Trifluoroacetic acid

Preloaded Wang resins, amino acids and coupling reagents purchased from NovaBiochem (Nottingham, England). The other chemicals for peptide synthesis were purchased from Sigma Aldrich (Carlsbad, CA, USA). Acrylic acid (Aldrich, Seelze, Germany), N-vinyl-2-pyrrolidone, ethyl acetate, benzoyl peroxide and cobalt naphthenate (Fluka, Seelze, Germany), Tetrahydrofuran (THF), trifluoroacetic acid (TFA), Thioanisole (Riedel-de Haen, Hannover, Germany), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (Sigma, Carlsbad, CA, USA) were of analytical grade. NaH₂PO₄, Na₂H-PO_4.7H₂O, NaCl were obtained from Fluka (Seelze, Germany) and NaN₃ was from Applichem (Darmstadt, Germany).

Caffeic acid (3,4-Dihydroxycinnamic acid) was acquired from Sigma-Aldrich, St. Louis, MO, and used as received without further purification. The molecular structure of caffeic acid in non-hydrolyzed form is illustrated in Table 1. Iron (II) sulfate heptahydrate (FeSO₄•7H₂O) was acquired from Panreac, Barcelona, Spain, and hydrogen peroxide (H₂O₂ 30% w/w) and titanium (IV) oxysulfate solution 1.9–2.1%, for determination of hydrogen peroxide, were acquired from Sigma-Aldrich, St. Louis, MO, USA. Sodium sulfite anhydrous (Na₂SO₃) was acquired from Merk, Darmstadt, Germany. Trifluoroacetic acid (HPLC grade, ≥99.0%) was acquired from Riedel-de Haën, Seelze, Germany, and acetonitrile (HPLC grade, ≥99.9%) was acquired from Chem-Lab, Zedelgem, Belgium. For pH adjustment, sodium hydroxide (NaOH) from Labkem, Barcelona, Spain, it was used, along with sulfuric acid (H₂SO₄, 95%) from Scharlau, Barcelona, Spain. Deionized water was used to prepare the respective solutions.

Dried fruit fibers of L. aegyptiaca were purchased from a local market in Taipei, Taiwan. N-acetylglucosamine, glucosamine, and ketamine were supplied by Sigma (St. Louis, MO, USA). Glucose and galactose were obtained from Nihon Shiyaku Industrial (Taipei, Taiwan). Trifluoroacetic acid and pyridine were provided by Riedel-de Haën (Seelze, Germany). n-Butanol was from Hayashi Pure Chemical (Osaka, Japan). Thin-layer chromatography (TLC) plates (Kieselgel 5554) and the solvents for high-performance liquid chromatography (HPLC) and analytical-grade reagents were obtained from Merck (Hohenbrunn, Germany). Pentobarbital was supplied by Siegfried AG (Zofingen, Switzerland).

Samples of CycA and isoA were provided by
TEVA Czech Industries (Opava-Komárov, Czech Republic). HPLC
grade methanol, trifluoroacetic acid (TFA), formic acid (FA), acetonitrile
(ACN), and LC-MS grade water were purchased from Honeywell (Prague,
Czech Republic). Deuterated solvents CD₂Cl₂ (99.80%D),
CD₃OD (99.80%D), and D₂O (99.96%D) were purchased
from VWR (Prague, Czech Republic), sodium trifluoroacetate (NaTFA),
and α-cyano-4-hydroxycinnamic acid (CHCA) were from Sigma-Aldrich
(Prague, Czech Republic), sodium iodide (NaI) was from Waters Corporation
(Wilmslow, U.K.) and peptide calibration standard II was from Bruker
Daltonics (Bremen, Germany).

Acetic acid, methanol, sodium chloride, and sucrose were purchased from Chembur (Piekary Śląskie, Poland), trifluoroacetic acid purchased from Honeywell Riedel-de Haen (Seelz, Germany). HPLC-grade methanol and acetonitrile were purchased in Merck (Darmstadt, Germany). Plant culture media components, plant growth regulators NAA (naphthalene-1-acetic acid), BAP (6-benzylaminopurine) and IBA (indole-3-butyric acid) and agar were purchased in Duchefa Biochemie (Haarlem, Netherlands). The following commercially available standards for HPLC analyses were used: verbascoside, isoverbascoside, verbenaline and hastatoside (ChromaDex^®, Los Angeles, California, USA) and caffeic acid, chlorogenic acid, ferulic acid, protocatechuic acid, rosmarinic acid, vanillic acid (Sigma-Aldrich Co., Munich, Germany). Scutellarin, scutellarein and apigenin 7-glucuronide obtained from ChemFaces (Wuhan, Hubei, China). Bacterial culture media: nutrient agar (NA), Müller-Hinton Broth (MHB) and Müller-Hinton agar (MHA) were purchased in BTL (Łódź, Poland). Resazurin sodium was purchased from Sigma-Aldrich Co. (St. Louis, USA). Ferrous chloride (FeCl₂) was obtained from Carlo Erba (Milan, Italy). Unless indicated otherwise all chemicals were purchased from Sigma-Aldrich (Milan, Italy).

The quinolones (Fig. S1) and sulfonamides (Fig. S2) under investigation were supplied by different pharmaceutical companies. Pure HPLC-grade acetonitrile, methanol, and dimethylsulfoxide were supplied by Scarlau (Barcelona, Spain). The other chemicals used in this study, including ortho-phosphoric acid, trifluoroacetic acid, sodium dihydrogen orthophosphate, and sodium hydroxide were supplied by Honeywell Riedel-de Haën (Seelze, Germany).
The instruments used in this study included a Jenway 3510, Essex-UK, England pH meter equipped with a glass electrode, and Agilent 1260 HPLC-UV series.
Each drug’s stock solution (2 mg mL^− 1) was prepared with a suitable solvent either (methanol, dimethylsulfoxide, water, or acetonitrile). These solutions were stored at 4 °C and then diluted with the mobile phase to achieve sample concentrations ranging (0.05–1 mg mL^− 1) before analysis.