Antiproliferative Sesquiterpenoids from Ligularia rumicifolia with Diverse Skeletons

Abstract

Twenty-two new sesquiterpenoids with four skeletal types and 15 known analogues were isolated from the whole plants of Ligularia rumicifolia. The structures of the isolates were elucidated based on comprehensive spectroscopic data analysis. Compound 1 is a C nor-sesquiterpenoid featuring a 6/6/6 tricyclic skeleton with a 9,13-ether bridge. The absolute configuration of 2 was established through single-crystal X-ray diffraction data. Compounds 13-16 exhibited in vitro antiproliferative activity against the four human tumor cell lines A-549, HGC-27, HeLa, and MV4-11. Specifically, compounds 13 and 16 showed antiproliferative activity against the MV4-11 cell line with IC values of 0.5 ± 0.2 and 1.1 ± 0.5 μM, respectively.

Eremophilane Sesquiterpenoids with Antibacterial and Anti-inflammatory Activities from the Endophytic Fungus Septoria rudbeckiae

“…Eremophilane sesquiterpenes, consisting of three isoprenes, possess the identical decalin framework with the eudesmanes and probably belong to a small group of sesquiterpenes. , Eremophilane sesquiterpenoids widely existed in numerous medicinal plants, especially in the Asteraceae family. − Subsequently, the metabolites of eremophilanes produced by theendophytic and marine fungi have increased remarkably, with some exhibiting multiple bioactivities including antifungal, anti-inflammatory, antivirus, antibacterial, and insecticidal activities. − Owing to the structural diversiform and unique biological activities of eremophilane sesquiterpenes, extensive phytochemical and biological investigations have been carried out by numerous scientists. − Consequently, further studies toward the development of novel and medicinally valuable sesquiterpenoids are essential.…”

Brønsted Acid Catalyzed Oxocarbenium-Olefin Metathesis/Rearrangements of 1H-Isochromene Acetals with Vinyl Diazo Compounds

“…Herein, we report the oxocarbenium-olefin metathesis/rearrangement reactions of 1 H -isochromene acetals with vinyl diazo compounds induced by bis­(trifluoromethanesulfonyl)­imide (HNTf 2 ) catalysis (Scheme c). Polysubstituted benzobicyclo[3.3.1]­oxocines, benzobicyclo[3.2.2]­oxepines, benzobicyclopropane, and naphthalenes that form the structural cores of various bioactive molecules, such as an antiproliferative sesquiterpenoid, the alkaloid stephadiamine, the hydroquinone terpenoid euchroquinol C, and the anticancer agent podophyllotoxin, are produced in good to excellent yields and selectivities.…”