Novel Indane Derivatives with Antioxidant Activity from the Roots of Anisodus tanguticus.

Four novel indane derivatives, anisotindans A-D (1-4), were isolated from the roots of Anisodus tanguticus. Their structures were established using comprehensive spectroscopic analyses, and their absolute configurations were determined by electronic circular dichroism (ECD) calculations and single-crystal X-ray diffraction analyses. Anisotindans C and D (3 and 4) are two unusual indenofuran analogs. ABTS•+ and DPPH•+ assays of radical scavenging activity reveal that all compounds (1-4) are active. Specifically, the ABTS•+ assay results show that anisotindan A (1) exhibits the best antioxidant activity with an IC50 value of 15.62 ± 1.85 µM (vitamin C, IC50 = 22.54 ± 5.18 µM).

[A pair of enantiomeric sesquiterpenoids from florets of Carthamus tinctorius].

This study investigated the chemical components from the florets of Carthamus tinctorius. Five compounds were isolated from C. tinctorius by column chromatography with silica gel and toyopearl HW-40 F, preparative thin-layer chromatography(TLC), and semi-preparative reverse phased high performance liquid chromatography(RP-HPLC). Their structures were identified by mass spectrometry(MS), one-dimension nuclear magnetic resonance(1 D-NMR), two-dimension nuclear magnetic resonance(2 D-NMR), and single-crystal X-ray diffraction as(-)-(2S,3S,5S,7S,10R)-eudesma-4(15)-en-2,3,11-triol(1 a),(+)-(2R,3R,5R,7R,10S)-eudesma-4(15)-en-2,3,11-triol(1 b), rosin(2),(+)-syringaresinol(3), and(E)-1-(4'-hydroxyphenyl)-but-1-en-3-one(4). Compounds 1 a and 1 b are a pair of enantiomeric sesquiterpenoids. Compound 1 a is a new eudesmene and is named(-)-plucheol A. Compound 1 a at 100 µmol·L~(-1) showed significant antioxidant activity against ABTS~(+·) and DPPH·, with the scavenging rates of 30.98%±4.17% and 27.52%±1.24%, respectively, while compound 1 b was inactive. In addition, compounds 1 a and 1 b showed no obvious anti-inflammatory activity.

[A novel phenylisoquinoline alkaloid with cardioprotective effect from Aconiti Lateralis Radix Praeparata].

Macroporous resin chromatography, silica gel column chromatography, preparative thin layer chromatography, and semi-preparative high performance liquid chromatography were performed to isolate two compounds from the acid extract of the lateral roots of Aconitum carmichaelii: a new 9-phenylisoquinoline alkaloid(1) and a known pavine alkaloid(2). Their structures were elucidated by spectroscopy. The absolute configuration of compound 1 was identified by electronic circular dichroism(ECD) and it was determined to be(aS)-7,8-dimethoxy-9-(2-carboxy-4,5-dimethoxyphenyl)-3,4-dihydroisoquinoline-1(2H)-one(1). The cardioprotective effects of 1 and 2 against doxorubicin-induced toxicity in H9 c2 cells were evaluated. Both of the isoquinoline alkaloids showed cardioprotective activity.

New Isoflavanes from Spatholobus suberectus and Their Cytotoxicity against Human Breast Cancer Cell Lines.

The rattans of Spatholobus suberectus Dunn are a traditional Chinese medicine activating blood circulation and removing stasis. They have often been used for the traditional Chinese medicinal treatment of breast cancer in modern China. In this study, four novel isoflavanes (1-3 and 5) and four known analogues (4 and 6-8) were isolated from an ethanolic extract of the rattans of S. suberectus. Their structures were elucidated by extensive spectroscopic analyses and electronic circular dichroism studies. MCF-7 and MDA-MB-231 human breast cancer cell lines were used to evaluate the cytotoxic effects of the isolates. Interestingly, compounds 1 and 2 only inhibited the proliferation of MCF-7 cells, while compound 6 showed a selective cytotoxicity against MDA-MB-231 cells. However, compound 4 had significant cytotoxicity against both MCF-7 and MDA-MB-231 cell lines.

