Simultaneous Extraction Optimization and Analysis of Flavonoids from the Flowers of Tabernaemontana heyneana by High Performance Liquid Chromatography Coupled to Diode Array Detector and Electron Spray Ionization/Mass Spectrometry

Table 1

Different variables for optimal extraction of flavonoids from the flowers of T. heyneana (aqueous ethanol as extraction solvent, 4⁵-L₁₆ design).

Levels	A	B	C	D	E
	Temp. (°C)	Ext. tim. (hrs)	Ethanol (%)	Material ratio (g : mL)	No. of ext. cycles
1	55	1	65	1 : 05	1
2	65	2	75	1 : 10	2
3	75	3	85	1 : 15	3
4	85	4	95	1 : 20	4