ABSTRACT
In this chapter, the authors review their work on the structural characterization of the major inactive and the minor cytokine-inducing glycolipids. Separation of bioactive glycolipids was performed according to previous methods with modification. To elucidate the structure of the complicated macromolecular glycol-ipid molecules, isolation of large amounts of the glycolipids is inevitably required. Neither cytokine-inducing nor antitumor activity was observed in the synthetic compounds. The authors have succeeded in separating Lipoteichoic acid (LTA) fraction from E. hirae American Association of Textile Chemists and Colorants 9790 into small amounts of cytokine-inducing active macromolecular glycolipids and an inactive major fraction that amounts to over 90 wt%; this favors the latter possibility rather than the former. LTA is a macroamphiphile widely distributed on the incell surface of Gram-positive bacteria. The structures of LTAs from various enterococcal and streptococcal species were studied by W. Fischer.