Discrimination of the Geographical Origin of the Lateral Roots of Aconitum carmichaelii Using the Fingerprint, Multicomponent Quantification, and Chemometric Methods.

Fuzi is a well-known traditional Chinese medicine developed from the lateral roots of Aconitum carmichaelii Debx. It is rich in alkaloids that display a wide variety of bioactivities, and it has a strong cardiotoxicity and neurotoxicity. In order to discriminate the geographical origin and evaluate the quality of this medicine, a method based on high-performance liquid chromatography (HPLC) was developed for multicomponent quantification and chemical fingerprint analysis. The measured results of 32 batches of Fuzi from three different regions were evaluated by chemometric analysis, including similarity analysis (SA), hierarchical cluster analysis (HCA), principal component analysis (PCA), and linear discriminant analysis (LDA). The content of six representative alkaloids of Fuzi (benzoylmesaconine, benzoylhypaconine, benzoylaconine, mesaconitine, hypaconitine, and aconitine) were varied by geographical origin, and the content ratios of the benzoylmesaconine/mesaconitine and diester-type/monoester-type diterpenoid alkaloids may be potential traits for classifying the geographical origin of the medicine. In the HPLC fingerprint similarity analysis, the Fuzi from Jiangyou, Sichuan, was distinguished from the Fuzi from Butuo, Sichuan, and the Fuzi from Yunnan. Based on the HCA and PCA analyses of the content of the six representative alkaloids, all of the batches were classified into two categories, which were closely related to the plants' geographical origins. The Fuzi samples from Jiangyou were placed into one category, while the Fuzi samples from Butuo and Yunnan were put into another category. The LDA analysis provided an efficient and satisfactory prediction model for differentiating the Fuzi samples from the above-mentioned three geographical origins. Thus, the content of the six representative alkaloids and the fingerprint similarity values were useful markers for differentiating the geographical origin of the Fuzi samples.

Cytotoxic Evaluation against Breast Cancer Cells of Isoliquiritigenin Analogues from Spatholobus suberectus and Their Synthetic Derivatives.

Five isoliquiritigenin analogues, including a new methylene-bridged bischalcone (1), were isolated from Spatholobus suberectus. Cytotoxicity screening of these isolates and several synthetic derivatives indicated that the introduction, removal, position modification, or glycosylation of hydroxy groups in isoliquiritigenin did not improve the resultant cytotoxicity against the MCF-7 and MDA-MB-231 human breast cancer cell lines. In addition, cyclization of OH-2' chalcones or reduction of the α,ß-unsaturated carbonyl double bond decreased such cytotoxicity substantially. However, methylation of hydroxy groups resulted in a marked increase in such cytotoxic activity. Among these active isoliquiritigenin analogues, 3',4',5',4″-tetramethoxychalcone (3h) was obtained as a compound with promising cytotoxic activity.

[Study on chemical constituents of seeds of Croton tiglium and their cytotoxicities].

Seven compounds were isolated from the seeds of Croton tiglium by preparative TLC, semi-preparative HPLC, and column chromatography over silica gel, MCI, and Sephadex LH-20, etc. Their structures were elucidated by spectroscopic data analysis as bis(2,3-dihydroxypropyl) nonanedioate (1), 12-O-(α-methyl)butyrylphorbol-13-decanoate (2), 12-O-tiglylphorbol-13-decanoate (3), (9S,10R,11E,13R)-9,10,13-trihydroxyoctadec-11-enoic acid (4), methyl (9S,10R,11E,13R)-9,10,13-trihydroxyoctadec-11-enoate (5), 4(1H)-quinolinone (6), and 5-hydroxy-2-pyridinemethanol (7). Compound 1 was a new compound and compounds 4-7 were isolated from family Euphorbiaceae for the first time. Compounds 2 and 3 showed cytotoxic activities against human lung cancer cell line A549 with IC50 values of 47.8 and 7.0 µmol•L ⁻¹, respectively, and against human hepatocarcinoma cell line HepG2 with IC50 values of 71.4 and 44.0 µmol•L ⁻¹, respectively.

