Lcq duo ion trap mass spectrometer

Plumbago indica and P. auriculata aerial parts were obtained from El-Mazhar botanical garden, Giza, Egypt after obtaining a permission to acquire the plant materials. The plants were authenticated by Mrs. Therease Labib, Consultant on Plant Identification at El-Orman Botanical Garden. Voucher specimens (Numbers: 14062020 and 15062020) were kept at the herbarium of the Department of Pharmacognosy, Faculty of Pharmacy, Cairo University. The air-dried materials (500 g, each) were subjected to exhaustive cold maceration using ethanol (70%) with frequent agitation. The extracts were separately evaporated under vacuum at 40 °C till complete dryness and furnished extraction yields of 10.8% and 9.8% for P. indica and P. auriculata, respectively.
A Thermofinnigan (Thermo Electron Corporation, USA) coupled with an LCQ-Duo ion trap mass spectrometer with an ESI source (ThermoQuest) system was utilized. The MS operated in the negative mode. The ions were detected in a full scan mode and mass range of 50–2000^{10 (link)}.

The LC system was ThermoFinnigan (Thermo Electron Corporation, Waltham, MA, USA) coupled with an LCQ-Duo ion trap mass spectrometer with an ESI source (ThermoQuest). The separation was achieved using a C18 reversed-phase column (Zorbax Eclipse XDB-C18, rapid resolution, 4.6 × 150 mm, 3.5 µm, Agilent, Santa Clara, CA, USA). A gradient of water and acetonitrile (ACN) (0.1% formic acid each) was applied from 5% to 30% ACN over 60 min with a flow rate of 1 mL/min with a 1:1 split before the ESI source. The samples were injected automatically using an autosampler surveyor ThermoQuest. The instrument was controlled by Xcalibur software (Xcalibur™ 2.0.7, Thermo Scientific, Waltham, MA, USA). The MS operated in the negative mode for better detection of the phenolic compounds with a capillary voltage of—10 V, a source temperature of 200 °C, and high-purity nitrogen as a sheath and auxiliary gas at a flow rate of 80 and 40 (arbitrary units), respectively. Collision energy of 35% was used in MS/MS fragmentation. The ions were detected in a full scan mode over a mass range of 50–2000 m/z.

A Thermofinnigan (Thermo Electron Corporation, USA) coupled with an LCQ-Duo ion trap mass spectrometer with an ESI source (ThermoQuest) system was utilized. A C18 reversed-phase column (Zorbax Eclipse XDB-C18, rapid resolution, 4.6 × 150 mm, 3.5 µm, Agilent, USA) was used to separate the analytes. A gradient of water and acetonitrile (ACN) (0.1% formic acid each) was applied from 5% to 30% ACN over 60 min with flow rate of 1 mL/min with a 1:1 split before the ESI source. The samples were injected automatically using autosampler surveyor ThermoQuest. The instrument was controlled by Xcalibur software (Xcalibur^TM 2.0.7, Thermo Scientific). The MS operated in the negative mode as before^{8 (link)}. The ions were detected in a full scan mode and mass range of 50–2000.

LC-MS/MS analysis was done on a Finnigan LCQ-Duo ion trap mass spectrometer with an ESI source (Thermo Quest, Austin, TX, USA) coupled to a Finnigan Surveyor HPLC system (MS pump plus, autosampler, and PDA detector plus) with an EC 150/3 NUCLEODUR 100-3 C18ec column (Macherey-Nagel, Düren, Germany).
A gradient of water and acetonitrile (ACN), without acid, was applied from 5% to 60% ACN in 45 min at 30 °C. Flow rate was 0.5 ml/min. Injection volume was about 20 µl. MS was operated in the negative mode with a capillary voltage of −10 V, source temperature of 220 °C, and high purity nitrogen as a sheath and auxiliary gas at a flow rate of 80 and 40 (arbitrary units), respectively. Ions were detected in a mass range of 50–2,000 m/z. Collision energy of 35% was used in MS/MS for fragmentation. Data acquisitions and analyses were done using Xcalibur™ 2.0.7 software (Thermo Fisher Scientific, Waltham, MA, USA).

HPLC-DAD-ESI-MS/MS was employed to investigate the chemical constituents of the extract. The LC system was Thermo Finnigan (Thermo electron Corporation, OK, USA), coupled with an LCQ Duo ion trap mass spectrometer with an ESI source (ThermoQuest). A Silica gel C18 reversed-phase column (Zorbax Eclipse XDB-C18, Rapid resolution, 4.6 × 150 mm, 3.5 µm (Agilent, CA, USA) was used for the separation process. Water with a gradient increase from 5% to 50% of acetonitrile (ACN) (with 1% formic acid each in the positive mode) was applied in 60 min, with a flow rate 1 mL/min, and then increased to 90% ACN in the next 30 min. The samples were injected automatically using auto sampler surveyor ThermoQuest. The instrument was controlled by Xcalibur software (Thermo Fisher Scientific Inc., OK, USA). The MS operating conditions were applied in the negative ion mode, as previously described by us [29 (link)]. The ions were detected in a full scan mode and mass range of 50–2000 m/z.

The LC system was Thermo Finnigan (Thermo Electron Corporation, Waltham, MA, USA). The reversed-phase column (Zorbax Eclipse XDB-C18, rapid resolution, 4.6 × 150 mm, 3.5 µm, Agilent, Santa Clara, CA, USA) was used. The mobile phase was water and acetonitrile (ACN) (0.1% formic acid each) and gradient was employed from 5 % to 30% CAN in 60 min with flow rate 1 mL/min with a 1:1 split before the ESI source. Autosampler surveyor ThermoQuest (Thermo Electron Corporation, Waltham, MA, USA) was used to inject the sample; the process was controlled by Xcalibur software (Xcalibur^TM 2.0.7, Thermo Scientific, Waltham, MA, USA) [23 (link)]. LCQ-Duo ion trap mass spectrometer (ThermoQuest Corporation, Austin, TX, USA) with an ESI source (ThermoQuest) was used and operated in the negative mode as described before [22 (link)]. Full scan mode with a mass range of 50–2000 m/z was employed to detect the ions.

Starting materials and reagents were purchased from Sigma-Aldrich (USA, Germany), and Alfa Aesar (Germany) and were used without further purification. Different solvents were purchased from Sigma-Aldrich and Fisher scientific and used directly without further purification. Solvents for column chromatography as ethyl acetate and hexane were dried by distillation. Reactions were followed up using analytical thin layer chromatography (TLC), on silica gel 60 F₂₅₄ packed on aluminium sheets (Merck®), and were visualised under UV light (254 nm). Intermediates monitoring was carried out using melting points. ¹H NMR spectra were determined on a Varian NMR instrument at 300 MHz in δ scale (ppm) and J (Hz) and referred to the deuterated solvent peak (DMSO-d₆ δ = 2.5 ppm). ¹³C NMR spectra were determined on the same instrument at 75 MHz and referred to the solvent peak (DMSO-d₆ δ = 39.52 ppm). LC-MS/MS analysis was performed on a Finnigan LCQ-Duo ion trap mass spectrometer with an ESI source (ThermoQuest) coupled to a Thermo Scientific Accela HPLC system (MS pump plus, autosampler, and PDA detector plus). Data acquisitions and analyses in LC-MS/MS were executed by Xcalibur^TM 2.0.7 software (Thermo Scientific). Compound (I) was purchased from Sigma-Aldrich (USA) and used as such without purification.