THE RELATIONSHIP BETWEEN LIPOPHILICITY OF N-ALKYL-N,N-DIMETHYLAMINE OXIDES AND THEIR EFFECTS ON THE THYLAKOID MEMBRANES OF CHLOROPLASTS

Interactions of N-alkyl-N,N-dimethylamine oxides with thylakoid lipids of chloroplasts result in the decrease of the arrangement and of the microviscosity of the lipid phase. An interaction of the above compoun ds with photosynthetic centres damages photosystem (PS) 2 and releases Mn2+ ions into interior of thylakoid membranes, causing a decrease in the oxygen evolution rate. These compounds also decrease the growth a nd chlorophyll synthesis of algae. The most effective compounds are do decyl- and tetradecyl- derivatives. The relationship between lipophili city and the extent of action has typical ''cut off'' dependence on th e alkyl chain length with the maximum for dodecyl- or tetradecyl-deriv atives.