(B) Totally free phenolic compounds from CHH2 grown at HT.297 and 326 nm
MS spectra showed a Napabucasin site deprotonated molecule [M-H]- at m/z 237 with fragment ions at m/z 163, 145 and 119. Hence, this peak was tentatively identified as procyanidin B, which was supported by its MS and UV spectra inside the literature20.(B) Cost-free phenolic compounds from CHH2 grown at HT.297 and 326 nm, which was the identical as that of caffeic acid. The [M-H-74]- ion at m/z 179 in peaks two and 4 is standard of that developed by the loss of a glycerol residue. Therefore, peaks 2 and 4 had been tentatively deduced as either 1-O-caffeoylglycerol or 2-O-caffeoylglycerol17, considering the fact that it was not probable to ascertain the substituent group positions. Peak 8 had exactly the same UV max of 310 nm as that of p-coumaric acid. MS spectra showed a deprotonated molecule [M-H]- at m/z 237 with fragment ions at m/z 163, 145 and 119. Fragment ions at m/z 163 and 119 appeared to correspond to deprotonated and decarboxylated p-coumaric acid, indicating the presence of p-coumaric acid. According to the above, this compound which lost the glycerol residue can generate a 163[M-H-74]- anion. Therefore, this compound was tentatively identified as 1-O-p-coumaroylglycerol or 2-O-p-coumaroylglycerol17. The UV spectral traits of peaks 16 and 17 have been similar to that of caffeic acid with max at about 326 nm, suggesting derivatives of caffeic acid. They had deprotonated molecule [M-H]- title= s-0034-1396924 at m/z 415 and fragmentation patterns with ions at m/z 253, 179 [caffeic acid ]-, 161 [caffeic acid -H2O]- and 135 [caffeic acid -CO2]-, which supported the presence of a caffeic acid residue. The fragment ion of m/z at 253 title= rstb.2014.0086 (415-162) could correspond to dehydrated caffeic acid attached to the caffeoylglycerol. From a comparison of literature information of UV and MS spectra, these two peaks had been tentatively identified as either 1,2-O-dicaffeoyglycerol or 1,3-O-dicaffeoyglycerol17. The deprotonated molecule ion [M-H]- showed peaks of 20 and 21 at m/z 399 and 429, respectively. Each peaks contained precisely the same ions at m/z 253, indicating that these two compounds may possibly also include a caffeoylglycerol residue. Peak 20 also showed two prominent ions at m/z 163 [p-coumaric acid-H]- and 235 [M-H- p-coumaric acid]-, suggesting it could happen to be derived from the loss of a p-coumaric acid residue. For peak 21, some fragment ions at m/z 235 and 193 had been detected. The ion at m/z 235 [M-H-194] indicated the loss of a ferulic acid moiety, though an additional ion at m/z 193, corresponded to deprotonated ferulic acid, suggested the presence of a ferulic acid moiety. Soon after comparisons with all the literature17, peaks 20 and 21 had been tentatively identified as p-coumaroyl-caffeoylglycerol and feruloyl-caffeoylglycerol, respectively. Flavanols. Peak 1 had a deprotonated molecular ion [M-H]- at m/z 577 and fragment ions at m/z 425 and 289 (Table 1). The ion at m/z 425 [M-H-152] might be developed by the removal of a B-ring from the heterocyclic ring of catechin derivatives with the Retro-Diels-Alder rearrangement inside the ESI unfavorable ion mode18.