Disesquiterpenoid and Sesquiterpenes from the Flos of <i>Chrysanthemum indicum</i>

One new disesquiterpenoid (1), two new sesquiterpenoids (2, 3), were isolated from the dry flos of Chrysanthemum indicum. The structures were elucidated by spectroscopic analysis, the absolute configurations of 1 and 3, were determined by single X-ray diffraction study.     

高乌头根中新的二萜生物碱

从高乌头根中分离得到3个新的冉乌头型的C₁₈-二萜生物碱高乌宁己(1)、高乌宁庚(3)、高乌宁辛(5)和一个新的牛扁碱型C₁₉-二萜生物碱高乌宁壬(7). 它们的结构通过IR, ¹H NMR, ¹³C NMR, MS予以确证.     

Rational development of a selection model for solvent gradients in single-step separation of ginsenosides from Panax ginseng using high-speed counter-current chromatography

A new model of solvent gradients selection was rationally developed for the preparative separation of target compounds. The solvent gradients were selected based on a three-stage screening process where stationary phase retention was ensured by introducing a new parameter termed as the phase ratio. The phase ratio was calculated after mixing the upper phase of a solvent system with the lower phase of a different solvent system (1:1, v/v). The developed model was applied to the one-step separation of eight ginsenosides from Panax ginseng. Three gradients were selected on the basis of new model and eight ginsenosides, Rb(1), Rb(2), Rc, Rd, Re, Rg(1), Rf, and Rh(1), were efficiently separated by high-speed counter-current chromatography coupled with evaporative light scattering detector. The structures of all compounds were characterized by electrospray-ionization mass spectrometry and nuclear magnetic resonance spectroscopy.     

Synthesis and Characterization of new Monomers and Polymers Containing Hindered Piperidine Groups

Abstract

Two new methacryloyl ureas, 1-(2-methylacryloyl)-3-(2,2,6,6-tetra-methylpiperidin-4-yl)-urea and 1-butyl-3-(2-methylacryloyl)-1-(2,2,6,6-tetramethylpiperidin-4-yl)-urea (monomer I and monomer II), were prepared by the addition reaction of 2-methylacryloyl iso-cyanate with 2,2,6,6-tetramethylpiperidin-4-yl-amine or butyl-(2,2,6,6-tetramethylpiperidin-4-yl)-amine in a molar ratio of 1:1 at low or room temperature. In a similar way, the syntheses of two new methacryloyl carbamates, 1-(2,2,6,6-tetra-methylpiperidin-4-yl)-3-(2-methylacryloyl)-carbamate and l-(1,2,2,6,6-pentamethyl-piperidin-4-yl)-3-(2-methylacryloyl)-carbamate (monomer III and monomer IV), were completed by the reaction of 2,2,6,6-tetra-methylpiperidin-4-ol or 1,2,2,6,6-pentamethylpiperidin-4-ol with 2-methylacryloyl isocyanate in the presence of dibutyltin dilaurate as catalyst at 60°C. The four new monomers were homopolymerized, and copolymerized with styrene by AIBN as initiator at 70°C. The structures of the new monomers and their polymers were characterized by FT-IR and NMR spectroscopy and by GPC.     

New sesquiterpenoid and triterpenoids from the fruits of Rhizophora mucronata

A new sesquiterpene (1) and two new pentacyclic triterpenoid esters (2, 3) together with three known compounds (4-6) were isolated from the fruits of Rhizophora mucronata. Their structures were elucidated by analysis of their spectroscopic data. The new compounds were characterized as 3-hydroxy-3,7,11-trimethyl-9-oxododeca-1,10-diene (mucronatone, 1), 3beta-E-caffeoyltaraxerol (2) and 3beta-Z-caffeoyltaraxerol (3).     

Structural determination of two new triterpenoids from Potentilla discolor Bunge by NMR techniques

Two new pentacyclic triterpenoids, 3alpha, 30-dihydroxylup-20(29)-en-27-oic acid (1) and (20S)-3alpha, 29-dihydroxylupan-27-oic acid (2) were isolated from the whole herbs of Potentilla discolor Bunge. The structures of these two new compounds were elucidated, and complete assignments of the (1)H and (13)C NMR spectroscopic data were achieved by 1D and 2D NMR experiments (HSQC, HMBC, (1)H-(1)HCOSY and ROESY).     

