LC-MS characterization of efficacy substances in serum of experimental animals treated with Sophora flavescens extracts

Novel chiral matrine derivatives as potential antitumor agents: Design, synthesis and biological evaluation

Since the thalidomide incident, research on chiral drugs has escalated immensely. Differences in drug configuration can lead to significant variations in therapeutic efficacy. Matrine, a natural product esteemed for its low toxicity and high water solubility, has garnered significant attention in research endeavors. Nonetheless, its precise target has proven elusive. In this study, we designed and synthesized a novel chiral matrine derivative. Their cytotoxicity against three types of tumor cells was assessed. Comparing the newly synthesized derivatives to the parent matrine, most compounds exhibited significantly enhanced inhibitory effects on cancer cells. Among them, Q12 exhibited the highest activity, with IC50 values of 8.31 μM against rat glioma cells C6, 6.3 μM against human liver cancer cells HepG2 and 7.14 μM against human gastric cancer cells HGC-27, meanwhile showing low toxicity. Based on IC50 values, we constructed a preliminary structure-activity relationship (SAR). Compound Q12 significantly suppressed the cloning and migration of HepG2 cells. Further mechanistic studies indicated that Q12 inhibited Topo I in HepG2 cells, leading to DNA damage, induction of G0/G1 cell cycle arrest and ultimately causing apoptosis. The molecular docking experiments provided a rational binding mode of Q12 with the Topo I-DNA complex. In vivo, experiments demonstrated that Q12 exhibited a higher tumor growth inhibition rate (TGI) compared to the positive control drug Lenvatinib, while maintaining good safety. In summary, it suggests that Topo I might be a potential target for matrine and Q12 represents a promising candidate for cancer treatment.

Novel matrinic acid derivatives bearing 2-anilinothiazole structure for non-small cell lung cancer treatment with improved Hsp90 targeting effect

Involved in mediating the folding and maturation of more than 300 client proteins, many of which are oncoproteins, Hsp90 has emerged as a promising drug target for cancer therapy. In particular, inhibiting Hsp90 plays a vital role in the treatment of non-small cell lung cancer. Owing to undesirable outcomes of Hsp90 inhibitors in clinical trials, a series of matrinic acid compounds bearing 2-anilinothiazole moiety were designed based on the structural features allocation shared among Hsp90 inhibitors within the ATP-binding pocket. Most of the compounds showed potent anticancer activities validated by MTT assay. Among them, the most potent compound C4 (IC₅₀  < 10 μM against four cell lines) was chosen for further mechanism study. Notably, C4 showed a better safety profile than 17AAG with a higher SI value. Thermal shift assay data indicated C4 exhibited a strong binding affinity with Hsp90 (-18.85 ± 0.56°C) comparable to radicicol. Mechanism studies verified that C4 significantly inhibited proliferation and migration activities of A549 cells. Besides, C4 can induce a prolonged G1-phase and cell apoptosis. Western blot analysis results indicated C4 could moderately suppress Hsp90 and upregulate Hsp70 expression. Furthermore, the downregulated trend of the client proteins of Hsp90, such as β-Catenin and Bcl-2, were consistent with the cellular effect of C4, suggesting that C4 could exert anticancer activity via targeting Hsp90. In the xenograft model in vivo, C4 effectively inhibited lung cancer growth without obvious side effects. Collectively, C4 could be a promising therapeutic agent for lung cancer and the novel scaffold provided new insights into the design of Hsp90 inhibitors.

Novel protein kinase C phosphorylated kinase inhibitor-matrine suppresses replication of hepatitis B virus via modulating the mitogen-activated protein kinase signal

HBV (hepatitis B virus) infection still threatens human health. Therefore, it is essential to find new effective anti-HBV compounds. Here, we identified matrine as a novel inhibitor of PKC (protein kinase C) phosphorylated kinase by screening a natural compound library. After HepG2.215 cells were treated with matrine, we carried out a phosphorylated proteomics sequence study and analyzed the prediction of related kinase expression level. In the case of HBV infection, it was found that PKC kinase mediates the activation of mitogen-activated protein kinase (MAPK) signaling pathway known as son of sevenless (SOS) activation. It was also found that PKC kinase inhibits the expression of C-X-C Motif Chemokine Ligand 8 (CXCL8) by inhibiting the activity of activating transcription factor 2/ cAMP response element binding protein (ATF2/CREB), and this effect is independent of its activated MAPK signaling pathway. Finally, Western blot was used to detect the expression of MAPK, ATF2, CREB3 phosphorylation and nonphosphorylation in matrine-treated cells and PKC-treated cells. PKC phosphorylated kinase inhibitor-matrine suppresses the replication of HBV via modulating the MAPK/ATF2 signal. Matrine is a good clinical drug to enhance the autoimmunity in the adjuvant treatment of chronic HBV infection.

