Bioactive cis-stilbenoids from the tubers of Scirpus yagara

Two new cis-stilbenoids, sciryagarol I (1) and II (2) were isolated from the EtOAc extract of the tubers of Scirpus yagara, together with four known compounds. The structures of all compounds were determined by comprehensive analyses of their spectroscopic data and comparison with literature information. The compounds 3, 4 and 6 were isolated for the first time from this genus. Some compounds were tested for their cytotoxicity against human tumor cell lines and antimicrobial activity. Compounds 1–4 showed significant cytotoxicity against the Hela cell lines with IC₅₀ values ranging from 7.21 to 61.21 μM. 1 and 2 exhibited some antimicrobial activity against Staphylococcus aureus and Candida albicans with uniform MICs of 79.3 μl/ml for 2, and 152 μl/ml for 1, respectively.     

泡桐(原变种)果实中抑菌性苯丙素苷成分的研究

研究了泡桐(原变种)果实的化学成分。采用Sephadex LH-20柱色谱及薄层色谱等方法进行分离,从其70%丙酮提取物水溶性部分分离得到4种苯丙素苷化合物,经波谱分析及理化性质分析,化合物分别鉴定为:毛蕊花苷(1)、异毛蕊花苷(2)、campneoside II(3)和isocampneoside II(4)。化合物1和2首次从该植物中得到。抑菌活性试验结果表明,泡桐(原变种)果实中分离得到的苯丙素苷化合物、丙酮提取物、乙酸乙酯溶及水溶性部分具有较高的抑菌活性,其中,对革兰氏阳性菌中表皮葡萄球菌的抑制能力最强。     

Steroidal saponins from Fritillaria pallidiflora Schrenk

Five new steroidal saponins, Pallidifloside D (1), Pallidifloside E (2), Pallidifloside G (5), Pallidifloside H (6) and Pallidifloside I (7), together with seven other steroidal saponins (3, 4, 8-12) were isolated from the dry bulbs of Fritillaria pallidiflora Schrenk. Their structures were established by spectroscopic techniques (IR, MS, 1D and 2D NMR) and chemical means. The isolated steroidal saponins were evaluated for cyotoxic activity against human C6 brain gliomas and Hela cervix cancer cell lines using MTT assays. Compounds 1, 10, 11, 12 showed cytotoxicity against C6 and Hela cell lines with IC(50) values in the range of 5.1-75.8μM.     

Five new furostanol saponins from the rhizomes of Tupistra chinensis

Five new furostanol saponins (1-5), together with three known compounds (6-8) were obtained from the n-butanol soluble fraction of ethanol extract from Tupistra chinensis. Their structures were determined on the basis of chemical methods and spectral data. The isolated compounds were tested in vitro for their cytotoxic activities against the A549, HepG 2 and Caski cancer cell lines. Among them, compounds 6, 7, and 8 showed cytotoxicity against A549 cancer cell lines with IC(50) values of 6.6, 6.7 and 29.1 μM, respectively.     

Xanthone derivatives from the fermentation products of an endophytic fungus Phomopsis sp.

Three new xanthones, 1,5-dihydroxy-3-hydroxyethyl-6-methoxycarbonylxanthone (1), 1-hydroxy-5- methoxy-3-hydroxyethyl-6-methoxycarbonylxanthone (2), and 1-hydroxy-3-hydroxyethyl- 8-ethoxycarbonylxanthone (3), along with seven known xanthones (4–10) were isolated from the fermentation products of an endophytic fungus Phomopsis sp.. Their structures were elucidated by spectroscopic methods including extensive 1D- and 2D-NMR techniques. Compounds 1–10 were also tested for their cytotoxicity against five human tumor cell lines (NB4, A549, SHSY5Y, PC3, and MCF7) by MTT method using paclitaxel as positive control. Compounds 1 and 3 showed cytotoxicity against A549 cell lines with IC50 values of 3.6 and 2.5 μM, respectively. In addition, 1 was cytotoxic to MCF7 cells with IC50 value of 2.7 μM.     

