Hydrochloric Acid → Sodium Chloride

Participants

Reaction Steps

HA-TBA prepared in Example 2-2 using HA-Na (50 kDa) as a starting material was dissolved at 10 mg/mL in anhydrous DMSO. Thereafter, the Chol-C2 hydrochloride prepared in Example 1-2 was added to each solution at the ratio relative to HA-TBA units indicated in Table 2 below. Then, DMT-MM was added at the ratio relative to HA-TBA units indicated in Table 2 below and stirred overnight at room temperature. Sodium nitrate was added to the reaction solution to 0.3M, and isopropyl alcohol (IPA) was added. The resulting precipitate was recovered, washed with IPA and ethanol. Thereafter, the precipitate was dissolved in ultrapure water and dialyzed successively against 0.15M NaCl aqueous solution and ultrapure water (SpectraPor 4, molecular weight cutoff (MWCO): 12 k-14 kDa). The resulting dialysate was lyophilized to give HA-C2-Chol as a white solid. HA-C2-Chol can also be obtained by subjecting the above reaction solution to the same treatment as that in Example 2-3-1 (lyophillization of the dialysate obtained by dialysis successively against 0.3M ammonia acetate/DMSO solution, 0.15M NaCl aqueous solution, and ultrapure water). The 1H-NMR spectrum of the product (introduction ratio 8%) as measured under the same conditions as those in Example 2-3-1 is shown in FIG. 7. The introduction ratio of cholesteryl groups relative to HA units calculated according to the formula indicated in Example 2-3-1 is shown in Table 2.

Provenance & Evidence