Equinox 55

Scanning electron microscopy (SEM) images (Tescan, MIRA II, Czech Republic) were applied to indicate the flower-shaped morphology of the fabricated HNFs. Energy dispersive X-Ray spectroscopy (EDX, Tescan, MIRA II, Czech Republic) and elemental mapping were incorporated to determine the composition and spatial distribution of elements in the constructed HNFs, respectively. Fourier transform infrared (FTIR) spectroscopy (Shimadzu, Equinox 55, Japan) was utilized for analyzing functional groups of organic and inorganic constituents of HNFs. The samples were dispersed in pressed KBr disks, and the spectra were recorded at 4000–400 cm⁻¹. Brunauer–Emmett–Teller (BET) analysis was performed (Microtrac, BELSORP MINI X, Japan) after degassing the samples under N₂. X-ray diffraction (XRD) analyses were carried out to identify the crystalline phase of the inorganic component using an X-ray diffractometer (Philips, PW1730, Philips, Eindhoven, Netherlands).

To determine the chemical structure of glycerol-liamocin, the high-resolution mass was determined using electrospray ionization (ESI)-QTRAP-3200 Mass Spectrometer (ESI-MS; Applied Biosystems). Ultraviolet (UV) and infrared (IR) spectra were recorded on Shimadzu UV-300 and FT-IR Equinox 55 spectrophotometers, respectively. Nuclear magnetic resonance (NMR) spectra were obtained on a JEOL JNM-ECA600, 600 MHz FT-NMR Spectrometer at 600 MHz for ¹H NMR and at 150 MHz for ¹³C NMR in CD₃OD. Chemical shifts are given in ppm (δ), with tetramethylsilane as the internal standard.

To determine the chemical composition of Fraction 2, the high-resolution mass spectrum was determined using an electrospray ionization (ESI)-QTRAP-3200 mass spectrometer (ESI-MS; Applied Biosystems, Forster, CA, USA). UV and IR spectra were recorded on Shimadzu UV-300 and FT-IR Equinox 55 spectrophotometers, respectively. Nuclear magnetic resonance (NMR) spectra were obtained on a JEOL JNM-ECA600, 600 MHz FT-NMR spectrometers at 600 MHz for ¹H NMR, and at 150 MHz for ¹³C NMR in CD₃OD. Chemical shifts are given in ppm with tetramethylsilane as the internal standard. Fraction 2 afforded a colorless gum which was identified as (+)-epiloliolide according to ESI-MS and NMR data: ESI-MS m/z 196.8 [M + H] ⁺, ¹H-NMR (300 MHz, CD₃OD) δ: 1.28 (3H, s, axial, H-10), 1.28 (1H, dd, J = 9.8 and 9.8 Hz, H-5), 1.31 (3H, s, H-9), 1.41 (1H, dd, J = 11.7 and 11.7 Hz, H-7), 1.58 (3H, s, axial, H-8), 2.00 (1H, ddd, J = 2.2, 4.3 and 13.0 Hz, H-5), 2.47 (ddd, J = 2.2, 3.9 and 11.7 Hz, H-7), 4.09 (1H, m, H-6), 5.77 (1H, s, H-3); ¹³C-NMR (75.5 MHz, CD₃OD) δ: 25.3 (C-10), 25.8 (C-9), 30.3 (C-8), 36.2 (C-4), 48.7 (C-7), 50.6 (C-5), 65.3 (C-6), 88.6 (C-7a), 113.7 (C-3), 174.0 (C-2), 183.9 (C-3a).