Solid-phase synthesis, characterization, and antibacterial activities of metallocene-peptide bioconjugates

This work shows how the introduction of an organometallic group enhances and modifies the specificity of biologically active peptides. Ferrocene was chosen as an organometallic group because it has been shown to alter the pharmacodynamic profile of bioactive compounds. A comparison with the isosteric cobaltocenium group allows one to explore the influence of charge and redox potential on the biological activity of the conjugates. Arginine and tryptophan containing peptides H-WRWRWR-NH(2) and H-RWRWRW-NH(2) and the metallocene peptide bioconjugates [M]-C(O)-RWRWR-NH(2) and [M]-C(O)-WRWRW-NH(2), where [M]=[Co(Cp)(C(5)H(4))](+), [Fe(Cp)(C(5)H(4))] were prepared by solid-phase peptide synthesis (SPPS). They were purified by HPLC, characterized by ESIMS and NMR spectroscopy, and tested for antibacterial properties against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus using the minimum inhibitory concentration (MIC) test. In most cases, no metal-specific activity could be observed. However, the conjugate [Fe(Cp)(C(5)H(4))-C(O)-WRWRW-NH(2)] 6 was found to be particularly effective against the Gram-positive S. aureus. The activity of this metallocene-pentapeptide conjugate (7.1 microM) was even better than the 20 amino acid naturally occurring pilosulin 2, which was used as a positive control. Unlike all other compounds tested, which were most active against the Gram-negative E. coli strain, the ferrocene conjugate 6 was the only compound in this series that was most active against Gram-positive bacteria. Given the health concerns resulting from multidrug resistant S. aureus strains, the incorporation of metallocenes may provide a novel line of attack.     

Synthesis and Antimicrobial Activity Evaluation of Imidazole-Fused Imidazo[2,1-b][1,3,4]thiadiazole Analogues

Three series of new imidazole-fused imidazo[2,1-b][1,3,4]thiadiazole analogues (compounds 20 a – g , 21 a – g , and 22 a – g ) have been synthesized, and their antibacterial and antifungal activities have been evaluated. All the target compounds showed strong antifungal activity and high selectivity for the test fungus Candida albicans over Gram-positive and -negative bacteria. N-((4-(2-Cyclopropyl-6-(4-fluorophenyl)imidazo[2,1-b][1,3,4]thiadiazol-5-yl)-5-(6-methyl-pyridin-2-yl)-1H-imidazol-2-yl)methyl)aniline ( 21 a ) showed the highest activity against C. albicans (MIC₅₀=0.16 μg/mL), 13 and three times that of the positive control compounds gatifloxacin and fluconazole, respectively. Compounds 21 a and 20 e did not show cytotoxicity against human foreskin fibroblast-1 cells, and compound 21 a was as safe as the positive control compounds in hemolysis tests. These results strongly suggest that some of the compounds produced in this work have value for development as antifungal agents.     

Studies on the Vilsmeier-haack reaction. Part XIII: Novel heterocyclo-substituted 4,4′-bi-pyrazolyl dithiocarbamate derivatives

5-Imino-3-methyl-l-phenyl-2-pyrazoline-4-dithiocarbamic acid (I) underwent simultaneous formylation and dimerization reactions with the Vilsmeier reagent giving 4-[5′-imino-3-(1″-formyl-2″-dimethylaminoethenyl)-3′-methyl-1′-phenyl-1′H-pyrazolo-4′-dithiocarbamyl-2,4-dihydro-3-imino-5-methyl-2-phenyl-1-pyrazoline]dithiocarbamate (II) which hydrolysed with sodium hydroxide to give 4-[3′-(1″-formyl-2″-hydroxyethenyl)-3′-methyl-1-phenyl-1′-H-pyrazolo-4′-dithiocarbamyl-1′-pyrazoline]dithiocarbamate-5,5′-dione (IV). Treatment of II and/or IV with morpholine, piperidine, piperazine, hydroxylamine, hydrazine hydrate or phenylhydrazine afforded the corresponding dipyrazolo-4,4′-dithiocarbamate derivatives with different heterocyclic systems at the 3-position. The structures of these compounds were confirmed by microanalysis data, IR and ¹H-NMR spectrometry. All synthesized compounds have been screened in vitro against Gram-positive and Gram-negative bacteria, and fungi.     

