[A new lupane-type triterpenoid from Dichroa hirsuta].

The chemical constituents from methanol extract of Dichroa hirsuta were separated by silica gel and Sephadex LH-20 column chromatography,high pressure preparative liquid chromatography( HPLC) and recrystallization. Their structures were elucidated by NMR and MS. Nine compounds were obtained and their structures were identified as 3ß,21α-O-diacetyl-lup-9( 11)-en-7ß-ol( 1),( Z)-methyl p-hydroxycinnamate( 2),cis-p-coumaric acid ethyl ester( 3),( E)-methyl p-hydroxycinnamate( 4),trans-p-coumaric acid ethyl ester( 5),4( 3 H)-quinazolinone( 6),7-hydroxycoumarin( 7),hydrangenol( 8) and thunberginol C( 9). Compound 1 is a new lupane-type triterpenoid,and compounds 1-5,8-9 were firstly isolated from this plant. Dual reporter assay results showed that compounds 2-5 could activate the Nrf2-ARE signaling pathway.

[Chemical constituents of Cassia siamea].

A total of ten compounds were isolated from the 90% Et OH extract of Cassia siamea by using various chormatographic techniques,and their structures were established as( 2' S)-2-( propan-2'-ol)-5,7-dihydroxy-benzopyran-4-one( 1),chrobisiamone( 2), 2-( 2'-hydroxypropyl)-5-methyl-7-hydroxychromone( 3), 2,5-dimethyl-7-hydroxychromone( 4), 2-methyl-5-acetonyl-7-hydroxychromone( 5),3-O-methylquercetin( 6),3,5,7,3',4'-pentahydroxyflavonone( 7),luteolin-5,3'-dimethylether( 8),4-( trans)-acetul-3,6,8-trihydroxy-3-methyl-dihydronapht halenone( 9) and 6-hydroxymellein( 10) based on the spectroscopic data.Compound 1 was a new compound,and 3,4,6,8 were isolated from this plant for the first time.

[Chemical constituents from roots and rhizomes of Rubia oncotricha and their cytotoxic activities].

Fourteen compounds, including rubiprasin D (1), rubiprasin B (2), rubiprasin C (3), oleanolic acid (4), methyl-5-hydroxy-dinaphtho[1, 2-2'3']furan-7, 12-dione-6-carboxylate (5), rubioncolin C (6), mollugin (7), furomollugin (8), 3-amino-2-methoxycarbonyl-1, 4-naphthoquinone (9), 1-hydroxy-2-methyl-9, 10-anthraquinone (10), 2-hydroxy-6-methyl-9, 10-anthraquinone (11), 1, 4-dihydroxy-2-hydroxymethyl-9, 10-anthraquinone (12), 2-hydroxy-1-methoxy-9, 10-anthraquinone (13), and 1-hydroxy-2-methoxy-6-methyl-9, 10-anthraquinone(14), were isolated from the methanol extract of the roots and rhizomes of Rubia oncotricha using various column chromatographies. Their structures were mainly determined on basis of NMR and MS spectroscopic data analyses. Among them, 1 is a new oleanane triterpene, and compounds 2-5, 9 and 11-13 were obtained from this plant for the first time. Cytotoxic and nematicidal activities of all these compounds were evaluated, and the results showed that only 4, 6, 11 and 12 exhibited cytotoxicities against A549, SGC-7901 and HeLa cancer cell lines. The IC50 of 6 were 19.42, 2.74, 8.07 µmol·L⁻¹, respectively.

NF-κB and JNK mediated apoptosis and G0/G1 arrest of HeLa cells induced by rubiarbonol G, an arborinane-type triterpenoid from Rubia yunnanensis.

