Racemic 3,4-dihydro-4-naphthyl-naphthalen-1(2H)-ones from Juglans regia flowers.

Three previously undescribed (±)-3,4-dihydro-4-naphthyl-naphthalen-1(2H)-one derivatives were isolated from Juglans regia flowers. Elucidation of the 2D structures of these first-reported compounds was completed via regular spectroscopic methods. The assignment of racemic nature of these compounds was achieved using the examination of their chiral HPLC profiles. (±)-2,3-Dihydro-4',8,8'-trihydroxy-(1,1'-binaphthalen)-4(1H)-one, (±)-2,3-dihydro-4',5,8,8'-tetrahydroxy-(1,1'-binaphthalen)-4(1H)-one, and (±)-2,3-dihydro-1',5,5',8-tetrahydroxy-(1,2'-binaphthalen)-4(1H)-one were the structures of these racemic compounds, all taking on central chirality. The resolution of all the racemic compounds was conducted and achieved using a chiral HPLC procedure. The absolute configurations of the three isolated pairs of enantiomers were assigned via time-dependent density functional theory calculations from the electronic circular dichroism data. The findings in this paper demonstrated that the relevant biochemical reactions for the construction of these 3,4-dihydro-4-naphthyl-naphthalen-1(2H)-one derivatives in the test plant are nonselective. The (±)-2,3-dihydro-4',8,8'-trihydroxy-(1,1'-binaphthalen)-4(1H)-one showed selective inhibitory activity on tumor cells growth, preliminarily supporting the application of Juglans regia flowers to protect against cancers in a few Chinese folk areas.

Sugar-free pregnane-type steroids from the roots of Cynanchum stauntonii.

Two new sugar-free 14,15-secopregnane-type steroids, 14-O-methyl-3-epi-hirundigenin (1) and 2-deoxyamplexicogenin A (2), along with two known sugar-free pregnane-type steroids, were isolated from the 95% ethanol extract of the roots of Cynanchum stauntonii. The structures of the new compounds were characterized on the basis of extensive spectroscopic analyses, mainly 1D and 2D NMR methods, albeit the MS experiments did not display the molecular ion peaks. Compound 2 was the aglycones of stauntosides J and K, etc., previously isolated from C. stauntonii. The isolation and identification of the new compounds graced the structural diversity of pregnane-type steroids from C. stauntonii.

[Research on certified reference material of emodin in rhubarb and its alcohol extract, water extract].

The certified reference materials (CRMs) of emodin in rhubarb and its alcohol extract, water extract were developed by using quantity transfer technology from single chemical composition to the complex systems. The CRM of emodin was used for quantity transfer, and high performance liquid chromatography (HPLC) method was used to determine the contents of emodin in different matrix composition. By establishing mathematical model and calculating the parts of uncertainty, the uncertainty values were finally gotten. CRMs of emodin in rhubarb, alcohol extract and water extract were accomplished. The content values of emodin were 0.40% ±0.03%, 1.15%±0.18%, 0.16%±0.08% (k=2,P=0.95), respectively. The established method for quantity transfer has successfully solved the technical problems that the value of active ingredient of traditional Chinese medicine can't be traced to SI units. The series of CRMs are assigned as grade primary reference materials, which are useful for quality control of the emodin content, also provide the accurate and reliable CRM, materials standard and standard methods.

[Lignans from cultivated Gynura nepalensis].

Taking application of some isolation and purification technologies, including solvent extraction, rude solvent isolation, column chromatographies on silica gel and Sephadex LH-20 , and preparative HPLC , 4 compounds were obtained from Gynura nepalensis cultivated in a suburban area of Beijing. Their structures were identified by spectroscopic methods in conjunction with comparison of the NMR data with literature values as 7S,8R-9'-O-ethyl-dehydrodiconiferyl-9-acetate (1), 9'-O-ethyl-dehydrodiconiferyl alcohol (2), dehydrodiconiferyl-9,9'-diacetate(3), and (+)-medioresinol(4), respectively. 1 is a new 2,3-dihydrobenzofuran-8,3'-neolignane type compound, and 2-4 were isolated from G.nepalensis for the first time. The complete assignment of the 1H- and 13C-NMR spectroscopic data of the four compounds recorded in DMSO-d6 was achieved.

Phenylpropanoids from the stems of Ephedra sinica.

Two new compounds of phenylpropanoids, (S)-N-((1R,2S)-1-hydroxy-1-phenylpropan-2-yl)-5-oxopyrrolidine-2-carboxamide (1) and (3R)-3-O-ß-d-glucopyranosyl-3-phenylpropanoic acid (2), were isolated from the stems of Ephedra sinica. Their structures were elucidated by in-depth examination of spectroscopic data, mainly including those from the 1D and 2D NMR and HRESIMS techniques, and chemical method. The absolute configurations of the two compounds were also corroborated through CD procedure.

Two new flavonoids from the roots of Scutellaria baicalensis.

