We also report the number of molecular formulas found in PubChem for the above mentioned mass accuracy.
The molecular formula was found to be C24H39NO7.
Open image in new window HRMS data of compound 2 supported the molecular formula C57H70N8O13 (found m/z 1075.5133, calcd. 1075.5135 for [M + H]+, Δ 0.2 ppm).
The formula found some success.
Studies of TCM formulas found that 99% of 200 government approved TCM formulas are histone-modifying.
The molecular formula for U4 was found to be C30H57N15.
This was consistent with a molecular formula of C35H40N4O9, as found in the HO-NCC 6 epi, suggesting the formal addition of an oxygen atom to 4 epi.
Three compounds found in both extracts are presented in Table 1, with their presumed molecular formulae and measured m/z values corresponding to identified ions obtained by ESI ToF mass spectrometry.
Additional file 1 details the complexity of the molecular formulae.
Böcker and Rasche [147] introduced fragmentation trees (see Figure 7) to find the molecular formula of an unknown, without using databases: Here, the highest-scoring fragmentation tree for each molecular formula candidate is used as the score of the molecular formula itself.