Matrine-Family Alkaloids: Versatile Precursors for Bioactive Modifications

Matrine-family alkaloids as tetracycloquinolizindine analogues from Traditional Chinese Medicine Sophora flavescens Ait, Sophora subprostrata and Sophora alopecuroides L possess various pharmacological activities and have aroused great interests over the past decades. Especially, a lot of matrine derivatives have been designed and synthesized and their biological activities investigated, and encouraging results have continuously been achieved in recent several years. These studies are helpful to develop more potent candidates or therapeutic agents and disclose their molecular targets and mechanisms. This paper reviews recent advances in the bioactive modifications of matrine-family alkaloids from derivatization of the C-13, C-14 or C-15 position, opening D ring, fusing D ring and structural simplification.

UPLC-MS identification and anticomplement activity of the metabolites of Sophora tonkinensis flavonoids treated with human intestinal bacteria

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Total flavonoids of S. tonkinensis showed obvious anticomplement activity after incubated with human intestinal bacteria.

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Eighteen flavonoids were identified from TFST and its metabolites by UPLC-ESI- LTQ/MS.

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Five glycosides were metabolized into three aglycones with more potent anticomplement activity.

Anticomplement activity played an important role in anti-inflammatory effects of traditional Chinese herbs. The total flavonoids of Sophora tonkinensis (TFST) were inactive on the complement system but showed obvious anticomplement activity after incubated with human intestinal bacteria in vitro. In order to discover the metabolic activation of TFST by intestinal flora, the constituents of TFST and its metabolites were identified by UPLC-ESI-LTQ/MS. Their anticomplement activities were evaluated through the classical and alternative pathway. As a result, eighteen flavonoids were identified, including seven flavonoid glycosides, five aglycones and six isoprenylated flavonoids. All the glycosides (daidzein-4′-glucoside-rhamnoside, sophorabioside, rutin, isoquercitrin, quercitrin, ononin, trifolirhizin) were metabolized into their corresponding aglycones in different extent by human intestinal bacteria, resulting in the contents of the five aglycones were highly increased in 24 h. However, no changes have occurred on the six isoprenylated flavonoids. Interestingly, three aglycones (quercetin, formononetin and maackiain) had significantly more potent anticomplement activities than their prototype glycosides. The results indicated that the enhancement of TFST anticomplement activity was attributed to the active aglycones, especially formononetin and quercetin, produced by human intestinal bacteria. These aglycones are likely to be among the potential active components of S. tonkinensis for its inhibiting inflammation effects.

Novel Sophoridine Derivatives Bearing Phosphoramide Mustard Moiety Exhibit Potent Antitumor Activities In Vitro and In Vivo

Novel mustard functionalized sophoridine derivatives were synthesized and evaluated for their cytotoxicity against of a panel of various cancer cell lines. They were shown to be more sensitive to S180 and H22 tumor cells with IC₅₀ values ranging from 1.01–3.65 μM, and distinctly were more cytotoxic to cancer cells than normal cell L929. In addition, compounds 7a, 7c, and 7e displayed moderate tumor suppression without apparent organ toxicity in vivo against mice bearing H22 liver tumors. Furthermore, they arrested tumor cells in the G1 phase and induced cellular apoptosis. Their potential binding modes with DNA-Top I complex have also been investigated.

Chinese herbal extract Su-duxing had potent inhibitory effects on both wild-type and entecavir-resistant hepatitis B virus (HBV) in vitro and effectively suppressed HBV replication in mouse model