ETHNOPHARMACOLOGICAL RELEVANCE: Rubia yunnanensis is a medicinal plant mainly grown in Yunnan province in Southwest China, and its root named "Xiaohongshen" has been used as a herb in Yunnan for the treatment of cancers. Three major types of chemical components, Rubiaceae-type cyclopeptides, quinones, and triterpenoids, were identified from R. yunnanensis, in which some of compounds including rubiarbonol G (RG), a unique arboriane-type triterpenoid, showed cytotoxicity on cancer cells. But the cytotoxic mechanism of RG has not been reported. AIM OF THE STUDY: To investigate the cytotoxic mechanism of RG on cancer cells. MATERIALS AND METHODS: RG was evaluated its cytotoxicity on 7 cancer cell lines by the SRB assay, and detected the effect on apoptosis and cell cycle arrest by Annexin V-FITC/PI apoptosis assay and DNA contents analysis. The expression and activity of apoptosis and cell cycle related proteins were also investigated by western blot and caspase activity assay. Furthermore, the effect of RG on NF-κB signaling was also tested by luciferase assay, western blot, and immunofluorescence staining. RESULTS: RG showed potent cytotoxicity on 7 human cancer cell lines, whose activity was attributed to apoptosis induction and G0/G1 arrest in HeLa cells. Results from the mechanism study showed that RG promoted the activation of ERK1/2 and JNK pathway in MAPK family, which in turn increased the expression of p53, thereby triggering the G0/G1 arrest through p53/p21/cyclin D1 signaling. Moreover, RG-mediated JNK activation down-regulated the expression of the anti-apoptotic protein Bcl-2, which caused the release of cytochrome c to the cytosol and activated the cleavage of caspase cascade and poly(ADP-ribose) polymerase, thereby inducing apoptosis in HeLa cells. In addition, RG was also found to inhibit the activation of NF-κB signaling by down-regulating the expression and attenuating the translocation to nucleus of NF-κB p65, by which the down-stream p53, cyclin D1, Bcl-2, and caspases were regulated, thereby triggering apoptosis and G0/G1 arrest in HeLa cells. CONCLUSION: These results indicated that RG induces mitochondria-mediated apoptosis and G0/G1 cell cycle arrest by activation of JNK signaling as well as inactivation of NF-κB pathway in HeLa cells, which suggests that RG is one of the key active ingredients accounting for the anti-tumor effect of R. yunnanensis.

Phytochemical Analysis of a Cytotoxic Fraction of Quassia silvestris using LC-HR-ESI-MSn.

INTRODUCTION: The genus Quassia is a promising source of secondary metabolites with biological potential including antimalarial and cytotoxic activities. Limited data are available on the phytochemistry and pharmacology of Quassia silvestris Cheek & Jongkind, a Cameroonian medicinal plant used to treat various ailments. OBJECTIVES: To carry out the bioassay-guided fractionation and LC-HR-ESI-MS analyses of the leaves extract from Q. silvestris; to purify the active fractions and isolate the major compounds using different chromatographic and spectroscopic methods. The obtained compounds will be evaluated for their biological activity. MATERIAL AND METHODS: Following the cytotoxic screening and LC-HR-ESI-MS profiling of fractions obtained from partition of the methanolic extract of Q. silvestris leaves, the CH2 Cl2 -soluble fraction which exhibited the highest cytotoxicity was retained for further investigations. RESULTS: Sixteen squalene-derived metabolites were identified with oxasqualenoid derivatives being the most predominant. Among the isolates, structure elucidation of two new oxasqualenoids quassiols E (1) and F (2), were achieved by NMR (one-dimensional (1D) and two-dimensional (2D)) and MS methods. The newly characterised compounds 1 and 2, together with the known tetraol (3) and 3-oxo-oleanoic acid (16) displayed moderate cytotoxicity. CONCLUSION: The identification and structural characterisation of highly oxidised squalene derived metabolites from this plant may provide important insight data for further pharmacological investigations. The LC-HR-ESI-MSn method reported here could be developed as a rapid and efficient tool for the analyses of structurally related compounds in the genera Quassia, Simarouba, and Eurycoma of the subfamily Simarouboideae. Copyright © 2016 John Wiley & Sons, Ltd.

Two New Cinnamyl Isovalerate Derivatives from Sabina gaussenii.

Chemical investigation of the 90% acetone extract of the branches and leaves of Sabina gaussenii led to the isolation of two new cinnamyl isovalerate derivatives (1-2) and eighteen known compounds (3-20). Their structures were determined mainly by means of MS, 1D- and 2D-NMR data, and this is the first time these compounds have been reported from this plant. The biological activity test results indicated that the 90% acetone extract showed cytotoxicity against the human lung adenocarcinoma (A549) cell line (IC50 = 0.98 ± 0.1 µg/mL), compound 6 showed cytotoxicities against human cervical carcinoma (HeLa) (IC50 = 0.4 ± 0.1 µM ) and human gastric carcinoma (BGC-823) (IC50 = 0.9 ± 0.2 µM) cancer cell lines, and compound 19 showed cytotoxicities against HeLa (IC50 = 1.5 ± 0.4 µM), BGC-823 (IC50 = 7.0 ± 0.8 µM ), and A549 (IC50 = 10.6 ± 1.5 µM ) cancer cell lines.

