RESUMEN
Stilbenes (based on the 1,2-diphenylethylene skeleton) are a class of plant polyphenols with rich structural and bioactive diversity. Twenty-six stilbenes, including five undescribed compounds (7,8-dioxy-4,3',5'-trihydroxystilbene, trans-13'-methoxygnetin H, suffruticosol E, paestibenetrimerols A and B), were isolated from the seedcases of Paeonia suffruticosa Andrews. Their structures were elucidated by spectroscopic analyses and comparison with previously reported data. The absolute configurations of trans-13'-methoxygnetin H, suffruticosol E, paestibenetrimerols A and B were assigned from their respective electronic circular dichroism (ECD) spectra. Additionally, the structures of known compounds suffruticosols A, B and rockiol B were revised and the absolute configurations of them, and along with (+)-davidiol A, were also further determined by ECD. The isolated compounds, trans-gnetin H, cis-gnetin H and suffruticosol E, were found to have potent cytotoxicity against the DU-145 and MDA-MB-231 cell lines with IC50 values of 4.89-8.61 µM. The preliminary antitumor structure-activity relationship of these stilbenes is discussed as well.
Asunto(s)
PaeoniaRESUMEN
Two pairs of unprecedented ß-carboline-phenylpropanoid heterogeneous alkaloids, (±)-pheharmines A-B (1-4), characterized by a morpholino[4,3,2-hi]ß-carboline core with two chiral centers, were isolated from the roots of Peganum harmala. The structures, including their absolute configurations, were identified using spectroscopic analyses and electronic circular dichroism (ECD) calculations. The biosynthetic hypothesis for the formation of pheharmines A-B was proposed. Compounds 1-4 exhibited moderate cytotoxic activities against HL-60 cell lines.
Asunto(s)
Alcaloides , Peganum , Humanos , Peganum/química , Peganum/metabolismo , Morfolinos/análisis , Morfolinos/metabolismo , Semillas , Estructura Molecular , Alcaloides/farmacología , Alcaloides/química , Carbolinas/farmacología , Carbolinas/químicaRESUMEN
Twenty-two cephalotaxine-type and ten homoerythrina-type alkaloids, including seven previously undescribed ones, were isolated from the twigs and leaves and the seed kernels of Cephalotaxus fortunei. Their structures were established by spectroscopic analysis, single crystal X-ray diffraction, and ECD calculation methods. Cephalofortunine A ß-N-oxide (1) is the first nitrogen-oxidized homoerythrina-type alkaloid. The isolated compounds were evaluated for their in vitro antiproliferative effects against two human leukemia cell lines (THP-1 and K562). All compounds showed different levels of antiproliferation in THP-1 and K562 cells with GI50 values of 0.24-29.55 µM. Hainanensine (31) was the most active against two cancer cell lines with GI50 values of 0.24 ± 0.07, and 0.29 ± 0.01 µM, respectively.
Asunto(s)
Alcaloides , Antineoplásicos Fitogénicos , Cephalotaxus , Alcaloides/química , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Cephalotaxus/química , Homoharringtonina , Humanos , Estructura Molecular , Hojas de la Planta/químicaRESUMEN
Eight cephalotaxine-type alkaloids (1-8), including two new compounds cephafortunines A and B (1-2), were isolated from the branches and leaves of Cephalotaxus fortunei var. alpina. Their structures were identified by a series of spectroscopic methods (MS, UV, IR, 1D, and 2D NMR) and comparison with the reported data of known analogs. The absolute configurations of 1 and 2 were determined by electronic circular dichroism (ECD) calculations. 1-8 were evaluated for their in vitro antiproliferation effects against two human leukemia cell lines (U937 and HL-60). All compounds showed different levels of antiproliferation effects against U937 cells with GI50 values of 4.21-23.70 µM. 4 and 5 were the most active against U937 cells with GI50 values of 4.21 and 6.58 µM and against HL-60 cells with GI50 values of 6.66 and 6.70 µM, respectively. 4 and 5 arrested HL-60 cell cycle in G0/G1 phase.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Cephalotaxus/química , Harringtoninas/farmacología , Antineoplásicos Fitogénicos/aislamiento & purificación , China , Células HL-60 , Harringtoninas/aislamiento & purificación , Humanos , Estructura Molecular , Fitoquímicos/aislamiento & purificación , Fitoquímicos/farmacología , Hojas de la Planta/química , Células U937RESUMEN
Two nonbiaryl axially chiral ß-carboline-quinazoline dimers, pegaharmols A (1) and B (2), were isolated from the roots of Peganum harmala. Their planar structures were elucidated by the spectroscopic methods of high-resolution mass spectrometry and 1D and 2D nuclear magnetic resonance (NMR). The stereochemistry was established by a comparison between the experimental data of NMR and electronic circular dichroism and the computed data by quantum mechanical calculations. It is discovered for the first time that the ß-carboline at the C-8 position is bonded to the vasicine at the C-9 position. 1 exhibited moderate cytotoxic activity against HL-60 and A549 cell lines.
