Oxoaporphine alkaloids and flavonols from Xylopia ferruginea (Annonaceae)

Anti-biofilm and anti-inflammatory active diterpene isolated from the fruit of Xylopia benthamii R.E.Fr

Xylopia benthamii (Annonaceae) is a plant with limited phytochemical and pharmacological evidence. Thus, using LC-MS/MS, we performed exploratory analyses of the fruit extract of X. benthamii, resulting in the tentative identification of alkaloids (1-7) and diterpenes (8-13). Through the application of chromatography techniques with the extract of X. benthamii, two kaurane diterpenes were isolated, xylopinic acid (9) and ent-15-oxo-kaur-16-en-19-oic acid (11). Their structures were established using spectroscopy (NMR 1D/2D) and mass spectrometry. The isolated compounds were submitted to anti-biofilm analysis against Acinetobacter baumannii, anti-neuroinflammatory and cytotoxic activity in BV-2 cells. Compound 11 (201.75 µM) inhibited 35% of bacterial biofilm formation and high anti-inflammatory activity in BV-2 (IC50 = 0.78 µM). In conclusion, the results demonstrated that compound 11 was characterized for the first time with pharmacological potential in the development of new alternatives for studies with neuroinflammatory diseases.

Xylopins A–F, six rare guaiane dimers with three different connecting modes from Xylopia vielana

Six rare guaiane-type sesquiterpene dimers xylopins A–F, having three different connecting modes through two direct C–C bonds, were isolated from the roots of Xylopia vielana. Their absolute configurations were established by NOESY analysis, Cu Kα X-ray crystallography, and experimental and calculated electronic circular dichroism spectra. Flow cytometry demonstrated the fact that compound 6 arrested the cell cycle at G2 phase and concentration-dependently induced apoptosis of DU145 cells. Furthermore, the EPT2-TGC cell model, zebrafish study and western blot analysis illustrated compound 6 could induce apoptosis by efficiently inhibiting the Wnt/β-catenin signaling pathway via decreasing the expression of β-catenin.

Six rare guaiane-type sesquiterpene dimers xylopins A–F, having three different connecting modes through two direct C–C bonds, were isolated from the roots of Xylopia vielana.

Novel total syntheses of oxoaporphine alkaloids enabled by mild Cu-catalyzed tandem oxidation/aromatization of 1-Bn-DHIQs

Novel total syntheses of oxoaporphine alkaloids such as liriodenine, dicentrinone, cassameridine, lysicamine, oxoglaucine and O-methylmoschatoline were developed. The key step of these total syntheses is Cu-catalyzed conversion of 1-benzyl-3,4-dihydro-isoquinolines (1-Bn-DHIQs) to 1-benzoyl-isoquinolines (1-Bz-IQs) via tandem oxidation/aromatization. This novel Cu-catalyzed conversion has been studied in detail, and was successfully used for constructing the 1-Bz-IQ core.