ACD/Labs Blog

Lorente and co-workers isolated two known compounds, pretomaymycin and oxotomaymycin, plus the previously unknown compound barmumycin from the culture broth of the marine actinomycete Streptomyces sp. BOSC-022A. Barmumycin (molecular formula C₁₅H₁₉NO₄)and its diacetate show antitumor activity at micromolar concentrations.

A reinvestigation of the NMR and IR results for natural schizocommunin led the researchers to propose a revised structure, quinazolinone. We suggested that if a CASE approach were used elucidate the structure when this compound was firstly isolated, the structure revision would be not necessary: for final structure confirmation X-ray crystallographic analysis would be sufficient.

To understand the molecular mechanism underlying the genus-specificity of ascidians' sperm chemotaxis, Matsumori et al investigated the structure of a novel compound Ascidia-SAAF 2 (molecular formula C₂₇H₄₄O₁₀S₂Na₂), which was isolated from the eggs of the ascidian Ascidia sydneiensis. Utilizing Structure Elucidator Suite allowed the correct structure of unknown, and its configuration upon a double bond to be determined.

Kim et al isolated and identified two unprecedented phosphorus-containing iodinated polyacetylenes, Phosphoiodyn A and B, from a Korean marine sponge Placospongia sp. Here we will describe the structural elucidation of Phosphoiodyn A (molecular formula C₁₆H₂₄O₄PI).

Aquatolide is a humulane-derived sesquiterpenoid lactone isolated from Asteriscus aquaticus. The structure originally proposed on the basis of 1D and 2D NMR analysis contains an exceedingly rare ladderane substructure. As a result of the quantum-chemical (QM) calculations of the 13C and 1H chemical shifts and associated coupling constants for a series of possible structures, it was shown that the proposed structure was incorrect. We applied a well-established Computer Assisted Structure Elucidation (CASE) method to the problem, in order to compare results with the QM method.

Wang and co-workers isolated Jatrophalactam (molecular formula C₂₀H₂₉NO₃), a novel diterpenoid lactam possessing an unprecedented skeleton from the roots of Jatropha curcas.

To understand the molecular mechanism underlying the genus-specificity of sperm chemotaxis of ascidians (a type of marine invertebrate filter feeders), Matsumori et al have investigated the structure of a novel compound Ascidia-SAAF 2 (molecular formula C₂₇H₄₄O₁₀S₂Na₂) isolated from the eggs of the ascidian Ascidia sydneiensis.

Marine mollusks of the genus Siphonaria, commonly known as false limpets, are shelled, air-breathing herbivores that are believed to have a marine ancestry. When disturbed, siphonariid limpets secrete a sticky white mucus rich in polypropionate secondary metabolites. Specimens were steeped in acetone, and the acetone extract was subjected to extensive chromatography to afford three new polypropionate metabolites. Spectroscopic data of Polypropionate 1 (molecular formula C₂₀H₃₂O₃) are used here to describe the structure elucidation of this compound using CASE techniques.

Le Goff et al reported the structural characterization of two novel alkylhydrazides produced by the bacterial strain Streptomyces sp. LMA-545. The structures were elucidated using 1D and 2D 1H and 13C NMR spectroscopic analysis and high-resolution mass spectrometry. 1H–15N NMR experiments were required for full structural elucidation. Here we investigate the structure elucidation of Geralcin A ( molecular formula C₁₅H₂₄N₂O₅), one of the three isolated novel compounds.