Studies on the constituents of Syringa species. XII. New glycosides from the leaves of Syringa reticulata (BLUME) HARA

Three new glycosides, 6'-O-alpha-D-galactopyranosylsyringopicroside (1), secologanoside 7-methyl ester (2) and (+)-lariciresinol 4'-O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranoside (3), were isolated from the leaves of Syringa reticulata. Their structures were established on the basis of chemical and spectral data. Compound 1 is the first naturally occurring iridoid di-glycoside having melibiose. Comparison of the spectral data of 2 and that previously recognized as secologanoside 7-methyl ester led to the conclusion that the recognized structure should be revised to the sodium salt of secoxyloganin (2').     

Studies on the constituents of Syringa species. X. Five new iridoid glycosides from the leaves of Syringa reticulata (Blume) Hara

Five new iridoid glycosides, (8Z)-ligstroside (1), (8Z)-nüzhenide (3), 6'-O-alpha-D-glucopyranosylsyringopicroside (4), 3'-O-beta-D-glucopyranosylsyringopicroside (5) and 4'-O-beta-D-glucopyranosylsyringopicroside (6) were isolated, together with a known one, (8E)-nüzhenide (2), from the leaves of Syringa reticulata. Their structures were established on the basis of chemical and spectral data. Compounds 1 and 3 are the first findings of a (8Z)-oleoside-type secoiridoid. Compound 4 is the first naturally occurring iridoid di-glycoside having an isomaltose.     

Lignans of the bark of Syringa volgaris

Two lignans have been isolated from the bark ofSyringa vulgaris and identified: (+)-lariciresinol 4-β-D-glucopyranoside (I) and -olivil 4-β-D-glucopyranoside (II). This is the first time that glycoside (9) has been described. All-Union Scientific-Research Institute of Medicinal Plants Scientific-Production Association, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 768–771, November–December, 1991.     

Two New Neolignans from the Stems of Syringa pinnatifolia Hemsl. var. alashanensis

Two new neolignans, syripinnalignins A and B ( 1 and 2 , resp.), were isolated from the 95% EtOH extract of the stem of Syringa pinnatifolia Hemsl . var. alashanensis. The structures of 1 and 2 were elucidated by spectroscopic methods, including UV, IR, HR‐ESI‐MS, and extensive 1D‐ and 2D‐NMR techniques.     

Iridoids of the bark of Syringa vulgaris

All-Union Scientific-Research Institute of Medicinal Plants, Scientific Production Combine, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 695–697, September–October, 1990.     

Lignans of the bark of Syringa volgaris

Two lignans have been isolated from the bark ofSyringa vulgaris and identified: (+)-lariciresinol 4--D-glucopyranoside (I) and -olivil 4--D-glucopyranoside (II). This is the first time that glycoside (9) has been described.All-Union Scientific-Research Institute of Medicinal Plants Scientific-Production Association, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 768–771, November–December, 1991.     

Phenolic compounds of the bark of Syringa amurensis

Chemistry of Natural Compounds -     

Studies on constituents with cytotoxic activity from the stem bark of Syringa velutina.

Cytotoxic compounds, oleuropein (1) and a phenylethanoid glycoside (2) were isolated from the stem bark of Syringa velutina KOM. along with coniferylaldehyde 4-O-glucoside, syringin, ligstroside, (+)-syringaresinol 4-O-glucoside, (+)-medioresinol 4"-O-glucoside and (-)-olivil 4"-O-glucoside. Phenylethanoid glycoside (2) was identified to be 3,4-dihydroxyphenylethyl alcohol 8-O-beta-D-glucopyranoside. This compound showed the most potent cytotoxic effect on several tumor cell lines (P-388, L-1210, SNU-5 and HL-60) among eight compounds isolated in the present study. We suggest that the 3,4-dihydroxyphenylethoxy moiety of this compound contributes to cytotoxicity.     

Two new secoiridoid glucosides from Syringa velutina Kom

Chemical investigation of Syringa velutina Kom. led to the isolation of two new secoiridoid glucosides. Their structures were identified as 6'-0-(6, 7-dihyrofoliamenthoyl)-8-epi-kingisidic acid (syrveoside A, 1) and 6'-O-menthiafoloyl-8-epi-kingisidic acid (syrveoside B, 2) on the basis of chemical and physicochemical evidence.     