Asunto(s)
Alcaloides/química , Antineoplásicos Fitogénicos/farmacología , Carbolinas/farmacología , Peganum/química , Raíces de Plantas/química , Quinazolinas/química , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Carbolinas/química , Carbolinas/aislamiento & purificación , Ensayos de Selección de Medicamentos Antitumorales , Células HL-60 , Humanos , Estructura Molecular , Extractos Vegetales/químicaRESUMEN
With bioassay- and chemistry-guided fractionation, seven new caged prenylxanthones including two scalemic mixtures, epiisobractatin (1), 13-hydroxyisobractatin (2), 13-hydroxyepiisobractatin (3), 8-methoxy-8,8a-dihydrobractatin (4), 8-ethoxy-8,8a-dihydrobractatin (5), garcibracteatone (6), and 8-methoxy-8,8a-dihydroneobractiatin (7), and the eight known compounds 8-15 were isolated from the leaves of Garcinia bracteata. The structures were unambiguously elucidated through analysis of spectroscopic data. The 2D structures and relative configurations of 1 and 5 were confirmed by X-ray crystallographic analysis. The separation of the enantiomers of 1-5 was accomplished by chiral-phase HPLC. The absolute configurations of the enantiomers of 1 and 5 were assigned by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. The absolute configurations of the related compounds were determined via comparisons of their ECD data with those of the enantiomers of 1 and 5, respectively. Notably, compound 7, with a neo caged skeleton, is the first representative of a novel type of caged xanthone lacking a Δ8(8a) double bond. The isolated compounds exhibited significant cell growth inhibitory activities in vitro against human leukemic HL-60 and K562 cell lines, with GI50 values ranging from 0.2 to 8.8 µM. A preliminary structure-activity relationship is discussed.
Asunto(s)
Garcinia/química , Hojas de la Planta/química , Xantonas/química , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Bioensayo/métodos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cromatografía Líquida de Alta Presión , Dicroismo Circular/métodos , Cristalografía por Rayos X/métodos , Células HL-60 , Humanos , Células K562 , Relación Estructura-Actividad , Xantonas/farmacologíaRESUMEN
Inspired by the intriguing structures and bioactivities of dimeric alkaloids, 11 new thalifaberine-type aporphine-benzylisoquinoline alkaloids, thalicultratines A-K, a tetrahydroprotoberberine-aporphine alkaloid, thalicultratine L, and five known ones were isolated from the roots of Thalictrum cultratum. Their structures were defined on the basis of NMR and HRESIMS data. The antiproliferative activities of compounds 1-17 were evaluated against human leukemia HL-60 and prostate cancer PC-3 cells. Most alkaloids showed potent cytotoxicity against selected cancer cells. Preliminary SARs are discussed. The most active new compound (3), with an IC50 value of 1.06 µM against HL-60 cells, was selected for mechanism of action studies. The results revealed that compound 3 induced apoptosis and arrested the HL-60 cell cycle at the S phase with the loss of mitochondria membrane potential. The nuclear morphological Hoechst 33258 staining assay was also carried out, and the results confirmed apoptosis.
Asunto(s)
Alcaloides/aislamiento & purificación , Alcaloides/farmacología , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Aporfinas/aislamiento & purificación , Aporfinas/farmacología , Medicamentos Herbarios Chinos/aislamiento & purificación , Medicamentos Herbarios Chinos/farmacología , Raíces de Plantas/química , Thalictrum/química , Alcaloides/química , Antineoplásicos Fitogénicos/química , Aporfinas/química , Alcaloides de Berberina , Medicamentos Herbarios Chinos/química , Células HL-60 , Humanos , Concentración 50 Inhibidora , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Relación Estructura-ActividadRESUMEN
Neobraclactones A-C (1-3), featuring an unprecedented further rearranged prenylxanthone skeleton with a unique octahydro-2H-1,3-dioxacyclopenta[c,d]inden-2-one scaffold, along with their biosynthesis-related known compound neobractatin (4), were isolated from the leaves of Garcinia bracteata. Their structures with absolute configurations were determined by extensive analyses of spectroscopic data and ECD calculations. Compounds 1 and 2 showed significant growth inhibition activities against the human leukaemia HL-60 and K562 cell lines with GI50 values from 0.40 to 0.86 µM.