This study aimed to investigate anti-HBV effect and major active compounds of Su-duxing, a medicine extracted from Chinese herbs. HBV-replicating cell lines HepG2.2.15 (wild-type) and HepG2.A64 (entecavir-resistant) were used for in vitro test. C57BL/6 mice infected by adeno-associated virus carrying 1.3 mer wild-type HBV genome were used for in vivo test. Inhibitory rates of Su-duxing (10 μg/mL) on HBV replicative intermediate and HBsAg levels were 75.1%, 51.0% in HepG2.2.15 cells and 65.2%, 42.9% in HepG2.A64 cells. The 50% inhibitory concentration of Su-duxing and entecavir on HBV replicative intermediates had 0.2-fold and 712.5-fold increase respectively for entecavir-resistant HBV compared to wild-type HBV. Su-duxing and entecavir combination showed a better anti-HBV effect than each single of agents. Mice treated with Su-duxing (45.0 mg kg^-1 d^-1 for 2 weeks) had 1.39 log₁₀ IU/mL decrease of serum HBV DNA, and 48.9% and 51.7% decrease of serum HBsAg and HBeAg levels. GeneChip and KEGG analysis proposed that anti-HBV mechanisms included relief of HBx stability and viral replication, deregulation of early cell cycle checkpoints, and induction of type I interferon. Quantitative RT-PCR verified that CCNA2, ATF4, FAS and CDKN1A expression levels had significant difference between Su-duxing-treated and control groups. Six active compounds (Matrine, Oxymatrine, Chlorogenic acid, Sophocarpine, Baicalein, and Wogonin) against HBV were identified in Su-duxing. Greater anti-HBV effects were observed in some compound pairs compared to each single compound. In conclusion, Su-duxing had potent inhibitory effects on both wild-type and entecavir-resistant HBV. Its effects were associated with coordinated roles of active compounds in its composition.

Design, synthesis and biological evaluation of matrine derivatives as potential anticancer agents

Using matrine (1) as the lead compound, a series of new 14-(N-substituted-2-pyrrolemethylene) matrine and 14-(N-substituted-indolemethylene) matrine derivatives was designed and synthesized for their potential application as anticancer agents. The structure of these compounds was characterized by ¹H NMR, ¹³C NMR and ESI-MS spectral analyses. The target compounds were evaluated for their in vitro cytotoxicity against three human cancer cell lines (SMMC-7721, A549 and CNE2). The results revealed that compound A6 and B21 displayed the most significant anticancer activity against three cancer cell lines with IC₅₀ values in range of 3.42-8.05 μM, which showed better activity than the parent compound (Matrine) and positive control Cisplatin. Furthermore, the Annexin V-FITC/PI dual staining assay revealed that compound A6 and B21 could significantly induce the apoptosis of SMMC-7721 and CNE2 cells in a dose-dependent manner. The cell cycle analysis also revealed that compound A6 could cause cell cycle arrest of SMMC-7721 and CNE2 cells at G2/M phase.

Kushenin combined with adefovir dipivoxil affects the HBV-DNA load in serum, immune functions and liver functions of patients with chronic hepatitis B

This study aimed to explore the effect of kushenin combined with adefovir dipivoxil on the load of hepatitis B virus DNA (HBV-DNA) in serum, in immune functions and in liver functions of patients with chronic hepatitis B. A sample of 80 patients with chronic hepatitis B was selected who were admitted to Weifang People's Hospital for treatment between January, 2013 and December, 2015. They were divided into the observation group (n=40) and the control group (n=40). The patients in both groups received adefovir dipivoxil, while those in the observation group additionally received the kushenin. Variations in HBV-DNA load and transforming growth factor-β1 (TGF-β1) in the two groups were detected before intervention, at 1 month, 3 months and 6 months after intervention. In addition, after intervention, we also observed the changes in CD4+, CD8+ and CD4+/CD8+, as well as the levels of immune globulin. Furthermore, in these two groups, we detected the changes in endotoxin in serum before and after intervention, the liver function after intervention, and the variations of hyaluronic acid (HA) and type III procollagen (PCIII) before and after intervention which were used to serve as the indicators for hepatic fibrosis. Results showed that at one month, 3 months and 6 months after intervention, HBV-DNA load and the level of TGF-β1 in the observation group were lower than those in the control group (P<0.05). In the observation group, the HBV-DNA load at 6 months after intervention was the lowest, sequentially followed by the levels at 3 months, at 1 month and before intervention (P<0.05). After intervention, the levels of CD4+ and CD8+ and CD4+/CD8+ in the observation group were higher than those in the control group (P<0.05). Moreover, the levels of immunoglobulin M (IgM), immunoglobulin G (IgG) and immunoglobulin A (IgA) were elevated in the observation group compared to the levels in the control group (P<0.05). Additionally, the level of endotoxin in serum, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBil). Besides, after intervention, the levels of HA and PCIII in the observation group were found to be lower than those in the control group before and after intervention (P<0.05). This study concludes that, for patients with chronic hepatitis B, kushenin combined with adefovir dipivoxil can remarkably decrease the HBV-DNA load, improve their immunity, ameliorate the liver function and delay the onset of liver cirrhosis.