Rubipodanin A, the First Natural N-Desmonomethyl Rubiaceae-Type Cyclopeptide from Rubia podantha, Indicating an Important Role of the N9-Methyl Group in the Conformation and Bioactivity.

One new cyclic hexapeptide named rubipodanin A (1), which is the first identified natural N-desmonomethyl Rubiaceae-type cyclopeptide, together with six known Rubiaceae-type cyclopeptides (2-7) were obtained using the TLC cyclopeptide protosite detection method with ninhydrin from the roots and rhizomes of Rubia podantha. The cyclopeptide structures were elucidated by extensive spectroscopic analysis, including 1D-NMR, 2D-NMR, IR, UV and MS. The solution conformation and biological activities of 1 and RA-V (4) were evaluated, and the results demonstrated that the N9-methyl group plays a vital role in the maintenance of the conformation and bioactivity.

Report: Cytotoxic flavonoids from the young twigs and leaves of Caesalpinia bonduc (Linn) Roxb.

The extraction, fractionation and recognition of flavonoids from the ethanolic extract of young twigs and leaves of C. bonduc were carried out. In addition, cytotoxic study of the flavonoids on two cancer cell lines, BGC-823 and HeLa was carried our using sulphorhodamine B assay. Seven flavonoids, six of which are being reported for the first time in this plant, were isolated. Their structures were identified by MS and NMR spectroscopic methods. Petroleum ether, ethyl acetate and water fractions exhibited moderate cytotoxic activity against HeLa cells. Five compounds showed cytotoxic activity against HeLa cell in comparison with Paclitaxel, while only one compound showed a good degree of cytotoxic activity against BGC-823 cell in comparison to Paclitaxel. The results obtained showed a structure - activity relationship.

Antimicrobial and cytotoxic constituents from native Cameroonian medicinal plant Hypericum riparium.

Bioassay guided fractionation of Hypericum riparium leaves extract has resulted in the isolation and characterization of three new compounds namely chipericumin E (1), hyperenone C (3), and hyperixanthone (5), together with twenty known compounds. Their structures were elucidated based on comprehensive interpretation of spectroscopic and spectrometric data. Compounds 1-4, and 6-8 displayed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) and cytotoxic effects on the human gastric cell line BGC-823 with IC50 values ranging from 6.54 to 18.50µM.

New cytotoxic naphthohydroquinone dimers from Rubia alata.

Two novel naphthohydroquinone dimers with unprecedented skeletons, rubialatins A (1) and B (2), were isolated from the herbal plant Rubia alata together with their precursor, mollugin (3). The structures were elucidated on the basis of NMR spectra and crystal X-ray diffraction. Compound 1, a racemate, was separated by chiral column chromatography, and the absolute configurations of the enantiomers were determined by the computational methods. Cytotoxicity of 1-3 was evaluated as well as the effect on the NF-κB pathway. Compound (+)-1 showed cytotoxicity and could inhibit NF-κB pathway. Meanwhile, 2 showed cytotoxicity and a synergistic effect with TNF-α on NF-κB activation.

Two new phenylpropanoids from Micromelum integerrimum.

AIM: To investigate the chemical and bioactive constituents from the stems and leaves of Micromelum integerrimum. METHOD: The chemical constituents were isolated and purified by silica gel, Sephadex LH-20, and HPLC. Their structures were mainly elucidated on the basis of extensive 1D- and 2D-NMR spectroscopy and mass spectrometry. Their cytotoxicity and antimicrobial activities were tested by the SRB and turbidimetric methods, respectively. RESULTS: Two new phenylpropanoids and two known coumarins were obtained, and their structures were identified as microintegerrin A (1), microintegerrin B (2), scopoletin (3), and scopolin (4). All of the compounds were tested for their cytotoxicity against three cancer cell lines (HeLa, A549, and BGC-823) and for antimicrobial activity against the fungus Candida albicans and the bacterium Staphylococcus aureus. CONCLUSION: Two new phenylpropanoids 1 and 2 were isolated and identified from the stems and leaves of M. intgerrimum. None of the compounds showed cytotoxic or antimicrobial activity at the tested concentration of 20 µg·mL(-1).

