Neoclerodane Diterpenes fromAmoora stellato-squamosa

Natural Product 2-Oxokolavenol Is a Novel FXR Agonist

Acetaminophen (APAP) toxicity is a common cause of hepatic failure, and the development of effective therapy is still urgently needed. Farnesoid X receptor (FXR), a member of the nuclear receptor superfamily, has been identified as a master gene for regulating enterohepatic metabolic homeostasis and has proven to be a promising drug target for various liver diseases. Through high-throughput chemical screening, the natural product 2-oxokolavenol was identified as a novel and selective FXR agonist. Further investigations revealed that 2-oxokolavenol exerts therapeutic efficacy against APAP-induced hepatocyte damage in an FXR-dependent manner. Mechanistically, 2-oxokolavenol forms two hydrogen bonds with M265 and Y369 of human FXR to compatibly fit into the ligand binding pocket of FXR, which potently leads to the recruitment of multiple co-regulators and selectively induces the transcriptional activity of FXR. Our findings thus not only reveal the direct target of natural product 2-oxokolavenol, but also provide a promising hit compound for the design of new FXR modulators with potential clinical value.

Three new diterpenes from Dysoxylum lukii and their NO production inhibitory activity

Three new diterpenes were isolated from the stems of Dysoxylum lukii Merr and characterized on the basis of spectral data. Neoclerod-13Z-ene-3α, 4β, 15-triol (3) exhibited the inhibition of lipopolysaccharide-induced nitric oxide production in RAW264.7 macrophages with an IC₅₀ value of 25.49 μM.[Formula: see text].

Chemical constituents of Pholidota cantonensis

Two 9,10-dihydrophenanthrenes trivially named phocantol and phocantone, two diterpenoid glycosidesnamed phocantoside A and phocantoside B were isolated from the ethanol extract of the air-dried whole plant of Pholidota cantonensis Rolfe, together with seventeen known compounds. The structures of the four compounds were identified as 1-hydroxy-2,7-dimethoxy-9,10-dihydrophenanthro-[4,5-bcd]furan, 5-hydroxy-2,7-dimethoxy-9,10-dihydro-1,4-phenanthrenedione, (8R,13E)-ent-labd-13-ene-3α,8,15-triol 15-O-β-D-gluco-pyranoside and (5S,8R,9S,10R)-cis-cleroda-3,13(E)-diene-15,18-diol 15-O-β-D-glucopyranosyl-18-O-β-D-glucopyranoside by chemical and spectroscopic methods, including 1D and 2D NMR. Twenty compounds were evaluated for their cytotoxic activities against mouse leukemia p388D1 cancer cells, and compound phocantone, phocantoside A, tanshinone IIA and syringate exhibited cytotoxic activity against the mouse leukemia p388D1 cancer cells with IC₅₀ values ranging from 13.37 to 27.5 μM.

Clerodane diterpenes: sources, structures, and biological activities

Covering: 1990 to 2015The clerodane diterpenoids are a widespread class of secondary metabolites and have been found in several hundreds of plant species from various families and in organisms from other taxonomic groups. These substances have attracted interest in recent years due to their notable biological activities, particularly insect antifeedant properties. In addition, the major active clerodanes of Salvia divinorum can be used as novel opioid receptor probes, allowing greater insight into opioid receptor-mediated phenomena, as well as opening additional areas for chemical investigation. This article provides extensive coverage of naturally occurring clerodane diterpenes discovered from 1990 until 2015, and follows up on the 1992 review by Merritt and Ley in this same journal. The distribution, chemotaxonomic significance, chemical structures, and biological activities of clerodane diterpenes are summarized. In the cases where sufficient information is available, structure activity relationship (SAR) correlations and mode of action of active clerodanes have been presented.