Rapid construction of the unique BCD ring system of tricyclo[6.2.1.0] undecane in the C19-diterpenoid alkaloid aconitine

A model study leading to the preparation of the unique tricyclo [6.2.1.0] undecane BCD ring systems of aconitine is described. The synthesis features an unprecedented diastereoselective oxidative dearomatization/dimerization/retro-DA/IMDA cascade reaction and a highly efficient Wagner-Meerwein rearrangement.     

Assembly of the 6/3/5/6 tetracyclic core of rearranged-type C19-diterpenoid alkaloids

A synthetic study toward the structurally complex rearranged-type C₁₉-diterpenoid alkaloids leading to construction of the strained 6/3/5/6 tetracyclic core is presented. The synthesis features an intramolecular Diels–Alder cycloaddition reaction to assemble the highly substituted central cyclopropane motif, which may serve as a key strategy for the total synthesis of relevant natural product molecules.     

Hemsleyaconitines F and G,Two Novel C19‐Diterpenoid Alkaloids Possessing a Unique Skeleton from Aconitum hemsleyanum

Hemsleyaconitines F and G ( 1 and 2 , resp.) were isolated from the EtOH extract of Aconitum hemsleyanum. Their structures were elucidated by extensive analyses of the IR, 1D‐ and 2D‐NMR, and MS data. The two C₁₉‐diterpenoid alkaloids 1 and 2 possess a novel skeleton, featuring a five‐membered D‐ring between C(9), C(13), C(14), C(15), and C(16), which is quite different from the previously isolated six‐membered D‐ring analogs.     

Salviskinone A, a diterpene with a new skeleton from Salvia przewalskii

A novel compound, named salviskinone A (1), was isolated from Salvia przewarskii. The compound has a rearranged carbon skeleton with a methyl unit at C-5 from abietane-type diterpene. Its structure and relative stereochemistry were elucidated by detailed spectroscopic analysis, including HREIMS and 2DNMR (COSY, HSQC, HMBC, and NOESY) spectra.     

Eremosides A – C,New Iridoid Glucosides from Eremostachys loasifolia

Eremosides A–C ( 1 – 3 ), three new iridoid glucosides, were isolated from the AcOEt‐soluble fraction of the EtOH extract of the whole plant of Eremostachys loasifolia, along with buddlejoside B ( 4 ), 10‐O‐benzoylcatalpol ( 5 ), and pakiside A ( 6 ) reported for the first time from this species. The structures of these compounds were elucidated by spectroscopic data including 2D‐NMR, FAB‐MS, ESI‐MS, as well as by acid and basic hydrolyses.     

Synthesis,Crystal Structures,and Fungicidal Activity of Novel 1,5‐Diaryl‐3‐(glucopyranosyloxy)‐1H‐pyrazoles

Five novel pyrazole‐coupled glucosides, 1,5‐diaryl‐1H‐pyrazol‐3‐yl 2,3,4,6‐tetra‐O‐acetyl‐β‐D ‐glucopyranosides 5a – 5e , were synthesized by the phase‐transfer catalytic reaction of 1,5‐diaryl‐1H‐pyrazol‐3‐ols 4a – 4e with acetobromo‐α‐D ‐glucose in H₂O/CHCl₃ under alkaline conditions, using Bu₄N⁺Br^? as catalyst. Then, glucosides 5a – 5c were deacetylated in a solution of Na₂CO₃/MeOH to yield the 1,5‐diaryl‐3‐(β‐D ‐glucopyranosyloxy)‐1H‐pyrazoles 6a – 6c . Their structures were characterized by ¹H,¹H‐COSY, ¹H‐, ¹³C‐, and ¹⁹F‐NMR spectroscopy, as well as elemental analysis. The structures of 5d and 6c were also determined by single‐crystal X‐ray diffraction analysis. A preliminary in vitro bioassay indicated that compounds 4e and 5d exhibited excellent‐to‐medium fungicidal activity against Sclerotinia sclerotiorum at the dosage of 10 μg/ml.     

New Iridoid and Secoiridoid Glucosides from the Roots of Gentiana manshurica

One new iridoid glucoside, 4″‐O‐β‐D ‐glucosyl‐6′‐O‐(4‐O‐β‐D ‐glucosylcaffeoyl)linearoside ( 1 ), and two new secoiridoid glucosides, 6′‐O‐acetylsweroside ( 2 ) and 6′‐O‐acetyl‐3′‐O‐[3‐(β‐D ‐glucopyranosyloxy)‐2‐hydroxybenzoyl]sweroside ( 3 ), were isolated from the dried roots of Gentiana manshurica (Gentianaceae), together with 11 known ones, including one iridoid glucoside, five secoiridoid glucosides, and five triterpenes. The structures of the new compounds were determined on the basis of detailed spectroscopic analyses and acidic hydrolysis.     

Two New Iridoid Glucosides from the Whole Plant of Patrinia scabiosifolia Link

As a traditional Chinese medicine, Patrinia scabiosifolia Link has been used to treat various inflammatory-related diseases, and recent studies have shown that it possesses potent anti-inflammatory activity. Therefore, phytochemical investigation on whole plants of P. scabiosifolia were carried out, which led to the isolation of two new iridoid glucosides, patriniscabiosides A (1) and B (2), together with six known compounds (3–8). The structural elucidation of all compounds was performed by HRESIMS and extensive spectroscopic analyses including IR, 1D, 2D NMR, and electronic circular dichroism (ECD). All the isolated compounds were tested for their anti-inflammatory activity using the NF-κB-Dependent Reporter Gene Expression Assay, and compound 3 displayed anti-inflammatory activity through the inhibition of the NF-κB pathway, with an inhibitory rate of 73.44% at a concentration of 10 μM.     

Two New Diterpenoid Glucosides from Clerodendrathus spicatus

Two new diterpenoid glucosides, clerodendranthusides B and C ( 1 and 2 , resp.), together with 16 known compounds, comprising four lignans, five miscellaneous phenylpropanoids, two flavonoids, one sesquiterpenoid glycoside, two triterpenoid glycosides, one megastigmane, as well as one anthraquinone, were isolated from the 50% EtOH extract of the whole plants of Clerodendrathus spicatus. Their structures were elucidated by chemical and spectroscopic methods.