Table 1.
Solvent system (v/v)a | KU/L (Valencene)b | KU/L (Nootkatone)b | α c | Purityd (%) |
Sf (%)e |
Elution time (min)f |
tR (min)i |
||||
---|---|---|---|---|---|---|---|---|---|---|---|
h – tg | t – hh | h – tg | t – hh | h – tg | t – hh | h – tg | t – hh | ||||
Hex–CHCl3–ACN (6:2:5) | 1.65 | 0.70 | 2.33 | 16.47 | 18.46 | 31.1 | 61.1 | 160–195 | 280–300 | 181 | 251 |
Hex–CHCl3–ACN (6:1:4) | 4.46 | 0.63 | 7.22 | 53.93 | 64.98 | 82.3 | 83.0 | 105–135 | 305–350 | 139 | 298 |
Hex–CHCl3–ACN (10:1:10) | 5.04 | 0.45 | 11.00 | 63.73 | 80.55 | 81.7 | 83.0 | 85–120 | 370–420 | 110 | 399 |
Hex–CH2Cl2–ACN (10:3:7) | 1.97 | 0.65 | 3.00 | 53.87 | 64.82 | 75.2 | 70.0 | 230–270 | 275–315 | 147 | 274 |
Hex–CH2Cl2–ACN (10:1:10) | 6.46 | 0.49 | 13.53 | 45.66 | 76.90 | 82.0 | 84.1 | 85–120 | 410–470 | 116 | 373 |
Hex–CH2Cl2–EtOAc–ACN (6:1:1:4) | 2.48 | 0.72 | 3.45 | 29.02 | 70.45 | 45.2 | 66.4 | 150–180 | 255–300 | 175 | 250 |
Hex–CH2Cl2–EtOAc–ACN (10:1:1:10) | 4.49 | 0.50 | 9.00 | 51.77 | 75.74 | 80.6 | 85.2 | 90–120 | 390–440 | 119 | 367 |
LtPet–(Et)2O–EtOH–H2O (5:0.5:4:0.5) | 7.28 | 0.69 | 10.55 | 56.25 | 64.23 | 72.4 | 84.1 | 130–155 | 310–370 | 155 | 274 |
LtPet–EtOH–H2O (5:4:1) | 28.64 | 0.95 | 30.17 | 75.87 | 61.85 | 79.2 | 86.9 | 160–185 | 180–230 | 192 | 209 |
LtPet–(Et)2O–EtOH–H2O (5:0.5:4:1) | 31.50 | 1.14 | 27.63 | 66.36 | 55.44 | 76.7 | 87.6 | 300–380 | 180–240 | 221 | 177 |
Hex– EtOAc–MeOH–H2O (5:1:4:1) | 28.68 | 1.11 | 25.84 | 75.51 | 55.26 | 82.2 | 91.2 | 185–210 | 145–170 | 218 | 182 |
Hex–MeOH–H2O (5:4:1) | 93.56 | 1.25 | 74.85 | 77.39 | 29.55 | 81.3 | 92.6 | 190–220 | 140–200 | 241 | 163 |
Hex, n-hexane; ACN, acetonitrile; EtOAc, ethyl acetate; LtPet, light petroleum (30–60 °C); (Et)2O, diethyl ether; EtOH, ethanol; MeOH, methanol.
The partition coefficients (K): in head–tail elution using the lower phase as the mobile phase, the K value was expressed as KU/L = AU/AL, where AU and AL was the peak area of the compound in the upper phase and the lower phase by GC, respectively; whilst in tail–head elution using the upper phase as the mobile phase, the K value is the reciprocal of KU/L, that is 1/KU/L.
α is the separation factor obtained by the ratio of K values between valencene and nootkatone, e.g. α = KU/L (Valencene)/KU/L (Nootkatone).
Percentage of peak areas of nootkatone analysed by GC–MS.
Sf, retention of the stationary phase, Sf = Vs/VC, where Vs is the volume of the retained stationary phase, VC is the total column volume.
The time range of nootakone fraction being eluted out.
Head–tail elution mode, using the lower phase as the mobile phase.
Tail–head elution mode, using the upper phase as the mobile phase.
tR, the theoretical retention time of nootkatone, calculated by tR = VR/F and VR = VC[1 + (K – 1)Sf], where VR was the retention volume of nootkatone, F was the flow rate of the mobile phase and K was the partition coefficient of nootkatone.