Metajapogenins A-C, Pregnane Steroids from Shells of Metaplexis japonica.

Phytochemical investigation of the shells of Metaplexis japonica (Thunb.) Makino, belonging to the family of Apocynaceae, afforded three new pregnane steroids, metajapogenins A-C, along with three known compounds. The structures of the new compounds were elucidated as 12ß,14ß,17ß-trihydroxypregna-3,5-dien-7,20-dione, 12ß,14ß,17ß,20ß-tetrahydroxypregna-3,5-dien-7-one; 3ß,12ß,14ß,17ß-tetrahydroxypregn-5-ene-7,20-dione on the basis of extensive spectroscopic evidence derived from 1D; 2D-NMR experiments and mass spectrometry. The known compounds included pergularin; 12-O-acetylpergularin; and pergularin-3-O-ß-d-oleandropyranose; which were identified for the first time in the shells of M. japonica.

Three new C21 steroidal glycosides isolated from Metaplexis japonica and their potential inhibitory effects on tyrosine protein kinases.

Three new steroidal glycosides, metapregnoside A-C (II-IV), together with one known compound, byzantionoside B (I), were isolated from the fresh whole herb of Metaplexis japonica by using high-speed countercurrent chromatography and semi-preparative liquid chromatography. Their structures and relative configurations were elucidated by spectroscopic methods including 1D NMR, 2D NMR and HR-ESI-MS. The potential targets of compound I-IV were identified by virtual screening. And the potential inhibitory effects of these compounds on tyrosine protein kinases were compared by molecular docking. Byzantionoside B (I) was the first isolated compound from Metaplexis genus. The docking score of metapregnoside C (IV) was the highest. And the sugar chain residues at position C-20 in the pregn-4-en-3-one derivatives is the main factor affecting their docking scores on tyrosine protein kinases Fes/Fps.

Bio-Derived Carbon with Tailored Hierarchical Pore Structures and Ultra-High Specific Surface Area for Superior and Advanced Supercapacitors.

We report here on a hollow-fiber hierarchical porous carbon exhibiting an ultra-high specific surface area, synthesized by a facile method of carbonization and activation, using the Metaplexis Japonica (MJ) shell. The Metaplexis Japonica-based activated carbon demonstrated a very high specific surface area of 3635 m2 g-1. Correspondingly, the derived carbonaceous material delivers an ultra-high capacitance and superb cycle life in an alkaline electrolyte. The pore-ion size compatibility is optimized using tailored hierarchical porous carbon and different ion sized organic electrolytes. In ionic liquids nonaqueous based electrolytes we tailored the MJ carbon pore structure to the electrolyte ion size. The corresponding supercapacitor shows a superior rate performance and low impedance, and the device records specific energy and specific power densities as high as 76 Wh kg-1 and 6521 W kg-1, as well as a pronounced cycling durability in the ionic liquid electrolytes. Overall, we suggest a protocol for promising carbonaceous electrode materials enabling superior supercapacitors performance.

Antibacterial and antioxidant flavonoid derivatives from the fruits of Metaplexis japonica.

Metaplexis japonica (Thunb.) Makino is widely distribution and cultivated as a vegetable in China. Chemical studies revealed that its stem and root are rich in polysaccharides, flavonoids, polyphenols, and steroids, which also exhibited interesting activities. However, little attention has been focused on the biological constituents in the fruits of M. japonica. In order to achieve the best use of M. japonica, a chemical investigation of the secondary metabolites of the fruits of M. japonica was performed, and led to the isolation of one new (1), along with eight known flavoniod derivatives (2-9). The antioxidant and antibacterial properties of the crude extract and compound 1 were deeply evaluated through antioxidant and antimicrobial assays. Among them, the crude extract showed significant antioxidant activities in all assays, as well as broad-spectrum antibacterial effects. These results suggested that crude extract of M. japonica would be a potential source as a possible preservatives for foods.

