Qp2010 plus instrument

The essential oil fractions from fresh leaves and roots (2.0 g) of P. aduncum were obtained by simultaneous distillation–extraction process using a Likens-Nickerson apparatus for 2 h and n-pentane (3 mL) as solvent. After extraction, an aliquot (1.0 μL) of the organic phase was analyzed by gas chromatography. Qualitative analysis was carried out on a GC–MS (Shimadzu QP2010 plus instrument) under the following conditions: Rtx-5MS silica capillary column (30 m × 0.25 mm × 0.25 mm film thickness); programmed temperature, 60–240 °C (3 °C/min); injector temperature, 200 °C; carrier gas, helium, adjusted to a linear velocity of 1.2 mL/min; injection type, splitless; split flow was adjusted to yield a 20:1 ratio; septum sweep was a constant 10 mL/min; EIMS, electron energy, 70 eV; temperature of the ion source and connection parts, 200 °C. The retention index was calculated for all the volatile constituents using a homologous series of n-alkanes (C8–C32, Sigma-Aldrich) (Van Den Dool and Kratz 1966 (link)). The identification of compounds was performed by comparison of mass spectrum and retention index with data present in the libraries of Adams (2007 ) and NIST (2011 ).

The chemical constituents of oleoresins were analyzed by GC-MS (Shimadzu QP 2010 plus instrument) with GCMS-QP 2010 Ultra DB-5 and GCMS-QP 2010 Ultra Rtx-5MS columns (30 m × 0.25 mm i.d., 0.25 µm). The experimental conditions are as follows: Carrier gas: helium with flow rate = 1.21 mL/min, and split ratio = 10.0. Oven temperature: 50–280°C with a temperature gradient of 3°C/min upto 210°C (isotherm for 2 min), and then 6°C/min upto 280°C. Identification of oleoresins components was performed by comparing their relative retention index (RI) values with mass spectra NIST (NIST version 2.1) and WILEY (7th edition) libraries, and also by matching the fragmentation pattern of the mass spectral data with those reported in the literature [21 ].

The leaf and root essential oils were obtained from fresh P. nigrum plant material (2.0 g) using a Likens–Nickerson apparatus with simultaneous extraction with n-pentane (3 mL) over a period of 2 h. For each essential oil extracted, a 1.0-mL aliquot (1.0 μL) was analyzed using gas chromatography–mass spectrometry (GC-MS) as previously described (da Trindade et al., Plants, 2019, 8(11), 442): Shimadzu QP2010 plus instrument; Rtx-5MS capillary column (30 m × 0.25 mm × 0.25 mm film thickness); temperature ramp of 60–240 °C at a rate of 3 °C/min; injector temperature of 200 °C; He carrier gas with 1.2 mL/min flow rate; split mode injection (20:1 split ratio); MS ionization voltage = 70 eV; ion source and detector temperature = 200 °C. Compound identification was achieved by comparison of the retention indices, determined using a homologous series of n-alkanes (C8–C32, Sigma–Aldrich, St. Louis, MO, USA) [21 (link)], and the mass spectral fragmentation patterns with those reported in the databases [22 ,23 ,24 ].