Triterpenoid saponins from Bupleurum marginatum and their anti-liver fibrotic activities.

A new triterpenoid saponin (1), along with five known compounds (2-6), was isolated from Bupleurum marginatum Wall. ex DC, of which compounds 2-4 were obtained for the first time from this plant. The structures were confirmed by the analysis of 1D, 2D NMR, and HR-ESIMS data, and comparison with previous spectral data. Anti-liver fibrotic activities of the isolates were determined as proliferation inhibition of LPS-induced activation of HSC-T6 in vitro.

[Cembranoids and their bioactivities in soft coral Sarcophyton glaucum].

Chemical constituents in soft coral Sarcophyton glaucum were separated and purified by various chromatographic methods. Based on the spectral data, physicochemical properties, and comparison with the data reported in the literature, nine cembranoids, including a new cembranoid named sefsarcophinolide(1) together with eight known cembranoids, namely(+)-isosarcophine(2), sarcomilitatin D(3), sarcophytonolide J(4),(1S,3E,7E,13S)-11,12-epoxycembra-3,7,15-triene-13-ol(5), sarcophytonin B(6),(-)-eunicenone(7), lobophytin B(8), and arbolide C(9), were identified. As revealed by biological activity experiment results, compounds 2-6 had weak acetylcholinesterase inhibitory activity, and compound 5 displayed weak cytotoxicity against K562 tumor cell line.

Bisabolanoic acid A, a new polychiral sesquiterpene with AChE inhibitory activity from a mangrove-derived fungus Colletotrichum sp.

A new polychiral bisabolane sesquiterpene, bisabolanoic acid A (1), was isolated from the mangrove-derived fungus Colletotrichum sp. SCSIO KcB3-2. Its planar structure was identified on the basis of spectroscopic data analysis (HRESIMS, 1D, and 2D NMR), and the absolute configurations of three chiral carbons were determined by experimental and calculated electronic circular dichroism (ECD) and optical rotatory dispersion (ORD), together with Mo2(OAc)4-induced ECD methods. Bisabolanoic acid A (1) showed moderate inhibitory activity against acetylcholinesterase (AChE) with IC50 value of 2.2 µM, and the in silico molecular docking was also performed.

Two new 2-phenylethylchromones from artificial agarwood by holing method.

Two new 2-(2-phenylethyl)chromone derivatives (1-2) were isolated from the ethyl acetate extract of artificial agarwood induced by holing method originating from Aquilaria sinensis (Lour.) Gilg, and they were isolated from this genus for the first time. The structures of these two new compounds were elucidated by extensive spectroscopic analyses, including UV, IR, one- and two-dimensional NMR and HRESIMS measurements. Bioassay tests of these two new compounds showed compounds 1 and 2 had weak inhibitory activity against acetylcholinesterase at a concentration of 50.0 µg/ml.

Two new terpenoids from the stems of Manihot esculenta.

A new eremophilane sesquiterpene, sporogen AO-2 (1), and a new beyerane diterpene, thecacorin C (2), together with two known compounds, longifoamide-B (3) and methylcholestane-3ß,5α,6ß-triol (4), were isolated from the stems of Manihot esculenta. The structures of the two new compounds were determined by spectroscopic techniques (UV, IR, MS, 1D, and 2D NMR). Antimicrobial assay showed that compound 3 possessed modest inhibitory effects on Saphylococcus aureus and methicillin-resistant S.aureus, diameters of inhibition zones of which were 7.5 and 8.0 mm, respectively. Compound 4 possessed modest inhibitory effect on S. aureus, the diameter of inhibition zone of which was 6.8 mm.

2-(2-phenylethyl)chromone derivatives in Chinese agarwood "Qi-Nan" from Aquilaria sinensis.