New constituents from the leaves of Morinda citrifolia

A new iridoid glycoside, citrifoside (1), and a new anthraquinone, 1,5,15-trimethylmorindol (2), together with 24 known compounds, were isolated from the leaves of Morinda citrifolia. The structures of the new compounds were elucidated by spectral data. 1,5,15-Trimethylmorindol (2) did not show significant cytotoxic activity by itself but showed cytotoxicity when combined with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), while citrifoside (1) did not show any activity even with TRAIL.     

Selenium containing macrocycles:transformation between Se-N/Se-S/Se-Se bonds

Macrocycles possess potential applications in supramolecular chemistry and biosystems.Thus development of new kinds of macrocycles is of significance.Herein,novel macrocycles containing Se-Se/Se-S bonds were synthesized via transformation between selenium related dynamic covalent bonds.A monomer containing two ebselen moieties was synthesized(M1).The Se-N bonds in M1 were reduced by dithiothreitol,forming Se-S linked dimer(D1).To realize the transformation from Se-S bonds to Se-Se bonds,guest molecules were added as template,triggering the formation of Se-Se linked dimer(D2).The formation of these two new kinds of macrocycles was determined by ~1H NMR and ~(77)Se NMR,and the necessity of guest molecules was also confirmed.The introduction of ebselen moieties and Se-S bonds or Se-Se bonds into macrocycles may endow it with new responsiveness and bioactivities,as well as new types of host-guest chemistry.     

New cytotoxic 14-membered macrolides from marine-derived fungus Aspergillus ostianus

Three new 14-membered macrolides, named aspergillides A, B, and C (1, 5, and 7), were isolated from marine-derived fungus Aspergillus ostianus strain 01F313, cultured in a medium composed of bromine-modified artificial seawater. The structures of the new compounds were determined by analyses of 1D and 2D NMR spectra. Their absolute configurations were elucidated by the modified Mosher's method and chemical conversions. The new compounds showed cytotoxic activity against mouse lymphocytic leukemia cells (L1210).     

Two triterpenoid saponins from Neonauclea sessilifolia

From the dried roots of Neonauclea sessilifolia (Rubiaceae), two new triterpenoid saponins, 3-O-beta-D-glucopyranosyl-(1-->2)-beta-D-quinovopyranosyl quinovic acid (1) and 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-quinovopyranosyl pyrocincholic acid 28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (2), were isolated, together with five known saponins. The structures of the new saponins were determined by spectroscopic and chemical means.     

A new alkaloid and its artificial derivative with an indazole ring from Nigella glandulifera

A new compound, nigeglanine (1), and its new artificial derivative (1a), were isolated from the seeds of Nigella glandulifera, together with a known aporphine alkaloid, fuzitine (2). Their structures were established by spectral analysis, including two-dimensional (2D)-NMR spectroscopy. Nigeglanine (1) is the third natural product determined to contain an indazole nucleus.     

New phenylalkanoids from Zingiber officinale

Two new phenylalkanoids, 3-hydroxy-1-(4'-hydroxy-3'-methoxy-phenyl)-hexan-5-one (1) and 3-hydroxy-1-(3',5'-dimethoxy-4'-hydroxyphenyl)-hexan-5-one (2) were isolated from the rhizomes of Chinese ginger (Zingiber officinale Roscoe (Zingiberaceae)). The structures of two new phenylalkanoids were elucidated by chemical and physical evidence.     

A new bisbenzylisoquinoline alkaloid from Plumulanelumbinis

One new bisbenzylisoquinoline alkaloid, neferine N-oxide(1), along with three known compounds,neferine(2), liensinine(3), and isoliensinine(4), were isolated from Plumulanelumbinis – the embryo of the seed of Nelumbonucifera. Their structures were elucidated by extensive spectroscopic analysis(MS,UV, IR, NMR), and the absolute configurations were determined by experimental circulardichroism(CD)spectra. Compound 1 is a new naturally occurring bisbenzylisoquinoline alkaloid with an N-oxide functionality, and the CD spectrum of(1R, 1'R) neferine is first reported. The antioxidant activities of compounds 1–4 were evaluated using the ORAC assay, which illustrated that all these compounds showed the different levels of oxygen radical absorbance capacity.     

