ACD/Labs Blog

Previously Wang et al reported three trace Lycopodium alkaloids, lycojaponicumins A and B with a 5/5/5/5/6 pentacyclic ring system and lycojaponicumin C with a 6/5/5/6 tetracyclic ring system. The same group later described the discovery of structurally unique alkaloid, Lycojaponicumin D (molecular formula was established to be C₁₆H₂₃NO₃), with an unprecedented 5/7/6/6 tetracyclic skeleton formed by an unusual C3-C13 linkage.

An aqueous extract of the roots of I. indigotica has been investigated by Chen and co-workers. In this work, the authors isolated and structurally characterized an indole alkaloid containing unusual dihydrothiopyran and 1,2,4-thiadiazole rings (molecular formula C₁₈H₁₇N₃O₂S₂).

Liao et al isolated and elucidated the structure of a new natural product named as Asperjinone (molecular formula C₂₂H₂₀O₆). Our analysis using ACD/Structure Elucidator resulted in the revision of the structure. The story of the structure revision is described in the Journal of Natural Products.

Ohlendorf and co-workers describe isolation and structure elucidation of Geranylphenazinediol (molecular formula C₂₂H₂₄N₂O₂), a phenazinediol substituted with an isoprenoid side chain. We used ACD/Structure Elucidator to elucidate structure of this new natural product using only its NMR spectroscopic data.

Plaza et al [1] isolated two new unusual depsipeptides, aetheramides A and B. Here we will discuss the computer-assisted structure elucidation (CASE) of aetheramide B (molecular formula C₄₁H₅₄N₂O₉) using ACD/Structure Elucidator.

El Aouad at al isolated a new naphthopyrone (structure 1) named Lasionectrin (molecular formula C₁₉H₂₀O₆) with antiplasmodial properties from fermentation broths of a Lasionectria species. The article constitutes the first account on the isolation of a natural product from fungi of this genus.

M. Cao and co-workers described the isolation and structure elucidation of 10 new alkaloids belonging to the Daphniphyllum alkaloids family. The spectral data presented for one of the compounds, Daphmacromine A (molecular formula C₂₅H₃₇NO₅), were used to challenge ACD/Structure Elucidator.

Wang et al isolated a novel alkaloid lycojaponicumin (molecular formula C₁₆H₂₁NO₄) from the alkaloidal extract in a trace amount, with a unique 5/5/5/5/6 pentacyclic ring system including two fused tetrahydroisoxazole rings. The structure was elucidated by spectroscopic methods and X-ray diffraction analysis.

A recent article highlighted the isolation and structure elucidation of a new natural product Psychotripine (molecular formula C₃₃H₃₄N₆), which exhibited a complex carbon skeleton comprised of 11 rings. We attempted the Computer-Assisted Structure Elucidation (CASE) of Psychotriptine using only the original limited and incomplete NMR data gathered from the original publication

Philip Williams and co-workers isolated a new cytotoxic peptide, Tasiamide B (molecular formula C₅₀H₇₄N₈O₁₂) containing the unusual amino acid-derived residue 4-amino-3-hydroxy-5-phenylpentanoic acid. The structure of the peptide was determined through a combination of 2D NMR experiments and HPLC analysis of degradation products. The experimental data was submitted to the Structure Elucidator Challenge to determine if the software could propose the same structure.