Novel α, β-Unsaturated Sophoridinic Derivatives: Design, Synthesis, Molecular Docking and Anti-Cancer Activities

Using sophoridine 1 and chalcone 3 as the lead compounds, a series of novel α, β-unsaturated sophoridinic derivatives were designed, synthesized, and evaluated for their in vitro cytotoxicity. Structure-activity relationship (SAR) analysis indicated that introduction of α, β-unsaturated ketone moiety and heterocyclic group might significantly enhance anticancer activity. Among the compounds, 2f and 2m exhibited potential effects against HepG-2 and CNE-2 human cancer cell lines. Furthermore, molecular docking studies were performed to understand possible docking sites of the molecules on the target proteins and the mode of binding. This work provides a theoretical basis for structural optimizations and exploring anticancer pathways of this kind of compound.

Matrine derivative YF-18 inhibits lung cancer cell proliferation and migration through down-regulating Skp2

Lung cancer is the leading cause of cancer related death which needs novel drugs to improve patient outcomes. In this study, we examined the ability of YF-18, a novel matrine derivative to inhibit the growth and migration of lung cancer cells. By cell cycle analysis, wound healing and transwell assays, we found that YF-18 induced G2/M cell cycle arrest and inhibited migration of lung cancer cells in a dose-dependent manner. Further results indicated that YF-18 inhibited cell proliferation and migration through down-regulating Skp2 and up-regulating its substrates, p27 and E-cadherin. Moreover, YF-18 inhibited A549-luciferase cell xenograft tumor growth in a dose-dependent manner. The findings indicate that YF-18 bears therapeutic potentials for lung cancer.

Synthesis and biological evaluation of matrine derivatives containing benzo-α-pyrone structure as potent anti-lung cancer agents

Matrine, an active component of root extracts from Sophora flavescens Ait, is the main chemical ingredient of Fufang Kushen injection which was approved by Chinese FDA (CFDA) in 1995 as an anticancer drug to treat non-small cell lung cancer and liver cancer in combination with other anticancer drugs. Owning to its druggable potential, matrine is considered as an ideal lead compound for modification. We delineate herein the synthesis and anticancer effects of 17 matrine derivatives bearing benzo-α-pyrone structures. The results of cell viability assays indicated that most of the target compounds showed improved anticancer effects. Further studies showed that compound 5i could potently inhibit lung cancer cell proliferation in vitro and in vivo with no obvious side effects. Moreover, compound 5i could induce G1 cell cycle arrest and autophagy in lung cancer cells through up-regulating P27, down-regulating CDK4 and cyclinD1 and attenuating PI3K/Akt/mTOR pathway. Suppression of autophagy attenuated 5i induced proliferation inhibition. Collectively, our results infer that matrine derivative 5i bears therapeutic potentials for lung cancer.

Synthesis and biological evaluation of matrine derivatives as anti-hepatocellular cancer agents

We delineate herein the synthesis and anti-cancer effects of 15 matrine derivatives. The in vitro growth inhibitory assays showed that most of the prepared compounds exhibited improved anti-proliferative activities towards cancer cells with IC50 17-109 times lower than that of matrine. Compounds CH6 showed the most potent anti-proliferative activities in the four tested cancer cell lines. Moreover, compound CH6 could induce G1 cell cycle arrest and inhibit cell migration in human hepatocellular cancer cell lines Bel-7402 and HepG2 through up-regulation of P21, P27 and E-cadherin and down-regulation of N-cadherin.

Alkaloids from Oxytropis ochrocephala and antiproliferative activity of sophoridine derivatives against cancer cell lines

Ten alkaloids (1-10), with sophoridine (1) as the most abundant component, were obtained from the whole plants of Oxytropis ochrocephala Bunge. Furthermore, eight new sophoridine derivatives (11-16, 20, 21), with modification on the C-14 position of 1 were synthesized. All compounds (1-16, 20, 21) were evaluated for antiproliferative activity against five human tumor cell lines. Among them, the newly synthesized derivative 20 exhibited the best inhibitory activity against the tested cell lines. Its activity was increased by more than fourfold as compared with parent compound 1.

