Dactyltronic Acids from the Sponge Dactylospongia elegans

Abstract

Two new cytotoxic tetronic acid derivatives with a rearranged drimane skeleton [1a and 1b], were isolated from the sponge Dactylospongia elegans, along with smenospongic acid [3], illimaquinone [4], dactylospongenones A, B, C, and D [5], and dictyoceratin C [6]. The structures of 1a and 1b were elucidated by spectroscopic and chemical methods. Treatment of 1 with base gave smenospongic acid [3], suggesting that this latter compound is an end-product of D. elegans metabolism. A biogenetic route from furoterpenes to the tetronic acids [1a and b] and smenospongic acid [3] is proposed.

Sesquiterpene Benzoxazoles and Sesquiterpene Quinones from the Marine Sponge Dactylospongia elegans

“…Sponges of the genus Dactylospongia , − in particular D. elegans , − have been widely investigated for their biologically active compounds. Aside from a lone macrolide, the majority of the reported metabolites are sesquiterpene quinones/quinols, ,,− , whose occurrence has been noted in a variety of other genera of marine sponges including Fenestraspongia , Petrosaspongia , Hyrtios , Spongia , Dysidea , and Smenospongia . Other terpenoids isolated from Dactylospongia spp.…”

A Ring‐Distortion Strategy from Marine Natural Product Ilimaquinone Leads to Quorum Sensing Modulators

“…To the best of our knowledge, this result is the first example of a ring contraction of a quinone with ozone . Performed on blue dye 4 the quinone ring is completely truncated and furnishes 29 and smenospongic acid ( 14 ) . Acid 14 clearly opens prospects for the introduction of alternative aromatic rings through, for example, the Barton‐Motherwell reaction …”

Catalytic Undirected Intermolecular C–H Functionalization of Arenes with 3-Diazofuran-2,4-dione: Synthesis of 3-Aryl Tetronic Acids, Vulpinic Acid, Pinastric Acid, and Methyl Isoxerocomate

“…Tetronic acid (4-hydroxy-2-5­[H]-furanone) functionality has attracted considerable attention in recent years as a distinctive feature of many natural products . Many tetronic acid derivatives display a wealth of biological activities which include insecticidal and acaricidal, HIV–I protease inhibitory, antineoplastic, antiinflammatory, and cyclooxygenase inhibitory activity . In addition, these tetronic acids are also of interest for their role as pigments in mushrooms and lichens .…”