A New Lycopodine Alkaloid from Phlegmariurus yunnanensis Ching

A new lycopodine alkaloid, 15α‐methyllycopodane‐5β,6β‐diol N‐oxide ( 1 ), was isolated from the whole plants of Phlegmariurus yunnanensis Ching , together with the two known alkaloids 15α‐methyllycopodane‐5β,6β‐diol ( 2 ) and lycoposerramine H ( 3 ), and four serratene‐type triterpenoids, serratenediol‐3‐acetate ( 4 ), serratenediol ( 5 ), lycocryptol ( 6 ), and serratriol ( 7 ). Their structures were elucidated on the basis of spectroscopic analyses, including HR‐ESI‐MS, ¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, HSQC, HMBC, and NOESY.     

Triterpenoids from the Stems of Schisandra glaucescens

Two new lanostane triterpenoids, schiglauzic acid ( 1 ) and schiglaucyclozic acid ( 2 ), together with two known ones, anwuweizic acid ( 3 ) and manwuweizic acid ( 4 ), were isolated from the stems of Schisandra glaucescens. Their structures were determined on the basis of extensive spectroscopic methods, including two‐dimensional NMR techniques, and were further confirmed by X‐ray crystallographic analysis.     

Synthesis of novel [3,2-b] furan-fused pentacyclic triterpenoids via gold - Catalyzed intramolecular heterocyclization of 2-alkynyl-3-oxotriterpene acids

A direct and atom-economical synthetic route to new [3,2-b] furan-fused pentacyclic triterpenoids has been developed, using gold-catalyzed 5-exo-dig heterocyclization of accessible 2-alkynyl derivatives of betulonic, ursonic, and oleanonic acids.     

Lanostane Triterpenoid Metabolites from a Penares sp. Marine Sponge Protect Neuro-2a Cells against Paraquat Neurotoxicity

The results of an investigation of the protective effects of five lanostane triterpenoids: 3β-acetoxy-7β,8β-epoxy-5α-lanost-24-en-30,9α-olide (1), 3β-hydroxy-7β,8β-epoxy-5α-lanost-24-en- 30,9α-olide (2), 29-nor-penasterone (3), penasterone (4), and acetylpenasterol (5), from a marine sponge, Penares sp., against paraquat-induced neuroblastoma Neuro-2a cell damage, are described. The influence of all compounds on viability of the Neuro-2a cells treated with paraquat (PQ) was studied with MTT and fluorescein diacetate assays as well as propidium iodide straining. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the compounds as well as their influence on reactive oxygen species (ROS) level and mitochondrial membrane potential in PQ-treated neuronal cells were analyzed. Finally, the effect of the compounds on intracellular level of heat shock protein 70 kDa (Hsp70) and neurite outgrowth in PQ-treated Neuro-2a cells were studied. Studied triterpenoids demonstrated protective effects against PQ-induced neurotoxicity associated with the ability to reduce ROS intracellular level and diminish mitochondrial dysfunction. Acetylpenasterol (5), as a more promising neuroprotective compound, significantly increased the viability of Neuro-2a cells incubated with PQ as well as decreased intracellular ROS level in these cells. Moreover, acetylpenasterol induced Hsp70 expression in PQ-treated cells. It was also shown to inhibit PQ-induced neurite loss and recovered the number of neurite-bearing cells. The relationship between neuroprotective activity of the investigated compounds 1–5 and their chemical structure was also discussed.     

Cyano Enone-Bearing Triterpenoid Soloxolone Methyl Inhibits Epithelial-Mesenchymal Transition of Human Lung Adenocarcinoma Cells In Vitro and Metastasis of Murine Melanoma In Vivo