One new flavone, 5,7-dihydroxy-8,2',3',6'-tetramethoxyflavone (1), and one new flavonol, 5,7,6'-trihydroxy-2'-methoxyflavonol (2), were isolated from the roots of Scutellaria baicalensis, and their structures were elucidated on the basis of extensive spectroscopic evidences, especially 1D and 2D NMR and HR-ESI-MS experiments. The structure features of these new compounds lie in the substitution at both C-2' and C-6' positions of B-ring by hydroxyl or methoxyl groups.

[Constituents with anti-oxidative activity from seeds of Jufeng grape].

Taking application of some isolation and purification technologies, including crushing, solvent extraction, preliminary solvent isolation, column chromatographies over silica gel and Sephadex LH-20 gel and preparative HPLC, 8 compounds were obtained from the seeds of Jufeng grape sourced from market. Their structures were identified by spectroscopic methods and comparison with literature values as Catechin (1), Epicatechin (2), quercetin (3), ethylgallate (4), rel-(2S, 3R) -2-(4-hydroxy-3-methoxyphenyl) -3- (hydroxymethyl)-5-(3-hydroxypropyl)-2,3-dihydrobenzofuran-7-ol (5), rel-(2α, 3ß)-7-O-methylcedrusin (6), rel-(1R,2S)-1-(4-hydroxy-3-methoxyphenyl) -2-(4-(3-hydroxypropyl) -2-methoxyphenoxy) propane-1,3-diol (7), and (+) -isolariciresinol (8), respectively. Compounds 5-8 were serial lignans isolated from the seeds of grape for the first time. Structurally, 5 and 6 belong in benzofuran-8,3'-neolignans, 7 in 8,4'-oxyneolignan, and 8 in 8,8' :2,7'-cyclolignan. According to in vitro activity evaluation conducted in cell model, compound 6 showed significant anti-oxidative ability, with the activity of RAW264. 7 cell superoxide dismutase being raised evidently in the test as compared with the positive anti-oxidative agents, compounds 1 and 2.

[Study on anti-oxidative effect of extracts from Cichorium endivia on HepG2 cells and its mechanism].

OBJECTIVE: To investigate the protective effect of extracts from Cichorium endivia (CEE) in H2O2-induced HepG2 cell oxidative stress injury, and explore the antioxidant mechanism of CEE in HepG2 cells. METHOD: The viability of H2O2-induced HepG2 cells and the intracellular ROS level were measured by MTT assay and DCFH-DA fluorescence staining assay. The antioxidant-response element (ARE)-Luciferase activity was tested in HepG2 cells stably transected by ARE reporter gene. The fluorescence quantitative RT-PCR was adopted to determine the mRNA expressions of genes containing ARE sequence in HepG2 cells. RESULT: The cell viability reduced, while the ROS level increased after HepG2 cells were treated by H2O2. Different concentrations of CEE could be added to significantly improve the above results. After HepG2 cells transected by ARE reporter gene were treated with different concentrations of CEE, the intracellular ARE activity could increase in a concentration-dependent manner. In addition, the mRNA expressions of regulatory genesGCLC, GCLM and HMOX-1 containing ARE sequence in HepG2 cells were up-regulated in a concentration-dependent manner by CEE. CONCLUSION: CEE inhibited the H2O2-injured HepG2 cells by reducing the ROS level. CEE's antioxidant mechanism for HepG2 cells may be closely related to the antioxidant defense system associated with its effect of activating Nrf2-ARE pathway in HepG2 cells.

[Study on chemical constituents from cultivated Gynura nepalensis].

Taking application of some isolation and purification technologies, such as solvent extraction, preliminary solvent isolation, column chromatographies over silica gel and Sephadex LH-20 gel and preparative HPLC, 10 compounds were obtained from Gynura nepalensis cultivated in the suburban area of Beijing. Their structures were identified by spectroscopic methods and comparison with literature as (3R) -3-hydroxy-ß-ionone (1), (3S,5R, 6S, 7E) -5, 6-epoxy-3-hydroxy-7-megastigmen-9-one (2), (+) -boscialin (3), 3, 6-trans-3-hydroxy-α-ionone (4), 3, 6-cis-3-hydroxy-α-ionone (5), 3, 4-cis-3, 4-dihydroxy-ß-ionone (6), ethyl caffeate (7), loliolide (8), 1H-indole-3-carbaldehyde (9), and 3-(hydroxyacetyl)indole (10), respectively. All compounds were isolated from the title plant for the first time, and with compounds 1, 2, 4-7, 9 and 10 being isolated from Gynura species for the first time. Structurally, the above compounds 1-6 belong to C13 nor-sesquiterpenoids, sharing the same carbon skeleton of megastigmane. According to this study, they are one of major kinds of chemical constituents of Gynura nepalensis and have important reference value for the investigation on phytotaxonomy of this species.

Three new steroidal glycosides from the roots of Cynanchum stauntonii.

Three new steroidal glycosides, named as stauntosides L, M, and N (1-3), along with one known C21 steroidal glycoside, anhydrohirundigenin monothevetoside (4), were isolated from the 95% ethanol extract of the roots of Cynanchum stauntonii. The structures of these new compounds were elucidated on the basis of extensive spectroscopic analyses, mainly 1D and 2D NMR, HRESI-MS, and chemical methods.