小叶臭黄皮的化学成分研究

从小叶臭黄皮(Clausena excavata Burm F.)的茎和叶中分离得到10个单萜基香豆素,分别鉴定为7-((E)-3'-甲基-4'-(8'-羰基-7',9'-烯-呋喃)-2'-烯)-香豆素(1)、7-((E)-3'-甲基-4'-(7'-甲基-8'-羰基-6'-烯-呋喃)-2'-烯)-香豆素(2)、7-((E)-3'-甲基-4'-(7'-甲基-6'-亚甲基-8'-羰基-呋喃)-2'-烯)-香豆素(3)、7-((E)-3'-甲基-4'-(9'-羟基-8'-羰基-6'-烯-呋喃)-2'-烯)-香豆素(4)、7-(3'-甲基-4'-(7'-甲基-8'-羰基-6'-烯-呋喃)-2',3'-环氧丁烷)-香豆素(5)、7-(3'-甲基-4'-(9'-羟基-8'-羰基-6'-烯-呋喃)-2',3'-环氧丁烷)-香豆素(6)、7-(3'-甲基-4'-(7'-甲基-7'-羟基-8'-羰基-6'-烯-呋喃)-2',3'-环氧丁烷)-香豆素(7)、7-(3'-甲基-4'-(7'-甲基-8'-羰基-呋喃)-2',3'-环氧丁烷)-香豆素(8)、5'-羟基葡萄内酯(9)和7-((E)-7'-羟基-3',7'-二甲基-2',5'-二烯)-香豆素(10),2个四降三萜,鉴定为11β-羟基-1α-乙酰基黄柏酮(11)、11β-羟基黄柏酮(12)和1个木脂素,鉴定为(-)-丁香脂素(13)。其中化合物11和13为首次从该植物中分离得到。测定了化合物1、2、3、11和12对癌细胞株A549、Hela和BGC-823的细胞毒活性,及其对白色念珠菌(Candida albicans)、金黄色葡萄球菌(Staphylococcus aureus)的抑菌活性。结果显示,化合物1对Hela和A549均有细胞毒活性,其半数抑制质量浓度(IC_(50))值分别为11.26和13.55 mg/L,化合物3对BGC-823有细胞毒活性,其IC_(50)值为16.65 mg/L,5个化合物对白色念珠菌和金黄色葡萄球菌均没有抗菌活性。     

Two new prenylated xanthones and a new prenylated tetrahydroxanthone from the pericarp of Garcinia mangostana

Two new prenylated xanthones and a new prenylated tetrahydroxanthone, garcimangosxanthone A–C (1–3), along with fourteen known xanthones were isolated from the pericarp of Garcinia mangostana. Their structures were elucidated on the basis of spectroscopic data. Compounds 1 and 2 exhibited in vitro cytotoxicity against A549, LAC and A375 cell lines with IC₅₀ values of 5.7–24.9 μM, which were comparable to those of doxorubicin.     

Triterpene saponins from the roots of Dipsacus asper and their protective effects against the Aβ(25-35) induced cytotoxicity in PC12 cells

Three new triterpene saponins, named asperosaponin A-C (1-3), together with seven known triterpene saponins (4-10) were isolated from the roots of Dipsacus asper. The structures of compounds 1-3 were elucidated on the basis of detailed spectroscopic analysis and chemical methods. Compounds 1-3, 6-10 had significantly protective effects in PC12 cells against the Aβ(25-35) induced cytotoxicity. All the compounds isolated showed no cytotoxic activity against three human cancer cell lines, A-549, Bel-7402 and BGC-823.     

Five new prenylated chalcones from Desmodium renifolium

Five unusual new prenylated chalcones, renifolins D–H (1–5), were isolated from whole Desmodium renifolium plants. All of their structures were determined by spectroscopic methods including 1D and 2D NMR. All of the isolates were evaluated for cytotoxicity using five tumor cell lines. Compounds 2 and 3 exhibited cytotoxicity against A549 cells, with IC₅₀ values of 2.8 and 2.2 μM, respectively.     

