Characterization of stereostructure by X-ray and technology of extracting in combination hydrolysis in situ of acankoreanogenin from leaves of Acanthopanax gracilistylus W.W.Smith

To study the stereostructure by X-ray and the technology of extracting acankoreanogenin from the leaves of Acanthopanax graeilistylus W. W. Smith （AGS）, the crystal structure was measured with a Bruker APEX-Ⅱ area-detector diffractometer instrument and the technology of extracting in combination hydrolysis in situ （ECHS） was compared with these of traditional methods. The crystal belongs to the monoclinic system, space group P2b with unit cell parameters： a=（8.3652±0.0006） nm, b=（24.721±0.002） nm, and c=（14.5587±0.0011） nm, α=90°, β=97.850 （4） °, γ=90 °, V=2982.51 nm3, Dc= 1.179 mg/m3, and the molecular number （Z） of elementary structures was 2. The comparisons show that the extraction rate of acankoreanogenin with ECHS methods is much higher than that of traditional methods. Then, central composite design-response surface methodology （CCD-RSM） was adopted for optimizing the extraction rate of ECHS methods. The optimized values of extraction parameters are as follows： for the for extraction process of acid hydrolysis are that extraction time 110.8 min, solvent-herb ratio 11.5 and acid content 5.25%; the best extraction process of basic hydrolysis are that extract time 120 min, solvent-herb ratio 8.7 and the alkali content 8.79%. Finally, the extracts were purified with decolorizing carbon after alkali solution and acid-isolation and purity of acankoreanogenin was 98.7%.

Preparative separation and quantitative determination of two kaurenoic acid isomers in root barks ofAcanthopanax gracilistylus

The kaurenoic acid-type diterpenoids in Acanthopanacis Cortex have been reported to be the major active components. However, the diterpenoids are present as position isomers that exacerbate the challenges in obtaining standards compounds. Little work has been done on the quantitative analysis of the diterpenoids in the herb. In the present study, two diterpenoid isomers ent-16βH,17-isovalerate-kauran-19-oic acid(1) and ent-16βH,17-methyl butanoate-kauran-19-oic acid(2) with high purity were separated by analytical HPLC, followed by recrystallization in acetone. Furthermore, an HPLC-ELSD method was developed and validated for simultaneous determination of 1 and 2 in 9 batches of Acanthopanacis Cortex samples. The HPLC separation and quantification was achieved in 40 min using an Agela Promosil C18 column eluted with a gradient of water and acetonitrile. The calibration curves showed good linearity(r^2 ≥ 0.999 9) within the test ranges. The LOD ranged from 0.407 2 to 0.518 0 mg and LOQ ranged from 1.018 0 to 1.295 0 mg. The precisions(%RSD) were within 1.47% for the two isomers. The recovery of the assay was in the range of 98.78%-99.11% with RSD values less than 2.76%. It is the first time to establish a quantitative HPLC method for the analysis of the bioactive kaurenoic acid isomers in the herb.

A New ent-Kaurane Glycoside from the Stems of Acanthopanax gracilistylus

Objective To study the chemical constituents from the stems of Acanthopanax gracilistylus. Methods The chemical constituents of the plant were isolated and puried by column chromatography and their structures were elucidated on the basis of physicochemical properties and spectral data. Results A new ent-kaurane glycoside, named kaurane acid glycoside A { 16α,17-dihydroxy-ent-kauran-19-oic 19-[β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl] ester} (1), was isolated from the n-butanol part. Conclusion Compound 1 is a new one.