Development and Validation of RP-HPLC Method for Vicenin-2, Orientin, Cynaroside, Betulinic Acid, Genistein, and Major Eight Bioactive Constituents with LC-ESI-MS/MS Profiling in <i>Ocimum</i> Genus
Aboli Girme, Prajkta Bhoj, Ganesh Saste, Sandeep Pawar, Amit Mirgal, Dipak Raut, Machindra J. Chavan, Lal Hingorani
Abstract
BACKGROUND: Ocimum genus, known as Tulsi or Basil, is a prominent botanical class in Asian culture, especially in India. The leaves have immunomodulatory, antioxidant, stress-relieving, and adaptogenic roles in traditional and modern medicine, with prominent usage in herbal teas and nutraceuticals. OBJECTIVE: An high-performance liquid chromatography-photodiode array (HPLC-PDA) method was developed and validated for quantification of vicenin-2, orientin, cynaroside, betulinic acid, genistein with syringic acid, rosmarinic acid, eugenol, carnosic acid, oleanolic acid, ursolic acid, luteolin, and apigenin and was confirmed using a novel electrospray ionisation-mass spectrometry (ESI-MS/MS) method in the Ocimum genus samples. METHOD: The methodology parameters were developed on an reverse phase (RP) C18 column with a gradient elution of 1 mL/min flow rate for 0.1% o-phosphoric acid and acetonitrile at 210 and 340 nm wavelengths. RESULTS: The validation data for 13 bioactive compounds showed good linearity (r2 > 0.99) with sensitive LOD (0.034-0.684 µg/mL) and LOQ (0.100-2.068 µg/mL) with recoveries (83.66-101.53%). The results of the quantification were found to be precise (RSD, <5.0%) and accurate (relative error (RE), -0.60-1.06). The method performance was verified by analyzing 10 samples of O. tenuiflorum from the 10 geographical states of India (RSD, <5.0%) and were found to be robust. This HPLC-PDA method with ESI-MS/MS confirmation was applicable to the 13 cultivars from O. thyrsiflorum, O. citriodorum, O. americanum, O. africanum, O. basilicum, O. gratissimum, and O. tenuiflorum species. CONCLUSIONS: The validated HPLC-PDA and LC-ESI-MS/MS method was found to be selective and suitable for analyzing 13 compounds in O. tenuiflorum and 12 cultivars from the Ocimum genus as a quality control tool. This method can be used in routine analysis as an inexpensive alternative to advanced techniques. HIGHLIGHTS: This work is the first to report for vicenin-2, orientin, cynaroside, betulinic acid, and genistein, with simultaneous analysis of eight bioactive compounds in the Ocimum genus.