UPLC-Q-TOF-MS based studies to evaluate the effect of extraction methodology on the yield of 6-shogaol, a biomarker of Z. officinale

The rhizome of Zingiber officinale (ver. Ginger) is one of the most widely used spice and extensively used in Indian traditional system of medicine. Its major chemical constituents are the pungent principles (2-5%) of which, 6-shogaol [1-(4-hydroxy-3-methoxyphenyl)-4-decen-3-one] (1) can be considered as the potent bio-marker in view of its highly potent biological activities such as anti-inflammatory, anticancer and anti-invasive. In order to identify the high 6-shogaol yielding Z. officinale sample, a highly efficient extraction method is desirable. With this objective, we have carried out detailed studies on the extraction of Z. officinale and evaluated with respect to its bio-marker. A rapid UPLC-QTOF MS method has been developed and validated for this purpose to estimate 6-shogaol quantitatively in various extracts. The analysis was carried out on an Acquity BEH C18 reverse phase column with gradient elution of acetonitrile-water containing 2 mM ammonium acetate using QTOF MS instrument operated with ESI source in both +ve and −ve ion modes. The calibration curve is linear with the correlation coefficient (r) and coefficient of determination (R2) were 0.9998 and 0.9997 respectively. The LOD and LOQ were found to be 6.26 ng/mL and 25 ng/mL respectively. The accumulation of 6-shogaol in various extracts was found to be in the range 0.045-0.732%. Interestingly, 6-shogaol was obtained maximum (0.73%) under ultrasound extraction conditions.