Methanol

A 30-mL supernatant sample collected from the desynchronized P. falciparum culture and a sample collected from the uninfected RBC culture were concentrated 2-fold by freeze-drying. The resulting suspension was acidified with 200 mL of concentrated hydrochloric acid (HCl_(aq)36% w/w, Labsynth) and extracted 3 times with 20 mL dichloromethane (Labsynth). The organic solvent was removed under a N_2(g) flux and the concentrate resuspended in 1 mL DMSO (Labsynth) and 2 mL methanol (Labsynth).

All reactants used were technical, analytical, pure, or reagent grades without being modified in their original composition. Hydrochloric acid (HCl, 37 wt.%), glycerol (C₃H₈O_3, 99 wt.%), sodium dodecyl sulfate (SDS) (NaC₁₂H₂₅SO_4, 90 wt.%), ethyl alcohol (C₂H₅OH, 99 wt.%), and methanol (CH₃OH, 99 wt.%) were provided by Labsynth. β-mercaptoethanol (C₂H₆OS, 99 wt. %), tris (hydroxymethyl) aminomethane-HCl (CNH₂(CH₂OH)_3, 99 wt.%), bromophenol blue (C₁₉H₁₀Br₄O₅S, 99 wt.%), acrylamide (C₃H₅ON, 99 wt.%), tris(2-carboxyethyl) phosphine (C₉H₁₅O₆P, 99 wt.%), formic acid (CH₂O_2, 95 wt.%), sodium form (NaCOOH, 99 wt.%), potassium acid phthalate (C₈H₅KO₄), and silver nitrate (AgNO_3, 98 wt.%) were sold by Sigma-Aldrich. Ethylenediaminetetraacetic acid (EDTA) (C₁₀H₁₆N₂O_8, 99 wt. %) and kerosene (C₁₂H_26, 99 wt. %) were provided by Neon and Natrielli, respectively. Potassium dichromate (K₂Cr₂O_7, 99.5 wt. %), mercury sulfate (Hg₂SO_4, 98 wt. %), silver sulfate (Ag₂SO_4, 99 wt.%), and potassium chromate (K₂CrO4, 99.5 wt.%) were purchased from PanReac. Sulfuric acid (H₂SO_4, 95–98 wt. %) and hexane (C₆H_14, ≥ 98.5 wt. %) were obtained from J.T.Baker.

The chemicals used in this study are as follows: methanol (A1085.01.BJ), aluminum chloride (C1036.01.AG), ethanol (A1084.01.BJ), and hydrochloric acid (A1028.01.BJ; Labsynth, Diadema, SP, Brazil); sodium tungstate-2-hydrate (230), triton X-100, and phosphomolybdic acid (443; Vetec Química Fina Ltda, Duque de Caxias, RJ, Brazil); gallic acid monohydrate (27645-250G-R), 1,1-diphenyl-2-picrylhydrazyl (DPPH^•; D9132), luminol (5-amino-2,3-dihydro-1,4-phthalazinedione; A8511-5G), phorbol-12-myristate-13-acetate (PMA; P8139), and Trypan blue (T6146-25G; Sigma-Aldrich, St. Louis, MO, USA); gelatin (microbiological grade; 214320, Difco, Laboratories, Detroit, MN, USA); dimethyl sulfoxide (DMSO; 3317275) (Merck-Schuchardt, Hohenbrunn, DE); “Kit” to determine lactate dehydrogenase enzyme (LDH Liquiform; 86-2/30—Labtest Diagnostica, Lagoa Santa, MG, Brazil). Drying carriers used are colloidal silicon dioxide (Aerosil 200, Evonik Degussa, Hanau, Germany), maltodextrin (MOR-REX 1910, Corn Products do Brasil), β-cyclodextrin (Kleptose; Roquette, Lestrem, FR), and gum Arabic (Encapsia; NEXIRA do Brasil, São Paulo, SP, Brazil).