Reticulatins A and B and hyrtioreticulin F from the marine sponge Hyrtios reticulatus

作者：Imada Kumiko; Sakai Eriko; Kato Hikaru; Kawabata Tetsuro; Yoshinaga Sosuke; Nehira Tatsuo; Terasawa Hiroaki; Tsukamoto Sachiko^*

来源：Tetrahedron, 2013, 69(34): 7051-7055.

DOI：10.1016/j.tet.2013.06.043

• Imidazole alkaloid
• Indole alkaloid
• Hyrtios reticulatus
• Marine sponge

Three new alkaloids, reticulatins A (1) and B (2) and hyrtioreticulin F (3), were isolated from the water-soluble fraction of an EtOH extract of the marine sponge Hyrtios reticulatus. Compounds 1 and 2 were found to be novel 1,3-dimethyl-5-(methylthio)imidazolium alkaloids. The structure of 3 was determined to be an indole alkaloid related to hyrtioreticulin E (8) and hyrtioerectine B (9), which were isolated previously from the n-BuOH-soluble fraction of the sponge extract. The presence of three NH units in 3 was indicated by the H-1-N-15 HSQC spectrum in D2O/H2O (5:95) containing 0.05% TFA measured at 5 degrees C. Compound 3 is likely biosynthesized from L-tryptophan, two units of L-alanine, and glycine by the Pictet-Spengler reaction. The absolute configurations of 1-3 were determined by the methods based on ECD spectra. In addition, the result for 1 was further confirmed by the PGME method.

• 出版日期2013-8-26