One undescribed and six known abietane diterpenoids were isolated as ligands for aryl hydrocarbon receptor (AhR) from leaves of Salvia officinalis, a folk medicine in the Mediterranean Sea area. The structure diterpenoid named (+)-(10R)-11,14-dioxoabieta-8,12-diene-12,20-diol was assigned by 1D/2D NMR spectroscopic HR-ESI-MS data. AhR ligand activity evaluated AhR-dependent luciferase reporter ...

A known ent-kaurane diterpenoid, ent-19-al-17,16β-dihydroxykaurane (1), together with the new one, ent-3β, 16β, 19-trihydroxykaurane (2), called leptophyllin, were isolated from aerial parts of Baccharis leptophylla. Their structures were established on the basis of NMR spectroscopic analysis. Based on this study the H and C NMR spectral data of compound (1) were completed by means of 2D NMR te...

A new halimane-type diterpenoid, echinohalimane A (1), was isolated from a gorgonian, identified as Echinomuricea sp. The structure of 1 was determined by spectroscopic methods and this compound was found to exhibit cytotoxicity toward various tumor cells and display an inhibitory effect on the release of elastase by human neutrophils. Echinohalimane A (1) is the first halimane analogue from th...

Chemical investigation into the minor constituents of Aphanamixis grandifolia yielded three new diterpenoid dimers, aphadilactones E-G (1-3) featuring a new carbon skeleton. Their structures and absolute configurations were fully established by comprehensive spectroscopic data analysis and ECD calculation. Discovery of another two new dimers (4 and 5) suggested the structure of recently reporte...

A short and efficient synthesis of the antitumor diterpenoid (+)-zerumin B has been accomplished starting from (+)-sclareolide. At the heart of the synthetic strategy lies the regioselective formation of the alpha-substituted gamma-hydroxybutenolide moiety of zerumin B. This was achieved by means of a [1,4] O-->C triisopropylsilyl migration followed by singlet oxygen (1 O 2) oxidation of the re...

The title compound, enmenol, C(20)H(30)O(6), a natural ent-kaurane diterpenoid, comprises five fused rings, four of which are six-membered. Cyclo-hexane ring A adopts a chair conformation, rings B and C adopt boat conformations, while ring D has an envelope conformation, and two intramolecular O-H⋯O interactions occur. In the crystal, inter-molecular O-H⋯O hydrogen bonds generate a two dimensio...

Tinospora cordifolia (Guduchi) is an important herb in folk and ayurvedic systems of medicine. This paper presents a critical review on chemical and biological properties of Tinospora cordifolia. Tinospora cordifolia contain various chemical constituents belonging to different classes such as alkaloids, diterpenoid lactones, glycosides and steroids. The most important biological properties repo...

Clerocidin, a diterpenoid natural product, has been shown in vitro to inhibit DNA religation following cleavage by topoisomerase II. Herein, we characterize the efficacy and specificity of clerocidin in HeLa cells. Our results suggest that clerocidin recognizes topoisomerase II as its main intracellular target and binds to this enzyme prior to formation of the 'cleavable complex' with DNA. Thes...

A novel 18-nor-clerodane diterpenoid named sagitone (1) was isolated from the 95% ethanol extract of dry roots of Tinospora sagittata var. yunnanensis together with the five known diterpenoids columbin (2), palmatoside C (3), fibleucin (4), tinophylloloside (5) and epitinophylloloside (6). The structure of the new compound 1 was determined based on MS, IR, 1D and 2D NMR spectral data. The compo...