Preparation, Characterization, and In Vitro Evaluation of Inclusion Complexes Formed between S-Allylcysteine and Cyclodextrins

Abstract

The present study prepared inclusion complexes of S -allylcysteine (SAC) and cyclodextrin (α, β, γ) by the freeze-drying (FD) method and verified the inclusion behavior of the solid dispersion. Also, the study investigated the effect of SAC/CD complex formation on liver tumor cells. Isothermal titration calorimetry (ITC) measurements confirmed the exothermic titration curve for SAC/αCD, suggesting a molar ratio of SAC/αCD = 1/1, but no exothermic/endothermic reaction was obtained for the SAC/βCD and SAC/γCD system. Powder X-ray diffraction (PXRD) results showed that the characteristic diffraction peaks of SAC and CDs disappeared in FD (SAC/αCD) and FD (SAC/γCD), indicated by a halo pattern. On the other hand, diffraction peaks originating from SAC and βCDs were observed in FD (SAC/βCD). Near-infrared (NIR) absorption spectroscopy results showed that CH and OH groups derived from SAC and OH groups derived from αCD and γCD cavity were shifted, suggesting complex formation due to intermolecular interactions occurring in SAC/αCD and SAC/γCD. Stability test results showed that the stability was maintained with FD (SAC/αCD) over FD (SAC/βCD) and FD (SAC/γCD). In 1 H– 1 H of NOESY NMR measurement, FD (SAC/αCD) was confirmed to have a cross peak at the CH group of the alkene of SAC and the proton (H-3, -5, -6) in the αCD cavity. In FD (SAC/γCD), a cross peak was confirmed at the alkyl group on the carbonyl group side of SAC and the proton (H-3) in the cavity of γCD. From the above, it was suggested that the inclusion mode of SAC is different on FD (SAC/CDs). The results of the hepatocyte proliferation inhibition test using HepG2 cells showed that FD (SAC/βCD) inhibited cell proliferation. On the other hand, FD (SAC/αCD) and FD (SAC/γCD) did not show a significant decrease in the number of viable cells. These results suggest that the difference in the inclusion mode may contribute to the stability and cell proliferation inhibition.

Characterization, Preparation, and Promotion of Plant Growth of 1,3-Diphenylurea/β-Cyclodextrin Derivatives Inclusion Complexes

“…The H-3 and H-6 protons of CD are located at the wide and narrow ring edges of CD, respectively . Tachikawa et al reported that 1 H– 1 H NOESY NMR spectroscopic results showed that S-allyl cysteine in garlic forms a cross-peak with H-6 of CD, revealing an inclusion mode . These results indicated that both βCD/DPU and HP-βCD/DPU are encapsulated by two molecules of CD from the narrow edge (H-6) to the wide edge (H-3), sandwiching the benzene ring of DPU.…”

Light-responsive MXenegel via interfacial host-guest supramolecular bridging

“…The DSC curve of αCD shows three broad endothermic peaks at 79, 115, and 139 °C. These peaks are mainly attributed to the water loss from αCD crystals 35 , 36 . Also, a broad endothermic peak at 80–95 °C is recorded for the AzoC6/2αCD mixture as a consequence of water loss from αCD.…”

Ternary Complex Microparticles Assembled from Vanillin, γ-Cyclodextrin, and Dextran: Fabrication, Structure, and Controlled Release Characteristics

“…When the dextran solution was titrated with γ-cyclodextrin (Fig. 5a,5d), no signi cant enthalpy changes were observed, suggesting that the dextran did not interact strongly with the γ-cyclodextrin (Tachikawa, et al, 2022). This phenomenon was attributed to the fact that the dextran was too large to enter the cavity in the γ-cyclodextrin, and that the dextran is primarily hydrophilic whereas the cavity is hydrophobic (Saffarionpour & Diosady, 2023).…”