A Heterodimer from P. kaurabassana Structure Elucidation

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).

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.

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.

Bautista et al reinvestigated the chemical composition of S. amarissima. As a result, Teotihuacanin (molecular formula C₂₀H₂₀O₆), an unusual rearranged clerodane diterpene with a new carbon skeleton containing a spiro-10/6 bicyclic system, was isolated from the leaves and flowers of Salvia amarissima.

Ni et al investigated Cephalotaxus mannii Hook f. which led to the isolation of three new diterpenoids, namely, mannolides A−C, and two new Cephalotaxus troponoids. We used the example of Mannolide A (molecular formula C₂₀H₂₄O₅) to challenge our ACD/Structure Elucidator Suite software.

H. Zhang et al observed interesting signals from very minor constituents from F. virosa in their MS analysis. A further fractionation of the fractions returned two extra new alkaloids, one of which, Flueggether A(molecular formula C₂₅H₃₀N₂O₅), is the first example of Securinega alkaloid oligomers which features an ether bond linkage.

Structures of ciliatonoids A-C, complete with absolute stereochemistry, were characterized by spectroscopic data, X-ray crystallography, and electronic circular dichroism (ECD) analysis. To challenge ACD/Structure Elucidator Suite, Ciliatonoid A (molecular formula C₂₆H₃₂O₅) was used. It featured an unprecedented limonoid architecture by way of a very unique cis-fused central motif (in red).

Song et al investigated the chemical constituents of the fruit of S. incarnata. They isolated five novel spirocyclic compounds, spiroschincarins A−E, featuring a unique 1-oxaspiro[6.6]tridecane moiety. Their structures, with absolute configurations, were determined by extensive spectroscopic studies. The structure elucidation of spiroschincarin A (molecular formula C₃₁H₃₈O₁₁) from NMR data was used for challenging ACD/Structure Elucidator.

Investigation of Cystodytes resulted in the isolation of five pyridoacridines, including shermilamines D and E. The structure of another compound, cycloshermilamine D, also isolated from the same tunicate in minute amounts (0.4% of the crude extract) was determined by Koren-Goldshlager et al, molecular formula C₂₁H₁₆N₄OS.

A highly brominated compound, 2,3,5,7-tetrabromobenzofuro[3,2-b]pyrrole (molecular formula C₁₀H₃Br₄NO), was extracted from a marine Protobacterium, Pseudoalteromonas sp.