.906 ?g/mL for the WiDR cell line, and 1,000, 500, 250, 125, 62.5, , , and 7.813 ?g/mL for the Vero cell line), 100 ?L of various concentrations of doxorubicin as a positive control (100, 50, 25, 12.5, 6.25, and 3.125 ?g/mL), and 100 ?L of medium without cells as a medium control. The plates were incubated at 5% CO2 and 37°C for 24 h. 2 37°C for 4 h. To the cells was then added 100 ?L of 10% sodium dodecyl sulfate in HCl 0.01 N; the cells were then incubated overnight to ensure that all formazan crystals were dissolved. The plates were read on a microplate enzyme-linked immunosorbent assay reader at 595 nm. The percentage of viable cells was determined according to the following formula: Cytotoxic activity was represented as the inhibitory concentration 50% (IC50) of each compound that was determined by probit analysis of the sample concentration versus cell viability. The selectivity index (SI) was calculated from the ratio of IC50 in Vero versus that in WiDR cells. SI values >3 were considered as having high selectivity. 25Shortly after therapy, the typical is got rid of, MTT service (ten ?L for every 100 ?L average) is actually added to most of the wells, and you will dishes was incubated within 5% CO