Avance 3 hd

Ultraviolet-visible (UV-Vis) absorption data were acquired on a UV-1800 (Shimadzu) spectrophotometer in spectroscopic grade solvents without further purification. NMR measurements were performed in standard 5 mm NMR tubes at 300 K. All the data were acquired on a Bruker AVANCE III HD 500 and 700 MHz NMR spectrometer. Solid-state ¹³C CP/MAS NMR spectra of PH-MOP and Oxz-MOP were recorded on a 400 MHz solid state NMR spectrometer (AVANCE III HD, Bruker, Germany) at KBSI Western Seoul center. Two-dimensional ROE spectra were measured with a spectral width of 8 kHz in 2 K data points using 16 scans for each of the 512 t₁ increments with 300 ms as a mixing time. Cyclic voltammetry (CV) was performed using an Epsilon electrochemical analyzer (EC Epsilon, BASi), and carried out in a three electrodes system, with Ag/Ag⁺ as the reference electrode, Pt foil as the counter electrode, and the platinum working electrode, with a scan rate of 100 mV s⁻¹. For the photo-mediated oxidative cyclization reaction, pyridinium acylhydrazones were UV-irradiated with 342 nm using the Lumatec Superlite 410. Scanning electron microscopy (SEM) images were captured on a JEOL 7800 field emission SEM (FE-SEM) operated at an accelerating voltage of 15 kV. FT-IR spectra were recorded using a spectrometer Vertex 70 (Bruker Optic, Billerica, MA, USA), equipped with a diamond ATR unit.

Variable-temperature NMR spectra were recorded on a 500 MHz NMR spectrometer Bruker Avance II™ HD (¹H at 500 MHz, ¹³C at 126 MHz) in DMF-d₇ and CD₃OH for solutions of approximately 1 mg of the peptide in 600 μL of the solvent. Proton spectra were referenced to the solvent signals δ = 2.75 and δ = 3.31, respectively. Proton spectra of CD₃OH solutions were recorded with presaturation of the intense OH signal. The characterization spectra of the prepared oligopeptides were recorded on a 500 MHz NMR spectrometer Bruker Avance III™ HD (¹H at 500 MHz, ¹³C at 126 MHz) or on a 600 MHz NMR spectrometer Bruker Avance III™ HD (¹H at 600 MHz, ¹³C at 151 MHz) in DMSO-d₆ (δ = 2.50 (¹H) and δ = 39.70 (¹³C)), DMF-d₇ (δ = 2.75 (¹H) and δ = 29.76 (¹³C)) or methanol-d₄ (δ = 3.31 (¹H) and δ = 49.00 (¹³C)). Complete signal assignment is based on homo- and heteronuclear correlation experiments COSY, TOCSY, ROESY, HSQC and HMBC. The solvents used were purchased from Eurisotop.