Kaempferide

(±)-Naringenin, Naringenin 7-O-methyl ether, kaempferol, and kaempferide (4′-O-methyl kaempferol) were purchased (analytical standard, Sigma-Aldrich). Naringenin 4′,7-dimethyl ether was synthesized as previously described (Kim et al., 2007) (link). For experiments with zebrafish larvae, dry samples were dissolved in 100 % dimethyl sulfoxide (DMSO, spectroscopy grade) as 100-fold concentrated stocks and diluted in embryo medium to a final concentration of 1 % DMSO content. Control groups were treated with 1 % DMSO (vehicle, VHC) in accordance with the final solvent concentration of tested compounds. For mice experiments, a mixture of polyethylene glycol M.W. 200 (PEG200) and 100 % DMSO (spectroscopy grade, Acros Organics) (PEG200:DMSO 1:1) was used as solvent and VHC.
Calculated LogP values (cLogP) of the compounds were estimated with the interactive LogP calculator XLogP (version 3) (Cheng et al., 2007) (link) based on the compound structure and were provided by PubChem as 2.4, 2.7, 3, 1.9, 2.2 for NRG, NRG-M, NRG-DM, KFL, and KFD, respectively.

Acetonitrile and acetic acid (both MS grade), methanol (HPLC grade), sodium carbonate, potassium chloride, hydrochloric acid and Folin-Ciocalteu reagent were purchased from Merck (Darmstadt, Germany). The SPE cartridges used for extraction and concentration of samples were Strata C18-E (500 mg/3 mL) obtained from Phenomenex (Torrance, CA). 2,2-Diphenyl-1picrylhydrazyl (DPPH) and phenolic compounds standards (protocatechuic acid -PrA, aesculin, 5-Ocaffeoylquinic acid -CQA, p-hydroxybenzoic acid -HBA, gentisic acid, p-hydroxyphenylacetic acid -HPA, vanillic acid -VA, aesculetin, caffeic acid -CA, rutin -Rut, p-coumaric acid -CouA, quercetin 3-O-glucoside, sinapic acid -SA, naringin -Nar, ferulic acid -FA, quercetin 3-O-rhamnoside -Que-3 rha, coniferyl aldehyde, quercetin -Que, eriodictyol -Erio, luteolin -Lut, naringenin -Narn, apigenin -Api, genistein -Gen, kaempferol -Kfrl, pinobanksin , isorhamnetin, chrysoeriol, genkwanin -Genkw, chrysin -Chry, pinocembrin -Pin, kaempferide -Kfrd, galangin -Gal, and acacetin -Aca) were supplied by Sigma-Aldrich (Steinheim, Germany).
Ultrapure water (ThermoFisher TKA MicroPure water purification system, 0.055 μS/cm) was used to prepare standard solutions and blanks. Syringe filters (13 mm, PTFE membrane 0.45 μm) were purchased from Supelco (Bellefonte, PA). Filter paper (Whatman No. 1) was supplied by Merck (Darmstadt, Germany).

Methanol and acetonitrile were purchased from Merck (New Jersey, USA). The water used for the mobile phase was purified by using a Milli-Q system (Direct-Q ® 3UV, Millipore, São Paulo, Brazil). STZ, apigenin, artepillin C, cinnamic acid, caffeic acid, ferulic acid, caffeic acid phenyl ester (CAPE), (+)-catechin, ethyl gallate, kaempferide, acacetin, naringenin, pcoumaric acid, protocatechuic acid, chrologenic acid, rutin, vanillin, vanillic acid, and all other high-purity chemicals were acquired from Sigma-Aldrich (St Louis, MO, USA). Nylon membranes (47 mm i.d. × 0.45 µm) were used to filter the samples and were purchased from São Paulo, Brazil.