This evidence supported by complete acid hydrolysis yielding glucose in the aqueous layer

of compound 5 only and apigenin was detected in the organic layer in check details both compounds (CoPC). 91H NMR spectrum showing an AX system exhibiting two ortho doublets each integrated for two protons of H-2′/6′, and of H-3′/5′ indicating 1′,4′-disubstituted B-ring of both compounds. The down-field shift of both H-6 and H-8 to 6.43 and 6.74 meta doublet and the anomeric proton signal at δ 5.22 ppm gave evidence for the presence of β-glycosidic moiety at 7-position in compounds 5. 1813C NMR spectra showed the carbon signals characteristic of apigenin nucleus and its glycosidation at 7-OH in compound 5 was indicated by slight up-field shift of C-7. The structure of the compounds was also confirmed by negative ESI-MS molecular ion peak of compound 9 as a free apigenin aglycone at m/z 269 [M–H]− and of compounds 5 at m/z 431 [M–H]− as apigenin glucoside and was compared with published data. 9, 17 and 21 1H NMR spectra of compound 11 showed flavanone structure indicated by the appearance of dd signal at δ 5.47 ppm integrated for one

proton of two J values (J = 12.8 and 2.8 Hz), assigned for H-2 and the dd of dd signal at δ 2.71 ppm, (1H, J = 17.0, 12.8 and 2.8 Hz, H-3). Negative ESI-MS of compound 11 at m/z 301 [M−H]− indicated its structure as naringenin. 17 and 22 Compound 8 was obtained as yellow amorphous powder (30 mg), showed UV spectra of two major absorption bands in methanol at λmax 265 nm (band II) and at λmax 366 nm (band I), Torin 1 chromatographic properties: Rf values; 0.68 (S1), 0.14 (S2); dull yellow spot under UV-light with no change on exposure to ammonia vapors, it gave greenish yellow color with FeCl3 and Naturstoff spray reagents. Negative ESI-MS spectrum exhibited a molecular ion peak at m/z 299 [M−H]−. 1H NMR (300 MHz, DMSO-d6): δ ppm; 12.60 (1H, s, OH-5), 7.80 (2H, d, J = 8.7 Hz, H-2′/6′), 7.34 (2H, d, J = 8.7 Hz, H-3′/5′), 6.40 (1H, d, J = 1.8 Hz, H-8), 6.20 (1H, d, J = 1.8 Hz, H-6), 3.81 (3H,

s, OCH3-4′). 13C NMR (75 MHz, for DMSO-d6): δ ppm 176.39 (C-4), 164.50 (C-7), 161.30 (C-5), 159.20 (C-4′), 156.68 (C-9), 147.35 (C-2), 136.28 (C-3), 130.10 (C-2′/6′), 120.53 (C-1′), 116.90 (C-3′/5′), 104.22 (C-10), 98.75 (C-6), 93.91 (C-8), 56.40 (OCH3-4′). The methylation of the hydroxyl group at 4′ was evident by the downfield shift of 3′/5′ protons (δ 7.34 ppm) and their carbons (δ 116.90 ppm), compared to that of kaempferol (δ 6.85 and 115.0 ppm, respectively) and the slight upfield shift of carbon of C-4 (δ 159.20 ppm) compared to that of kaempferol (δ 160.0 ppm).