D hydrolysis, derivatization, and GC analysis. Also, two ketomethyls at C 21.15 (3H, s, H

D hydrolysis, derivatization, and GC analysis. Also, two ketomethyls at C 21.15 (3H, s, H 2.12) and 21.02 (3H, s, H two.02) and two carbonyl at C 172.29 and 171.96 carbons signals had been observed, which infers that two acetyl groups existed within the sugar chain. In the HMBC spectrum, one Sutezolid web particular proton of keto-methyl at H 2.12 was correlated with one carbonyl carbon signal at C 172.29 and C 74.65 (C-4, Rha); additionally, H-4 of Rha (H 4.95) was correlated with C 172.29, suggesting that 1 acetyl was connected at C-4 of Rha. In the same way, a different acetyl was substituted at C-2 of Rha, elaborated by the cross-peaks amongst H 2.02 and C 171.96/C 73.46 (C-2, Rha) and among H five.29 (H-2, Rha) and C 171.96. In comparison to two, it was further confirmed by the up-field shifts of H five.29 (H-2 of Rha, C 1.2 ppm) and H 4.95 (H-4 of Rha, C 1.43 ppm). The configuration of D-apiose affirmed the chemical shifts of C 112.54 (C-1), 78.49(C-2), 80.68(C-3), 75.41 (C-4), and 65.56 (C-5) [20]. The a configuration of L-rhamnopyranosyl was confirmed by the chemical shifts of Rha C-5 at C 67.34 [21]. The anomeric proton coupling constants of L-arabopyranose (J = 7.6 Hz 7.0 Hz) suggests that the configuration was an orientation [19]. Thus, compound three was deterMolecules 2021, 26, x FOR PEER Evaluation 9 of 17 mined as 15-oxo-18-nor-(20R,22R,25R)-spirost-5,13-diene-1,3,21,23,24-pentol-1-O–Dapiofuranosyl-(13)-2,4-diacetyl–L-rhamnopyranosyl-(13)-a-L-arabinopyranoside.HO OH O O O O O OH H OH OH OH O O H3C O O O O OH OH HO H O O HO H H H H H CH3 O H O H H H H OH O OH O H H HO O H H H OH H CH3 O O O OH H O H HO O O HO O OHOH-1H COSYHMBCNOESYFigure four. Important 1 H-1H COSY, HMBC, and NOESY correlations of compound three. Figure four. Crucial 1H- 1 HCOSY, HMBC, and NOESY correlations of compound three.Compound 4, named Pamaiosides D, a white amorphous was positive to LieberCompound four, named Pamaiosides D, a white amorphous Ziritaxestat custom synthesis strong,strong, was positive to Liebermann Burchard and chemical reactions. The pseudomolecular ion peak ion peak mann Burchard and MolischMolisch chemical reactions. The pseudomolecular was meawas measured inside the HR-ESI-MS m/z 993.3969 [M 993.3969 [M Na] C46 H66 O22 for sured within the HR-ESI-MS spectrum atspectrum at m/z Na] (calculated for(calculated Na, C46H66O22Na, 993.3943), corresponding to formula C46 H formula C46H66O . Compared 993.3943), corresponding for the molecular the molecular 66 O22 . Compared22with 3, only with 3, only two the position of one particular acetyl one particular acetyl the sugar the sugar linkages, have been two distinctions,distinctions, the position of group andgroup and linkages, had been detected detected (Tables 1). The acetyl group replaced at C-21, which was evidenced by the altered proton chemical shifts at H 3.46 (H-4 of Rha, C -1.49 ppm), Ha 4.19 (Ha-21, C 0.45 ppm), and Hb 4.33 (Hb-21, C 0.54 ppm). It was further acknowledged by the crosspeaks between H two.08 (3H, s, CH3CO-)/Ha 4.19, Hb four.33 (H-21), and C 172.90 (CH3CO-) inMolecules 2021, 26,9 of(Tables 1). The acetyl group replaced at C-21, which was evidenced by the altered proton chemical shifts at H 3.46 (H-4 of Rha, C -1.49 ppm), Ha four.19 (Ha-21, C 0.45 ppm), and Hb 4.33 (Hb-21, C 0.54 ppm). It was further acknowledged by the cross-peaks in between H 2.08 (3H, s, CH3 CO-)/Ha four.19, Hb 4.33 (H-21), and C 172.90 (CH3 CO-) inside the HMBC spectrum (Figure 5). Furthermore, the correlations for Api H-1 (H 5.18) to Rha C-3 (C 77.91), Rha H-1 (H five.28) to Ara C-4 (C 75.62), and Ara H-1 (H 4.30) to C-1 (C 85.33) in the HMBC spectra c.