Triterpenoids and lignans from the stems of Schisandra glaucescens

Two new triterpenoids, 24(E)-3α,12α-dihydroxyl-lanost-9(11),24-dien-26-oid acid (1) and 3,4-seco-24(Z)-6α,7β-dihydroxyl-cycloart-4(28),24-dien-3,26-dioic-3-methyl ester (2), and ten known ones (3–12), together with eight lignans (13–20), were isolated from the stems of Schisandra glaucescens. Their structures were established on the basis of extensive spectroscopic analyses. Compounds 1–3, 5–7, 9, 11–13 and 15–18 were isolated from this species for the first time. 1 and 2 were evaluated for their in vitro cytotoxicities against the mouse cancer B16 cell line, human cancer HepG2 and MCF7 cell lines by MTT assay.     

Novel lignans from the stems and leaves of Trachelospermum jasminoides

Two novel 5-methoxydibenzylhydroxybutyrolactone lignans named 5-methoxytracheloside and 5-methoxytrachelogenin were isolated from the stems and leaves of Trachelospermum jasminoides(Lindl.) Lem.,their structures were determined as(8S,8’S)-8’- hydroxy-3,3’,4,5-tetramethoxylignan-9,9’-olide-4’-O-β-D-glucopyranoside and(8S,8’S)-4’,8’-dihydroxy-3,3’.4,5-tertramethoxylignan -9,9’-olide by various spectroscopic analysis.5-Methoxytracheloside was a new compound and 5-methoxytrachelogenin was isolated from natural source for the first time.     

Two new lignans from the stem bark of Magnolia obovata and their cytotoxic activity

Two new lignans, 4-methoxymagnaldehyde B (1) and coumanolignan (2), were isolated from the stem bark of Magnolia obovata, together with 11 known compounds (3-13). The structures of compounds 1 and 2 were determined to be 5'-allyl-2'-hydroxyphenyl-4-methoxy-3-cinnamic aldehyde (1) and 6-allyl-8-(5'-allyl-2'-hydroxyphenyl)coumarin (2) on the basis of spectroscopic and physicochemical analyses including 2D NMR and high-resolution EI-MS. Compounds 1-8, 11, 12, and 13 were tested in vitro for their cytotoxic activities against the HeLa, A549, and HCT116 cancer cell lines. Among the compounds tested, compound 1 showed the strongest cytotoxic activity against the HCT116 cancer cell line, with an IC(50) value of 1.3 microg/ml.     

Cytotoxic lignans from the stems of Styrax camporum (Styracaceae)

An ethanolic extract from the stems of Styrax camporum Pohl (Styracaceae), a plant traditionally used for gastrointestinal diseases, was fractionated and subjected to flash chromatography and afforded two benzofuran lignans, egonol and homoegonol, and one furofuran lignan, (+/-)syringaresinol, which were identified by spectral data interpretation. Their cytotoxic activities against Hep-2 (larynx epidermoid carcinoma), HeLa (human cervix carcinoma) and C6 (rat glioma) cell lines were evaluated using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) assay at several concentrations for 24h. Activities could be observed for egonol against C6 (IC50 = 3.2 microg/mL) and Hep-2 (IC50 = 3.6 microg/mL) cell lines, and for homoegonol against C6 (IC50 = 4.9 microg/mL) and HeLa (IC50 = 5.3 microg/mL) cells.     

Two new lignans from Horsfieldia kingii

Two new dibenzylbutyrolactol lignans and three known dibenzylbutyrolactone lignans were isolated from the twigs and leaves of Horsfieldia kingii. Their structures were elucidated by spectroscopic analysis. Cytotoxicity evaluation of these compounds against five human tumour lines showed no inhibitory effects.     

Two new lignans from Dipteronia dyeriana

A new sesquilignan, 7＇,8＇-didehydroherpetotriol （1）, and a new lignan glycoside, （＋）-isolariciresinol-9＇-O-α-L-rhamnopyra- nosy1-（1→6）-[3-D-glucopyranoside （2）, were isolated from the branches of Dipteronia dyeriana. Their structures were elucidated by spectroscopic methods and chemical evidence. Compound 1 possessed inhibitory activity against human leukaemia K562 cells with an IC50 value of 39 μmol/L.     

A new benzylisoquinoline alkaloid from stems of Nelumbo nucifera

A new benzylisoquinoline alkaloid, named nelumstemine （1）, 1-（4＇-hydroxybenzoyl）-6,7-dimethoxy-3,4-dihydroisoquinoline, was isolated from the stems of Nelumbo nucifera Geartn. Its structure was established on the basis of spectral analysis.     

A new bischromanone from the stems of Semecarpus caudata

From an CHCl₃-soluble fraction of the stems of Semecarpus caudata, one new bischromanone named semecarpanone (1), together with 5 known flavonoids (2–6) were isolated. Their structures were elucidated based on interpretation of spectroscopic data. The stereo-configuration of 1 was identified based on the calculated and experimental coupling constants. Compounds 4–6 showed potent tyrosinase inhibitory activity with the IC₅₀ values ranging from 15.0 to 76.3 μM.     

A new triterpenoid compound from stems and leaves of American ginseng

A new dammarane-type triterpenoid compound was isolated from stems and leaves of American ginseng. The structure of the new sapogenin was elucidated by the combined analysis of NMR and HR-ESI-MS as dammar-20S, 25S-epoxy-3β, 12β, 26-triol (1). Compound 1 showed cytotoxic effect on human SM7721 and human Hela cells in vitro.     

Studies on a medicinal parasitic plant: lignans from the stems of Cynomorium songaricum

Eight phenolic compounds including two new lignan glucopyranosides together with a known alkaloid were isolated from the stems of Cynomorium songaricum RUPR. (Cynomoriaceae). Their chemical structures were elucidated on the basis of spectral and chemical evidence. The chemotaxonomic significance of these metabolites is discussed.     

