Chlorinated bisabolene sesquiterpenoids from the whole plant of Parasenecio rubescens

Highly oxidized sesquiterpenoids from Parasenecio rubescens and assessment of their cytotoxicity

A phytochemical investigation of the whole plant of Parasenecio rubescens (S. Moore) Y. L. Chen yielded 14 previously undescribed, highly oxidized bisabolane-type sesquiterpenoids, named pararunines L-Y, along with one known oplopane-type sesquiterpenoid. The structural elucidation of these compounds was accomplished through comprehensive spectroscopic analysis, including nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) techniques. Motivated by traditional uses and previous studies on this genus, all isolated compounds were subjected to in vitro cytotoxicity assays against four human cancer cell lines (MCF-7, Hela, HCT116, and HT-29). Considering that the reported chemical constituents of numerous other species within this genus primarily consist of eremophilane-type sesquiterpenoids, our findings not only expand the structural diversity of bisabolane-type sesquiterpenoids but also contribute valuable scientific evidence to the chemotaxonomy of this genus.

A Survey of Recently Discovered Naturally Occurring Organohalogen Compounds

The discovery of naturally occurring organohalogen compounds has increased astronomically in the 55 years since they were first discovered─from fewer than 50 in 1968 to a combined 7,958 described examples in three comprehensive reviews. The present survey, which covers the period 2021-2023, brings the number of known natural organohalogens to approximately 8,400. The organization is according to species origin, and coverage includes marine and terrestrial plants, fungi, bacteria, marine sponges, corals, cyanobacteria, tunicates, and other marine organisms.