Table 2: Characterization of phenolic compounds of the spent hops extract using their spectral characteristic in UPLC-DAD (retention time, λmax) and negative ions in UPLC–ESI-MS.
| Compounds | tR (min) | λmax (nm) | [M-H]- | [MS-MS-] (m/z) |
| Neochlorogenic acid | 2.30 | 320 | 353 | 235/191/147 |
| B-type PA-trimer | 2.57 | 280 | 865 | 577/407/289 |
| B3 dimer | 2.64 | 280 | 577 | 407/289 |
| B-type PA-trimer | 2.98 | 280 | 865 | 577/407/289 |
| (+)- Catechin | 3.11 | 280 | 289 | 245/203 |
| B1 dimer | 3.38 | 280 | 577 | 407/289 |
| Chlorogenic acid | 3.50 | 320 | 353 | 235/191/147 |
| B2-dimer | 3.87 | 280 | 577 | 407/289 |
| Cryptochlorogenic acid | 3.50 | 320 | 353 | 235/191/147 |
| Feruloylquinic acid | 3.98 | 322 | 367 | |
| (-)-Epicatechin | 4.65 | 280 | 289 | 245/203 |
| Procyanidin C1 | 5.04 | 280 | 865 | 577/407/289 |
| B4 dimer | 5.27 | 280 | 577 | 407/289 |
| B-type PA-trimer | 5.42 | 280 | 865 | 577/407/289 |
| Quercetin-3-hexosylrutinoside | 5.59 | 353 | 771 | 609/591/301 |
| Quercetin-3-dihexoside | 6.00 | 353 | 625 | 463/301 |
| Quercetin-hexosiderhamnoside-rhamnoside | 6.23 | 353 | 755 | 609/463/301 |
| Quercetin-hexosiderhamnoside | 6.60 | 355 | 609 | 463/301 |
| Quercetin-hexoside | 7.10 | 355 | 463 | 301 |
| 1-[2(Methylpropanoyl) phloroglucinyl] glucoside (multifidol-glucoside) | 7.14 | 287 | 358 | 196 |
| Quercetin-hexosiderhamnoside | 7.25 | 355 | 609 | 463/301 |
| Quercetin-3-O-hexoside | 7.36 | 355 | 463 | 301 |
| Quercetin-O-deoxyhexose-Odeoxyhexoside | 7.50 | 355 | 593 | 447/301 |
| Quercetin-3-O-acetylhexoside | 8.02 | 350 | 506 | 463/445/301 |
| Kempferol-3-O-rutinoside | 8.35 | 340 | 593 | 447/327/285 |
| Kempferol-3-O-hexoside | 8.52 | 340 | 447 | 327/285 |
| Kaempferol -3-O-acetylhexoside | 9.37 | 340 | 489 | 285 |