Cytotoxic dammarane-type triterpenoids from the leaves of Viburnum sambucinum

Unveiling the pharmacological potential of plant triterpenoids in breast cancer management: an updated review

Breast cancer is the most prevalent type of cancer, the fifth leading cause of cancer-related deaths, and the second leading cause of cancer deaths among women globally. Recent research has provided increasing support for the significance of phytochemicals, both dietary and non-dietary, particularly triterpenoids, in the mitigation and management of breast cancer. Recent studies showed that triterpenoids are promising agents in the treatment and inhibition of breast cancer achieved through the implementation of several molecular modes of action on breast cancer cells. This review discusses recent innovations in plant triterpenoids and their underlying mechanisms of action in combating breast cancer within the timeframe spanning from 2017 to 2023. The present work is an overview of different plant triterpenoids with significant inhibition on proliferation, migration, apoptosis resistance, tumor angiogenesis, or metastasis in various breast cancer cells. The anticancer impact of triterpenoids may be attributed to their antiproliferative activity interfering with angiogenesis and differentiation, regulation of apoptosis, DNA polymerase inhibition, change in signal transductions, and impeding metastasis. The present review focuses on several targets, mechanisms, and pathways associated with pentacyclic triterpenoids, which are responsible for their anticancer effects. We could conclude that natural triterpenoids are considered promising agents to conquer breast cancer.

Molecular properties, structure and chiral resolution of secondary metabolites from the leaves of Viburnum chingii

A chemical investigation of leaves of Viburnum chingii afforded eleven compounds, including one undescribed lignan (1), a pair of known phenylpropanoid enantiomers (2a/2b), and eight known lignans (3-10). Their structures were elucidated by detailed spectroscopic and comparative literature data analysis. The absolute configurations of compounds 1 was determined by comparing the experimental ECD data with the calculated values. The compounds 2a/2b were separated successfully by a chiral chromatographic column. In addition, the acetylcholinesterase (AChE) inhibitory activities of described compounds were evaluated.

Two new iridoids and triterpenoid analogues from the leaves of Viburnum chingii and their anti-acetylcholinesterase activity

Two undescribed split-ring iridoids (1-2) with six known triterpenes (3-8) and one steride (9) were isolated from the Viburnum chingii. Compound 2 possessed an unprecedented split-ring iridoid skeleton formed by electrocyclic reaction and split ring. The structures and absolute configurations of the new iridoids were established by NMR, HRESIMS, and ECD calculations. All the isolated compounds were tested for AChE inhibitory activity. Biologically, 1, 2, 3, 4, and 7 displayed significant AChE effects compared to the positive control donepezil, and have also been subjected to molecular docking studies.

Recent Advance on Chemistry and Bioactivities of Secondary Metabolites from Viburnum Plants: An Update

Viburnum species are a group of small trees or shrubs that are of great ornamental and medicinal values. Some of them have been used for a long time both as conventional and ethnic medicine. Viburnum fruits, eaten in fresh and processed forms, have been revealed to contain various health-promoting nutrients. With the increasing research on Viburnum plants, they are considered to be an abundant resource of bioactive natural products possessing diverse pharmacological properties and unique chemical structures, that is powerfully proved by the existence of structurally novel vibsane-type diterpenoids which only occur in Viburnum species, newly discovered lignan constituents with unusual side chains and other noteworthy natural components. This review describes 185 new and 228 known secondary metabolites from Viburnum genus between 2008 and 2020, including their chemical structures, sources and bioactivities, and highlights the corresponding structure-activity relationships.

Iridoid Constituents of Viburnum brachybotryum

Eleven new iridoids, brachybones A-K (1-11), were isolated from the twigs of Viburnum brachybotryum. Their structures including absolute configurations were determined by spectroscopic data analysis and from the electronic circular dichroism (ECD) spectra. All of the compounds 1-11 possess one or two acetoxysenecioate substituents. Furthermore, compounds 5-7 and 11 feature a Cl atom in the molecule, while compounds 9-11 exhibit a cagelike rigid skeleton through an unusual oxo bridge from C-3 to C-8 or C-10. The isolates were evaluated for cytotoxic activity against the HCT-116, A549, and Hela cell lines, and the results showed compounds 10 and 11 to be active against HCT-116 cells.

Paeonone A, a novel nonanortriterpenoid from the roots of Paeonia lactiflora

Paeonone A (1), a unique nonanortriterpenoid, and a new octanortriterpenoid, paeonone B (2), were isolated from the roots of Paeonia lactiflora, together with a known analogue, palbinone (3). Paeonone A (1) is the first example of naturally occurring nonanortriterpenoid with a diketo acid group. Extensive NMR and HRESIMS experiments were applied to identify the structures of 1 and 2, and their absolute configurations were solved by single-crystal X-ray diffraction and ECD data. Biological properties of 1-3 were explored against pancreatic lipase and cancer cell lines.