Asunto(s)
Garcinia/química , Xantonas/aislamiento & purificación , Conformación Molecular , Xantonas/químicaRESUMEN
Investigation of the alkaloids from Peganum harmala seeds yielded two pairs of unique racemic pyrroloindole alkaloids, (±)-peganines A-B (1-2); two rare thiazole derivatives, peganumals A-B (3-4); six new ß-carboline alkaloids, pegaharmines F-K (5-10); and 12 known analogues. Their structures, including stereochemistry, were elucidated through spectroscopic analyses, quantum chemistry calculations, and single-crystal X-ray diffraction. Notably, the incorporation of pyrrole and indole moieties in peganines A-B, thiazole fragments in peganumals A-B, and a C-1 α,ß-unsaturated ester motif in pegaharmine F (5) are all rare, and their presence in the genus Peganum were demonstrated for the first time. All isolates were tested for antiproliferative activities against the HL-60, PC-3, and SGC-7901 cancer cell lines, and compounds 9, 11, 12, and 13 exhibited moderate cytotoxicity against HL-60 cancer cell lines with IC50 values in the range of 4.36-9.25 µM.
Asunto(s)
Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/aislamiento & purificación , Alcaloides Indólicos/química , Alcaloides Indólicos/aislamiento & purificación , Peganum/química , Semillas/química , Antineoplásicos Fitogénicos/farmacología , Carbolinas/química , Ensayos de Selección de Medicamentos Antitumorales , Medicamentos Herbarios Chinos/farmacología , Células HL-60 , Humanos , Alcaloides Indólicos/farmacología , Concentración 50 Inhibidora , Estructura Molecular , Resonancia Magnética Nuclear BiomolecularRESUMEN
In this study, we screened 17 medicinal plants for binding activity to G-quadruplex d(TTGGGTT)4 by (1)H NMR spectroscopy and found that the crude extract of Peganum harmala L. seeds showed the most potential binding activity. Subsequently, (1)H NMR- and bioassay-guided isolation of the extract of P. harmala L. was performed to obtain four pairs of partially racemized ß-carboline alkaloids, pegaharmines A-D (1-4). Their structures and absolute configurations were determined by extensive NMR analyses, X-ray crystallography, ECD calculations, and CD exciton chirality approaches. Interestingly, pegaharmine D (4), which showed the strongest G-quadruplex interaction, exhibited significant cytotoxic activity against three cancer cell lines. This work contributed a practical strategy for the discovery of novel G-quadruplex ligands from natural products and provided potential insights for using ß-carboline alkaloids as anticancer lead compounds specifically targeting G-quadruplexes.
Asunto(s)
Antineoplásicos Fitogénicos/química , Carbolinas/química , Oligodesoxirribonucleótidos/química , Peganum/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Secuencia de Bases , Vías Biosintéticas , Carbolinas/aislamiento & purificación , Carbolinas/farmacología , Ensayos de Selección de Medicamentos Antitumorales , G-Cuádruplex , Células HL-60 , Humanos , Concentración 50 Inhibidora , Estructura Molecular , Peganum/metabolismo , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/farmacología , Semillas/químicaRESUMEN
Two pairs of enantiomeric alkaloid dimers, (±)-macleayins A (1) and B (2), representing a novel dimerization pattern of two different types of alkaloids via a C-C σ-bond, were isolated from the aerial parts of Macleaya cordata. The enantiomeric separation was achieved by chiral chromatography. Their structures and stereochemistry were determined by the analysis of extensive spectroscopic data, electronic circular dichroism calculation, and single-crystal X-ray diffraction data. (-)-Macleayin A exhibits modest cytotoxic activity against HL-60 cell line with the IC50 value of 3.51 µM.
Asunto(s)
Alcaloides/síntesis química , Alcaloides/química , Cromatografía Líquida de Alta Presión , Cristalografía por Rayos X , Ensayos de Selección de Medicamentos Antitumorales , Células HL-60 , Humanos , Concentración 50 Inhibidora , Conformación Molecular , Estructura Molecular , Resonancia Magnética Nuclear Biomolecular , Papaveraceae/química , Componentes Aéreos de las Plantas/química , EstereoisomerismoRESUMEN
Four quinolone alkaloids (1-4) and three indole alkaloids (20-22), together with 30 known alkaloids (5-19, 23-37), were isolated from the fruits of Euodia rutaecarpa. Their structures were established by spectroscopic analyses. The in vitro cytotoxic activities of these alkaloids against leukaemia HL-60 and prostate cancer PC-3 cell lines were evaluated.