Five new 2-(2-phenylethyl)chromone derivatives, qinanones A-E (1-5), together with eight known 2-(2-phenylethyl)chromone derivatives (6-13), were isolated from the Et2O extract of high-quality Chinese agarwood "Qi-Nan" originating from Aquilaria sinensis. The structures of the new 2-(2-phenylethyl)chromones were elucidated by spectroscopic techniques (UV, IR, 1D and 2D NMR) and MS analyses. In the bioassay for acetylcholinesterase inhibitors, compounds 1-6, 10, and 12 exhibited weak inhibitory activities (inhibition percentage ranged from 10 % to 24 % at the concentration of 50 µg/mL). Compared with other agarwoods, "Qi-Nan" was different in containing 2-(2-phenylethyl)chromones with unsubstituted chromone rings.

A new antibacterial denitroaristolochic acid from the tubers of Stephania succifera.

A new denitroaristolochic acid, demethylaristofolin C (1), together with six known alkaloids, crebanine N-oxide (2), (-)-sukhodianine-ß-N-oxide (3), palmatine (4), corydalmine (5), dehydrocorydalmine (6), and corynoxidine (7), was isolated from the tubers of Stephania succifera. The structure of demethylaristofolin C was elucidated by spectroscopic techniques (UV, IR, 1D, and 2D NMR) and HR-ESI-MS analyses. These compounds exhibited antibacterial activities against Staphylococcus aureus and methicillin-resistant S. aureus strains in different degrees.

A new antibacterial phenanthrenequinone from Dendrobium sinense.

A new phenanthrenequinone, named denbinobin B (1), together with three known phenanthrenes was isolated from the whole plant of Dendrobium sinense T. Tang et F.T. Wang, an endemic and endangered orchid to Hainan Island. The new compound was elucidated using a combination of 1D, 2D NMR (COSY, HMQC, and HMBC) techniques, and HR-ESI-MS analyses. Compound 1 exhibited moderate antibacterial activity against Staphylococcus aureus with the diameter of the inhibition zone of 16.5 mm.

Two new acridone alkaloids from the branch of Atalantia buxifolia and their biological activity.

Two new acridone alkaloids, 3-methoxy-1,4,5-trihydroxy-10-methylacridone (1) and 2,3-dimethoxy-1,4,5-trihydroxy-10-methylacridone (2), were isolated from the ethanol extract of the branch of Atalantia buxifolia. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR. Compounds 1 and 2 exhibited significant antibacterial activity against Staphylococcus aureus and weak inhibitory effect on acetylcholinesterase.

Characterization and determination of 2-(2-phenylethyl)chromones in agarwood by GC-MS.

Agarwood is the fragrant resinous heartwood obtained from certain trees in the genus Aquilaria belonging to the family Thymelaeaceae. 2-(2-Phenylethyl)chromones and characteristic sesquiterpenes are the main classes of aromatic compounds isolated from agarwood. Although there are many sesquiterpenes, relatively few 2-(2-phenylethyl)chromones have been determined in agarwood by GC-MS. After analysis of the MS spectra of eighteen 2-(2-phenylethyl)chromone derivatives isolated from agarwood and identified by NMR spectroscopy, together with the reported MS data and characteristic of structures of 2-(2-phenylethyl)chromones, the MS characterization, fragmentation patterns and characteristic fragment peaks for the compounds were deduced and a table summarizing MS characterization of 2-(2-phenylethyl)chromones in agarwood is presented. All the 2-(2-phenylethyl)chromones previously reported in agarwood are substituted by methoxy or/and hydroxy groups, except for one compound. Due to the fact they all possess the same basic skeleton (molecular weight: 250) and similar substituent groups (methoxy or hydroxy groups), a formula (30m + 16n = MW - 250) is provided to calculate the number of methoxy (m) or hydroxy (n) groups according to molecular ion peak or molecular weight (MW). We deduced that the characteristic fragmentation behaviors of the 2-(2-phenylethyl)chromones are the cleavages of the CH2-CH2 bond between chromone moiety and phenyl moiety. Thus, characteristic fragment ions, such as m/z 91 [C7H7], 107 [C7H6+OH], 121 [C7H6+OCH3], 137 [C7H5+OH+OCH3] are formed by different substituted benzyl moieties, while characteristic fragment ions such as m/z 160 [C10H8O2], 176 [C10H7O2+OH], 190 [C10H7O2+OCH3], 220 [C10H6O2+OCH3×2] are formed by different substituted chromone moieties. Furthermore, rules regarding to the relationship between the positions of hydroxy or methoxy groups and the relative abundances of benzyl and chromone fragment ions have been deduced. Elucidation of how the positions of hydroxy or methoxy groups affect the relative abundances of benzyl and chromone fragment peaks is also provided. Fifteen unidentified compounds of an artificial agarwood sample analyzed by GC-MS, were preliminary determined as 2-(2-phenylethyl)chromones by analysis of their MS characterization and by comparison of their MS spectra with those of 18 standard compounds or 2-(2-phenylethyl)chromones reported in literature according to the above-mentioned methods and rules. This report will be helpful for the analysis and structural elucidation of 2-(2-phenylethyl)chromones in agarwood by GC-MS, and provides fast and reliable characterization of the quality of agarwood.

