Aphapolin A, a nemoralisin-type diterpenoid possessing a unique 4/5-fused-ring system that is unprecedented in previously reported nemoralisin diterpenoid, and aphapolin B, a novel nemoralisin-type diterpenoid derivative containing a benzofuran moiety, along with a new natural product were isolated from Aphanamixis polystachya (Wall.) R. Parker. Their structures and absolute configurations were elucidated by spectroscopy data, X-ray crystallography diffraction analysis, and electronic circular dichroism calculations. Plausible biosynthetic pathways of aphapolins A and B were also delineated.

Ten new tirucallane-type triterpenoids, represented by a rearranged skeleton dysolenticin A (1), dysolenticin B (2), a rare trinortriterpenoid dysolenticin C (3), three tirucallane triterpenoid derivatives with a hemiketal moiety dysolenticins D–F (4–6), dysolenticins G–I (7, 9, 10), and the new alkaloid dysolenticin J (12), together with seven known analogues were isolated from the twigs and leaves of Dysoxylum lenticellatum. Their structures were elucidated by extensive spectroscopic methods, and those of compounds 1, 3, 4, 6, and 10 were confirmed by single-crystal X-ray diffraction experiments. Dysolenticin J (12) showed significant vasodilative effects on intact rat aortic rings with a diastolic degree of 87.4% at 10 μg/mL.

A dimeric eremophilane sesquiterpene lactone with a cyclobutane ring, biliguhodgsonolide (1) and an uncommon seco-sesquiterpene derivative, (4S,5S,6R,10R)-8,9-seco-12-hydroxyeremophil-7(11)-en-14,6;12,8-diolid-9-al (2), were isolated from the roots and rhizomes of Ligularia hodgsonii Hook. Their structures, including the absolute stereochemistry, were elucidated by spectroscopic data and CD analysis. The cyclobutane ring was confirmed by single-crystal X-ray diffraction.A dimeric eremophilane sesquiterpene lactone with a cyclobutane ring, biliguhodgsonolide (1) and an uncommon seco-sesquiterpene derivative, (4S, 5S, 6R, 10R)-8,9-seco-12-hydroxyeremophil-7(11)-en-14,6;12,8-diolid-9-al (2), were isolated from the roots and rhizomes of Ligularia hodgsonii Hook.

A phytochemical study on the whole plant of Sonchus arvensis and its antioxidant activity has been carried out. Three quinic acid derivatives (1–3), the rarely naturally occurring (p-hydroxyphenylacetyl) quinic acids, and two eudesmanolides (4 and 5) were newly found. Four known eudesmanolides (6–9) were isolated from the plant for the first time. Their structures were characterized by HRESIMS, IR, UV, 1D NMR, and 2D NMR. 1,1-Diphenyl-2-picrylhydrazyl (DPPH·)-scavenging activity was evaluated for each of the above 9 compounds (1–9) in comparison to standard antioxidants (caffeic acid and ascorbic acid). However, none proved to have a positive activity. The absence of antioxidant activity could be caused by the absence of ortho or para-diphenolic groups in all detected compounds, that are responsible of the activity against free radicals by an electron transfer reaction.

AimsKushecarpin D (KD) is a novel flavonoid isolated from the traditional Chinese herbal medicine Kushen (the dried root of Sophora flavescens Ait). As part of our continuous effort to explore Chinese traditional medicinal herbs and to identify novel natural anticancer products, the antiangiogenic properties of KD were examined in vitro using a human umbilical vein endothelial cell line (ECV304).Main methodsThe SRB and Trypan Blue exclusion assays were used to evaluate the effect of KD on cell proliferation. The antiangiogenic activities of KD were evaluated through studies of cell migration, cell adhesion, and tube formation. DCFH-DA and DHE fluorescent assays were used to detect the reactive oxygen species (ROS) levels. Catalase activity was detected using the colorimetric ammonium molybdate method. Cell cycle and apoptosis were measured using flow cytometry and the Hoechst 33258 staining assay.Key findingsThe results indicated that KD showed antiangiogenic activity via inhibitory effects on cell proliferation, cell migration, cell adhesion, and tube formation. ROS levels were down-regulated and catalase activity was up-regulated after treatment with KD. The cell cycle was arrested at the G2/M phase, while no apoptosis was observed using the Hoechst 33258 staining assay or following the flow cytometric analysis of the sub-G1 proportion.SignificanceThe antiangiogenic properties of KD, in combination with its anti-proliferative effect and ability to induce cell cycle arrest without inducing apoptosis, make it a good candidate for development as antitumor agent. However, further studies are essential to elucidate its mechanism of action.