The isolated compounds were submitted to
1D and
2D
1H and
13C-NMR spectra, such as COSY, HSQC, and HMBC, which were obtained on a Bruker
Avance DRX 400 instrument (Bruker
®, Billerica, MA, USA). Tetramethylsilane (TMS) was used as an internal reference, and deuterated methanol (CD
3OD, Cambridge Isotope Laboratories, Inc.,
® Tewksbury, MA, USA) was used as a solvent.
In the TLC analyses on
silica gel 60 (Merck
®, Kenilworth, NJ, USA), ethyl acetate/formic acid/acetic acid/water (100:11:11:27) was used as mobile phase NP/PEG developer (Sigma-Aldrich
®, San Luis, MO, USA) and as reference compounds
quercetin (Sigma-Aldrich
®, San Luis, MO, USA) and
isoquercitrin (Sigma-Aldrich
®, San Luis, MO, USA).
In preparing the samples for analysis by LC–MS, 2.5 mg of each extract and/or fractions were weighed directly into Eppendorf-type flasks, and 1.0 mL of ultrapure methanol (Merck
®, Kenilworth, NJ, USA) was added. For the complete dissolution of the samples, sonication was used in an ultrasound bath; then the samples were centrifuged at 10,000 rpm for 5 min. The supernatant was filtered through 0.22 µm pore PVDF (polyvinylidene fluoride) filters and transferred to vials for use in CLUE-FR analysis.
Lima L.D., Reis A.C., Sousa J.A., Valente G.M., de Mello Silva B., Magalhães C.L., Kohlhoff M., Teixeira L.F, & Brandão G.C. (2023). Anti–Zika Virus Activity and Isolation of Flavonoids from Ethanol Extracts of Curatella americana L. Leaves. Molecules, 28(6), 2546.
