Three new anthraquinones from the twigs of Cassia fistula and their bioactivities.

Three previously unreported anthraquinones, fistulaquinones A-C (1-3), together with three known ones (4-6) were isolated from the twigs of Cassia fistula. Their structures were determined by means of extensive NMR and MS spectroscopic analyses. All the isolated compounds were tested for their anti-tobacco mosaic virus (anti-TMV) activity, and compound 3 showed significant activity with inhibition rate of 34.5% at 20 µM concentration, even more potent than positive control. Additionally, compounds 1-6 exhibited moderate cytotoxicity with IC50 values ranging from 2.8 to 9.4 µM for some tested human tumor cell lines.

[A new cytotoxic alkaloid from roots of Alangium chinense].

We have carried out the chemical investigation on the roots of Alangium chinense. The chemical constituents from the roots of A.chinense were isolated and purified by various chromatographic techniques, such as silica gel, MCI-Gel resin, Sephadex LH-20 and high performance liquid chromatography. As a result, three alkaloids (1-3) were isolated from 90% EtOH extracts of the roots of this plant. Their structures were elucidated by physical-chemical properties and spectral data. Among them, compound 1 is a new compound, determined as 8-hydroxy-3-hydroxymethyl-6,9-dimethyl-7H-benzo[de]isoquinolin-7-one. Cytotoxicity of the compounds was evaluated by the MTT method. Compound 1 displayed cytotoxicity against NB4, A-549, SHSY5Y, PC-3 and MCF-7 cell lines with IC50 values of 4.2, 3.5, 5.7, 2.8 and 3.9 µmol•L⁻¹, respectively.

Antiviral and Cytotoxic Isocoumarin Derivatives from an Endophytic Fungus Aspergillus oryzae.

Oryzaeins A-D (1-4), four new isocoumarin derivatives, along with five known ones (5-9) were isolated from solid cultures of an endophytic fungus Aspergillus oryzae. Their structures were elucidated by detailed spectroscopic analysis and by comparison with reported data of related derivatives. Among them, compounds 1 and 2 represent the first examples of isocoumarins possessing an unusual 2-oxopropyl group and a rare 3-hydroxypropyl group. Compounds 1 and 2 displayed moderate anti-tobacco mosaic virus activities with inhibition rates of 28.4% and 30.6%, respectively, at the concentration of 20 µM. The new compounds showed moderate inhibitory activities against several human tumor cell lines with IC50 values in the range of 2.8-8.8 µM. Supporting information available online at http://www.thieme-connect.de/products.

Three new biphenyls from the twigs of Garcinia tetralata and their anti-tobacco mosaic virus activity.

Phytochemical investigations on the ethanol extract of the twigs of Garcinia tetralata resulted in the isolation of three new biphenyls, tetralatabiphenyls A-C (1-3), along with three known biphenyl derivatives (4-6). Structural elucidations of 1-3 were performed by spectroscopic methods such as 1D and 2D NMR spectra, in addition to high-resolution mass spectra. Compounds 1-6 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compound 3 showed high anti-TMV activity with inhibition rate of 31.1%. Compounds 1, 2, and 4-6 also showed modest anti-TMV activities with inhibition rates in the range of 18.9-24.5%, respectively.

[A new isoindole alkaloid from leaves of Cassia siamea].

A new isoindole alkaloid (1), has been isolated from the leaves of Cassia siamea by using various chromatographic techniques. Compound 1 is a new compound, determined as 5-(hydroxymethyl)-2-methyl-6-prenylisoindolin-1-one, and it displayed cytotoxicity against NB4, A549, SHSY5Y, PC3 and MCF7 cell lines with IC50 values of 3.2,4.6,2.8,6.4, 2.5 µmol•L⁻¹, respectively.

[A new furan-2-carboxylic acid from stem bark of Cassia alata].

A new furan-2-carboxylic acid, 5-[3-(hydroxymethyl)-4,5-dimethoxyphenyl]-3-methylfuran-2-carboxylic acid(1),has been isolated from the bark of Cassia alata by using various chromatographic techniques. It displayed cytotoxicity against NB4, A549, SHSY5Y, PC3 and MCF7 cell lines with IC50 values of 2.5, 1.2, 2.2, 3.6 and 1.9 µmol•L⁻¹, respectively.

