Structure and biological activities of hypochlorite oxidized zymosan

Zymosan (ZMI), a strong complement activating yeast cell preparation, is al so a potent inflammatory substance, which shows immunopharmacological activ ity. Major component of ZYM is beta -glucan but contains other constituents , such as mannan, protein, and nucleic acid. We applied sodium hypochlorite (NaClO) treatment to ZYM to reduce impurities and compared the activity wi th native/parent ZYM. Oxidized ZYM (OX-ZYM) became a nitrogen-free agent. B y NMR analysis of native OX-ZYM and zymolyase (endo-1,3-beta -glucanase) di gest, OX-ZYM was found to contain 1,3-beta -linked and 1,6-beta -linked glu can moieties, while the latter degraded by sodium metaperiodate treatment. OX-ZYM also contained small amounts of anionic groups, partly reducible by sodium borohydride. Degree of polymerization (DP) of 1,6-beta -glucan moiet y was estimated to be about DP10-DP50 by MALDI-TOF-MS analysis. In comparis on with ZYM activities, OX-ZYM and derivatives showed strong antitumor acti vity to solid form of Sarcoma 180 in mice, and showed strong activity on al ternative pathway of complement, but lost secondary response to ZYM-immune mice. These facts strongly suggested that a particulate form of beta -gluca n was prepared by NaClO treatment of ZYM and at least a part of ZYM-mediate d biological activity was found unmediated by beta -glucan moiety. (C) 2001 Elsevier Science Ltd. All rights reserved.