2.2. Purification and identification of SFE-CO2 extracts
The purification of SFE-CO2 extracts from P. diospyrifolium
leaves yielded a new benzoic acid derivative named as 4-methoxy-
3-[(E)-3-methyl-1,3-butadien-1-yl]-5-(3-methyl-2-buten-1-yl)-
benzoic acid (1) (Fig. 1). SFE-CO2 was effective for extracting this
compound. The molecular formula of (1) was determined to be
C18H22O3 by analysis of its EI-MS [m/z: 286 (100)] and NMR data
(Table 2). The splitting pattern in the 1H NMR spectrum (300 MHz)
of the two aromatic protons [dH 8.15 (d; J = 1.8 Hz)] and [dH 7.81