Curcumanes E and F, two rare sesquiterpenoids with a dicyclo[3.3.1]nonane moiety, from Curcuma longa and their vasorelaxant activities.

Two new sesquiterpenoids, curcumanes E (1) and F (2), were isolated from the rhizome of Curcuma longa, and their structures and absolute configurations were examined using extensive spectroscopic analyses and ECD calculations. Interestingly, compounds 1 and 2 are diastereoisomers possessing a rare sesquiterpenoid skeleton that has been reported only once before. Both curcumanes E and F exhibit significant vasorelaxant effects against KCl-induced contraction of rat aortic rings, with EC50 values of 5.10 ± 0.79 and 5.58 ± 1.77 µM, respectively. These findings enrich the data concerning this rare type of sesquiterpenoids and further indicate that these rare sesquiterpenoids can effectively reduce blood pressure.

Cardioprotective effects and concentration-response relationship of aminoalcohol-diterpenoid alkaloids from Aconitum carmichaelii.

Fuzi, a well-known traditional Chinese medicine developed from the lateral roots of Aconitum carmichaelii Debx., has been widely used for the treatment of heart failure. In order to search for active compounds from Fuzi, a phytochemical study was performed, which resulted in the isolation of 14 aminoalcohol-diterpenoid alkaloids, including one new compound (1). Their cardioprotective effects against doxorubicin-induced toxicity in H9c2 cells were evaluated. All of the alkaloids showed cardioprotective effects in a nonmonotonic concentration-response manner, with the maximum protection rates ranging from 17.96 ± 2.93% to 98.31 ± 0.35%. Compound 5 exhibited the most potent cardioprotective activity. Taking the maximum protection rate as an indicator, the preliminary structure-activity relationship analysis indicated that the substitutions of C-1, C-13, C-15, C-16, and N and the configurations of OMe-6 and OH-15 are important structural features for the cardioprotective activities of the aminoalcohol-diterpenoid alkaloids.

New sesquiterpenoids from the stems of Dendrobium nobile and their neuroprotective activities.

Three new sesquiterpenoids, (+)-(1R,2S,3R,4S,5R,6S,9R)-3,11,12-trihydroxypicrotoxane-2(15)-lactone (1), (-)-(1S,2R,3S,4R,5S,6R,9S,12R)-3,11,13-trihydroxypicrotoxane-2(15)-lactone (2), and (+)-(1R,5R,6S,8R,9R)-8,12-dihydroxy-copacamphan-3-en-2-one (3), together with five known compounds, were isolated from the n-butanol soluble fraction of a 95% EtOH extract of the stems of Dendrobium nobile. Their structures were determined by extensive spectroscopic analysis. Particularly, to solve difficult stereochemical problems, electronic circular dichroism calculations, NMR data calculations, and a single-crystal X-ray diffraction were performed. Interestingly, compounds 1 and 2 were picrotoxinin-type sesquiterpenoids with an unusual C15,2-lactone ring. All new sesquiterpenoids (1-3) showed a significant neuroprotective activity against H2O2-induced oxidative damage in PC12 cells. Notably, at 25 and 50 µM, compounds 1 and 2 showed the best protective effects, even better than the positive control (vitamin E).

Picrotoxane sesquiterpenoids from the stems of Dendrobium nobile and their absolute configurations and angiogenesis effect.

Five picrotoxane sesquiterpenoids belonging to the unusual dendrobine-type (1 and 4) and the picrotoxinin-type (2, 3, and 5) were isolated from the stems of Dendrobium nobile Lindl. Their structures were established by spectroscopic analyses and physical properties. Compound 1 was a new dendrobine analogue. Although the planar structure of 2 and 3 had been reported, their absolute configurations were first determined by single-crystal X-ray diffraction and circular dichroism. Compound 2 exhibited angiogenesis effect against sunitinib-induced damage on intersegmental blood vessels in Tg (flk1: EGFP) and Tg (fli1: nEGFP) transgenic zebrafish at concentrations of 3.13, 6.25, 12.50, and 25.00µM.