Bioactive monoterpene phenol dimers from the fruits of Psoralea corylifolia L.

Nine undescribed monoterpene phenol dimers, bisbakuchiols D-L (1-9), were isolated from the fruits of Psoralea corylifolia L. Their structures were elucidated based on extensive spectral analysis. The absolute configurations of 1-9 were specified by experimental and quantum chemical calculations of ECD spectra, and that of 1 was further established by X-ray diffraction analysis using Cu Kα radiation. Bisbakuchiols (1-4) were composed of two bakuchiols, one of which was cyclized via a C-7'/ C-12' single bond to form a six-member ring, and connect to each other by C-4-O-C-13' bonds. Bisbakuchiols (7-9) had a pyran ring by linkage of C-8-O-C-12. In the enzyme assay, compounds 5 and 9 exhibited significant PTP1B inhibitory activities with IC50 values of 0.69 and 0.73 µM, and compounds 1 and 3 showed moderate PTP1B inhibitory activities. Furthermore, a molecular docking simulation of PTP1B and active compounds 5 and 9 showed that these active compounds possess low binding affinities ranging from -6.9 to -7.1 kcal/mol.

Neuroprotective triterpene saponins from the leaves of Panax notoginseng.

Two new triterpene saponins, namely notoginsenoside Ng5 (1) and notoginsenoside Ng6 (2) were isolated from the leaves of Panax notoginseng, along with five known ones. Their structures were determined by chemical methods, NMR and X-ray experiments. The absolute configuration of compound 3 with four sugar units was confirmed by single crystal X-ray analysis. Compounds 2-4 and 6 inhibited PC12 cell damage induced by serum deprivation, and increased cell viability from 58.7 ± 6.7% to 66.7 ± 4.5%, 76.1 ± 6.1%, 64.7 ± 5.2% and 67.2 ± 5.0% at 10 µM, respectively.

Bioactive flavonoid dimers from Chinese dragon's blood, the red resin of Dracaena cochinchinensis.

Seven flavonoid dimers, biflavocochins A-G, together with six known compounds were isolated from the red resins of Dracaena cochinchinensis (Chinese dragon's blood). Their structures were elucidated based on extensive spectroscopic analysis. The absolute configurations of 1-7 was assigned by experimental and quantum chemical calculated ECD spectra, and that of 4 was further established by X-ray diffraction analysis using Cu Kα radiation. Compounds 1-3 are novel dimers of homoisoflavonoid and dihydrochalcone with a unique dibenzopyran ring. Compounds 2, 6, 7 exhibited moderate PTP1B inhibitory activities in an enzyme assay. Compound 1 showed neuroprotective effect on serum deficiency-induced cellular damage in PC12 cells.

New 18(4→3)-Abeo-Abietanoids from Tripterygium wilfordii.

Three 18(4→3)-abeo-abietanoids, a new natural product and two new compounds, named tripordolides A⁻C (1⁻3), were isolated from the leaves of Tripterygium wilfordii. Their structures were elucidated on the basis of their spectroscopic analysis, and the absolute configuration of compounds was confirmed by CD and X-ray crystallographic analysis using anomalous scattering of Cu Kα radiation. Compounds 1 and 3 showed moderate inhibitory activities against NO production in lipopolysaccharide-induced (LPS) RAW 264.7 macrophages in vitro.

Hepatoprotective glycosides from the rhizomes of Imperata cylindrical.

Three new C-methylated phenylpropanoid glycosides (1, 2), a new 8-4'-oxyneolignan (3), together with two known analogs (4, 5), were isolated from the rhizomes of Imperata cylindrical Beauv. var. major (Nees) C. E. Hubb. Their structures were determined by spectroscopic and chemical methods. Compounds 1, 2, and 5 (10 µM) exhibited pronounced hepatoprotective activity against N-acetyl-p-aminophenol (APAP)-induced HepG2 cell damage in vitro assays. Furthermore, their antioxidant activities against Fe2+-cysteine-induced rat liver microsomal lipid peroxidation and the effects on the secretion of TNF-α in murine peritoneal macrophages (RAW264.7) induced by lipopolysaccharides were evaluated.

Two new saponins from the leaves of Panax notoginseng.

Two new saponins, notoginsenosides Ng1 (1) and Ng2 (2), together with seven known compounds (3-9), were isolated from the leaves of Panax notoginseng. Their structures were elucidated by UV, IR, HRESIMS, and NMR experiments. Compounds 6 and 7 showed moderate cytotoxic activities against HCT-116, with IC50 values of 4.98 and 0.64 µmol/L, respectively.

