10 shogaol

In this study, we used fluconazole resistant C. albicans strain DAY185 (minimum inhibitory concentration >1,024 μg/ml). C. albicans was maintained in potato dextrose agar (PDA) or potato dextrose broth (PDB). The gingerols and shogaols (6-gingerol, 8-gingerol, 10-gingerol, 6-shogaol, 8-shogaol, and 10-shogaol) used in this study were purchased from Sigma-Aldrich (St. Louis, USA) and dissolved in dimethyl sulfoxide (DMSO). DMSO was used as a negative control for all experiments and the concentration of DMSO in media did not exceed 0.1% (vol/vol), which did not affect the antibiofilm or antivirulence activities. Cell growths and turbidities were measured using spectrophotometer (UV-160, Shimadzu, Japan) at 620 nm.

The standards of 6-gingerol and 10-shogaol were purchased from Sigma-Aldrich (St. Louis, MO, USA). Water, formic acid, and acetonitrile of spectroscopic grade were produced by J. T. Baker (Center Valley, PA, USA).
Nitric (V) acid (65%) and hydrochloric acid (36%) were of Suprapur Grade and were bought from Merck (Darmstadt, Germany). High purity deionized water (resistivity 18.2 MΩcm) obtained using an Ultrapure Millipore Direct-Q-R 3UV (Merck, Darmstadt, Germany) was used throughout the analysis. Quartz crucibles and polypropylene recipients were applied for the digestion and storage of digests, respectively.
A series of standard solutions of Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn at a concentration of 1000 mg/L (Merck, Germany) was used to plot the calibration curve for each element.
Diethyl ether and silica gel (230–400 mesh) applied in the GC-MS analysis of the extracts were produced by Merck (Germany). A C9–C25 hydrocarbon solution used as a reference mixture for GC-MS analysis was purchased from Sigma-Aldrich.