Table 1.
Compounds identified as secoiridoid glycosides with key positive and negative mode neutral losses and putative assignments included.
| Compound | (pos*) Rt/min |
[M+Na]+ m/z |
[M-H]− m/z |
Molecular formula | Fragments of [M + Na]+ | Fragments of [M–H]− | Assignment | References | |||
|---|---|---|---|---|---|---|---|---|---|---|---|
| – 162 | –194 | –232 | –264 | –386 | |||||||
| Iridoid glycoside standards | |||||||||||
| 7 | 1.2 | 413.1057 | 389.1089 | C16H22O11 | Y | – | – | – | – | Monotropein standard | |
| 8* | 12.6 | 399.1256 | 375.1297 | C16H24O10 | Y | – | – | – | – | Loganic acid standard | |
| 9 | 14.9 | 709.2293 | 685.2349 | C31H42O17 | Y | Y | Y | Y | Y | Nuzhenide standard | |
| 10 | 15.7 | 563.1715 | 539.1770 | C25H32O13 | Y | Y | Y | Y | – | Oleuropein standard | |
| 11 | 15.8 | 1095.3500 | 1071.3562 | C48H64O27 | Y | Y | Y | – | Y | GL3 standard | |
| Putative iridoid glycosides in ash leaf extracts | |||||||||||
| 12 | 12.0 | 443.1157 | not obs | C17H24O12 | Y | Y | n/a | n/a | n/a | 10-hydroxyoleoside 11-methyl ester | 37 |
| 13* | 12.4 | 427.1213 | 403.1246 | C17H24O11 | Y | Y | – | – | – | Oleoside methyl ester/secologanoside methyl ester | 7,38 |
| 14 | 12.7 | not obs | 525.1606 | C24H30O13 | n/a | n/a | – | – | – | Demethyloleuropein | 35,39 |
| 15 | 13.1 | 589.1729 | 565.1774 | C23H34O16 | Y | Y | – | – | Y | Methylglucooleoside or isomer | 7 |
| 16 | 13.3 | not obs | 509.1658 | C24H30O12 | n/a | n/a | Y | – | – | Demethylligustroside | 39 |
| 6 | 13.3 | not obs | 449.1301 | C18H26O13 | n/a | n/a | – | – | – | N3-hydroxytyrosol | 36 |
| 1 | 13.5 | 589.1728 | 565.1774 | C23H34O16 | Y | Y^ | – | – | Y | P2/N2 methylglucooleoside or isomer | 7 |
| 17 | 14.8 | 579.1680 | 555.1719 | C25H32O14 | Y | Y | – | – | – | 10-hydroxyoleuropein | 36 |
| 18 | 14.9 | 709.2311 | 685.2349 | C31H42O17 | Y | Y | Y | Y^ | – | Isomer of nuzhenide/excelside B | 35 |
| 19 | 14.9 | 441.1376 | 417.1402 | C18H26O11 | Y | Y | Y | Y | – | Oleoside dimethyl ester | 7,40 |
| 20 | 15.0 | 709.2323 | 685.2349 | C31H42O17 | Y | Y | Y | Y^ | Y | Isomer of nuzhenide/excelside B | 35 |
| 2 | 15.1 | 709.2311 | 685.2349 | C31H42O17 | Y | Y | Y | Y^ | Y | Isomer of nuzhenide/excelside B | 27,35 |
| 21 | 15.3 | 563.1729 | 539.1170 | C25H32O13 | Y | Y | – | Y | – | 10-hydroxyligustroside | 7 |
| 3 | 15.4 | 709.2308 | 685.2349 | C31H42O17 | Y | Y | Y^ | – | Y | P1/N4; isomer of nuzhenide/excelside B | 27 |
| 22 | 15.5 | 1033.3161 | 1009.3194 | C46H58O25 | Y | Y | Y | Y | Y | Oleoacetoside | 35,40–42 |
| 23 | 15.7 | 563.1725 | 539.1170 | C25H32O13 | Y | Y | Y | Y | Y | Oleuropein (10) | 7 |
| 24 | 15.9 | 547.1782 | 523.1821 | C25H32O12 | Y | Y | – | – | Y | Excelsioside | 7 |
| 25 | 16.0 | 741.2935 | 717.2975 | C33H50O17 | Y | Y | Y | Y | Y | Isomer of jashemsloside C/D | 43 |
| 26* | 16.1 | 625.2092 | 601.2138 | C27H38O15 | Y | Y | – | – | – | Frameroside/2″-epi-frameroside | 44 |
| 27 | 16.2 | 783.3401 | 759.3445 | C36H56O17 | Y | Y | Y | Y | – | Isomer of (9) from R. glutinosa | 45 |
| 28 | 16.2 | 757.2878 | 733.2924 | C33H50O18 | Y | Y^ | – | – | Y | Jaspofoliamoside A or isomer | 41 |
| 29 | 16.3 | 933.2989 | 909.3034 | C42H54O22 | Y | Y | – | – | – | GL5 or isomer | 7,8,35 |
| 30 | 16.3 | 547.1783 | 523.1821 | C25H32O12 | Y | Y | Y | Y | – | Ligustroside | 7 |
| 31 | 16.7 | 933.3004 | 909.3034 | C42H54O22 | Y | Y | Y | – | Y | GL5 or isomer | 7,8,35 |
| 4 | 17.0 | 933.2987 | 909.3034 | C42H54O22 | Y | Y | – | – | – | P7—GL5 or isomer | 27,35 |
| 32* | 17.1 | 967.3426 | 943.3453 | C43H60O23 | Y | Y | – | – | Y | Isomer of pulosarioside | 46 |
| 33 | 17.4 | 981.3565 | 957.3609 | C44H62O23 | Y | Y | Y | Y | Y | Jaspofoliamoside E or isomer | 47 |
*indicates compounds with significant retention time shifts (> 2 min earlier) in negative mode compared to positive ion mode due to different mobile phases.
^denotes this peak is observed but is very small; < 3% intensity of base peak.