Sesquiterpenes from Rhizomes of Cyperus rotundus with Cytotoxic Activities on Human Cancer Cells in vitro

Two new sesquiterpenes, cyperusol A₃ ( 1 ) and 3β‐hydroxycyperenoic acid ( 2 ), along with three known sesquiterpenes, britanlin E ( 3 ), 1β,4α‐dihydroxyeudesm‐11‐ene ( 4 ), and 11,12‐dihydroxyeudesm‐4‐en‐3‐one ( 5 ), were isolated from the AcOEt‐soluble fraction of rhizomes of Cyperus rotundus L. The structures of 1 and 2 were elucidated by physical and spectroscopic methods (¹H‐ and ¹³C‐NMR, 2D‐NMR, and MS). All of the isolates, 1 – 5 , were evaluated for their cytotoxic activities against human ovarian cancer cells (A2780) and endometrial adenocarcinoma cells (Ishikawa) using MTT assays.     

Unified approach to the sesquiterpenoids,lauranes and cyclolauranes: Total synthesis of (±)-isolaurene

A general approach to the total synthesis of sesquiterpene, isolaurene (1a) and cyclolaurene (2a) is featured from commercially available 3-methyl cyclopenten-2-one. The strategy includes a Stork-Danheiser sequence concomitant with a Ni(II)-catalyzed conjugate addition of methyl group onto 3-aryl 2-methyl cyclopenten-2-one to afford the advanced intermediate 11. A methyllithium addition onto compound 11 with an eventual dehydration completed the total synthesis of isolaurene (1a) in 5 steps (58.3% overall yields).     

Terpenoids from Croton regelianus

Two new terpenoids, the bisnorditerpene rel‐(5β,8α,10α)‐8‐hydroxy‐13‐methylpodocarpa‐9(11),13‐diene‐3,12‐dione ( 1 ) and the guaiane sesquiterpene rel‐(1R,4S,6R,7S,8aR)‐decahydro‐1‐(hydroxymethyl)‐4,9,9‐trimethyl‐4,7‐(epoxymethano)azulen‐6‐ol ( 2 ), together with seven known compounds, were isolated from Croton regelianus var. matosii. The structures of the isolated compounds were determined by HR‐ESI‐TOF and a combination of 1D‐ and 2D‐NMR experiments.     

Discovery of novel sesquiterpenoids from a gorgonian Menella sp.

A novel sesquiterpenoid, menelloide A (1), which was found to possess a new carbon skeleton, and a new guaiane-type sesquiterpenoid, menelloide B (2), along with (+)-chloranthalactone B (3), an enantiomer of the known sesquiterpenoid, chloranthalactone B (4), were isolated from a gorgonian coral identified as Menella sp. The structures of sesquiterpenoids 1-3 were established by spectroscopic methods and by comparison of the data with those of related metabolites. Sesquiterpenoids 1 and 3 displayed inhibitory effects on the generation of superoxide anion by human neutrophils.     

Novel nardosinane type sesquiterpenoids from Nardostachys chinensis Batal

Five new sesquiterpenoids Nardosinanone A–E (1–5), were isolated from the extract of Nardostachys chinensis, and their structures were determined by extensive spectroscopic analysis. Compound 1 featured a nardosinane sesquiterpenoid with an unusual tricyclic skeleton. Compounds 2–4 were new nardosinane sesquiterpenoids bearing a rare 10,11-epoxy group. The absolute configurations were determined by single-crystal X-ray diffraction analysis, ECD calculation method, the CD analysis of the in situ formed [Rh₂(OCOCF₃)₄] complex, and the CD data analysis based on the octane rule of cyclohexanone.     

Synthesis of 5,6-dehydro-7-oxoisodrimenin from drim-8-en-7-one

The natural drimane sesquiterpenoid lactone 5,6-dehydro-7-oxoisodrimenin was synthesized from drim-8-en-7-one as well as from 7-oxoisodrimenin.     

Two New Oplopanol Esters from Ligularia narynensis

Mainly species of Ligularia have long been used for treatment of fever, inflammation, detoxication, invigorating the circulation of blood and smoothing pain1. So far the opl- opane derivatives were not found in the genus Ligularia. Here we report the stru…     

Further Highly Oxygenated Guaiane Lactones from the South China Sea Gorgonian Menella sp.

Four new highly oxygenated guaiane lactones, 1‐epimenverin B ( 1 ), menverin F ( 2 ), 1‐deoxymenverin F ( 3 ), and menverin G ( 4 ), together with the two known related analogues menverins B ( 5 ) and C ( 6 ), were isolated from the South China Sea gorgonian Menella sp. Their structures and relative configuration were elucidated by analysis of spectroscopic data and by comparison with those of known related compounds.     

Two New Guaiane Sesquiterpenes from the Fruits of Daucus carota

Two new sesquiterpenes, 11‐(acetyloxy)torilolone ( 1 ) and 1β‐hydroxytorilolone ( 2 ) were obtained from the fruits of Daucus carota. Their structures were elucidated on the basis of various spectroscopic analyses and chemical evidence.