Determination by GC-MS-SIM of furanoditerpenes in Pterodon pubescens Benth.: development and validation

The crude hydroalcoholic extract from fruits of P. pubescens is widely used because of its anti-rheumatic, antinociceptive and anti-inflammatory activities. Furanoditerpenes have a vouacapan skeleton and are involved with the pharmacological activity of the oil extracted from P. pubescens fruits. Furanoditerpenes methyl 6α-acetoxy-7β-hydroxyvouacapan-17β-oate and methyl 6α-hydroxy-7β-acetoxyvouacapan-17β-oate from P. pubescens were isolated and identified. The present study developed and validated a GC-MS-SIM method for the separation and quantification of vouacapan constituents in a semipurified extract from P. pubescens fruits. The GC-MS analyses were carried out using a system equipped with a HP-5 capillary column (30 m × 0.25 mm). Temperature program: 100°C (4°C min(-1))-270°C (5 min), injector 260°C, detector 270°C. Helium was used as the carrier gas (0.7 bar, 1 mL min(-1)). The MS was taken at 70 eV. Scanning speed was 0.5 scans s(-1), from 50 to 650. Sample volume was 1 μL. Split 1:20. Analyses for validation of methodology were conducted by GC-MS-SIM (Single Ion Monitoring), where the ions monitored were 131, 145 and 146 (between 43 and 44.5 min), 105, 145 and 197 (from 44.5 to 45.3 min) and 131, 178 and 312 (from 45.3 to 48.5 min).Validation of the analytical method was based on the following parameters: linearity, robustness, limits of detection and quantification, precision (within-day and between-day variabilities), recovery and stability. The method was linear over a range of 12.81-2.56 μγμΛ(-1) of vouacapan 1, 112.78-22.56 μg mL(-1) of vouacapan 2, and 333.34-66.67 μg mL(-1) of vouacapans 3 and 4, with detection limits of 0.39, 3.45 and 9,44 μg mL(-1) and quantification limits of 1.19, 10.47 and 28.62 μg mL(-1), respectively. Recovery values were 100.69%, 97.48% and 96.98% for vouacapans 1, 2 and 3-4, respectively. Thus, the method was efficient to separate and quantify furanoditerpenes in the extract or fraction.