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78 PROCEEDINGS OF INTERNATIONAL SCIENTIFIC CONFERENCE ON APPLIED BIOTECHNOLOGYCompound 1: White amorphous powders; 1H-NMR (methanol-d4, 400 MHz, %u03b4H ppm): 8.06 (2H, d, 9.1 Hz, H-2%u2019 and H-6%u2019), 7.07 (2H, d, 9.1 Hz, H-3%u2019 and H-5%u2019), 6.51 (1H, s, H-8), 3.88 (6H, s, 3-OMe and 4%u2019-OMe), 3.79 (3H, s, 6-OMe); 13C-NMR (methanol-d4, 100 MHz, %u03b4H ppm): 180.4 (C-4), 163.5 (C-4%u2019), 159.0 (C-2), 157.8 (C-8a), 153.9 (C-7), 153.7 (C-5), 139.4 (C-3), 132.0 (C-6), 131.3 (C-2%u2019 and C-6%u2019), 123.9 (C-1%u2019), 115.2 (C-3%u2019 and C-5%u2019), 104.1 (C4a), 95.2 (C-8), 61.3 (6-OMe), 60.6 (3-OCH3), 56.9 (4%u2019-OMe).Compound 2: Yellow amorphous powders; 1H-NMR (methanol-d4, 400 MHz, %u03b4H ppm): 7.31 (2H, H-2%u2019 and H-6%u2019), 6.81 (2H, H-3%u2019 and H-5%u2019), 6.03 (2H, s, H-6 and H-8), 5.35 (1H, d, 12.7 Hz, H-2), 3.79 (3H, s, 7-OMe), 3.13 (1H, t, 15.1 Hz, H-3a), 2.71 (1H, d, 17.0 Hz, H-3b); 13C-NMR (methanol-d4, 100 MHz, %u03b4H ppm): 198.2 (C-4), 169.6 (C-7), 165.3 (C-5), 164.7 (C-8a), 159.1 (C-4%u2019), 131.0 (C1%u2019), 129.1 (C-2%u2019 and C-6%u2019), 116.4 (C-3%u2019 and C-5%u2019), 95.8 (C-6), 95.0 (C8), 80.6 (C-2), 56.3 (7-OMe), 44.1 (C-3).2.3. Antioxidative assay The investigated compound%u2019s capacity to scavenge DPPH radicals has been evaluated by an experimental antioxidative assay [6]. In short, EtOH was used to dilute DPPH (0.15 mM). 1.4 %u03bcL of compounds 1-2 (400, 200, 100, 50, and 25 %u03bcg/mL) were mixed with 200 %u03bcL of this solution. For 30 min, the mixture was kept at 25 oC in a 96-microplate. A UV-Vis spectrophotometer was then used to detect the absorbance at 517 nm. The following formula was used to get the scavenging percentage (SC, %) of DPPH: SC (%) = [(A %u2013 B)/A] %u00d7100. In this case, A stands for the absorbance of the control reaction, and B for the absorbance when a tested or standard sample is present. Three duplicates of each experiment were conducted. A positive control was ascorbic acid. Using Microsoft Excel, the IC50 value, also referred to as the