Synthesis and biological evaluation of sophoridinol derivatives as a novel family of potential anticancer agents

New N-substituted sophoridinic acid/ester and sophoridinol derivatives were synthesized and evaluated for their cytotoxic activity in human HepG2 hepatoma cells from the lead sophoridine (1). Among the newly synthesized compounds, sophoridinol 7i displayed a potential antiproliferative activity with an IC50 of 3.1 μM. Importantly, it exerted an almost equipotent effect against both wild MCF-7 and adriamycin (AMD)-resistant MCF-7 (MCF-7/AMD) breast carcinoma cell lines. Its mode of action was to arrest the cell cycle at the G0/G1 phase, consistent with that of the parent 1. In addition, compound 7i also showed a reasonable ClogP value and favorable pharmacokinetic property with an area under the concentration-time curve (AUC) of 10.3 μM·h in rats, indicating an ideal druggable characteristic. We consider sophoridinol derivatives to be a novel family of promising antitumor agents with an advantage of inhibiting drug-resistant cancer cells.

Dibenzoyl and isoflavonoid glycosides from Sophora flavescens: inhibition of the cytotoxic effect of D-galactosamine on human hepatocyte HL-7702

Twelve new dibenzoyl derivatives sophodibenzoside A-L (1-12) and five new isoflavone glycosides (13-17) have been isolated from the roots of Sophora flavescens together with eight known compounds (18-25). Notably, the use of acetic acid-d4 was required to enable identification of the dibenzoyl glycoside structures. Compounds 1, 2, 13, 14, and 19 exhibited weak inhibition of the cytotoxic effect of d-galactosamine on the human hepatic cell line HL-7702.

Antiviral activity and underlying molecular mechanisms of Matrine against porcine reproductive and respiratory syndrome virus in vitro

Porcine reproductive and respiratory syndrome (PRRS), caused by porcine reproductive and respiratory syndrome virus (PRRSV), is an acute infectious disease. The prevalence of PRRS has made swine industry suffered huge financial losses. Matrine, a natural compound, has been demonstrated to possess anti-PRRSV activity in Marc-145 cells. However, the underlying molecular mechanisms were still unknown. The main objective of our study was to discuss the effect of Matrine on PRRSV N protein expression and PRRSV induced apoptosis. Indirect immunofluorescence assay (IFA) and Western blot were used to assess the effect of Matrine on N protein expression. Apoptosis was analyzed by fluorescence staining. In addition, the effect of Matrine on caspase-3 activation was investigated by Western blot. Indirect immunofluorescence assay and Western blot analysis demonstrated that Matrine could inhibit N protein expression in Marc-145 cells. And Matrine was found to be able to impair PRRSV-induced apoptosis by inhibiting caspase-3 activation.

Identifying 2 prenylflavanones as potential hepatotoxic compounds in the ethanol extract of Sophora flavescens

Zhixue capsule is a prescription for hemorrhoid commonly used in traditional Chinese medicine. This drug was recalled by the State Food and Drug Administration in 2008 because of severe adverse hepatic reactions. Zhixue capsule is composed of ethanol extracts of Cortex Dictamni (ECD) and Sophora flavescens (ESF). In our preliminary study, we observed the hepatotoxic effects of ESF on rat primary hepatocytes. However, ECD did not exhibit hepatotoxicity at the same concentration range. In this study, ESF was evaluated for its potential hepatotoxic effects on rats. Bioassay-guided isolation was used to identify the material basis for hepatotoxicity. Treatment with 1.25 g/kg and 2.5 g/kg ESF significantly elevated the alanine aminotransferase and aspartate aminotransferase levels in the serum. The changes in the levels of transaminases were supported by the remarkable fatty degeneration of liver histopathology. Further investigations using bioassay-guided isolation and analysis indicated that prenylated flavanones accounted for the positive hepatotoxic results. Two isolated compounds were identified, kurarinone and sophoraflavanone G, using nuclear magnetic resonance and mass spectrometry techniques. These compounds have potent toxic effects on primary rat hepatocytes (with IC50 values of 29.9 μM and 16.5 μM) and human HL-7702 liver cells (with IC50 values of 48.2 μM and 40.3 μM), respectively. Consequently, the hepatotoxic constituents of S. flavescens were determined to be prenylated flavanones, kurarinone, and sophoraflavanone G.

