. 2019 Mar 8;56(4):1939–1953. doi: 10.1007/s13197-019-03660-6

Table 1.

Retention time (t_R), retention factor (k), separation factor (α), peak purity and analytical precision of prenylflavonoids and hop bitter acids in surplus yeast

Peak No.	Compound	t_R (min)^a	Retention factor (k)^a	Separation factor (α)^ac	Peak purity (%)^b	Intra-day variability RSD (%)^d	Inter-day variability RSD (%)^d
1	Isoxanthohumol	4.64	1.81	1.73 (1, 2)^b	99.6	3.56^b	2.39^b
2	8-prenylnaringenin	6.82	3.13	1.37 (2, 3)	99.3	7.23^b	7.67^b
3	6-prenylnaringenin	8.71	4.28	1.06 (3, 4)	97.6	3.27^b	3.47^b
4	Cohulupone	9.16	4.55	1.09 (4, 5)	98.5	3.16^b	1.61^b
5	Xanthohumol	9.82	4.95	1.02 (5, 6)	88.0	1.52^b	0.68^b
6	Hulupone	10.00	5.06	1.14 (6, 7)	99.3	2.26^b	0.78^b
7	Adhulupone	11.20	5.79	1.16 (7, 8)	97.6	7.24^b	4.30^b
8	Unknown	12.55	6.60	1.14 (8, 9)	–^e	–	–
9	Trans-isocohumulone	12.71	6.70	1.06 (9, 10)	97.6	8.00^a	8.49^a
10	Cis-isocohumulone	14.30	7.67	1.01 (10, 11)	–	6.56^a	5.76^a
11	Trans-isohumulone	14.46	7.76	1.04 (11, 12)	96.1	5.44^a	8.34^a
12	Cis-isohumulone	14.93	8.05	1.02 (12, 13)	–	1.45^a	2.03^a
13	Trans-isoadhumulone	15.22	8.22	1.05 (13, 14)	95.7	1.77^a	2.80^a
14	Cis-isoadhumulone	15.86	8.61	1.13 (14, 15)	–	1.81^a	1.65^a
15	Cohumulone	17.67	9.71	1.15 (15, 16)	99.0	6.63^b	3.22^b
16	Humulone	20.11	11.19	1.03 (16, 17)	99.7	1.37^b	1.02^b
17	Adhumulone	20.63	11.50	1.11 (17, 18)	94.8	2.47^b	2.09^b
18	Prehumulone	22.71	12.76	1.01 (18, 19)	94.1	2.71^b	8.85^b
19	Postlupulone	22.87	12.86	1.01 (19, 20)	99.7	8.82^b	9.74^b
20	Adprehumulone	23.02	12.95	1.09 (20, 21)	97.1	3.38^b	6.67^b
21	Colupulone	24.90	14.09	1.07 (21, 22)	98.1	3.15^b	2.51^b
22	Lupulone	26.64	15.15	1.02 (22, 23)	97.1	3.77^b	3.45^b
23	Adlupulone	27.12	15.44	1.10 (23, 24)	94.5	4.43^b	4.70^b
24	Prelupulone	29.62	16.95	1.02 (24, 25)	99.4	8.23^a	8.55^a
25	Adprelupulone	30.16	17.28	1.02 (24, 25)	93.5	4.69^a	6.75^a

^aData collected from HPLC–MS–MS

^bData collected from HPLC–DAD

^cNumbers in parentheses represent values between two neighboring peaks

^dRSD% = (SD/mean) × 100%

^e“–” Data not available