[A new sesquiterpene from seeds of Cassia occidentalis and its cytotoxicity].

For the purpose of finding new bioactive agents from ethnic medicines, the chemical study on Dai Medicine Cassia occidentalis was carried out. The chemical constituents from the seeds of C. occidentalis were isolated by column chromatographic methods on silica gel, MCI-Gel resin, Sephadex LH-20, and high performance liquid chromatography. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. The cytotoxicity of the compound for NB4, A549, SHSY5Y, PC3, and MCF7 cells line was also assayed by using the MTT method. Two sesquiterpenes (1 and 2) were isolated from this plant. Compound 1 is a new compound and named as methyl 6-(hydroxymethyl)-4-isopropyl-7-methoxynaphthalene-1-carboxylate. Compound 1 also displayed high cytotoxicity with the tested cancer cell-lines.

[A new cytotoxic isocoumarin from endophytic fungus Aspergillus versicolor].

A new isocoumarin, along with five known ones,were isolated from the fermentation products of an endophytic fungus Aspergillus versicolorby using various chromatographic techniques.Their structures were elucidated on the basis of extensivespectroscopic analysis, including 1D-and 2D-NMR techniques. Compound 1 was evaluated for cytotoxicity against five human tumor cell lines. The results showed that 1 exhibited weak cytotoxicityagainst NB4, SHSY5Y and MCF7 cells with IC50 values of 6.8, 4.3,8.8 µmol•L⁻¹, respectively.

Flavones from Cassia siamea and their anti-tobacco mosaic virus activity.

Two new flavones, siameflavones A and B (1 and 2), together with five known flavones (3-7) were isolated from the stem of Cassia siamea. Their structures were elucidated by spectroscopic methods including extensive 1D and 2D NMR techniques. Compounds 1-5 were evaluated for their anti-tobacco mosaic virus (Anti-TMV) activity. The results showed that compounds 1-5 showed weak anti-TMV activity with inhibition rates in the range of 11.6-18.5%.

[A new flavone from stems of Garcinia bracteata and its anti-TMV activity].

A phytochemical investigation on the stems of Garcinia bracteata collected from Xishuangbanna resulted in the isolation of a new flavone. By analysis of the HRESIMS, IR, UV, 1D and 2D NMR spectra, the structure of the new compound was determined as 7-methoxy-4',6-dihydroxy-8-isobutyryl-flavone(1). Compound 1 was also tested for its anti-tobacco mosaic virus(TMV) activity. Results suggested the 1 possessed remarkable anti-TMV activity, with an inhibition rate of 28.2%.

[Phenylpropanoids and phenylethanol from flowers of Rosa rugosa].

A new phenylpropanoid (1), together with seven known ones (2-8), has been isolated from the flowers of Rosa rugosa collected from Shanxi province by using various chromatographic techniques. Compound 1 is a new compound, and it displayed cytotoxicity against NB4, SH-SY5Y, PC3, A549 and MCF7 cell lines with IC50 values of 8.2, 6.2, 4.3, 2.8, and 9.6 µmol · L⁻¹ respectively.

Versicolols A and B, two new prenylated isocoumarins from endophytic fungus Aspergillus versicolor and their cytotoxic activity.

Versicolols A and B (1 and 2), two rare prenylated isocoumarin derivatives, along with five known isocoumarins (3-7) were isolated from the fermentation products of an endophytic fungus Aspergillus versicolor. Their structures were elucidated on the basis of extensive spectroscopic analysis, including 1D- and 2D-NMR techniques. Compounds 1 and 2 were evaluated for their cytotoxicity against five human tumor cell lines. The results showed that compounds 1 exhibited weak cytotoxicity against A549 and MCF7 cells with IC50 values of 9.4 and 8.8 µm, and compound 2 exhibited weak cytotoxicity against SHSY5Y and MCF7 cells with IC50 values of 8.2 and 6.8 µm, respectively.