Toonasindiynes A-F, new polyacetylenes from Toona sinensis with cytotoxic and anti-inflammatory activities.

The plants of genus Toona are well known for diverse limonoid secondary metabolites, while polyacetylenes are rarely found from Toona species. In this work, six new polyacetylenes toonasindiynes A-F (1-6) and six known analogues (7-12) were isolated from the root bark of Toona sinensis. Their structures and absolute configurations were elucidated by HRESIMS, 1D and 2D NMR spectroscopic analysis, modified Mosher's method, and biosynthetic consideration.

Eucalrobusone C suppresses cell proliferation and induces ROS-dependent mitochondrial apoptosis via the p38 MAPK pathway in hepatocellular carcinoma cells.

Background: Eucalyptus extracts have anti-cancer activity against various cancer cells. Formyl-phloroglucinol meroterpenoids (FPMs), which are typical secondary metabolites of the genera Eucalyptus, have many important pharmacological activities.

Purpose: Eucalrobusone C (EC), a new bioactive phytochemical, was first isolated from the leaves of Eucalyptus robusta in our laboratory.

(1) H NMR-Guided Isolation of Formyl-Phloroglucinol Meroterpenoids from the Leaves of Eucalyptus robusta.

Nine formyl-phloroglucinolmeroterpenoids (FPMs), namely, eucalrobusones A-I (1-9), were isolated from the leaves of Eucalyptus robusta by tracking the phenolic hydroxyl (1) H NMR peaks. The Snatzke helicity rules for the Cotton effects of twisted benzene rings were applied to elucidate the absolute configurations of the FPMs. These findings, along with NMR spectroscopy, the circular dichroism (CD) exciton chirality method, and CD calculations, allowed complete structures for the FPMs to be assigned.

Sarglaperoxides A and B, Sesquiterpene-Normonoterpene Conjugates with a Peroxide Bridge from the Seeds of Sarcandra glabra.

Sarglaperoxides A (1) and B (2), a pair of unusual sesquiterpene-normonoterpene conjugates with a peroxide bridge, were isolated from the seeds of Sarcandra glabra. The structures and absolute configurations of 1 and 2 were determined on the basis of spectroscopic data analysis, including MS, NMR, CD, and XRD. The two compounds were screened in antimicrobial, anti-inflammatory, and cytotoxic bioassays and showed moderate bioactivities.