Triterpenoids from the fruits of Azadirachta indica (Meliaceae)

Four new triterpenoids, indicalilacols A-D (1–4), were isolated from the MeOH extract of the fruits of Azadirachta indica, including a new 19(10 → 9β)abeo-tirucallane derivative, two new tirucallane-type triterpenoids, and a new euphane-type triterpenoid, along with three known tirucallane-type triterpenoids. Their structures were elucidated on the basis of spectroscopic analyses. The absolute configuration of 2 was elucidated by the chemical conversion of 2 into 21-oxo-melianodiol 24,25-acetonide. Compounds 2, 6–8 exhibited moderate cytotoxicity against three human cancer cell lines, including multidrug-resistant (MDR) cancer cells (KB-C2). Although compound 5 was not cytotoxic against any of the tested cancer cell lines, 5 showed cytotoxicity against KB-C2 cells in the presence of 2.5 μM colchicine, suggesting that 5 might have an MDR-reversal effect.     

A new dimeric resveratrol from the roots of Shorea roxburghii

A new resveratrol dimer, roxburghiol A (1) together with eleven known compounds were isolated from the roots of Shorea roxburghii. Their structures were identified on the basis of spectroscopic evidence and physicochemical properties. All isolated compounds were evaluated for their cytotoxicity (KB and HeLa cells). Compounds 8 and 9 showed potent cytotoxicity against both KB and HeLa cell lines with IC₅₀ values of 6.5, 8.5 and 8.7, 10.1 μg/mL, respectively.     

Sesquiterpenes from the aerial part of Chloranthus japonicus and their cytotoxicities

Four new sesquiterpenes, chlorajapolides F–I (1–4), along with nine known terpenoids (5–13) were isolated from the aerial part of Chloranthus japonicus. Their structures were elucidated on the basis of spectroscopic analysis, and a lindenane sesquiterpene, named 9-hydroxy-heterogorgiolide, previously isolated from the C. japonicus, was revised as its 8-epimer (1a). Moreover, methanol extract (ME), EtOAc fraction (EF), water fraction (WF), and all isolates (1a, 1–13) were evaluated for their cytotoxicities using two human cancer cell lines.     

Cytotoxic and anti-inflammatory ent-kaurane diterpenoids from Isodon wikstroemioides

Seven new ent-kaurane diterpenoids, isowikstroemins A–G (1–7), were isolated from EtOAc extracts of the aerial parts of Isodon wikstroemioides. Their structures were elucidated by extensive spectroscopic analysis. The isolates were evaluated for their cytotoxicity against five human tumor cell lines, and compounds 1–4 exhibited significant activity with IC₅₀ values ranging from 0.9 to 7.0 μM. In addition, compounds 1, 2, 3, 4, and 7 exhibited inhibitory activity against nitric oxide (NO) production in LPS-activated RAW264.7 macrophages.     

Bioactive flavones and biflavones from Selaginella moellendorffii Hieron

Three new flavones named 5-carboxymethyl-4′,7-dihydroxyflavone (1), its ethyl ester (2) and butyl ester (3) were isolated from the herb Selaginella moellendorffii Hieron., together with ten known compounds. Their structures were elucidated on the basis of spectroscopic and chemical analysis. Selected compounds were evaluated for their anti-HBV and cytotoxic activity. Among them, compounds 2 and 3 displayed inhibitory activity in vitro on hepatitis B virus (HBV) surface antigen (HBsAg) secretion of the Hep G2.2.15 cell line with IC₅₀ values of 0.17 mg/ml and 0.46 mg/ml, and on HBV e antigen (HBeAg) secretion with IC₅₀ values of 0.42 mg/ml and 0.42 mg/ml, respectively. Compounds 7, 8, 10 and 12 exhibited selective cytotoxicity against the three human cancer cell lines tested.     