TLC and HPLC analysis of syringin in Syringa vulgaris

Using HPLC, the component composition of the bark ofSyringa vulgaris has been studied and a procedure has been developed for the quantitative determination of syringin in raw material from this plant. The seasonal dynamics of the accumulation of syringin in the bark of common lilac has been studied with the aid of a chromatospectrophotometric method and HPLC analysis.All-Union Scientific-Research Institute of Medicinal Plants Scientific-Production Combine, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 45–49, January–February, 1992.     

A pair of humulane sesquiterpenoid enantiomers from Syringa pinnatifolia

Two humulane-type sesquiterpenoids, namely (+)-alashanoid I (1a) and (–)-alashanoid I (1b), were isolated as a pair of enantiomers from the peeled stems of Syringa pinnatifolia. Their structures were elucidated by extensive spectroscopic data (1?D and 2?D NMR, UV, and IR), and the absolute configurations were resolved by X-ray diffraction and experimental and calculated ECD data analysis.     

Phenolic composition,antioxidant and antinociceptive activities of Syringa vulgaris L. bark and leaf extracts

Metabolite profile, antioxidant and antinociceptive activities of Syringa vulgaris bark and leaf methanolic extracts were investigated. By means of HPLC-DAD-ESI-TOF and HPLC-DAD-ESI-MS/MS, a total of 33 phenolics were identified, including 15 secoiridoids, 6 phenylpropanoids, 3 flavonoids, 3 lignans and 6 low molecular weight phenols. Validated quantitative analysis show that syringin (2.52%) and rutin (1.13%) are the main phenolic compounds in bark and leaf, respectively. Notable radical scavenging and antinociceptive activities of the bark and leaf extracts were confirmed by in vitro DPPH^● and ABTS^●+ assays and by in vivo hot-plate method in mice, respectively. Our results could lay the scientific basic of future clinical perspectives of lilac bark and leaf.     

A new 6,9′-cyclolignan from Syringa pinnatifolia

A new lignan, 4,4′-dihydroxy-3,3′-dimethoxy-6,9′-cycloligna-7,8′-dien-9′-al, was isolated from the stem of Syringa pinnatifolia Hems1. var. alashanensis MA. et S.Q. Zhou (S. pinnatifolia). This is the first report on the structure elucidation of a new compound based on spectroscopic methods including UV, IR, ESI-MS, 1D NMR and 2D NMR techniques.     

Chemical Profile,Cytotoxic Activity and Oxidative Stress Reduction of Different Syringa vulgaris L. Extracts

Syringa vulgaris L. (common lilac) is one of the most popular ornamental species, but also a promising not comprehensively studied source of bioactive compounds with important therapeutic potential. Our study was designed to characterize the chemical composition and to assess the antioxidant and cytotoxic properties of ethanolic extracts obtained from S. vulgaris L. flowers, leaves, bark, and fruit. The chemical profile of the ethanolic extracts was investigated using chromatographic (HPLC-DAD-ESI⁺, GC-MS) and spectral (UV-Vis, FT-IR) methods, while the protective effect against free radicals was evaluated in vitro by different chemical assays (DPPH, FRAP, CUPRAC). The cytotoxic activity was tested on two tumoral cell lines, HeLa, B16F10, using the MTT assay. Significant amounts of free or glycosylated chemical components belonging to various therapeutically important structural classes, such as phenyl-propanoids (syringin, acteoside, echinacoside), flavonoids (quercetin, kaempferol derivatives) and secoiridoids (secologanoside, oleuropein, 10-hydroxy oleuropein, demethyloleuropein, syringalactone A, nuzhenide, lingstroside) were obtained for the flowers, leaves and bark extracts, respectively. Furthermore, MTT tests pointed out a significant cytotoxic potential expressed in a non-dose-dependent manner toward the tumoral lines. The performed methods underlined that S. vulgaris extracts, in particular belonging to flowers and leaves, represent valuable sources of compounds with antioxidant and antitumoral potential.