Synthesis of Tetrahydrocarbazol-4-ones via Rh(III)-Catalyzed C-H Activation/Annulation of Arylhydrazines with Iodonium Ylides.

The rhodium(III)-catalyzed C-H activation followed by intramolecular annulation reactions between arylhydrazines and iodonium ylides under suitable conditions has been described. Tetrahydrocarbazol-4-ones are readily achieved with moderate to excellent yields. The synthetic protocol features a wide range of substrates with high functional group tolerance. The gram-scale reaction and derivatization of the product demonstrate the synthetic practicality and utilization of this method.

Poly(3,4-ethylenedioxythiophene) Bearing Pyridylboronic Acid Group for Specific Recognition of Sialic Acid.

Conducting polymers tethered with molecular recognition elements are good candidates for biosensing applications such as detecting a target molecule with selectivity. We develop a new monomer, namely, 3,4-ethylenedioxythiophene bearing a pyridylboronic acid moiety (EDOT-PyBA), for label-free detection of sialic acid as a cancer biomarker. PyBA, which is known to show specific binding to sialic acid in acid conditions is used as a synthetic ligand instead of lectins. PyBA confirms the enhanced binding affinity for sialic acid at pH 5.0-6.0 compared with traditional phenylboronic acid. Poly(EDOT-PyBA) is electrodeposited on a planar glassy carbon electrode and the obtained film is successfully characterized by X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, water contact angle measurements, and electrochemical impedance spectroscopy. The specific interaction of PyBA with sialic acid at the solution/electrode interface is detected by differential pulse voltammetry in a dynamic range 0.1-3.0 mM with a detection limit of 0.1 mM for a detection time of 3 min. The sensitivity covers the total level of free sialic acid in human serum and the assay time is the shorter than that of other methods. The poly(EDOT-PyBA) electrode successfully detects spiked sialic acid in human serum samples. Owing to its processability, mass productivity, and robustness, polythiophene conjugated with "boronolectin" is a candidate material for developing point-of-care and wearable biosensors.

Two New Compounds from Artemisia sacrorum.

Two new compounds, named as sacric acid A (1) and sacric acid B (2), were isolated from the EtOAc extract of Artemisia sacrorum Ledeb. This is the first report on the structure elucidation of these compounds based on UV, IR, and extensive ID and 2D NMR spectroscopic, and ESI-MS techniques.

Anti-inflammatory effects, nuclear magnetic resonance identification, and high-performance liquid chromatography isolation of the total flavonoids from Artemisia frigida.

The aerial parts of Artemisia frigida Willd. are used to treat joint swelling, renal heat, abnormal menstruation, and sore carbuncle. The anti-inflammatory effects of A. frigida have been well-known in folk medicine, suggesting that components extracted from A. frigida could potentially treat inflammatory disease. With the aim of discovering bioactive compounds, in this study, we extracted total flavonoids from the aerial parts of A. frigida and investigated their anti-inflammatory effects against inflammation induced by carrageenan and egg albumin in rats. At the doses studied, total flavonoids (100 mg/kg, 200 mg/kg, and 400 mg/kg) and some isolated compounds (30 mg/kg) showed significant and dose-dependent anti-inflammatory effects. According to the high-performance liquid chromatography analysis of the total flavonoids from A. frigida, there are five major compounds, namely, 5-hydroxy-3',4'-dimethoxy-7-O-ß-d-glucuronide (F1), 5-hydroxy-3',4',5'-trimethoxy-7-O-ß-d-glucuronide (F2), 5,7,3'-trihydroxy-6,4'-dimethoxyflavone (F3), 5,3'-dihydroxy-6,7,4'-trimethoxyflavone (F4), and 5,3'-dihydroxy-3,6,7,4'-tetramethoxyflavone (F5), which may explain the anti-inflammatory activity.

Analgesic effects and structural elucidation of two new flavone C-glycosides from Artemisa sacrorum.

The present study was designed to isolate and characterize the analgesic compounds of Artemisa sacrorum Ledeb. The EtOAc crude extracts from the aerial parts of Artemisa sacrorum Ledeb were separated by chromatography and the structures of new compounds were elucidated based on spectral analyses. Analgesic activities of the isolated compounds were assessed in rats with hot plate test and paw pressure assay. Two new flavone C-glycosides, named as Sacroroside A and B (Compounds 1 and 2) were isolated from the EtOAc crude extract of the aerial parts ofArtemisa sacrorum Ledeb. They showed significant analgesic effects. In conclusion, Compounds 1 and 2 are new natural products, which show significant analgesic effects in a dose-dependent manner.

Two new compounds from Paeonia lactiflora.

Two new compounds, namely 5-methyl-4,2',3',5'-tetrahydroxy-4'-methoxy-2-aldehyde biphenyl (1) and 1,8-dioxo-1,8-dihydropyrano[3,4-c]pyran-3,6- dicarboxyl acid, diethyl ester (2), were isolated from the 95% ethanol extract of the roots of Paeonia lactiflora Pall. The structures of 1 and 2 were elucidated by spectroscopic methods, including UV, IR, HR-ESI-MS and extensive 1D and 2D NMR techniques.

A biflavonoid glycoside from Lomatogonium carinthiacum (Wulf) Reichb.

A biflavonoid glycoside with a new carbon skeleton, named carinoside A, was isolated from the n-BuOH crude extract of the whole plant of Lomatogonium carinthiacum (Wulf) Reichb. The structure of the new compound was elucidated by using spectroscopic methods, including UV, IR, HR-ESI-MS and extensive 1D and 2D NMR techniques.

[Study on Chemical Constituents of Panzeria alaschanica].

OBJECTIVE: To study the chemical constituents of the ethyl acetate extract from Panzeria alaschanica. METHODS: The chemical constituents of ethyl acetate extract from Panzeria alaschanica were isolated and purified by silica gel. Their structures were i- dentified by means of spectra. RESULTS: Nine compounds were obtained and identified as 7-Methoxy coumarin (1), Isorhamnetin (2), Caf- feic acid (3), 5-Hydroxy-7,3',4'-trimethoxyflavone (4), 5-Hydroxy-7,4'-dimethoxyflavone (5),Kaempferol (6), Isorhamnetin-3-O-ß-D- glucoside (7) Kaempferol-3-O-ß-D-glucoside (8), and Isorhamnetin-7-O-ß-D-glucuronyl-(1-->6)-O-α-L-rhamnoside (9). CONCLUSION: Compounds 1-4,6,7 and 9 are isolated from this plant for the first time.

A new sesquiterpene from Ixeris chinensis.

The petroleum ether (PE) extract from Ixeris chinensis was submitted to chromatographic separation. A new sesquiterpene, namely 14-noreudesma-3-hydroxy-3-en-2,9-dione, was isolated from the PE extract. The structures of the sesquiterpene was elucidated by using spectroscopic methods, including UV, IR, HR-ESI-MS and extensive 1D and 2D NMR techniques.