Simple and high yield synthesis of (±)10,10′-dimethyl-dotriacontan-1,1′-diol as a building block for branched bola compounds. Preparation of (±)10,10′-dimethyl-dotriaconta-1,1′-diyl-bis[2-(trimethylammonio)ethyl phosphate] and the corresponding unbranched equivalent

The synthesis of a specially methyl branched bipolar hydrocarbon chain is described by alkylation of 1,12-dibromododecane with two equivalents of the dianion of undec-10-enoic acid. The subsequent transformation includes the reduction of the carboxyl groups to methyl branches and the hydroboration of the terminal olefines. The resulting 1,32 diol is suitable for phosphorylation in order to form the corresponding 1,1′bis-phosphocholine.     

Consumption of cyanogenic bamboo by a newly discovered species of bamboo lemur

Three species of bamboo-eating lemurs were found to be sympatric in the southeastern rain forests of Madagascar. Sympatric species generally differ in habitat utilization or diet, but these three closely related bamboo lemurs lived in the same habitat and all ate bamboo. Behavioral observation revealed that they did select different parts of the bamboo, and chemical analyses confirmed that there was a difference in the secondary compound content present in those selections. The growing tips of Cephalostachyum ef uiguieri selected by the golden bamboo lemur (Hapalemuraureus) contained 15 mg of cyanide per 100 g fresh weight bamboo while the leaves of C. perrieri selected by the gentle bamboo lemur (H. griseus)and the mature culms of C. cf uiguieri selected by the greater bamboolemur (H. simus) did not contain cyanide. Since each individual golden bamboo lemur ate about 500 g of bamboo per day, they daily ingestedabout 12 times the lethal dose of cyanide. The mechanism by which this small primate avoids the acute and chronic symptoms of cyanide poisioning is unknown.     

Structural elucidation of 13-acetoxylichesterinic and 13-acetoxyprotolichesterinic acids,two aliphatic lichen metabolites from Neuropogon trachycarpus

From the lichen Neuropogon trachycarpus, six aliphatic acids related to lichesterinic acid have been isolated: neuropogolic, murolic, isomuronic an     

Restoration of a normal phenotype, microtubular pattern and DNA synthesis in embryonic fibroblasts concanavalin A pretreated

The present research investigated the time required for reconstructing normal microtubular pattern and the phenotype of cells after short-term (30 min.) and long-term (24 hrs.) pretreatment with the lectin concanavalin A (Con A). Short-term pretreatment led to the formation of incomplete tubules within 2 and 24 hrs. in cells cultured in 199 medium alone. The addition of serum to the medium reversed the globular phenotype and allowed the formation of normal microtubules, even after prolonged pretreatment with Con A. Whereas long-term Con A treatment provoked a reduction in DNA synthesis in 199 alone, in serum-added 199 the percentage of 3H-thymidine incorporation of treated cells tended to reach that of controls over time.