Am 500

Column chromatographic procedures were performed using silica gel (80–120 mesh and 200–300 mesh, Qingdao Marine Chemical Co. Ltd., Qingdao, China) and Sephadex™ LH-20 gel (40–70 μm; Merck, Darmstadt, Germany), whereas precoated silica gel (GF254, Qingdao Marine Chemical Co. Ltd., Qingdao) plates were used for TLC analyses. Spots were visualized by heating silica gel plates sprayed with 10% H₂SO₄ in EtOH. UV spectra were recorded using a Waters UV-2401A spectrophotometer equipped with a DAD and a cell of 1 cm pathlength. Methanolic samples were scanned from 190 to 400 nm in 1 nm steps. Semipreparative HPLC was performed on an Agilent 1120 apparatus equipped with a UV detector and a reversed-phase C₁₈ column (5 μm, 10 × 250 mm, Welch Ultimate XB-C18). 1D (¹H, ¹³C) spectra of all compounds were recorded on Bruker AM-600, AM-500, and AM-400 NMR spectrometers (Bruker, Karlsruhe, Germany), with TMS as the internal reference. |Enzymatic activity experiments were performed using SpectraMax i3x (Molecular Devices, Austria).

HRESIMS measurements used an Agilent 6546 Accurate-Mass Q-TOF, hyphenated with a 1290 Agilent Infinity II LC system (Agilent, Palo Alto, CA, USA). The chromatographic system was fitted with a Zorbax RRHD Eclipse Plus C₁₈ column (2.1 × 50 mm, 1.8 μm). ¹H and ¹³C NMR data were recorded on an AM-500 (500 MHz) Bruker 700 MHz NMR spectrometer (Bruker Daltonics, Bremen, Germany) using TFA-d or DMSO-d₆ as solvent (Euriso-Top, Saint-Aubin, France).
Pandamine (1). White amorphous solid; mp = 256 °C; [α]_D^25.0 − 77 (c 1, CH₃OH); IR ν_max 3300, 3050, 1650, 1600, 1540, 1500, 1250 cm⁻¹; λ_max (log ε) 230 (3.59), 260 (1.80) and 285 (1.80); ¹H and ¹³C NMR data, see Table 1; HR-ESI-MS m/z 553.3394 [M + H]⁺ (calculated for C₃₁H₄₅N₄O₅, 553.3384). MS/MS spectrum was deposited in the GNPS spectral library under the identifier CCMSLIB00010128917.

The spectra of synthesized compounds were recorded at the Center for the Collective Use “Chemistry” of the Ufa Institute of Chemistry of the UFRC RAS and RCCU “Agidel” of the UFRC RAS. ¹H and the ¹³C-NMR spectrum were recorded on a “Bruker AM-500” (Bruker, Billerica, MA, USA, 500 and 125.5 MHz, respectively, δ, ppm, Hz) in CDCl₃, internal standard tetramethylsilane. The mass spectra were obtained on a liquid chromatograph–mass spectrometer LCMS-2010 EV (Shimadzu, Kyoto, Japan). The melting points were detected on a micro table “Rapido PHMK05” (Nagema, Dresden, Germany). The optical rotations were measured on a polarimeter “Perkin-Elmer 241 MC” (Perkin Elmer, Waltham, MA, USA) in a tube length of 1 dm. Elemental analysis was performed on a Euro EA-3000 CHNS analyzer (Eurovector, Milan, Italy); the main standard is acetanilide. Thin-layer chromatography analyses were performed on Sorbfil plates (Sorbpolimer, Krasnodar, Russian), using the solvent system chloroform–ethyl acetate, 40:1. Substances were detected by 10% H₂SO₄ with subsequent heating to 100–120 °C for 2–3 min. The oleanolic acid was purchased in Xi’an Rongsheng Biotechnology Co Ltd. (ISO9001:2008 and GMP certified company). Compounds 5 [26 (link)], 13 and 14 [37 (link)], 21 [38 ], 23 [35 (link)] were obtained according to the methods described previously.