Clerodane and ent‐Kaurane Diterpene Glycosyl and Glycoside Derivatives from the Leaves of Casearia sylvestris

Five new clerodane diterpene glycosyl derivatives, caseariasides A–E ( 1 – 5 , resp.) and three new ent‐kaurane diterpene glucosides, sylvestrisides C–E ( 6 – 8 , resp.) were isolated from the leaves of Casearia sylvestris. Their structures were determined on the basis of chemical and spectroscopic analyses.     

Triterpenoids from the Edible Leaves of Photinia serrulata

Five new triterpenoids, serrulatins A–E ( 1 – 5 ), including two new artifacts, together with ten known serrulatins, were isolated from the edible leaves of Photinia serrulata after extraction and purification. Their structures were identified on the basis of spectroscopic methods including 2D NMR experiments. Compounds 1 and 3 are unusual ursolic triterpenoids characterized by the occurrence of a C(13)?C(18) bond.     

Development of a comprehensive method for analyzing clerodane‐type diterpenes and phenolic compounds from Casearia sylvestris Swartz (Salicaceae) based on ultra high performance liquid chromatography combined with chemometric tools

This work describes the development and optimization of an analytical method utilizing liquid chromatography and chemometrics to evaluate and differentiate two varieties of Casearia sylvestris Swartz (Salicaceae) from São Paulo State (Brazil) based on their secondary metabolite profiles. Previously, analytical studies only concerned the analysis of clerodane‐type diterpenes. Therefore, considering the importance of including phenolic compounds in such analysis, we used design of experiments to simultaneously extract and detect the largest number of compounds from both chemical classes. This new strategy allowed a comprehensive chromatographic analysis of C. sylvestris, and the results for the two varieties exhibited an interesting distribution according to their original ecosystems, suggesting a strong correlation to the main metabolites found in each species group. Besides their inherent morphological differences, C. sylvestris variety lingua, mainly found in Cerrado areas, predominantly contains phenolic compounds, while C. sylvestris variety sylvestris, mainly found in Atlantic Forest areas, contains mostly clerodane‐type diterpenes. Finally, it was also possible to observe differences in the secondary metabolite composition within each group depending on the place where samples were collected.     

Alkaloids from the Twigs and Leaves of Daphniphyllum macropodum

Three new alkaloids, macrodumines A–C ( 1 – 3 , resp.), along with ten known analogs, were isolated from the twigs and leaves of Daphniphyllum macropodum. Their structures were elucidated on the basis of spectroscopic methods. The 11‐OH configuration of the known alkaloid hydroxydaphgraciline ( 4 ) was assigned as α for the first time by comparing the NMR data with those of macrodumine C ( 3 ).     

Meliarachins A–K: Eleven Limonoids from the Twigs and Leaves of Melia azedarach

Eleven new limonoids, meliarachins A–K ( 1 – 11 , resp.), together with five known ones, were isolated from the twigs and leaves of Melia azedarach. The structures of the new compounds were elucidated on the basis of spectroscopic analysis. Compounds 4 and 8 exhibited moderate antibacterial activities against Gram‐positive bacteria.     

Nonalkaloid Constituents from Stemona japonica

Five new nonalkaloid constituents, a neolignan, japonin A ( 1 ), a macrocyclic lactone, japonin B ( 2 ), a (phenylethyl)benzoquinone, japonin C ( 3 ), a phenanthraquinone, japonin D ( 4 ), as well as a dihydrostilbene, stilbostemin M ( 5 ), were isolated from the roots of Stemona japonica, together with eight known compounds. Their structures were established by spectroscopic analyses.     

Chromenone Glucosides Acylated with Monoterpene Acids from the Leaves of Eucalyptus camaldulensis var. obtusa

Three new chromenone glucosides acylated with monoterpene acids, eucamaldusides A ( 1 ), B ( 2 ), and C ( 3 ), were isolated from the leaves of Eucalyptus camaldulensis var. obtusa, together with the five known compounds ursolic acid lactone, obtusilin, β‐sitosterol glucoside, 4‐hydroxybenzoic acid, and cypellocarpin C. The structures of the new compounds were established by exhaustive 1D‐ and 2D‐NMR spectroscopic studies. Their configuration was determined by measuring the [α]_D of the known methyl esters of the monoterpene acids obtained by methanolysis of 1 – 3 .     

Three New E‐Secoursane Triterpenoid Saponins from the Leaves of Ilex dunniana

Three new triterpenoid saponins with an 18,19‐secours‐13(18)‐ene skeleton, dunnianaolactones A–C ( 1 – 3 , resp.), together with nine known compounds i.e., the ursane‐type triterpene saponin 4 , the two benzofuran lignans 5 and 6 , five flavonoid glycosides, and 4‐hydroxybenzoic acid, were isolated from the leaves of Ilex dunniana Levl . (Aquifoliaceae). Their structures were elucidated by means of spectroscopic and chemical methods. The configuration of dunnianaolactone A ( 1 ) was further confirmed by X‐ray crystal‐structure analysis.     