Introduction of α-cyano α,β-unsaturated carbonyl moiety into natural cyclic compounds markedly improves their bioactivities, including inhibitory potential against tumor growth and metastasis. Previously, we showed that cyano enone-bearing derivatives of 18βH-glycyrrhetinic (GA) and deoxycholic acids displayed marked cytotoxicity in different tumor cell lines. Moreover, GA derivative soloxolone methyl (SM) was found to induce ER stress and apoptosis in tumor cells in vitro and inhibit growth of carcinoma Krebs-2 in vivo. In this work, we studied the effects of these compounds used in non-toxic dosage on the processes associated with metastatic potential of tumor cells. Performed screening revealed SM as a hit compound, which inhibits motility of murine melanoma B16 and human lung adenocarcinoma A549 cells and significantly suppresses colony formation of A549 cells. Further study showed that SM effectively blocked transforming growth factor β (TGF-β)-induced epithelial-mesenchymal transition (EMT) of A549 cells: namely, inhibited TGF-β-stimulated motility and invasion of tumor cells as well as loss of their epithelial characteristics, such as, an acquisition of spindle-like phenotype, up- and down-regulation of mesenchymal (vimentin, fibronectin) and epithelial (E-cadherin, zona occludens-1 (ZO-1)) markers, respectively. Network pharmacology analysis with subsequent verification by molecular modeling revealed that matrix metalloproteinases MMP-2/-9 and c-Jun N-terminal protein kinase 1 (JNK1) can be considered as hypothetical primary targets of SM, mediating its marked anti-EMT activity. The inhibitory effect of SM on EMT revealed in vitro was further confirmed in a metastatic model of murine B16 melanoma: SM was found to effectively block metastatic dissemination of melanoma B16 cells in vivo, increase expression of E-cadherin and suppress expression of MMP-9 in lung metastatic foci. Altogether, our data provided valuable information for a better understanding of the antitumor activity of cyano enone-bearing semisynthetic compounds and revealed SM as a promising anti-metastatic drug candidate.     

Mixture of closely related isomeric triterpenoid derivatives: Separation and purification by reversed-phase high-performance liquid chromatography

Summary Twelve triterpenes were isolated from the alcoholic extract ofMentha villosa as their acetyl methyl ester derivatives. This vegetal specimen, which was collected in the Horto de Plantas Medicinais da Universidade Federal do Ceará, Fortaleza, Brazil, is used as popular remedy in the treatment of amebiasis, giardiasis and shistosomiasis. The separation and purification of the triterpenoid derivatives from complex mixtures of closely related isomeric triterpenoid acids has been performed successfully by reversed-phase HPLC.     

Intercedenol A and B, Two New Triterpenoids from the Sea Cucumber Mensamaria intercedens

Two new triterpenoids named intercedenol A and B were isolated from the acid hydrolysate of the crude glycoside fraction. The structures were elucidated by ESI-MS and NMR spectrum.     

Triterpenoids fromAbies species

Two new lanostane lactones were isolated from a neutral part of an ethereal extract of dried needle-free shoots of Siberian fir. Their structures were proposed based on comparison of their¹³C and¹H NMR spectra with the spectra of known triterpenoid lactones with similar structures. For Part 22, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2064–2066, October, 1998.     

Epikatonic acid from Austroplenckia populnea: structure elucidation by 2D NMR spectroscopy and X‐ray crystallography

From the chloroform extract of Austroplenckia populnea, epikatonic acid, friedelin, populnonic acid, abruslactone A, salaspermic acid and 22β‐epi‐maytenfolic acid were isolated. The structure and stereochemistry of epikatonic acid were established by two‐dimensional NMR spectroscopic techniques (HMQC, HMBC and NOESY) and later confirmed by single crystal X‐ray diffraction as 3β‐hydroxy‐olean‐12‐en‐29‐oic acid, which unambiguously established the configuration of the hydroxyl group at C‐3 as 3β‐OH and the carboxyl group at C‐20 as 20α‐COOH. The crystal structure shows two independent molecules in the asymmetric unit. The crystal packing is stabilized by four O–H·O intermolecular hydrogen bonds, which give rise to infinite double chains along the c axis. Copyright © 2002 John Wiley & Sons, Ltd.     

Highly Acetylated Lanostane‐Type Triterpenoids from Coprinus cinereus 120

Two new highly acetylated lanostane‐type triterpenoids, coprinacin A ( 1 ) and coprinacin B ( 2 ), were isolated from the basidiomycetous strain Coprinus cinereus 120. The chemical structures of 1 and 2 were elucidated by spectroscopic analyses, including 1D‐ and 2D‐NMR experiments and FT‐ICR‐MS, and their in vitro cytotoxic activities against the human‐tumor cell line HeLa were established as modest.