Studio di componenti del lattice di Euphorbia characias

The aim of the present study was to contribute to the knowledge of the components of the latex, a milky fluid exudated from the Mediterranean shrub Euphorbia characias. The antioxidant and acetylcholinesterase inhibitory activities were explored in E. characias. The latex was extracted using several conventional methods and a new procedure involving the use of the trichloroacetic acid. The results of this research indicate that E. characias latex exhibits antioxidant activities, is rich in total polyphenolic and flavonoids content and exhibited substantial inhibition of acetylcholinesterase activity. A natural rubber was identified and characterized for the first time in the latex of E. characias. Four different methods, i.e. acetone, acetic acid, trichloroacetic acid and Triton® X-100, followed by successive treatments with cyclohexane/ethanol, were employed to extract the natural rubber. The higher yield (14%) was achieved after extraction with acetic acid. E. characias rubber showed a molecular weight of 93000 with a Mw/Mn of 2.9. 1HNMR, 13C NMR and FTIR analysis revealed the characteristic of the cis- 1,4-polyisoprene typical of natural rubber. The enzyme catalyzing the rubber molecule elongation is cisprenyltransferase called “rubber transferase”. We cloned the cDNA encoding for the E. characias rubber transferase by RT-PCR. The cDNA contains an open reading frame of 810 bp encoding a protein of 270 amino acids (GenBank JX564541). The cDNA nucleotide sequence and the deduced amino acid sequence appear to be highly homologous to the sequence of several plant cis-prenyltransferases. The results provided novel insight into latex components and will ultimately benefit the broader understanding of E. characias latex composition.