Two new eupodienone lignans from Gymnotheca chinensis

Two new eupodienone lignans, named gymnothelignan T(1) and gymnothelignan U(2) were isolated from the whole plants of endemicmedicinal plant of Gymnotheca chinensis(Saururaceae). The structures of the new compounds were elucidated by means of HRMS, 1D and 2D NMR. Compound 1 was tested for cytotoxic activity in HCT15, HCT116, A549, MCF-7 and HepG2 cells and exhibited no appreciable activity against these tested cell lines with IC50 values above 50 mmol/L.     

A new coruleoellagic acid derivative from stems of Rhodamnia dumetorum

A new coruleoellagic acid derivative, 3,3′,4,4′,5′-pentamethylcoruleoellagic acid (1) together with nine known compounds, hexamethylcoruleoellagic acid (2), 3,4,3′-tri-O-methylellagic acid (3), heptaphylline (4), 7-methoxymukonal (5), dentatin (6), sinapaldehyde (7), gallic acid (8), 2,6-dimethoxy-4H-pyran-4-one (9) and β-sitosterol (10) were isolated from the stems of Rhodamnia dumetorum. Their structures were identified by physical and spectroscopic data (IR, 1D and 2D NMR, and MS). Compounds 1, 2 and 7-10 were tested for antibacterial activity against six pathogenic bacterial strains (Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, and Methicillin resistant S. aureus (MRSA)).     

A new amide from the stems of Cinnamomum reticulatum Hay

Cinnaretamine, a new amide, has been isolated from Cinnamomum reticulatum Hay (Lauraceae), together with six known compounds, N-trans-feruloylmethoxytyramine, N-cis-feruloylmethoxytyramine, (+)-syringaresinol, p-hydroxybenzoic acid, syringic acid and vanillic acid. The structure of cinnaretamine was determined on the basis of spectroscopic analysis.     

A new dihydrochalcone glycoside from the stems of Homalium stenophyllum

A new dihydrochalcone glycoside, phloretin-4-O-β-D-glucopyranoside (1), together with seven known flavonoids (2–8), were isolated from the stems of Homalium stenophyllum. The structure of 1 was elucidated by extensive spectroscopic methods and the known compounds were identified by comparisons with data reported in the literature. The known compounds (2–8) were isolated from the genus Homalium for the first time. All compounds were evaluated for their antibacterial activities against six pathogenic bacteria in vitro.     

A new morphinandienone alkaloid from the stems of Fissistigma tungfangense

A new morphinandienone alkaloid, fissistigmine A (1), together with three known alkaloids (2?4), were isolated and identified from the stems of Fissistigma tungfangense. Among them, fissistigmine A (1) represents the first example of a novel naturally occurring morphinandienone alkaloid with a unique cleavage of the C-9?N-17 bond. All isolated compounds were evaluated for their anti-rheumatoid arthritis activities via examining their anti-proliferative effects on synoviocytes in vitro. Compound 1 exhibited inhibitory effect on the proliferation of synoviocytes with an IC₅₀ value of 114.6 ± 2.2 μM.     

A new phenolic glycoside from the stems of Hydnocarpus hainanensis

A new phenolic glycoside (1) was isolated from the stems of Hydnocarpus hainanensis, along with 11 known compounds. The structures of all compounds were deduced using 1D, 2D NMR spectroscopic methods. The anti-oxidation activities of several compounds were also evaluated.     

A new cytotoxic naphthoquinone from Paepalanthus latipes

Quinones constitute an important class of naturally occurring compounds. They are found in plants, fungi and bacteria. Large number of quinones has been associated with antitumor, antibacterial, antimalarial and antifungal activities. In this work we describe the isolation, structure determination and the cytotoxic index of a new 1,4-naphthoquinone isolated from the capitula of Paepalanthus latipes.     

A new triterpenoid glycoside from the leaves and stems of Duranta repens

A new triterpenoid glycoside (1) was isolated from the methanol extract of the leaves and stems of Duranta repens L. (Verbenaceae) along with 14 known compounds consisting of eight triterpenoids, four iridoids, one phenylethanoid glycoside and one flavonoid. The chemical structure of 1 was determined to be bayogenin 3-O-[β-D-glucopyranoside]-28-O-[α-L-rhamnopyranosyl-(1→5)-O-β-D-apiofuranosyl-(1→4)-O-α-L-rhamnopyranosyl-(1→2)-O-α-L-arabinopyranosyl] ester, based on spectroscopic data. In addition, the inhibitory effects of the isolates on lipoxygenase activity were examined. Among them, acteoside and apigenin resulted in 94 ± 3.6% and 82 ± 4.7% inhibition, respectively, at 0.5 mM.     

A new cycloartane triterpenoid from the leaves and stems of Fritillaria hupehensis

A new triterpenoid has been isolated from the leaves and stems of Fritillaria hupehensis Hsiao et K.C.Hsia.Its structure wasestablished as(23Z)-9,19-cycloart-23-ene-3α,25-diol 1 through chemical and spectroscopic studies including 2D NMR.Anotherknown triterpenoid 9,19-cycloart-25-ene-3β,24ξ-diol 2 was also isolated.     

Ananasic acid: A new trihydroxytriterpenecarboxylic acid from pineapple stems

From the stems of commercially grown pineapple (Ananas comosus var Cayenne) we have isolated 3β,11α,15α-trihydroxycycloart-24-en-26-oic (ananasic) acid (6) and determined its structure by spectral determinations and by comparison with the known 3β-hydroxycycloart-24-en-26-oic (mangiferolic) acid (3a).