Hydroxycamptothecine

The study investigated the extraction of alkaloids and glycosides from the Camptotheca acuminata Decne using deep eutectic solvent (DES). 18 types of deep eutectic solvents (DESs) were prepared, and it was found that the extraction performance of choline chloride (ChCl)-formic acid (FA) was optimal, surpassing traditional solvents such as methanol/70% methanol.In comparison to methanol, the extracted amount of compounds by DES was 2-3 times higher.The extraction processes involving the molar ratio of ChCl-FA, pH, DES/H2O mass ratio, solid/liquid ratio, as well as ultrasonic power were optimized.A math. model for solid/liquid extraction kinetics from Camptotheca acuminata Decne was developed.The extraction mechanism was investigated using SEM (SEM), Fourier transform IR spectroscopy (FT-IR), and ¹H NMR(¹H NMR).The results revealed that the DES caused dissociation in Camptotheca acuminata Decne and formed hydrogen bonds with Camptothecin (CPT).Meanwhile, d. functional theory (DFT) calculations verified that FA-based exhibited the highest extracted amount for CPT.In addition, this study investigated the recovery rate of DES, and the results showed that after 10 cycles, the DES system remained effective for the extraction of alkaloids and glycosides.

Hypoxia is a common characteristic of tumors and associated with poor outcome in most cancer types, thus hypoxia-triggered combined therapeutic systems with well-defined structure hold significant promise for achieving specific and effective tumor destruction.Herein, a water-soluble perylene diimide (PDI) cyclophane "Gemini Box" (GBox-14+) is demonstrated as both a hypoxia-responsive photothermal agent and a drug capsule for tumor-specific combination therapy.First, owing to the covalent enclosure of PDI chromophore by double-sided mol. straps, GBox-14+ can significantly stabilize labile PDI radical anions generated through bioreduction at the lesion site of hypoxic tumors, leading to high-efficiency near-IR photothermal ablation of tumors.Meanwhile, GBox-14+ can act as a mol. capsule to bind water-insoluble antitumor drugs camptothecin and hydroxycamptothecin in 1:1 host-guest stoichiometry with high affinities, greatly enhancing the water solubility of drugs.Eventually, such drug-loading cyclophane system as a hypoxia-activated photothermal/drug combined therapeutic platform exhibits more effective inhibition of tumor growth than the single treatment under identical conditions.This study significantly extends the application range of host-guest cyclophane systems and opens a promising avenue to structurally uniform combined therapeutic agents against hypoxic tumors with improved specificity.