Asunto(s)
Antineoplásicos Fitogénicos/química , Evodia/química , Alcaloides Indólicos/química , Quinolonas/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Frutas/química , Células HL-60 , Humanos , Alcaloides Indólicos/aislamiento & purificación , Masculino , Estructura Molecular , Extractos Vegetales/química , Neoplasias de la Próstata/patología , Quinolonas/aislamiento & purificaciónRESUMEN
Peganumine A (1), a new dimeric ß-carboline alkaloid characterized by a unique 3,9-diazatetracyclo[6.5.2.0(1,9).0(3,8)]pentadec-2-one scaffold, was isolated from the seeds of Peganum harmala. The structure including the absolute configuration was determined by spectroscopic data, X-ray crystallography, ECD calculation, and CD exciton chirality approaches. Compound 1 showed moderate cytotoxic activity against MCF-7, PC-3, and HepG2 cells and selective effects on HL-60 cells with an IC50 value of 5.8 µM.
Asunto(s)
Alcaloides/aislamiento & purificación , Antineoplásicos Fitogénicos/aislamiento & purificación , Carbolinas/aislamiento & purificación , Peganum/química , Alcaloides/química , Alcaloides/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Carbolinas/química , Carbolinas/farmacología , Cristalografía por Rayos X , Ensayos de Selección de Medicamentos Antitumorales , Células HL-60 , Células Hep G2 , Humanos , Concentración 50 Inhibidora , Conformación Molecular , Estructura Molecular , Semillas/químicaRESUMEN
A novel series of substituted 1,2,3-benzotriazines and pyrido[3,2-d]-1,2,3-triazines were synthesized. The abilities of these compounds to inhibit the VEGFR-2 kinase activity and the proliferation of human microvascular endothelial cells (MVECs) were determined. 6-Methoxy-4-substituted-1,2,3-benzotriazines and 4-substituted-6-chloro-pyrido[3,2-d]-1,2,3-triazines have the abilities of inhibiting the VEGFR-2 kinase activity, but only the 4-substituted-6-chloro-pyrido[3,2-d]-1,2,3-triazines exhibit good growth inhibitory effects on MVECs. Compound 6-chloro-4-(3-trifluoromethylanilino)-pyrido[3,2-d][1,2,3]triazin (11d) is less half active than PTK787 to inhibit the VEGFR-2 kinase activity, but is more active than PTK787 to inhibit the growth of MVECs. The potential binding modes of 6d, 11d, and CTZ12 in complex with their putative intracellular target, VEGFR-2, were predicted using Surflex-Dock.
Asunto(s)
Células Endoteliales/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Piridinas/farmacología , Triazinas/farmacología , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Humanos , Modelos Moleculares , Estructura Molecular , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Piridinas/síntesis química , Piridinas/química , Relación Estructura-Actividad , Triazinas/síntesis química , Triazinas/química , Receptor 2 de Factores de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Two new 7,6'-coupled naphthylisoquinolines, namely ancistrotectorines A (1) and B (2), two new 5,3'-coupled naphthylisoquinolines, namely ancistrotectorines C (3) and D (4), and one new 7,8-coupled naphthylisoquinoline, namely ancistrotectorine E (5), together with 9 known naphthylisoquinoline alkaloids, hamatine (6), ancistrobertsonine B (7), ancistrocladinine (8), hamatinine (9), ancistrotanzanine A (10), ancistrotanzanine B (11), ancistrotectoriline B (12), 7-epi-ancistrobrevine D (13), and ancistrotectorine (14), were isolated from the 70% EtOH extract of Ancistrocladus tectorius. Their structures were elucidated based on the extensive analysis of spectroscopic data (1D, 2D NMR and MS). Compound 5 exhibited inhibitory activities against HL-60, K562 and U937 cell lines with IC50 values of 1.70, 4.18 and 2.56 µM respectively.
