Structural Elucidation of Compound 1: A Chain Compound with Multiple Unsaturated Bonds and Carboxylic Acid Moieties

Compound 1 was obtained as a 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 seven ene hydrogen or oxygenic protons in the 1H NMR spectrum suggests the possibility of multiple unsaturated bonds in the molecule. The 13C NMR and HSQC spectra confirm the presence of olefinic and carboxylic carbons, indicating the presence of both unsaturated and carboxylic acid moieties in the molecule. The seven methyl singlets suggest the presence of multiple methyl groups in the molecule.

Based on the molecular formula and the NMR data, it is speculated that Compound 1 may be a chain compound with low oxidation degree, containing multiple unsaturated bonds and carboxylic acid moieties. Further analysis, such as COSY and HMBC experiments, may be required to determine the exact structure of the compound.