Phytochemical analysis of the OSAE and OSWE was done using a
6520 Accurate Q-TOF (Agilent Santa Clara, CA) mass spectrometer
coupled to HPLC. Metabolites of the extracts were separated using
HPLC according to Dutta et al. (2007) on reverse phase column
(Zorbax Eclipse XDB-C
,4.650 mm, 1.8 m). Solvent A and solvent
B of mobile phase were water with acetic acid (0.1% v/v) and
methanol with acetic acid (0.1%) respectively. A controlled flow rate
of 0.2 mL/min was maintained for the following linear gradient
elution in terms of solvent B: (i) 20–55% from 0 to 15 min, (ii) 55–
90% from 15 to 20 min, (iii) 90% isocratic from 20 to 23 min, (iv) 90–
20% from 23 to 26 min, and (v) isocratic 20% from 26 to 35 min