New dicyclopeptides from Dianthus chinensis.

One new dicyclopeptide cyclo-(L-N-methyl Glu-L-N-methyl Glu) (1), together with one new natural dicyclopeptide cyclo-(L-methyl Glu ester-L-methyl Glu ester) (2), and two known dicyclopeptides cyclo-(L-methyl Glu ester-L-Glu) (3), and cyclo-(L-Glu-L-Glu) (4), were isolated from the aerial parts of Dianthus chinensis L. Their structures were determined by spectroscopic analyses and chemical methods.

A new lignan glycoside from Chamaecyparis obtusa var. breviramea f. crippsii.

A new lignan glycoside, (-)-(8S, 8'R)-thujastandin-4-O-beta-D-glucopyranoside (1), together with fourteen known lignanoids (2-15) and one coumarin (16) were isolated from the branches and leaves of Chamaecyparis obtusa var. breviramea f. crippsii. Their structures were elucidated by extensive spectroscopic and spectrometric analysis. Compound 16 exhibited cytotoxicity against A549, BGC-823 and Hela cell lines with IC50 values of 25.9, 20.9 and 18.5 microM, respectively.

Astershionones A-F, six new anti-HBV shionane-type triterpenes from Aster tataricus.

Six new shionane-type triterpenes, astershionones A-F (1-6), were obtained from the roots and rhizomes of Aster tataricus. Their structures were elucidated on the basis of spectroscopic data, mainly NMR and MS data. The absolute configuration of 1 was determined by single crystal X-ray diffraction analysis and CD analysis. 3 showed inhibitory activity against HBsAg and HBeAg secretion with IC50 values of 23.0 and 23.1 µM, and cytotoxicity against HepG 2.2.15 cells with a CC50 value of 170.5 µM. 3 also exhibited inhibitory activity against HBV DNA replication with an IC50 value of 22.4 µM.

Astataricusones A-D and astataricusol A, five new anti-HBV shionane-type triterpenes from Aster tataricus L. f.

Five new shionane-type triterpenes, astataricusones A-D (compounds 1-4) and astataricusol A (5), together with one known shionane-type triterpene 6 were obtained from the roots and rhizomes of Aster tataricus L. f. Their structures were elucidated on the basis of spectroscopic data, mainly NMR and MS data. The absolute configurations of 1 and 4 was determined by single crystal X-ray diffraction and CD analysis. Compound 2 showed inhibitory activity on HBsAg secretion with an IC50 value of 23.5 µM, while 2 and 6 showed inhibitory activities on HBeAg secretion with IC50 values of 18.6 and 40.5 µM, and cytotoxicity on HepG 2.2.15 cells with CC50 values of 172.4 and 137.7 µM, respectively. Compounds 2 and 6 also exhibited inhibitory activities on HBV DNA replication with IC50 values of 2.7 and 30.7 µM, respectively.

8-9' linked neolignans with cytotoxicity from Alpinia conchigera.

Five new 8-9' linked neolignans conchigeranals A-E (1-5), together with three known compounds galanganal (6), galanganols A (7) and B (8), were isolated from the whole plant of Alpinia conchigera. Their structures were established by spectroscopic analysis, including 2D-NMR spectroscopic techniques. Cytotoxicities of compounds 1-8 were tested against two cancer cell lines A549 and Hela. Results showed that 4, 5, 7 and 8 exhibited cytotoxicity against A549 with the IC50 values of 12.36, 9.72, 10.26, 13.05 µg/ml, respectively, and 1-8 against Hela with the IC50 values from 1.53 to 5.29 µg/ml.

Apoptosis induction and G2/M arrest of 2-methyl-1,3,6-trihydroxy-9,10-anthraquinone from Rubia yunnanensis in human cervical cancer Hela cells.