Chemical constituents from the stems of Hydrangea paniculata.

Further study on the constituents from the stems of Hydrangea paniculata Sieb resulted in isolation of two new compounds 1-2, including 1 monoterpenoid and 1 phenolic glycoside, along with 10 known compounds. Their structures were elucidated on the basis of spectroscopic data, including UV, IR, MS, and NMR experiments, along with chemical methods. At 10 µM, compounds 1 and 2 exhibited comparable activities with bicyclol in vitro assays for hepatoprotective activity against APAP-induced HepG2 cell damage.

Total synthesis and neuroprotective effect of O-methylmurrayamine A and 7-methoxymurrayacine.

O-Methylmurrayamine A (7) and 7-methoxymurrayacine (8) are natural products isolated from Murraya koenigii and Murraya siamensis, respectively. In this paper, we report the synthesis of 7 and 8 which are featured in the key step of cyclization to form carbazole intermediate 5 with mild conditions. The structures were confirmed by 1H NMR, 13C NMR, and HR-ESI-MS. In addition, compounds 7 and 8 were tested for their neuroprotective effects against H2O2-induced PC12 cell damage. The results showed that compounds 7 and 8 have neuroprotective effect.

Three new coumarin glycosides from the stems of Hydrangea paniculata.

Three new coumarin glycosides (1-3), together with three known compounds (4-6), have been obtained from the stems of Hydrangea paniculata Sieb. Their structures were elucidated based on spectroscopic data and chemical evidence. In addition, compounds 1-3 were screened for their neuroprotective effects against serum deprivation-induced PC12 cell damage, hepatoprotective activities against DL-galactosamine-induced toxicity in HL-7702 cells and their ability to inhibit LPS-induced nitric oxide production in the murine microglia BV2 cell line, but they were inactive.

Anti-inflammatory pentacyclic triterpenes from the stems of Euonymus carnosus.

Three new lupane-type triterpenoids (1-3), three new oleane-type triterpenoids (4-6), as well as two known compounds (7-8) were isolated from Euonymus carnosus. The structures of the compounds were elucidated on the basis of spectroscopic data analyses, including UV, IR, MS, and NMR experiments. The inhibitory on LPS-induced NO production in microglia BV2 cells of compounds 1-8 were also evaluated. Compounds 1 and 2 showed moderate abilities to inhibit NO production, with IC50 values of 5.99 and 8.47µM, respectively.

New Phenylpropanoid and Coumarin Glycosides from the Stems of Hydrangea paniculata Sieb.

A new phenylpropanoid glycoside (1), and two new coumarin glycosides (2, 3), together with two known compounds (4, 5), have been isolated from the stems of Hydrangea paniculata Sieb. Their structures have been determined by spectroscopic and chemical methods. Furthermore, compound 1 (50 µM) exhibited significant hepatoprotective activity against N-acetyl-p-aminophenol (APAP)-induced HepG2 cell damage in vitro assays.

Bioactive isopimarane diterpenoids from the stems of Euonymus oblongifolius.

Seven isopimarane diterpenes and one abietane diterpene, together with six known sesquiterpene derivatives, were isolated from the stems of Euonymus oblongifolius. Their structures were elucidated on the basis of spectroscopic analyses, and the absolute configuration of euonymusisopimaric acid A was confirmed by single-crystal X-ray crystallographic analysis using anomalous scattering of Cu Kα radiation. All of the isolated compounds were evaluated for their ability to inhibit LPS-induced nitric oxide production in the murine microglia BV2 cell line, and for their cytotoxic activity against five human cancer cell lines. Euonymusisopimaric acids A, E and F inhibited LPS-induced nitric oxide production in the murine microglia BV2 cell line, with IC50 values of 2.4, 4.8, and 1.6 µM, respectively. Euonymusisopimaric acid B exhibited moderate cytotoxicity against A549 cell line growth, with an IC50 value of 2.6 µM.

Bioactive Coumarins from the Stems of Clausena emarginata.

Five new coumarins, clauemarmarins I - M (1 - 4), together with 10 known analogs (5 - 14), were isolated from the stems of Clausena emarginata. Compounds 8 - 13 were obtained from this plant for the first time. Their structures were established and elucidated by comprehensive analysis of spectroscopic data. The absolute configurations of 1 - 4 were further determined by their electronic circular dichroism spectroscopy. Compounds 5, 7, 12, and 14 exhibited inhibitory effects on LPS-induced NO production. Compounds 5 - 7 showed selective neuroprotective effects in Aß25 - 35 model at 10 µm.

