ACD/Labs Blog

Tronoharine was isolated in a small amount as a minor alkaloid from a sample of T. corymbosa and given a proposed structure. In a more recent work, it was obtained in a more significant amount, which enabled the authors to reevaluate the previously proposed structure. Structure Elucidator Suite was used to confirm the newly proposed structure of Tronoharine ((molecular formula C₂₁H₂₄N₂O₂).

Zhao et al isolated two novel rearranged triterpenoids from the leaves and twigs of A. chensiensis.—Spirochensilides A and B. The spectroscopic data used to elucidate the structure of Spirochensilide A (molecular formula C₃₀H₄₂O₅), a compound containing unprecedented spiro-[5,6]system, were used to challenge ACD/Structure Elucidator Suite.

S.P. Wong  et al investigated the alkaloid content of K. arborea Blume, and reported the isolation and structure determination of a new pentacyclic monoterpenoid indole alkaloid, Arboridinine (molecular formula C₁₉H₂₂N₂O), characterized by an unprecedented molecular skeleton.

Two heterodimers comprising an anthraquinone moiety linked to a 3-methylbenzodihydroisocoumarin unit were isolated from P. kaurabassana tubers. The NMR spectroscopic data presented therein were used by us to challenge the ACD/Structure Elucidator system, by attempting to successfully elucidate structure 1 (molecular formula C₃₁H₂₄O₁₀).

Fan et al isolated two PPAPs, Garcimulins A and B, including a pair of enantiomers [(+)-Garcimulin A and (-)-Garcimulin A)] with the unique caged tetracyclo[5.4.1.11,5.09,13]tridecane skeleton from the leaves and twigs of G. multiflora. The spectroscopic 1D and 2D NMR data used by the authors for structure elucidation of Garcimulin A (molecular formula C₃₈H₅₀O₆) were input into ACD/Structure Elucidator Suite.

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).