Asunto(s)
Isoquinolinas/aislamiento & purificación , Leucemia/tratamiento farmacológico , Magnoliopsida/química , Naftoles/uso terapéutico , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Antineoplásicos Fitogénicos/uso terapéutico , Células HL-60 , Humanos , Concentración 50 Inhibidora , Isoquinolinas/química , Isoquinolinas/farmacología , Células K562 , Estructura Molecular , Naftoles/química , Naftoles/aislamiento & purificación , Naftoles/farmacología , Fitoterapia , Extractos Vegetales/química , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéutico , Hojas de la Planta/química , Tallos de la Planta/química , Células U937RESUMEN
Six new triterpene saponins, clematomandshurica saponins F-K (1-6), together with a known compound (7), were isolated from the roots and rhizomes of Clematis mandshurica. Their structures were elucidated on the basis of spectroscopic evidence and hydrolysis. Compounds 5-7 exhibited antiproliferative effects against PC-3 human prostate cancer cells with GI50 values of 1.29, 1.50, and 0.71 µM, respectively.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Clematis/química , Saponinas/farmacología , Triterpenos/farmacología , Antineoplásicos Fitogénicos/química , Isótopos de Carbono/análisis , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular , China , Humanos , Hidrólisis , Espectroscopía de Resonancia Magnética , Medicina Tradicional China , Estructura Molecular , Raíces de Plantas/química , Plantas Medicinales , Rizoma/química , Saponinas/química , Saponinas/aislamiento & purificación , Triterpenos/química , Triterpenos/aislamiento & purificaciónRESUMEN
Five new 3,4-seco-lanostane-type triterpenoids, seco-coccinic acids G-K (1-5), and a known compound, seco-coccinic F, were isolated from the roots of Kadsura coccinea (Lem.) A.âC. Sm. Their structures were elucidated by spectroscopic methods, including 2D-NMR and HR-MS techniques. The cell growth inhibitory effects of these compounds were assayed in human leukemia HL-60 cells, and it was found that 1, 5, and 6 showed antiproliferative effects with GI50 values of 28.4, 15.2, and 16.6 µM, respectively.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Medicamentos Herbarios Chinos/farmacología , Kadsura/química , Lanosterol/farmacología , Triterpenos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Medicamentos Herbarios Chinos/química , Medicamentos Herbarios Chinos/aislamiento & purificación , Células HL-60 , Humanos , Lanosterol/química , Lanosterol/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Estructura Molecular , Raíces de Plantas/química , Plantas Medicinales , Espectrometría de Masa por Ionización de Electrospray , Triterpenos/química , Triterpenos/aislamiento & purificaciónRESUMEN
Five new diketopiperazines, prenylcyclotryprostatin B (1), 20-hydroxycyclotryprostatin B (2), 9-hydroxyfumitremorgin C (3), 6-hydroxytryprostatin B (4), and spirogliotoxin (5), were isolated from the marine-derived fungus Aspergillus fumigatus YK-7, along with nine known compounds, 6-14. Their structures were elucidated by spectroscopic methods, and their antiproliferative effects on human leukemic monocyte lymphoma U937 and human prostate cancer PC-3 cell lines were assessed in vitro. Compounds 10, 12, and 13 exhibited significant cell growth-inhibitory activities against U937 cell line, with the IC(50) values of 1.8, 0.2, and 0.5 µM, respectively.
Asunto(s)
Aspergillus fumigatus/química , Dicetopiperazinas/aislamiento & purificación , Neoplasias de la Próstata/tratamiento farmacológico , Antineoplásicos/química , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Dicetopiperazinas/química , Dicetopiperazinas/farmacología , Humanos , Espectroscopía de Resonancia Magnética , Masculino , Biología Marina , Estructura Molecular , Células U937/efectos de los fármacosRESUMEN
Five xanthones, 1,4,5,6-tetrahydroxyxanthone (1) and bracteaxanthones III-VI (2-5) together with twenty-six known compounds (6-31), were isolated from the ethanol extract of the stem bark of Garcinia bracteata. Their structures were elucidated via spectroscopic analyses. Growth inhibitory activities of these compounds against the human leukaemic HL-60 cell line were measured in vitro. Compounds 7, 11, and 29 exhibited moderate activities with GI(50) values of 2.8, 3.4, and 3.1 µM, respectively, and a preliminary structure-activity relationship is discussed.
Asunto(s)
Antineoplásicos Fitogénicos/química , Garcinia/química , Xantonas/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Antineoplásicos Fitogénicos/farmacología , Células HL-60 , Humanos , Resonancia Magnética Nuclear Biomolecular , Corteza de la Planta/química , Tallos de la Planta/química , Xantonas/aislamiento & purificación , Xantonas/farmacologíaRESUMEN
A new bisamide N1-acetyl-N7-phenylacetyl cadaverine (1) and a series of diketopiperazines including a new diketopiperazine cyclo(2-hydroxy-Pro-R-Leu) (2), together with a new natural product cyclo(4-hydroxy-S-Pro-S-Trp) (3) and two known leucine-based diketopiperazines cyclo(4-hydroxy-R-Pro-S-Leu) (4) and cyclo (S-Pro-R-Leu) (5), were isolated from ethyl acetate extract of a fermentation broth of a marine-derived Streptomyces sp. Their structures were elucidated by the interpretation of spectroscopic analysis. The antitumor activities of compounds 1-3 against HL-60 cell lines were tested by MTT assay.