Chemical constituents from pericarpium of Metaplexis japonica / 中草药

Objective: To study the chemical constituents from the pericarpium of Metaplexis japonica. Methods: The petroleum ether, dichloromethane and ethyl acetate fractions of 95% ethanol extract from M. japonica were isolated and purified by silica gel, Sephadex LH-20, MPLC and preparative HPLC, etc. The structures of the obtained compounds were identified by physicochemical properties and spectral data. Results: Ten compounds were isolated and identified as (15β,21α)-dihydroxypregna-17,20-trimethylene oxide-4,6-dien-3-one (1), 25-hydroperoxycyc-loart-23-en-3β-ol (2), α-amyrin (3), scoparone (4), aleuritin (5), syringaresinol (6), pergularin-3-O-β-D-oleanodropyranose (7), (20β)-21-dihydroxypregna-4,6-dien-3-one (8), blumenol A (9) and 4-pregnen-20,21- diol-3-one (10). Conclusion: Compound 1 is a new C21 steroidal compound named metajapogenin F, compounds 2 and 10 are isolated from the genus Metaplexis for the first time, and compound 8 is isolated from this plant for the first time.

Chemical constituents from Metaplexis japonica / 中成药

AIM To study the chemical constituents from Metaplexis japonica (Thunb.) Makino.METHODS The dichloromethane fraction of 95％ ethanol extract from M.japonica was isolated and purified by silica and preparative HPLC column,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Nine compounds were isolated and identified as dibutyl phthalate (1),(Z)-2-ethylidene-3-methylsuccinic acid (2),dehydrololiolide (3),medioresinol (4),isovanillin (5),vomifoliol (6),β-sitosterol (7),daucosterol (8),pregnenolone (9).CONCLUSION Compounds2-4 are isolated from genus Metaplexis for the first time,compounds 5-8 are first isolated from this plant.

Analysis of Volatile Oil and Fatty Oil in Seed of Metaplexis japonica / 中国药房

OBJECTIVE:To analyze fatty oil and volatile oil in seed of Metaplexis japonica. METHODS:Fatty oil and vola-tile oil in seed of M. japonica were analyzed by GC-MS:HP-5MS quartz capillary column,high purity nitrogen as carrier gas, flow rate of 1 mL/min,injector temperature of 220 ℃,primary column temperature of 120 ℃(temperature programmed),column pressure of 80 kPa,split sampling,split ratio of 20:1,sample size of 1 μL. Mass condition:electron bombardment ion source, electron energy of 70 eV,interface temperature of 250 ℃,mass scanning range of m/z 50-550,scanning interval of 1.0 s. The dif-ference of volatile components in seed of M. japonica before and after processing was analyzed by HSGC-MS:HP-5MS quartz cap-illary column,high purity nitrogen as carrier gas,flow rate of 1 mL/min,headspace heating temperature of 90 ℃,heating time of 30 min,primary column temperature of 80 ℃(temperature programmed),column pressure of 80 kPa,split sampling,split ratio of 20:1,sample size of 1 μL. Mass condition:electron bombardment ion source,electron energy of 70 eV,interface temperature of 210 ℃,mass scanning range of m/z 50-550,scanning interval of 1.0 s. RESULTS:A totall of 30 components were identified in fatty oil,among which relative contents of linoleic acid,oleic acid,palmitic acid were in high level;54 components were identi-fied in volatile oil,main components were terpenes,among which relative contents of cananga oil diene,thujopsene,dehydro aro-madendrene were in high level. Terpinen-4-ol was found and dihydrocarveol increased 100% after frying,compared with before fry-ing. CONCLUSIONS:The study basically confirm main component of fatty oil and volatile oil in seed of M. japonica;there is dif-ference of volatile components in seed of M. japonica before and after frying.

Simultaneous Determination of Amino Acids, Nucleosides and Nucleobases in Different Parts of Metaplexis japonica(Thunb.) Makino Processed by Different Methods by UFLC-QTRAP-MS/MS / 中国药学杂志

OBJECTIVE: To establish an UFLC-QTRAP-MS/MS method for simultaneous determination of 15 kinds of amino acids and 12 kinds of nucleosides and nucleobases in different parts of Metaplexis japonica(Thunb.) Makino processed by different methods. METHODS: The analysis was carried out on a Waters XBridge Amide column(2.1 mm×100 mm, 3.5 μm) with elution by mobile phase of 0.2% formic acid in acetonitrile-0.2% formic acid in water at a flow rate of 0.6 mL·min-1. The column temperature was maintained at 30 ℃. The target compounds were analyzed by positive ion multiple reaction monitoring(MRM) mode. RESULTS: Twenty-seven multiple constituents showed good linearity(r>0.997 3) in the ranges of the tested concentrations. The average recoveries of the 27 components were 98.17%-100.75% with relative standard deviations of 0.90%-2.49%. CONCLUSION: The established method is accurate and precise, which provides a reliable solution for selecting the parts and the optimal processing method of Metaplexis japonica(Thunb.)Makino.