Polyhydroxypregnane Glycosides from the Roots of Cynanchum otophyllum

Six new polyhydroxypregnane glycosides, namely cynotophyllosides A–F ( 1 – 6 ), together with five known steroids, were isolated from the roots of Cynanchum otophyllum. Their structures were elucidated by extensive spectroscopic methods (especially 2D‐NMR techniques) and acid‐catalyzed hydrolysis. Furthermore, high field 1D‐ and 2D‐NMR experiments were employed to elucidate the structure of 8 previously deduced only on the basis of LC/MS data.     

Iridoids from the Bark of Alstonia scholaris

Four new 11‐noriridoids named scholareins A–D ( 1 – 4 ), along with three known derivatives, isoboonein ( 5 ), alyxialactone ( 6 ), and loganin ( 7 ), were isolated from EtOH extracts of the bark of Alstonia scholaris by chromatographic methods. Their structures were identified by extensive mass‐spectrometric and spectroscopic (especially 2D‐NMR) experiments.     

Cycloheximide Derivatives from the Fruits of Dipteronia dyeriana

The phytochemical investigation of Dipteronia dyeriana (Aceraceae) resulted in the isolation and identification of three new cycloheximide derivatives: dipteronines A–C ( 1 – 3 ). Their structures were elucidated based on the 1D‐ and 2D‐NMR spectra. Dipteronine A ( 1 ) is the first example of a 10,11‐secocycloheximide. Cytotoxic and antifungal activities of these isolates were also evaluated.     

New Benzofuranylpropanoids from the Roots of Codonopsis lanceolata

Three new benzofuranylpropanoids, lanceolunes A–C ( 1 – 3 ), were isolated from the roots of Codonopsis lanceolata. Their structures were determined by means of HR‐ESI‐MS, extensive 1D‐ and 2D‐NMR spectroscopic, and chemical evidence.     

New Alkaloids from Aconitum vaginatum

Two new amide alkaloids, vaginatunine A and B ( 1 and 2 , resp.), and a new C₁₈‐diterpenoid alkaloid vaginatunine C ( 3 ), together with four known alkaloids, were isolated from the tubers of Aconitum vaginatum. Their structures were determined by means of spectroscopic analyses and comparison of the data with those reported previously.     

Three New Glycosides from the Stems of Miliusa balansae

Three new glycosides with the same saccharides, namely miliusoside A ( 1 ), miliusoside B ( 2 ), and miliusoside C ( 3 ), together with five known compounds were isolated from the stems of Miliusa balansae. Their structures were elucidated on the basis of detailed spectroscopic analysis and by comparison with the spectra of related model compounds. There was a rarely encountered α‐D ‐apiose moiety occurring in all new compounds.     

Triterpene Saponins from the Leaves of Ilex pernyi

Eight new triterpene saponins, ilexpernosides C–J ( 1 – 8 , resp.), and eight known triterpene saponins were isolated from the 70% EtOH extract of the leaves of Ilex pernyi. The structures of the new compounds were elucidated by spectroscopic data and chemical degradation.     

Limonoids from the Twigs and Leaves of Chukrasia tabularis

Seven new limonoids, tabularisins J–P ( 1 – 7 , resp.), together with eight known compounds, were isolated from the twigs and leaves of Chukrasia tabularis. Their structures were determined primarily by spectroscopic methods. The potassium channel blocking activities of some of these isolates were evaluated, and a few of them exerted significant activities on the delayed rectifier (I_K) K⁺ current.     

Novel Bibenzyl Derivatives from the Tubers of Bletilla striata

Three novel bibenzyl derivatives, blestritins A–C ( 1 – 3 ), along with 18 known constituents, were isolated from the tubers of Bletilla striata (Orchidaceae), a traditional Chinese medicine used for the treatment of tuberculosis and haemorrhage of the stomach and lungs. Their structures were identified on the basis of spectroscopic analyses.     

Secondary Metabolites from the Leaves of Litsea lii var. nunkao‐tahangensis

Investigation of the leaves extract of Litsea lii var. nunkao‐tahangensis led to the isolation of five new butanolides, litsealiicolide A ( 1 ), isolitsealiicolide A ( 2 ), litsealiicolide B ( 3 ), isolitsealiicolide B ( 4 ), and isolitsealiicolide C ( 5 ), along with 17 known compounds. Their structures were determined through in‐depth spectroscopic and mass‐spectrometric analyses. Among the isolates, compounds 1 and 2 were cytotoxic against MCF‐7, NCI‐H460, and SF‐268 cell lines in vitro. Compound 5 and isolinderanolide B ( 6 ) showed marginal cytotoxic activity against these three cell lines in vitro.     

Polyhydroxylated Steroids from the South China Sea Gorgonian Anthogorgia sp.

Four new polyhydroxylated steroids, namely anthogorgsteroids A–D ( 1 – 4 ), were isolated from the South China Sea gorgonian Anthogorgia sp. The structures of these compounds were elucidated by detailed spectroscopic analyses and comparison with reported data.