ACD/Labs Blog

R.R. Ravu and coworkers performed work searching for new antibiotics against drug-resistant bacteria. Preliminary fractionation of the crude extracts of the B. amyloliquefaciens subsp. plantarum strain AP183 afforded activity-enriched fractions that contained an apparently unknown active compound with strong UV absorptions. A scale-up fermentation of this Bacillus strain was conducted, leading to the isolation and identification of Bacillusin A (molecular formula C₆₈H₉₂O₁₈).

The authors' efforts focusing on lingzhi meroterpenoids from G. sinensis led to the isolation of a meroterpenoidal hybrid metabolite, called Sinensilactam A (molecular formula C₂₀H₂₁NO₈), which contains a rare 2H-pyrrolo[2,1-b][1,3]- oxazin-6(7H)-ring system.

Wang and coworkers collected the branches and leaves of Croton laevigatus and performed an intensive chemical analysis. They isolated and elucidated structures of two diterpenoids, laevinoids A (molecular formula C₂₀H₂₂O₅) and B, which represent a new rearranged ent-clerodane scaffold with an unusual 3/5 bicyclic motif.

Zhao and co-workers isolated two new Securinega alkaloids (virosaines A and B) with an unprecedented skeleton and elucidated their structures. We used the spectroscopic data presented in by the authors to establish the structure of Virosaine A (molecular formula C₁₂H₁₃NO₄) which had been confirmed by X-ray diffraction.

Meng et al. investigated potentially biologically active substances from the chemical constituents of the stems of S. glaucescens. As a result, a novel triterpenoid possessing an unusual 6/7/9-fused tricyclic ring system was obtained, which was designated as Schiglautone A (molecular formula C₃₀H₄₆O₆).

While studying the herb Aconitum barbatum Pers. var. puberulum Ledeb., Mu et al isolated six new C18-diterpenoid alkaloids including Puberunine (molecular formula C₂₃H₃₅NO₇) that possesses an unusual rearranged 7-membered ring. This structural feature is unprecedented in the field of diterpenoid alkaloids.

Studies aimed at the discovery of trace alkaloids in S. nux-vomica led Fu and co-workers to the isolation of Strynuxlines A and B, two novel alkaloids possessing an unprecedented skeleton with a 6/5/9/6/7/6 hexacyclic ring system. Here we will describe how Strynuxlines A (molecular formula C₂₃H₂₄N₂O₅) could be identified with the assistance of a CASE-based approach using ACD/Structure Elucidator Suite.

In search for bioactive compounds from the mushroom Stropharia rugosoannulata, Wu et al discovered four novel steroids named strophasterols A, B, C, and D which contained a very unique and unprecedented carbon skeleton. Here we will describe the computerized structure determination of Strophasterol A (molecular formula C₂₈H₄₄O₄).

Here we describe a total synthesis of a hypothetical alternative structure and its spectroscopic confirmation, representing a huge amount of work done by the authors to disprove the original structure. We used their example to ask what solution would be obtained if the authors used ACD/Structure Elucidator Suite for processing the spectroscopic data of the unknown.

Tang et al carried out a phytochemical investigation on the stems of T. flavidus collected in China. They reported the identification of five degraded diterpenoids, including the tetranorditerpenoid dimers trigoflavidols A and B. Spectroscopic data acquired for Trigoflavidol A (molecular formula C₃₅H₃₂O₁₀), possessing a rearrangement skeleton with a spiroketal core moiety, was used for challenging ACD/Structure Elucidator Suite.