Terpenoids and coumarins isolated from the fruits of Poncirus trifoliata

Four new triterpenes, 21alpha-methylmelianodiol (1), 21beta-methylmelianodiol (2), hispidol A 25-methyl ether (3) and hispidol B 25-methyl ether (4), and a new coumarin, isoschininallylol (5), were isolated from the fruits of Poncirus trifoliata RAFINESQUE, along with seventeen known compounds. The structures of the new compounds (1 - 5) were elucidated by interpretation of their spectroscopic data.     

Two new compounds from the roots of Ilex pubescens

A new triterpenoid glycoside, heterobetulinic acid 3-O-β-D-glucopyranosyl(1?→?2)-β-D-xylopyranoside (1), together with a new phenylacrylic acid derivative, 3'S,4'-dihydroxyl-2'-methylene-but-1'-enyl caffeate (2), were isolated from the roots of Ilex pubescens. Their structures were elucidated by HR-ESI-MS, 1-D and 2-D NMR analyses and chemical methods. In addition, the absolute configuration of 2 was established by the application of a modified Mosher's method.     

Ficusmicrochlorin A-C, two new methoxy lactone chlorins and an anhydride chlorin from the leaves of Ficus microcarpa

Two new methoxy lactone chlorins ficusmicrochlorin A (1) and ficusmicrochlorin B (2), and one new anhydride chlorin ficusmicrochlorin C (3), along with eight known pheophytins were isolated from the leaves of Ficus microcarpa. Their structures were determined by the extensive 1D- and 2D-NMR techniques. New pheophytin compound was rarely obtained from natural sources. In the past ten years, only three new natural pheophytins were characterized.     

Secondary metabolites from Paronychia argentea

Two new oleanane saponins (1 and 2) and one new flavonol glycoside (3) together with six known flavonoids, were isolated from the aerial parts of Paronychia argentea. Their structures were elucidated by 1D and 2D NMR experiments including 1D-TOCSY, DQF-COSY, NOESY, HSQC, and HMBC spectroscopy, as well as ESI-MS analysis.     

Three New Bisabolocurcumin Ethers from the Rhizomes of Curcuma longa L.

Three new bisabolocurcumin ethers, named demethoxybisabolocurcumin ether ( 1 ), bisabolocurcumin ether ( 2 ), and didemethoxybisabolocurcumin ether ( 3 ), along with two known compounds, 4 and 5 , were isolated from the AcOEt extract of the rhizomes of Curcuma longa L. Their structures were established by the analysis of NMR and MS data. The new compounds 1 – 3 , which possess a new 1,7‐diarylheptanoid skeleton linked with a bisabolone‐type sesquiterpene substructure by a C? O bond, were found for the first time in a natural source.     

Three new fatty acids from the roots of Boehmeria nivea (L.) Gaudich and their antifungal activities

Three new unsaturated fatty acids, (Z)-9,10,11-trihydroxy-12-octadecenoic acid (1), (Z)-7,8,9-trihydroxy-10-hexadecenoic acid (2) and (Z)-12-keto-7,8,9-trihydroxy-10-hexadecenoic acid (3) were isolated from the roots of Boehmeria nivea (L.) Gaudich, along with a known unsaturated fatty acid, (E)-8,11,12-trihydroxy-9-octadecenoic acid (4). The structures of the new compounds were established by HR ESI-MS, (1)H, (13)C, 2D ((1)H-(1)H COSY, HSQC, HMBC) NMR experiments. The known compound was identified by a comparison of its spectral data with published references. The three new compounds showed some antifungal activities by agar assay.     

A New Triterpenoid Saponin and a New Glycoside from Epigynum aurilum

A new triterpenoid saponin with novel sugar moiety (1), a new trisaccharide derivative (2), as well as a known monosaccharide derivative (3), were isolated from the dried stem of Epigyhum aurilum. The structures of compounds 1 and 2 were determined by MS and NMR spectram analyses.