Diterpenoid and phenolic constituents from corn silk (Zea mays) with PTP1B inhibitory activity.

Chemical investigation of corn silk resulted in the isolation of nine secondary metabolites, including a new ent-kaurane diterpenoid, zeamaysditerpene A (1) and eight known compounds, stigmaydene A (2), stigmaydene J (3), stigmaydene L (4), stigmane D (5), demethyltorosaflavone D (6), chrysoeriol 6-C-ß-boivinopyranosyl-7-O-ß-D-glucopyranoside (7), deoxypodophyllotoxin (8), and α-peltatin glucoside (9). Their structures were elucidated using a combination of spectroscopic methods, including 1D and 2D NMR and HRESIQTOF mass spectra. The absolute configuration of 1 was deduced by applying electronic circular dichroism (ECD) calculation method. Among the isolates, only 6 displayed significant inhibition against PTP1B activity in a dose-dependent manner, with an IC50 value of 10.7 ± 0.1 µM. Furthermore, molecular docking simulation was carried out to explore the action perspective of 6 inside the enzyme PTP1B. This finding suggests that 6 might be a potential lead for the development of a new anti-diabetic agent.

Isoryanodane diterpene derivatives from Barringtonia macrocarpa.

From the MeOH residue of Barringtonia macrocarpa branches and leaves, one new isoryanodane diterpene, barringisol (1), and two new isoryanodane diterpene glucosides, barringisosides A and B (2 and 3), were obtained using various chromatographic isolations. The structural characterization was confirmed by spectroscopic methods including 1D, 2D NMR and HR-ESI-QTOF-MS. This is the first isolation of isoryanodane diterpene derivatives from Barringtonia species. Moreover, the in vitro cytotoxicity of 1-3 on three human cancer cell lines (HepG2, LNCaP and MCF7) was also accessed using SRB assays.

Phenolic Glycosides from the Leaves of Iodes cirrhosa Turcz. with Cytotoxic and Antimicrobial Effects.

In the present study, 14 phenolic glycosides, including one new neolignan glycoside, iodescirrhoside A (1), three new flavonol glycosides, iodescirrhosides B-D (2-4), and 10 known metabolites were obtained from the methanol extract of Iodes cirrhosa leaves. Structural elucidation was performed by interpretating the 1D- and 2D- NMR, HR-ESI-MS, and CD spectra in comparison with literature data. All compounds were noncytotoxic to LU-1, HepG2, MCF-7, SK-Mel-2, and LNCaP cancer cell lines. Compound 11 significantly inhibited the growth of E. faecalis. In contrast, weak inhibition was observed for 1-9 and 14 against E. faecalis, for 1, 6-8, and 11 against S. aureus, for 6 and 13 against B. cereus, and 2, 4, and 6-9 against C. albicans.

Three new muurolane-type sesquiterpene glycosides from the whole plants of Balanophora fungosa subsp. indica.

Three new muurolane type sesquiterpene glycosides, named balanoindicosides A - C (1 - 3), were isolated from the whole plant of Balanophora fungosa subsp. indica using various chromatographic methods. Their structures were determined by extensive analysis of HR-ESI-MS and NMR spectroscopy. The stereochemistry of muurolane sesquiterpene backbone was demonstrated by NOESY analysis. Configuration of C-12 in compounds 2 and 3 could be distinguished by chemical shift value of C-14. Compounds 1-3 exhibited weak cytotoxic activity towards HepG-2, HL-60, LU-1, and MCF-7 cell lines.

Anti-inflammatory coumarins from Paramignya trimera.

CONTEXT: Paramignya trimera (Oliv.) Burkill (Rutaceae) has been used to treat liver diseases and cancer. However, the anti-inflammatory effects of this medicinal plant and its components have not been elucidated. OBJECTIVE: This study investigated chemical constituents of the P. trimera stems and evaluated anti-inflammatory effects of isolated compounds. MATERIALS AND METHODS: Cytotoxicity of isolated compounds (5-40 µM) toward BV2 cells was tested using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) for 24 h. Inhibitory effects of isolated compounds (5-40 µM) on nitrite and PGE2 concentrations were determined using Griess reaction and PGE2 ELISA kit, respectively (pretreated with the compounds for 3 h and then stimulated for 18 h with LPS). Inhibitory effects of compounds (5-40 µM) on iNOS and COX-2 protein expression were evaluated by Western blot analysis (pretreated with the compounds for 3 h and then stimulated for 24 h with LPS). RESULTS: Seven coumarins were isolated and identified as: ostruthin (1), ninhvanin (2), 8-geranyl-7-hydroxycoumarin (3), 6-(6',7'-dihydroxy-3',7'-dimethylocta-2'-enyl)-7-hydroxycoumarin (4), 6-(7-hydroperoxy-3,7-dimethylocta-2,5-dienyl)-7-hydroxycoumarin (5), 6-(2-hydroxyethyl)-2,2-dimethyl-2H-1-benzopyran (6), and luvangetin (7). Compounds 1-4 and 7 inhibited NO and PGE2 production in LPS-stimulated BV2 cells, with IC50 values ranging from 9.8 to 46.8 and from 9.4 to 52.8 µM, respectively. Ostruthin (1) and ninhvanin (2) were shown to suppress LPS-induced iNOS and COX-2 protein expression. DISCUSSION AND CONCLUSION: The present study provides a scientific rationale for the use of P. trimera in the prevention and treatment of neuroinflammatory diseases. Ostruthin and ninhvanin might have potential therapeutic effects and should be considered for further development as new anti-neuroinflammatory agents.