[Spectral characteristics of white organic light-emitting devices based on phosphorescent system of three iridium chelates].

A white organic light-emitting device (WOLED) with a yellow phosphorescence material, bis[2-(4-tertbutylphenyl) benzothiazolato-N,C2 '] iridium (acetylacetonate) [(t-bt)2Ir(acac)], and two blue phosphorescence materials, iridium(Ill) bis (4', 6'-difluorophenylpyridinato) tetrakis(1-pyrazolyl) borate (FIr6) and bis[(4, 6-difluorophenyl)-pyridinato-N, C2 '] (picolinate) iridium (III) (FIrpic), were fabricated. Stable white emission was realized by using undoped ultrathin yellow emissive layer (EML), two doped blue EMLs together with the proper thickness of an interlayer confining the exciton. The WOLED performed pure white light emission with the Commissions Internationale de l'Eclairage (CIE) coordinates of (0.29+/-0.01, 0.34+/-0.01) from 6 to 14 V. Moreover, electroluminescence (EL) characteristics of the devices were also studied to verify the emissive mechanism from a phosphorescent system consisting of three iridium chelates. Also, the results showed that the triple-phosphor-element EMLs WOLED had lower efficiency roll-off owing to the stable recombination zone.

Two new triterpenoid saponins from Bupleurum marginatum Wall. ex DC.

Two new triterpenoid saponins (1 and 2), together with two known saponins (3 and 4) were isolated from Bupleurum marginatum Wall. ex DC. Their structures were elucidated by the comprehensive spectroscopic analysis. Compounds 1 and 2 represented the rare example of an oleanane-type triterpenoid with two sugar moieties at C-3 and C-28. The cytotoxic activity of four compounds was evaluated against normal heptocell BRL-3A in vitro.

A fatty acid glycoside from a marine-derived fungus isolated from mangrove plant Scyphiphora hydrophyllacea.

To study the antimicrobial components from the endophytic fungus A1 of mangrove plant Scyphiphora hydrophyllacea Gaertn. F., a new fatty acid glucoside was isolated by column chromatography from the broth of A1, and its structure was identified as R-3-hydroxyundecanoic acid methylester-3-O-α-l-rhamnopyranoside (1) by spectroscopic methods including 1D and 2D NMR (HMQC, (1)H-(1)H COSY and HMBC) and chemical methods. Antimicrobial assay showed compound 1 possessed modest inhibitory effect on Saphylococcus aureus and methicillin-resistant S. aureus (MRSA) using the filter paper disc agar diffusion method.

Meroterpenes from endophytic fungus A1 of mangrove plant Scyphiphora hydrophyllacea.

Four new meroterpenes, guignardones F-I (1-4), together with two known compounds guignardones A (5) and B (6) were isolated from the endophytic fungus A1 of the mangrove plant Scyphiphora hydrophyllacea. Their structures and relative configurations were elucidated by spectroscopic data and single-crystal X-ray crystallography. A possible biogenetic pathway of compounds 1-6 was also proposed. All compounds were evaluated for inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus.

