Fig. 12. (A) Chemical structures of stigmasterol–amino acid conjugates and protonation and deprotonation of stigmasteryl phenylalaninate in tetrachloromethane; (B) 13C CP MAS NMR of (a) 8a solid; (b) 8b solid, and xerogels of 8b obtained from (c) benzene gel of 8a; (d) from CCl4 gel of 8a, and (e) CCl4 gel of 8b (4% w/v). (C) 13C solid state NMR of (a) 8b solid and (b) xerogel from 1-butanol gel of 8b. Reproduced with permission from ref. 47, Copyright © 2011 Elsevier Inc.