GC/MS analysis of high-performance liquid chromatography fractions from Sophora flavescens and Torilis japonica extracts and their in vitro anti-neosporal effects on Neospora caninum

We analyzed alcoholic extracts of herbs possessing anti-neosporal activity against Neospora (N.) caninum. To identify the chemical components of Sophora (S.) flavescens and Torilis (T.) japonica associated with anti-neosporal activity, specific fractions were isolated by high-performance liquid chromatography (HPLC). In vitro activity of the fractions against N. caninum was then assessed. Gas chromatography/mass spectrometry (GC/MS) was used to identify and quantify specific anti-neosporal molecules in the herbal extracts. Almost all HPLC fractions of S. flavescens and T. japonica had higher levels of anti-neosporal activity compared to the not treated control. Active constituents of the extracts were sophoridane, furosardonin A, and tetraisopropylidene-cyclobutane in S. flavescens; 5,17-β-dihydroxy-de-A-estra-5,7,9,14-tetraene, furanodiene, and 9,12-octadecadienoic acid (Z,Z)-(CAS,1) in T. japonica.

Characterization of alkaloids in Sophora flavescens Ait. by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry

Sophora flavescens Ait., a well-known Chinese herbal medicine, is widely used in clinical practice for the treatment of viral hepatitis, cancer, gastrointestinal hemorrhage, and skin diseases. This paper is the first report on a method based on the combined use of high-performance liquid chromatography, photodiode array detection, and electrospray ionization tandem mass spectrometry for the comprehensive and systematic separation and characterization of bioactive alkaloids in Sophora flavescens Ait. A total of 22 constituents were identified on the basis of the extracted ion chromatograms for different [M+H](+) ions of the alkaloids present in S. flavescens Ait. Among these, 5 constituents were unambiguously identified by comparing the experimental data on their retention times and MS(n) spectra with those of the authentic compounds, and 17 other constituents were tentatively identified on the basis of their MS(n) fragmentation behaviors and/or molecular weight information from literatures. Furthermore, some characteristic fragmentation pathways of the alkaloids in S. flavescens Ait. were detected and examined. This information may be useful for characterizing the bioactive alkaloids present in S. flavescens Ait. and for possible applications in formulations.

Phytochemical analysis of an antiviral fraction of Radix astragali using HPLC-DAD-ESI-MS/MS

Radix astragali (Huangqi in Chinese) is a well-known traditional Chinese medicinal herb that has been used clinically in China for centuries to cure various diseases. To profile the antiviral constituents of this herb, a high-performance liquid chromatography-diode array detector-electrospray ionization-tandem mass spectrometry (HPLC-DAD-ESI-MS/MS) analytical method was developed to separate and determinate the active part of the extract of Radix astragali, which showed potent inhibition of several viruses. By comparing their retention time and MS data with those obtained from the authentic compounds and the published data, a total of 18 compounds, comprising 11 flavonoids and 7 saponins, were identified. This study provides an approach to rapidly characterize bioactive constituents in traditional Chinese medicines (TCMs).

Potential new inorganic antitumour agents from combining the anticancer traditional Chinese medicine (TCM) matrine with Ga(III), Au(III), Sn(IV) ions, and DNA binding studies

Three new compounds of Ga(III), Au(III), Sn(IV) with matrine (MT), [H-MT][GaCl(4)] (1), [H-MT][AuCl(4)] (2) and [Sn(H-MT)Cl(5)] (3), have been synthesized and characterized by elemental analysis, IR, ESI-MS and single crystal X-ray diffraction methods. The crystal structural analyses indicate that 1 and 2 are ionic compounds, whereas 3 is a tin(IV) complex formed by the monodentate MT via its carbonyl oxygen atom of MT coordinating to Sn(IV). Their in vitro cytotoxicity towards eight selected tumour cell lines has been evaluated by MTT (3-[4,5-Dimentylthiazole-2-yl]-2,5-diphenpyltetra-zolium bromide) method, and compounds 1 and 2 exhibit enhanced activity, such as 1 to SW480, 2 to HeLa, HepG2 and MCF-7, which exceeds matrine and cisplatin, and display synergistic contribution of their components. The cell cycle analyses show that compounds 1, 3 and MT exhibit cell cycle arrest at the G(2)/M phase. Interactions of these compounds with calf thymus DNA (ct-DNA) have been investigated by spectroscopic analyses. The planar extension of the intercalative metal-matrine compounds increases the interaction of the metal-matrine with DNA, indicating that the cationic metal ions and configuration of the intercalated metal-matrine will affect the extent of interaction. Compound 2, [H-MT][AuCl(4)], exhibits more intensive binding ability to DNA, which may correlate with intercalation and other action mode. The circular dichroism spectra of the ct-DNA bound with metal-MT compounds also suggest that ct-DNA interacted with 1, 2, 3 does not influence its secondary structure. Furthermore, both compounds 1 and 2 exhibit effective inhibition ability to topoisomerase (TOPO I) at concentration of 50 μM, while matrine and compound 3 do not.