A new sesquiterpene lactone from Elephantopus tomentosus.

A new sesquiterpene lactone, named tomenphantopin H (1), together with two known germacranolides, 2ß-methoxy-2-deethoxy-8-O-deacylphantomolin-8-O-tiglinate (2) and 2-deethoxy-2-hydroxyphantomolin (3), was isolated from the whole plant of Elephantopus tomentosus Linn. The new compound was completely elucidated using a combination of 1D and 2D NMR techniques (COSY, HMQC, and HMBC) and HR-ESI-MS analyses. All compounds exhibited antibacterial activity.

Two new meroterpenes from endophytic fungus A1 of Scyphiphora hydrophyllacea.

Two new meroterpenes, guignardone D (1) and guignardone E (2), were isolated from endophytic fungus A1 of Scyphiphora hydrophyllacea Gaertn. F. Their structures were established based on spectroscopic methods including 1D and 2D NMR (HMQC, (1)H-(1)H COSY, HMBC, and ROESY).

A new tetranortriterpenoid from the roots of Atalantia buxifolia.

A new tetranortriterpenoid, named 6-deacetyl-severinolide, together with six known tetranortriterpenoids severinolide, acetyl-isoepiatalantin, 7-isovaleroylcycloepiatalantin, cycloepiatalantin, 7-isovaleroylcycloseverinolide, and atalantin, was isolated from the ethanol extract of the roots of Atalantia buxifolia collected in Hainan. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR (HMQC, ¹H-¹H COSY, HMBC, and NOESY).

Two new triterpenoid saponins from the leaves of Ilex kudingcha.

Two new triterpene saponins, ilekudinchosides F (1) and G (2), along with three known saponins were isolated from the leaves of Ilex kudingcha C. J. Tseng. The new compounds were characterized as 3ß,19α-dihydroxy-12α-ethoxy-urs-13(18)-ene-28,20ß-lactone-3-O-[ß-D-glucopyranosyl(1 → 3)]-[α-L-rhamnopyranosyl(1 → 2)]-α-L-arabinopyranoside (1) and 3ß,19α-dihydroxy-12α-methoxy-urs-13(18)-ene-28,20ß-lactone-3-O-[α-L-rhamnopyranosyl(1 → 2)]-α-L-arabinopyranoside (2). The new structures were elucidated by spectroscopic methods including 1D and 2D NMR, HR-TOF-MS, and CD spectrometry, and the known compounds were identified by the comparison of their NMR and HR-TOF-MS data with those reported in the literature.

Cytotoxic and antibacterial flavonoids from dragon's blood of Dracaena cambodiana.

Chemical studies on the constituents from the dragon's blood of Dracaena cambodiana led to the discovery of three new flavonoid derivatives (1- 3) and six known compounds (4- 9). The structures of the three new compounds were elucidated by NMR and MS spectroscopic analyses. All compounds were evaluated for their growth inhibitory activity against human cell lines K-562, SMMC-7721, and SGC-7901, as well as antibacterial activities against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA). As a result, compounds 1, 2, 5, 7, and 9 showed cytotoxicity against K-562, SMMC-7721, and SGC-7901 cell lines. All these compounds were observed to exhibit antibacterial activities against S. aureus, and compounds 1- 4, 6, 8, and 9 were observed to exhibit antibacterial activity against MRSA.

Cytotoxic cardenolide glycosides from the seeds of Antiaris toxicaria.

Bioassay-guided fractionation of the ethanolic extract from the seeds of Antiaris toxicaria led to the isolation of three new cardiac glycosides named toxicarioside J, toxicarioside K, and toxicarioside L, together with a known glucostrophalloside. The structures of the new compounds were elucidated by spectroscopic methods including HRESIMS, UV, IR, and 1D, 2D NMR techniques. The cytotoxic activities of these cardiac glycosides against human gastric (SGC-7901) and human hepatoma (SMMC-7721) cell lines were evaluated, and all of them exhibited significant cytotoxicity.