Structure Elucidation of Compound 1: A Low Oxidation State Chain Compound with Multiple Unsaturated Bonds

Compound 1 was obtained as colorless oil, and its molecular formula was established as C29H42O7 by HR-ESI-MS (m/z 525.2826 [M+Na]+, calcd. 525.2823), indicating nine degrees of unsaturation. Analysis of the 1H NMR data (Table.) showed the presence of seven methyl singlets at δH 1.60 (s), 1.65 (s), 1.70 (s), 1.74 (s), 1.95 (s), 2.00 (s) and 2.11 (s), one methyl doublet δH 0.86 (d, J = 7.0 Hz), seven ene hydrogen or oxygenic protons at δH 5.03 (t, J = 5.1 Hz), 5.07 (d, J = 9.8 Hz), 5.16 (d, J = 8.4 Hz), 5.22 (t, J = 7.3 Hz), 5.49 (t, J = 6.9 Hz), 5.72 (t, J = 8.3 Hz), and 5.82 (brs), and other signals located in high fields δH 1.10-3.10. The 13C NMR and HSQC spectra revealed the presence of 29 carbon signals, consisting of eight methyls, five methylenes, eight methines (including four sp2 and four sp3 hybridization carbons), and seven quaternary carbons (including three olefinic and five carboxylic carbons). According to the above information, it is speculated that the compound may be a chain compound with low oxidation degree.

The presence of nine degrees of unsaturation and the high number of double bond and oxygenic proton signals suggest the possibility of multiple unsaturated bonds in the compound. The presence of carboxylic carbons in the 13C NMR spectrum indicates the presence of carboxylic acid groups in the molecule. The seven methyl singlets and one methyl doublet suggest the presence of multiple methyl groups in the molecule, possibly in different chemical environments. The high fields signals suggest the presence of electron-donating groups in the molecule. Overall, based on the spectroscopic data, Compound 1 is likely a low oxidation state chain compound with multiple unsaturated bonds and methyl groups, and carboxylic acid groups. Further analysis, such as COSY and HMBC, may be necessary to fully elucidate the structure of Compound 1.