Di- and Triterpenoids from the Leaves of Casearia balansae and Neurite Outgrowth Promoting Effects of PC12 Cells

A bioassay-guided phytochemical investigation of the leaves of Casearia balansae led to the isolation of six new cucurbitane-type triterpenoid derivatives (balanterpenes A-F, 1-6) and four new clerdoane-type diterpenoids (balanterpenes G-J, 7-10). The structures of 1-10 were established on the basis of extensive analysis of NMR spectroscopic data, X-ray crystallography, and experimental and calculated electronic circular dichroism spectra. Compound 1 features a ring-expanded triterpenoid skeleton with the C-19 methyl involved in the ring formation, compound 6 possesses a rare hexanortriterpenoid scaffold, and compounds 7-10 may be four new diterpenoid artifacts presumably formed during the extraction and purification processes. Compounds 3 and 7-10 showed promoting effects on neurite outgrowth of PC12 cells with EC50 values in the range 2.9-10.0 μM.

New salicin derivatives from the leaves of Populus euphratica

Chemical investigation of the leaves of Populus euphratica Oliv. led to the isolation and identification of 13 compounds for the first time, among which 6'-O-cis-cinnamoylsalicin (1) and 6'-O-benzoylsalicortinol (2) were new compounds. The spectral data of 6'-O-trans-cinnamoylsalicin (3) and salicortinol (4) were reported for the first time. Their structures were elucidated on the basis of detailed spectroscopic analysis and comparisons with literature values.

[Studies on the chemical constituents of Rhodiola rosea]

OBJECTIVE

To separate and identify the chemical constituents of n-BuOH extraction from the roots of Rhodiola rosea in Xinjiang.

METHODS

The column chromatography was used to separate consituents. The structures were elucidated by chemical reactions and MS, 1H-NMR, 13C-NMR, and 2D-NMR spectral data.

RESULTS

Six compounds were isolated and identified as salidroside (I), kaempferol-7-O-alpha-L-rhamnopyranoside(II), herbacetin-7-O-alpha-L-rhamnopyr-anoside(III), herbace-tin-7-0-(3"-O-beta-D-glucopyran-oside)-alpha-L-rhamnopyranoside(IV), 5, 7, 3', 5'-tetrahydroxy-flavanone(V), sucrose(VI).

CONCLUSION

Compound V is isolated from this plant for the first time.

[Structure-activity relationships of phenylethanoid glycosides in plants of Cistanche salsa on antioxidative activity]

OBJECTIVE

To study the structure-activity relationships of phenylethanoid glycosides in plants of Cistanche salsa on antioxidative activity.

METHODS

By the assay systems of DPPH*, the antioxidant activity of six phenylethanoid glycosides from plants of Cistanche salsa was determined to investigate the relationship between the antioxidant activities and phenylethanoid glycosides's structural characteristics.

RESULTS

The antioxidative activity of phenylethanoid glycosides was variant with dose-dependent effect. The sequence of the strength of the antioxidative activity of the six components was shown to be 2'-Acetylacteoside > Acteoside > or = Tubuloside B > or = Isoacteoside > Echinacoside > Cistanoside A.

CONCLUSION

The antioxidative activity of phenylethanoid glycosides is related to the number of phenolic hydroxyl, steric hindrance, 2-acetyl on the middle glucopyranose, and the location of phenolic hydroxyl. Additionally, it may be related to the alpha, beta-unsaturated ketone of phenl-2-propenoyl.

[Studies on the chemical constituents from Xinjiang Punica granatum]

OBJECTIVE

To study the chemical constituents from Punica granatum.

METHODS

The chemical constituents were isolated by column chromatography on silica gel and MCI-gel CHP 20P, Sephadex LH-20. Their structures were elucidated on the basis of spectral analysis and physical constants.

RESULTS

Ten compounds were isolated and elucidated as: gallic acid (1), methyl gallate (2), ellagic acid (3), (+) catechin (4), isoquerecitrin (5), D-mannitol (6), ursolic acid (7), Oleanolic acid (8), beta-Sitosterol (9) and Daucosterol (10).

CONCLUSION

Compounds 1-10 are isolated from this plant for the first time.

[Studies on chemical constituents from EtOAc fraction of Sorbus tianschanica]

OBJECTIVE

To study the chemical constituents of Sorbus tianschanica.

METHOD

The compounds were isolated and purified by recrystallization and chromatography with silica gel and resin. Their structures were identified by physicochemical properties and spectral analysis.

RESULT

Seven compounds were isolated from the EtOH extraction and six structures were identified as benzoic acid (1), benzyl-O-beta-D-glucopyranoside (2), ursolic acid (3), 2alpha-hydroxyursolic acid (4), hyperoside (5), quercetin-3-O-glucoside (6).

CONCLUSION

Compounds 1-5 were isolated from S. tianschanica for the first time.

[Studies on chemical constituents of cultivated Cistanche salsa]

OBJECTIVE

To study the chemical constituents of cultivated Cistanche salsa.

METHODS

Compounds were isolated and purified on several chromatography, and then were identified by physico-chemical properties and structurally elucidated by spectral analysis.

RESULTS

Seven compounds were isolated and identified as beta-sitosterol (I), daucosterol (II), beta-sitosteryl glucoside 3'-O-heptadecoicate (III), 8-hydroxygeraniol 1-beta-D-glucopyranoside (IV), 2-methanol-5-hydroxy-pyridine (V), betaine (VI), galactitol (VII).

CONCLUSION

The chemical constituents of artificial cultivated Cistanche salsa are studied for the first time. Among them, compound III and IV are isolated from the plant for the first time, compound V is isolated from this genus for the first time.