Benzoquinones in stages of the life-cycle of the cestode Spirometra mansonoides

Ubiquinone-10 and rhodoquinone-10 were detected in stages of the life-cycle of a pseudophyllidean cestode, Spirometra mansonoides, by chromatographic. UV spectrophotometric, proton nuclear magnetic resonance spectrometric and electron impact mass spectrometric methods. Ubiquinone-10 was identified in 1-day-old eggs and cotacidia, and rhodoquinone-10 in coracidia, plerocercoids and adult tapeworms. Tentative identification were also made of ubiquinone-10 in procercoids and rhodoquinone-10 in 10-day-old eggs. The roles of benzoquinones in helminth aerobic and anaerobic metabolism are discussed in relation to their distribution in stages of the S. mansonoides life-cycle.