2-Methyl-1,3,6-trihydroxy-9,10-anthraquinone (MTA), one of the major components isolated from the traditional Chinese medicine Rubia yunnanensis, exhibited inhibitory activity on the proliferation of several human cancer cell lines. The results from an annexin V-FITC (fluoresein-5-isothiocyanate) apoptosis assay and DNA content analysis showed that MTA exerted cytotoxicity via apoptosis induction and G2/M cell cycle arrest in human cervical carcinoma HeLa cells. Further, MTA was found to induce apoptosis of HeLa cells through the mitochondria-mediated pathway. It caused the translocation of Bax to the mitochondria and release of cytochrome c into the cytosol, which caused the cleavage of caspase and poly(ADP-ribose) polymerase and finally triggered the apoptosis. Furthermore, the p53/p21/Cdc2-cyclin B1 signaling was found related to the G2/M arrest caused by MTA. The over-expression of p21 and down-expression of cyclin B1 caused by MTA inactivated the Cdc2-cyclin B1 complex of G2/M checkpoint and finally caused the G2/M arrest in HeLa cells. This study demonstrated that MTA is a potential anti-cancer component of R. yunnanensis, a folk anti-cancer herb used in Yunnan, China.

Plant cyclopeptide RA-V kills human breast cancer cells by inducing mitochondria-mediated apoptosis through blocking PDK1-AKT interaction.

In the present paper, we examined the effects of a natural cyclopeptide RA-V on human breast cancer cells and the underlying mechanisms. RA-V significantly inhibited the growth of human breast cancer MCF-7, MDA-MB-231 cells and murine breast cancer 4T1 cells. In addition, RA-V triggered mitochondrial apoptotic pathway which was indicated by the loss of mitochondrial membrane potential, the release of cytochrome c, and the activation of caspase cascade. Further study showed that RA-V dramatically inhibited phosphorylation of AKT and 3-phosphoinositide dependent protein kinase 1 (PDK1) in MCF-7 cells. Moreover, RA-V disrupted the interaction between PDK1 and AKT in MCF-7 cells. Furthermore, RA-V-induced apoptosis could be enhanced by phosphatidylinositol 3-kinase inhibitor or attenuated by over-expression of AKT in all the three kinds of breast cancer cells. Taken together, this study shows that RA-V, which can induce mitochondria-mediated apoptosis, exerts strong anti-tumor activity against human breast cancer. The underlying anti-cancer mechanism of RA-V is related to the blockage of the interaction between PDK1 and AKT.

A new phenolic glycoside from Chamaecyparis obtusa var. breviramea f. crippsii.

A new phenolic glycoside, 3-methoxyphenol 1-O-α-L-rhamnopyranosyl-(1→6)- O-ß-D-glucopyranoside (1), was isolated from the 90% acetone extract of the branches and leaves of Chamaecyparis obtusa var. breviramea f. crippsii along with another 10 known phenolics 2-11. Their structures were determined mainly by means of MS, 1D- and 2D-NMR data. Cytotoxicities of compounds 3 and 5-11 were tested on BGC-823, Hela and A549 cancer cell lines, the results showed that compound 8 was bioactive and its IC(50) values were 6.9, 29.7 and 52.9 µM, respectively.

Terpene and lignan glycosides from the twigs and leaves of an endangered conifer, Cathaya argyrophylla.

Labdane diterpene glycosides cathargyroside A and cathargyroside B, monoterpene glycosides vervenone-10-O-ß-D-glucopyranoside and vervenone-10-O-ß-D-apiofuranosyl-(1″→6')-ß-D-glucopyranoside, as well as lignan glycosides cedrusinin-4-O-α-L-rhamnopyranoside and (+)-cyclo-olivil-9'-O-ß-D-xylopyranoside, along with 39 known compounds, were obtained from the methanol extract of the twigs and leaves of Cathaya argyrophylla. These compounds were identified mainly by analyzing their NMR and MS data. Almost all of these compounds were hitherto unknown in this genus. The isolated compounds were screened against Candida albicans and Staphylococcus aureus for antimicrobial assay, and against K562, HT-29, BEL-7402, SGC-7901, B16, BGC-823, U251 and A549 cancer cell lines for cytotoxic activities. One compound showed antimicrobial activity against C. albicans, and four of them displayed cytotoxicity. Similarity analysis on the chemical constituents of the genera Cathaya, Picea and Pinus supported their close phylogenetic relationships.