Diterpenoids from Acanthopanax brachypus Harms.

Four diterpenoids, including two new ones, namely noracanthopanin A (1) and acanthopanolide B (2), and two known ones, ent-pimara-9(11),15-dien-19-oic acid (3) and ent-kaur-16-en-19-oic acid (4), were isolated from the stem bark of Acanthopanax brachypus Harms. Their structures were elucidated by physicochemical and spectroscopic analyses. Compound 1 and 2 exhibited moderate cytotoxicities against HO-8910 cells with IC50 values of 65.21±0.23 and 31.43±1.01 µg/ml, respectively, and 2 showed selective weak cytotoxicity against SMMC-7721 cells (IC50 89.67±2.54 µg/ml).

Triterpenoid saponins from the stem bark of Acanthopanax brachypus HARMS.

Two new triterpenoid saponins, brachyposide A (1) {3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucuronopyranosyl-2beta,3beta,16alpha,23-tetrahydroxyolean-12-en-28-oic acid 28-O-beta-D-apiofuranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl ester} and brachyposide B (2) {3-O-beta-D-glucopyranosyl-(1-->3)-beta-D-galactopyranosyl-(1-->3)-beta-D-glucuronopyranosyl-2beta,3beta,23-trihydroxyolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl-(1-->4)-[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester}, together with four known triterpenoid saponins, including tabguticoside A, nipponoside D, palmatoside E and ciwujianoside A(1), were isolated from the stem bark of Acanthopanax brachypus. Their structures were elucidated on the basis of spectroscopic and chemical evidence.

[Study on chemical constituents and antimicrobial activity of the essential oil from Acanthopanax brachypus].

OBJECTIVE: The chemical constituents and antimicrobial activity of the essential oil from Acanthopanax brachypus were studied. METHODS: The essential oil was extracted from the stem of A. brachypus by steam distillation, and its antimicrobial activity was tested in vitro. The chemical constituents were separated and identified by GC-MS, and the relative contents of each constituent was determined by area normalization. RESULTS: The essential oil showed some certain antibacterial activities against the tested strains escherichia coli, bacillus subtilis, staphylococcus aureus, pseudomonas aeruginosa and candida albicans except aspergillus niger. Forty-seven constituents were separated and identified, accounting for 91.37% of the total oil. The main constituent were Heptanoic acid (7.05%), Vanillin (6.09%), trans-Linalool oxide (6.07%), 1-methyl-2-(-methylethyl)-Benaene (5.83%), alpha-Phellandrene (5.14%), n-Hexadecanoic acid (5.15%) and beta-Myrcene (5.07%). CONCLUSION: The essential oil of A. brachypus contained varied active constituent, has a certain antimicrobial activity, this result will provide some scientific references for the pharmacological further research of A. brachypus.

Study on the interactions of kaempferol and quercetin with intravenous immunoglobulin by fluorescence quenching, fourier transformation infrared spectroscopy and circular dichroism spectroscopy.

The interactions of kaempferol and quercetin with intravenous immunoglobulin (IVIG) were studied in vitro by spectroscopic methods including fluorescence spectra, Fourier transformation infrared (FT-IR) spectra and circular dichroism (CD) spectra. The binding parameters for the reactions calculated according to the Sips equation suggested that the bindings of IVIG to kaempferol and quercetin were characterized by two binding sites with the average affinity constants K(o) at 1.032 x 10(4) M(-1) and 1.849 x 10(4) M(-1), respectively. The binding of IVIG with quercetin is stronger than that of IVIG with kaempferol. They were of non-specific and weak drug-protein interactions. Docking was used to calculate the interaction modes between kaempferol and quercetin with IVIG. The secondary structural compositions of free IVIG and its kaempferol, quercetin complexes were calculated by the FT-IR difference spectra, self-deconvolution, second derivative resolution enhancement and the curve-fitting procedures of amide I band respectively, which are in good agreement with the analyses of CD spectra. The effect of 3'-OH substituent in quercetin is distinct between the interactions of IVIG with kaempferol and quercetin for the secondary structure of the protein. The observed spectral changes indicate a partial unfolding of the protein structure, but the typical beta structural conformation of IVIG is still retentive in the presence of both drugs in aqueous solution. The average binding distances between the chromophores of IVIG with kaempferol (4.30 nm) and quercetin (4.35 nm) were obtained on the basis of the theory of Förster energy transfer. IVIG can serve as transport protein (carrier) for kaempferol and quercetin.