Hepatoprotective pyranocoumarins from the stems of Clausena emarginata.

Seven pyranocoumarins, clauemarmarins A-G, along with 6 known analogues were isolated from the stems of Clausena emarginata. Their structures were elucidated by extensive spectroscopic analyses, and the absolute stereochemistries at C-6″ of clauemarmarin B, C and D and the absolute configurations of clauemarmarin E, F and G were determined by ECD experiments. Compounds clauemarmarin C, D and two known analogues exhibited hepatoprotective activities against DL-galactosamine-induced damage in WB-F344 cells at the concentration of 10 µM.

Limonoids with neuroprotective activity from the stems of Clausena emarginata.

Two new limonoids, clauemargines M-N (1-2), together with five known compounds (3-7), were isolated from the stems of Clausena emarginata, and compounds 6 and 7 were gained from this plant for the first time. Their structures were established and elucidated on the basis of comprehensive spectroscopic analysis. The absolute configurations of 1-2 were further determined by the octant rule of saturated cyclic ketone. Compounds 1, 2, 4, and 5 showed moderate neuroprotective effects against L-glutamic acid-induced cellular damage in human neuroblastoma SK-N-SH cells at 10 µM.

Three new lignanosides from the aerial parts of Lespedeza cuneata.

Three new lignanosides (+)-(8S,7'S,8'S)-burselignan-9'-O-ß-d-glucopyrano side (1), (+)-(8R,7'S,8'R)-isolariciresinol-9'-O-ß-d-fucopyranoside (2), (-)-(8S, 7'R,8'R)-methoxyisoariciresinol-9'-O-α-l-rhamnoside (3), along with four known compounds, were isolated from the aerial parts of Lespedeza cuneata (Dum.Cours.) G.Don. The fucopyranoside has not been reported in this genus previously. Their structures and absolute configurations were elucidated on the basis of comprehensive spectroscopic analyses (UV, IR, HR-ESI-MS, 1D and 2D NMR, CD), as well as by comparison with known analogues in the literature. Compounds 2 and 6 showed moderate hepatoprotective activities.

Phenylpropanoid and lignan glycosides from the aerial parts of Lespedeza cuneata.

Four phenylpropanoid glucosides (1-4) and five lignan glycosides (5-9) were isolated from the aerial parts of Lespedeza cuneata, together with three known lignan glycosides (10-12). Their structures were elucidated on the basis of spectroscopic analyses, and the absolute configurations of compounds 5-9 were determined from the CD spectra. In addition, the compounds were tested for their ability to activate the transcription effect on xbp1 promoter. Compounds 4, 5, 7, 9, 10, and 12 could activate the transcription of xbp1 to varying degrees, with EC50 values ranging from 0.18 to 0.64 µM.

Carbazole and amide alkaloids from the stems of Clausena lansium.

Two new carbazole alkaloids, claulansine S (1) and claulansine T (2), and one new amide alkaloid, clauamide A (3), together with four known analogues (4-7) were isolated from the stems of Clausena lansium. Their structures were elucidated on the basis of spectroscopic analyses, including UV, IR, and NMR experiments (HSQC, HMBC, and NOE experiments). Compounds 4 and 6 showed moderate hepatoprotective activities.

Monoterpenes from the leaves of Hydrangea paniculata and their hepatoprotective activities.

Three new monoterpenes, hydrangines A-C (1-3), together with four known compounds, were isolated from the ethanol extract of the leaves of Hydrangea paniculata. The structures of new isolates were elucidated on the basis of extensive 1D and 2D NMR analyses, and their absolute configurations were determined by comparison of experimental and calculated electronic circular dichroism spectra. In in vitro bioassays at 10 µM, compounds 1-6 showed hepatoprotective activities against dl-galactosamine-induced toxicity in HL-7702 cells.

Clauemarazoles A-G, seven carbazole alkaloids from the stems of Clausena emarginata.

Seven new carbazole alkaloids, clauemarazoles A-G, together with 19 known analogues were isolated from the stems of Clausena emarginata. Their structures were established on the basis of spectroscopic analyses, and the absolute configurations of compounds 1a, 1b, 5a, and 5b were confirmed by their ECD spectroscopy. Compounds 4, 13, 15, and 17 exhibited inhibitory abilities on LPS-induced NO production. Compounds 10-12, 20, 22, and 24 displayed hepatoprotective effects against DL-galactosamine-induced damage in WB-F344 cells.