Dimethyl sulfoxide dmso d6

Discrete poly(ethylene glycol) (dPEG₂₀, FW = 882 g/mol, Ð = 1.00) was purchased from Quanta Biodesign Limited (Plain City, OH, USA). Doxorubicin hydrochloride (DOX.HCl, CAS 25316-40-9) was purchased from AvaChem Scientific (San Antonio, TX, USA). DL-α-tocopherol (Vitamin E, purity 97+%) was obtained from Alfa Aesar (Tewksbury, MA, USA). Thiol-functionalized folic acid (FA-SH) was synthesized as reported in [28 (link)]. Candida antarctica lipase B immobilized on acrylic resin (CALB, Novozyme 235), Vinyl acrylate (VA, <600 ppm MEHQ as inhibitor), diethanolamine (DEA, 99%), tetrahydrofuran (THF, ACS reagent grade), n-hexane (Hexane, ACS reagent grade), and anhydrous dimethyl sulfoxide (DMSO, ≥99.9%) were purchased from Sigma-Aldrich (Darmstadt, Germany) and used without further purification. Other solvents, such as anhydrous diethyl ether (95.8%, BHT free ACS Certified), methanol (ACS Certified), and acetone (ACS Certified), were obtained from Fisher Chemicals (Pittsburgh, PA, USA). Deuterated solvents, such as dimethyl sulfoxide (DMSO d6, purity 99.9%), chloroform (CDCl₃, purity 99.8%), methylene chloride (CD₂Cl₂, purity 99.9%), and methanol (CD₃OD, purity 99.8%) were purchased from Cambridge Isotope Laboratories (Tewksbury, MA, USA).

A MX-500 Bruker spectrometer was used to measure one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectra. The chemical shifts (δ) were calculated (ppm) relative to TMS and J scalar coupling constants reported in Hz. MS analyses were carried out on an Agilent triple quadrupole 6410 QQQ LC/MS mass spectrometer with an ESI ion source (nebulizer gas pressure is 60 psi, gas temperature is 350 °C, and flow rate is 12 L/min), operating in the negative and positive scan modes of ionization through direct infusion method using methanol–water (4:6 v/v) at a flow rate of 0.5 mL/min. Separations and purifications of secondary metabolites were carried out by using column chromatography either on silica gel 70–230 mesh or RP-18 (E. Merck, Darmstadt, Germany). RP-18 (Merck) and pre-coated silica gel 60 F254 TLC plates were used to check the fractions, and the spots were detected by UV light and by spraying with ceric sulphate and sulfuric acid reagent followed by heating on a hot plate (TLC plate heater III CAMAG, Muttenz, Switzerland). Analytical and reagent grade solvents were obtained from Sigma-Aldrich (St. Louis, MO, USA). NMR deuterated methanol (CD₃OD) and dimethylsulfoxide (DMSO-d₆) were purchased from Cambridge Isotope Laboratories (Tewksbury, MA, USA).