Ultra 3000 series

The putative spots of Taxol were scraped-off from the TLC silica gel plates, purified, and the purity and concentration were determined by the UV–Vis analyses at λ ₂₂₇ nm (RIGOL, Ultra-3000 Series) comparing to authentic Taxol [39 (link)]. Blank media under the same conditions were used as negative baseline for the spectrophotometric analyses. FT-IR spectrum of the purified Taxol samples was analyzed by JASCO FT-IR 3600 spectrophotometer. The Taxol sample was grinded with KBr pellets, pressed into discs under vacuum, and the absorption was measured in the region 400 to 4000 cm⁻¹ [3 (link)], comparing to authentic one. The chemical structure of extracted Taxol was confirmed from the HNMR spectroscopy (JEOL, ECA-500II, 500 MHz NMR) comparing to authentic Taxol. The samples were dissolved in CDCl₃, chemical shifts are given in ppm (δ-scale), and the coupling constants are expressed in hertz (Hz).

The putative spots of camptothecin, were scraped from the silica plate, dissolved in methanol, and scanned by UV–Vis spectrophotometer (RIGOL, Ultra-3000 Series) at λ300–400 nm. The concentration of the putative camptothecin was determined comparing to authentic concentration of camptothecin, using methanol as blank baseline. The FT-IR spectra of camptothecin were analyzed with a Bruker FT-IR Spectrometer in a range of 400–4000 cm⁻¹ with KBr pellets. The chemical identity of camptothecin was verified by liquid chromatography tandem mass spectrometry (LC–MS/MS) with Thermo Scientific LCQ Deca mass spectrometer and Hypersil Gold C18 column, with an electrospray source in positive and negative ion modes. The mobile phases A (0.1% formic acid), and B (acetonitrile in 0.1% formic acid) were used [10 (link), 34 (link), 35 (link)]. The gradient elution system was 2–98% mobile phase B over 30 min at a flow rate of 0.2 mL/min for 40 min. The chemical identity of the resolved signals was determined regarding their retention times and mass spectral fragmentation pattern, regarding to the authentic camptothecin.