New cytotoxic diarylheptanoids from the rhizomes of Alpinia officinarum Hance

Two new dimeric diarylheptanoids, named Alpinin C (1) and D (2), a new natural product of diarylheptanoid (3) along with three known diarylheptanoids (4–6) were isolated from the rhizomes of Alpinia officinarum Hance. Their structures were elucidated based on extensive spectroscopic analyses (1D and 2D NMR, HRTOFMS, IR). The isolated compounds were evaluated for their cytotoxicity against human tumor cell lines HepG2, MCF-7, T98G and B16-F10. Compound 1 showed selective cytotoxicity against cell lines of MCF-7 and T98G, while compound 6 showed significant cytotoxicity to the all tested tumor cell lines with IC₅₀ in the range from 8.46 to 22.68 μmol/L.     

Cytotoxic sesquiterpenes and lignans from Saussurea deltoidea

Two new sesquiterpenes deltoiden A (1) and deltoiden B (2), and two new lignans deltoignan A (9) and deltoignan B (10), together with 14 known compounds, including six sesquiterpenes 3-8 and three lignans 11-13, were isolated from the whole plant of Saussurea deltoidea. Compounds 3-8 and 11-17 were isolated for the first time from this plant. Their structures were established by spectroscopic analysis, including 2D-NMR spectroscopic techniques. Cytotoxicities of compounds 1-13 were tested against three cancer cell lines A549, Hela and SMMC-7721. Results showed that 5, 6 and 7 exhibited cytotoxicity against SMMC-7721 with the IC(50) values of 6.49, 9.53, 1.23 μg/ml, 5 and 7 against A549 with the IC(50) values of 4.99 and 5.35 μg/ml, 5, 6, 7, 13 against Hela with the IC(50) values of 1.40, 4.75, 0.93 and 5.42 μg/ml, respectively. The structure-activity relationships of sesquiterpenes 1-8 were discussed on the base of cytotoxic results.     

Antibacterial effect of Dryopteris crassirhizoma against methicillin-resistant Staphylococcus aureus

Methanol extract and its fractions (hexane, EtOAc, n-BuOH, and H2O) of Dryopteris crassirhizoma were investigated for antibacterial activity against methicillin-resistant Staphylococcus aureus. The hexane fraction showed a good antibacterial activity against all tested strains.     

New pregnane saponins from Ecdysanthera rosea and their cytotoxicity

Two new pregnane saponins elucidated as ecdysantheroside A (1) and ecdysantheroside B (2) and six known compounds (3-8) based on spectral data (MS, IR, 1D and 2D NMR) were isolated from the stem bark of Ecdysanthera rosea. The cytotoxicity against six cell lines of these compounds was tested by MTT assay. The results revealed that compounds 5 and 7 showed cytotoxicity against all the cell lines. Compound 2 showed cytotoxicity against cells A549, MDA435, HepG2, and HUVEC, while compound 4 showed cytotoxicity against cells A549, CEM, and HUVEC. Compound 6 had cytotoxicity against the others except cell HepG2.     

Stilbenes and flavonoids from Artocarpus nitidus subsp. lingnanensis

The first stilbene possessing a γ-aminobutyric acid lactam function, artocarpene (1), and a new flavanone, 2-hydroxynaringenin 4′-O-β-d-glucopyranoside (2), were isolated from the stems of Artocarpus nitidus subsp. lingnanensis along with four known compounds, 2-hydroxynaringenin (3), oxyresveratrol (4), 3,4′,5-trihydroxy-3′-prenylstilbene (5) and norartocarpetin (6). Their structures were elucidated on the basis of spectroscopic data. Compounds 1 exhibited weak antioxidant activity and 2 displayed weak cytotoxicity against human lung cancer A549 cell line.     

Knipholone anthrone from Kniphofia foliosa induces a rapid onset of necrotic cell death in cancer cells

The present study examines the comparative cytotoxicity of knipholone (KP) and knipholone anthrone (KA) in leukaemic and melonocyte cancer cell lines. It was found that KA induces a rapid onset of cytotoxicity with IC₅₀ values ranging from 0.5 to 3.3 μM. In comparison to KA, KP was 70–480-times less toxic to cancer cells. Morphological and biochemical studies revealed that the cytotoxicity of KA was coupled with a quick loss of membrane integrity leading to necrotic cell death. The study identified KA as a new class of natural potential anticancer agent with a wide range of toxicological and pharmacological implications.