The influence of phlorotannins and bromophenols on the feeding behavior of marine herbivores was determined using bioassay of Turbo cornutus. It was found that phloroglucinol and its oligomers isolated from the brown ...The influence of phlorotannins and bromophenols on the feeding behavior of marine herbivores was determined using bioassay of Turbo cornutus. It was found that phloroglucinol and its oligomers isolated from the brown alga Eisenia bicyclis (eckol, fucofuroeckol A, phlorofucofuroeckol A, dieckol, and 8,8’-bieckol) had a deterrent effect against feeding behavior of T. cornutus in the concentration of algal body, respectively. In the case of the examination of 0.1 mM concentration, although fucofuroeckol A and phlorofucofuroeckol A significantly reduced feeding by T. cornutus, phloroglucinol and 8,8’-bieckol did not show any significant influence on feeding behavior, and eckol and dieckol had stimulating activity. 2,4-Dibromophenol and 2,4,6-tribromophenol, which are major components of extracellular secretions from Eisenia and Ecklonia species, caused the death, the torpidity, and the decreased appetite of T. cornutus at the concentration of 0.1 mM. In addition, 2,4-dibromophenol had strong feeding deterrent activity at the concentration of 1 μM. These results indicate that phlorotannins and bromophenols act as chemical defense agents of brown algae against environmental stresses such as the herbivore attack.展开更多
The Mandate of the Sacred Vessel takes"the Han House(Hanjia汉家)asa conceptual fulcrum and"achieving Great Peace"(zhi Taiping致太平)asa shared value ideal,interpreting the Han Dynasty as a sacred belief...The Mandate of the Sacred Vessel takes"the Han House(Hanjia汉家)asa conceptual fulcrum and"achieving Great Peace"(zhi Taiping致太平)asa shared value ideal,interpreting the Han Dynasty as a sacred belief community that transcends the Liu clan and is shared by monarchs and ministers.This community,through the founding mythology,cosmology,and"the theology of calamity,'united different social strata from Confucian scholars and social elites to early Daoists,elaborately constructing a"sacred political"dynasty that transcends hierarchies.However,there has always been an inherent tension within it between theidealof"AllunderHeaven is forthepublic"(tianxia weigong天下为公)and therealityof"AllunderHeavenbelongs to the family"(jiatianxia家天下).The maintenance of its sanctity entirely depends on whether imperial power can assume the public responsibility of"achieving Great Peace."In the late period of the dynasty,the Yellow Turban Movement challenged the established sacred order.Under official suppression,it was forced to shift from the initial mission of"assisting the Han"to a revolution of"replacing the Han,"which profoundly reflected the shared value pursuits and ideological background of society at that time.In the medieval history after the collapse of the political entity,the Hanjia as a political symbol appeared repeatedly,revealing the lasting formative power of the sacred concepts of the Han dynasty on the political culture of later generations.展开更多
文摘The influence of phlorotannins and bromophenols on the feeding behavior of marine herbivores was determined using bioassay of Turbo cornutus. It was found that phloroglucinol and its oligomers isolated from the brown alga Eisenia bicyclis (eckol, fucofuroeckol A, phlorofucofuroeckol A, dieckol, and 8,8’-bieckol) had a deterrent effect against feeding behavior of T. cornutus in the concentration of algal body, respectively. In the case of the examination of 0.1 mM concentration, although fucofuroeckol A and phlorofucofuroeckol A significantly reduced feeding by T. cornutus, phloroglucinol and 8,8’-bieckol did not show any significant influence on feeding behavior, and eckol and dieckol had stimulating activity. 2,4-Dibromophenol and 2,4,6-tribromophenol, which are major components of extracellular secretions from Eisenia and Ecklonia species, caused the death, the torpidity, and the decreased appetite of T. cornutus at the concentration of 0.1 mM. In addition, 2,4-dibromophenol had strong feeding deterrent activity at the concentration of 1 μM. These results indicate that phlorotannins and bromophenols act as chemical defense agents of brown algae against environmental stresses such as the herbivore attack.
文摘The Mandate of the Sacred Vessel takes"the Han House(Hanjia汉家)asa conceptual fulcrum and"achieving Great Peace"(zhi Taiping致太平)asa shared value ideal,interpreting the Han Dynasty as a sacred belief community that transcends the Liu clan and is shared by monarchs and ministers.This community,through the founding mythology,cosmology,and"the theology of calamity,'united different social strata from Confucian scholars and social elites to early Daoists,elaborately constructing a"sacred political"dynasty that transcends hierarchies.However,there has always been an inherent tension within it between theidealof"AllunderHeaven is forthepublic"(tianxia weigong天下为公)and therealityof"AllunderHeavenbelongs to the family"(jiatianxia家天下).The maintenance of its sanctity entirely depends on whether imperial power can assume the public responsibility of"achieving Great Peace."In the late period of the dynasty,the Yellow Turban Movement challenged the established sacred order.Under official suppression,it was forced to shift from the initial mission of"assisting the Han"to a revolution of"replacing the Han,"which profoundly reflected the shared value pursuits and ideological background of society at that time.In the medieval history after the collapse of the political entity,the Hanjia as a political symbol appeared repeatedly,revealing the lasting formative power of the sacred concepts of the Han dynasty on the political culture of later generations.
