Tetrahedron Letters,Vol.28,No.l3,pp 1409-1412,1987 oo40-4039/87 $3.00 + .OO Printed in Great Britain Pergamon Journals Ltd. STYLOTELLINE, A NEW SESQUITERPENE ISOCYANIDE FROM THE SPONGE Stylotella sp. APPLICATION OF ZD-NMR IN STRUCTURE DETERMINATION * Mary PaPs, Catherine Fontaine, Dominique Laurent+ Stsphane La Barre tt and Eric Guittet Institut de Chimie des Substances Naturelles, CNRS, 91190 Gif-sur-Yvette, France. ’ Centre ORSTOM, BP A5, Noumsa, New Caledonia. tt Laboratoire des Plantes Msdicinales, Caledonia. Abstract: The sesquiterpene isocyanide __ . __ stylotelline isolated from the marine sponge Stylotella sp. was assigned the structure la (absolute stereochemis- try) on the basis of spectral - zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFE essentially 2D-NME-- and chemical data. CNRS, RP 463, Noumga, New Terpenoid isocyanides have been found previously in marine sponges, but still represent a relatively rare class of natural products showing cyto- toxic, antibiotic or antifeedant properties. 1 We report here the isolation and structure determination of a new sesquiterpene isocyanide, stylotelline la, from the sponge Stylotella sp. 2 The sponge was freeze-dried and continuously extracted with methylene chloride. Silica gel chromatography of the crude extract gave la as an oil - (yield 0.16% of the sponge dry weight). Stylotelline la, [aID-47' (CHC13, c = 1.7) had the molecular formula C16H2SN (MS and l3C NMR) and showed IR absorption at 2140 cm -l (i&C). Its planar structure was readily assigned on the basis of NMR data. 14 1 0 2 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA 10 8 = c5, , = /‘I1 ‘2 15 I k. : 13 PY / / la R= iEc 2 l,b R= NHCHO tram ___- 1409