**2. Results**

#### *2.1. Confirmation of the Isolated Lanosteryl Triterepene (RA-3)*

RA-3 was routinely isolated and purified from the chloroform extract of *P. longifolia* stem bark using chromatographic techniques. The physical (white crystals, >95% pure, melting point 204–205 ◦C) and spectral data (IR (KBr) vmax = 3469, 1683 cm–1, molecular formula C31H50O3) of this compound were in agreemen<sup>t</sup> with previous reports from our laboratory [14,18]. The expected chemical structure of the compound was confirmed as methyl-3β-hydroxylanosta-9,24-dien-21-oate (Figure 1).

**Figure 1.** Methyl-3β-hydroxylanosta-9,24-dien-21-oate (RA-3), a lanosteryl triterpene from *P. longifolia*.
