Pale yellow color amorphous powder, UV (MeOH) nm: 345; IR (KBr) cm−1: 3450 (hydroxyl),1705 (carbonyl), 1630 and characteristic signals; EIMS m/z: 410 [M]+; 1H NMR (400 MHz, CDCl3): δ 1.58 (3H, s, H-24), 1.67 (3H, s, H-23), 1.80 (3H, s, H-25), 2.08 (4H, m, H-19 & 20), 3.0 (2H, m, H-9), 3.12 (2H, m, H-8), 3.42 (2H, d, J = 6.7 Hz, H-16), 5.04 (1H, t, J = 6.7 Hz, H-21), 5.16 (1H, t, J = 6.7 Hz, H-17), 6.37 (1H, dd, J = 2.1, 8.7 Hz, H-5), 6.38 (1H, d, J = 2.1 Hz, H-3), 6.68 (1H, d, J = 8.2 Hz, H-11), 6.74 (1H, d, J = 8.2 Hz, H-12), 7.60 (1H, d, J = 8.7 Hz, H-6), 12.8 (1H, s, OH-2); 13C NMR (100 MHz, CDCl3): δ 16.2 (C-25), 17.7 RG 7204 (C-24), 25.7 (C-23), 25.9 (C-16), 26.3 (C-20), 27.8 (C-9), 39.6 (C-19), 39.7 (C-8), 103.6 (C-3), 107.8 (C-5), 112.8 (C-12), 113.7 (C-1), 121.4 (C-11), 121.7 (C-17), 123.7 (C-21), 126.0 (C-15), 131.1

(C-10), 132.2 (C-6), 132.3 (C-22), 138.9 (C-18), 142.4 (C-14), 142.8 (C-13), 162.6 (C-4), 165.2 (C-2), 204.0 (C-1); EIMS m/z (rel. The compound was obtained as pale yellow color amorphous Selleckchem SAHA HDAC powder from fraction.2. It was readily recognized as chalcone derivative based on its spectral data. Its molecular formula has been fixed as C25H30O5 on the basis of mass, M+ 410. Its UV spectrum showed lambda max value is 345 nm indicating that the molecule is having conjugation. Its IR spectrum showed specific absorption bands at 3450 (hydroxyl), 1705 (carbonyl) and 1630 (aromatic) cm−1. The 1H NMR spectrum (Fig. 1) clearly showed the presence of three double bonded methyls at δ 1.58, 1.67 and 1.80

each as singlet, four allylic methylene Thiamine-diphosphate kinase groups at δ 2.08 as multiplet and another methylene group α – to the carbonyl group at δ 3.12 as multiplet. Further, the spectrum also showed two benzylic methylene groups at δ 3.00 (m) and 3.42 (d, J = 6.7 Hz). The second benzylic group showed doublet indicates that this methylene group coupled with only one neighbouring proton. Additionally, the spectrum showed two olefinic protons at δ 5.16 (t, J = 6.7 Hz) and 5.04 (t, J = 6.7 Hz) coupled with methylenic protons, two ortho coupled aromatic protons at δ 6.68 and 6.74 each as doublet (J = 8.2 Hz) belongs to one phenolic ring and three more additional aromatic protons at δ 6.38 (d, J = 2.1 Hz), 6.37 (dd, 2.1 & 8.7 Hz) and 7.60 (d, J = 8.7 Hz) belongs another tri-substituted phenolic ring. The carbon spectrum clearly showed twenty-five carbons. Of which, three methyl carbons, five methylene carbons, four olefinic carbons, twelve aromatic carbons and one ketonic carbon at δ 203.8.