Deuterated dimethyl sulfoxide dmso d6

Unless otherwise specified, all reagents and materials used were obtained without additional purification from commercial suppliers. Betulinic acid (BA) (≥98%), 1-octanol, and acetonitrile (for HPLC, gradient grade) were obtained from Sigma-Aldrich (Steinheim am Albuch, Germany). L-aspartic acid, L-isoleucine, L-leucine, L-methionine, L-proline, L-threonine, and L-valine of purity ≥98% were purchased from FluoroChem (Derbyshire, UK). L-serine (≥98.5%), L-phenylalanine (≥98.5%), L-proline (≥98.5%), and L-cysteine (≥98%) were provided by Carl Roth (Karlsruhe, Germany). L-alanine (>99.0%) was acquired from Bachem (Bubendorf, Switzerland) and L-lysine (≥98.0%, anhydrous) from Glentham Life Sciences (Corsham, UK). L-phenylalanine (99%) was provided by Alfa Aesar (Ward Hill, MA, USA). L-tryptophan (>98.5%) was purchased from TCI. Thionyl chloride (99.5%) was provided by Across Organic Geel (Geel, Belgium). Ammonium hydroxide solution 25% (NH₃.H₂O) of analytical grade was purchased from StanLab (Lublin, Poland). Ethanol (99.8%) was provided by Merck (Darmstadt, Germany). Methylene chloride and DMSO of high purity were provided by Chempur (Gliwice, Poland). Deuterated dimethyl sulfoxide (DMSO-d₆) (99.8%) was obtained from Deutero GMBH (Kastellaun, Germany).

Hexane (chem. pure., grade 2) and acetone (chem. pure) were purchased from Cryochrom (St. Peterburg, Russia) and Khimmed (Moscow, Russia), respectively, and used for the plant biomass extraction. To remove impurities, the acetone was additionally purified by distillation. In HPLC separations, gradient grade acetonitrile (Cryochrom, St. Peterburg, Russia), ACS reagent grade formic acid (≥96%, Merck, Darmstadt, Germany), and ultrapure Type I water with a resistivity of 18.2 MΩ·cm obtained in the Milli-Q system (Millipore, Molsheim, France) were used for the mobile phase preparation. Deuterated dimethylsulfoxide (DMSO-d₆) and methanol (CD₃OD) with a purity of > 99.8%, purchased from Deutero GmbH (Kastellaun, Germany), were used in NMR analysis. HPLC grade methanol (Khimmed, Moscow, Russia) was used as a solvent in photochemiluminescence antioxidant activity determination and as a sample preparation in preparative HPLC separations.