Structure of (2R)-5,7-dihydroxyflavanone from ChemSketch. showed: 42.51-CH2-; 78.84-CH-O; 95.52 =CH-; 96.40 =CH-; 102.25 =C-; 127.06 2(=CH-); 129.04 2(=CH-); 139.08 =C-; 163.17 =C-O; 163.92 =C-O; 167.17 =C-O; 196.40-C=O. (2R)-5,7-dihydroxyflavanone effectively inhibited cell viability in cancer cells of the prostate, breast, colon, cervix, and lung: The viability of PC3 prostate, MDA-MB231 breast, HT29 colon, SiHa cervix and A549 lung cells was analyzed 48 hours after treatment at concentrations between 5 and 200 mg/L of flavanone via MTT assay. Data obtained showed an inhibition of the percentage of cell viability compared to control (Figure 1A). The inhibitory concentration at which we observe 50% in cell viability (IC50) calculated from the non-linear curve regression showed that (R) pinocembrin was more cytotoxic against A549 and MDA-MB-231 with IC50 values of 30.91 mg/L and 45.06 mg/L respectively (Figure 1B). Further, the IC50 values for (R) pinocembrin, were consistently lower than those for quercetin on cells except for breast cancer cell line MDA-MB-231, where the IC50 for quercetin was 28.5 mg/L. The most significant difference was observed in A549 lung cells where the IC50 value of quercetin was 184.44 mg/L (Figure 2). According to the results of comet assay, the flavanone had not significant genotoxic effects in the majority of the cells tested only on A549 lung cells with 61 % of DNA damage, comparatively to the effect of the positive control VCR, with a 65 % of DNA damage. (Figure 3). To complement genotoxicity and cytotoxicity data, it was done a morphological analysis on A549 cells by immunofluorescence microscopy, finding changes in the shape and integrity of the cytoskeleton, increasing of the nucleus area, and inhibition of the cell growth in response to damage occurring after treatment with the flavanone (Figure 4). (2R)-5,7-dihydroxyflavanone induced cell cycle arrest on A549 cells in G1 phase: Additionally, cell cycle distribution analysis was done on A549 cells by flow cytometry and it resulted in G1 phase arresting during 24 and 48 h of treatment, and consequent cell death at 72 h of treatment (Figure 5).

Contexts in source publication

Context 1

... Retro Diels Alder is obtained the fragment m/z 152 (76), for consecutive loss of two CO molecules is obtained the fragments m/z 124 (64) and m/z 96 (24) that loss the fragment C2H2 to obtain the peak m/z 69 (24) (Figure 6), that matches that determined by 13 CJMOD. 1 HNMR spectrum presents signals at for an AMX coupling system at 2.78 dd 18 and 3 Hz CHa; 3.24 dd 18 and 12Hz CHb; 5.57 dd 12 and 3Hz -O-CH for ring C of a flavanone; signals at 5,90 ppm and 5,93 ppm, corresponding to = CH at C6 and C8 of the A ring and signals 7,51ppm 7,40 that integrates for 5(= CH) corresponding to the protons of B ring, the signal at 12,11 ppm is characteristic of OH at C5 of a flavonoid. The signals at 163,17ppm, 163,92 ppm, and 167,17 ppm in the spectrum 13 CJMOD are quaternary carbons of a benzene ring, which are bonded to oxygen, 3(= C-O) corresponding to the C 5,6,9 of the ring A. The signals at 42,51ppm (-CH2); -78,84 ppm (CH-O) and 196,40ppm (-C = O) confirm the flavanone (Figures 7). ...

Context 2

... Retro Diels Alder is obtained the fragment m/z 152 (76), for consecutive loss of two CO molecules is obtained the fragments m/z 124 (64) and m/z 96 (24) that loss the fragment C2H2 to obtain the peak m/z 69 (24) (Figure 6), that matches that determined by 13 CJMOD. 1 HNMR spectrum presents signals at for an AMX coupling system at 2.78 dd 18 and 3 Hz CHa; 3.24 dd 18 and 12Hz CHb; 5.57 dd 12 and 3Hz -O-CH for ring C of a flavanone; signals at 5,90 ppm and 5,93 ppm, corresponding to = CH at C6 and C8 of the A ring and signals 7,51ppm 7,40 that integrates for 5(= CH) corresponding to the protons of B ring, the signal at 12,11 ppm is characteristic of OH at C5 of a flavonoid. The signals at 163,17ppm, 163,92 ppm, and 167,17 ppm in the spectrum 13 CJMOD are quaternary carbons of a benzene ring, which are bonded to oxygen, 3(= C-O) corresponding to the C 5,6,9 of the ring A. The signals at 42,51ppm (-CH2); -78,84 ppm (CH-O) and 196,40ppm (-C = O) confirm the flavanone (Figures 7). ...