Synthesis and Antibacterial Activities of 1-Alkyl-3-methacryloyl (Acryloyl) of Benzimidazolone (Thione) Derivatives

A series of (28) 1-alkyl-3-methacryloyl (acryloyl)-benzimidazolone (thione) deriv-atives were synthesized. The structures of the new derivatives were confirmed by (1)H-NMR, (13)C-NMR and ESI-MS spectral analysis. The antibacterial activities of these compounds against several strains of bacteria, such as Bacillus cereus, Bacillus subtilis, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, were evaluated by methods of paper disc-diffusion and broth mciro-dilution. Methacryloyl derivatives displayed higher antibacterial activities against tested bacterial strains than those of acryloyl derivatives in in vitro tests. A structure-activity relationship (SAR) study revealed that the presences of the methacryloyl moieties is essential to the antibacterial activities of the compounds.     

Antimicrobial Siloxane Statistical and Graft Copolymers Substituted with t-Butylamine and t-Butylammonium Biocidal Functions

Two kinds of new biocidal siloxane copolymers were synthesized, poly-[3(t-butylamino)propyl]methylsiloxane-co-(3-chloropropyl)methylsiloxane] and poly[dimethylsiloxane-co-(3-mercaptopropyl)methylsiloxane]-g-poly-2(t-butylamino)ethyl methacrylate]. Water-soluble derivatives of these copolymers, having charged ammonium groups, were also obtained. The copolymers were tested against two Gram-positive and three Gram-negative bacterial strains. The antibacterial tests for the water-soluble copolymers with charged ammonium groups were performed in aqueous solutions. Both these copolymers were active against the Gram-positive bacterial strains and inactive or moderately active against Gram-negative bacteria. The uncharged, insoluble, t-butylamine substituted copolymers were tested using a two-phase water-copolymer system. In this test both copolymers having the uncharged t-butylamine functions showed a high biocidal potency against the bacteria studied including those Gram-negative ones.     

新型吡唑-4-酰胺类衍生物设计、合成与生物活性

为寻找高生物活性的吡唑酰胺类化合物,设计、合成一系列含硫结构的N-吡啶基吡唑-4-酰胺类衍生物,目标化合物结构经1HNMR、13CNMR和有机元素分析或高分辨质谱确证,并进行了杀虫及杀菌活性测试研究。初步杀虫活性测试结果表明,目标化合物在200mg/L对东方粘虫具有中等杀虫活性。同时,测试了目标化合物在50mg/L对5种病菌的离体抑菌活性,化合物N-[(4-氯-2-甲基-6-甲酰胺基)苯基]-1-(3-氯-2-吡啶基)-3-硫甲基-1H-吡唑-4-甲酰胺If和N-[(4-氯-2-甲基-6-环丙基酰胺基)苯基]-1-(3-氯-2-吡啶基)-3-硫甲基-1H-吡唑-4-甲酰胺Ig对番茄早疫病菌显示了良好的活性,分别为65.2%和67.1%, 高于对照药百菌清,值得进一步研究。     

Study of Biological Activities and ADMET-Related Properties of Novel Chlorinated N-arylcinnamamides

A series of eighteen 4-chlorocinnamanilides and eighteen 3,4-dichlorocinnamanilides were designed, prepared and characterized. All compounds were evaluated for their activity against gram-positive bacteria and against two mycobacterial strains. Viability on both cancer and primary mammalian cell lines was also assessed. The lipophilicity of the compounds was experimentally determined and correlated together with other physicochemical properties of the prepared derivatives with biological activity. 3,4-Dichlorocinnamanilides showed a broader spectrum of action and higher antibacterial efficacy than 4-chlorocinnamanilides; however, all compounds were more effective or comparable to clinically used drugs (ampicillin, isoniazid, rifampicin). Of the thirty-six compounds, six derivatives showed submicromolar activity against Staphylococcus aureus and clinical isolates of methicillin-resistant S. aureus (MRSA). (2E)-N-[3,5-bis(trifluoromethyl)phenyl]- 3-(4-chlorophenyl)prop-2-enamide was the most potent in series 1. (2E)-N-[3,5-bis(Trifluoromethyl)phenyl]-3-(3,4-dichlorophenyl)prop-2-enamide, (2E)-3-(3,4-dichlorophenyl)-N-[3-(trifluoromethyl)phenyl]prop-2-enamide, (2E)-3-(3,4-dichloro- phenyl)-N-[4-(trifluoromethyl)phenyl]prop-2-enamide and (2E)-3-(3,4-dichlorophenyl)- N-[4-(trifluoromethoxy)phenyl]prop-2-enamide were the most active in series 2 and in addition to activity against S. aureus and MRSA were highly active against Enterococcus faecalis and vancomycin-resistant E. faecalis isolates and against fast-growing Mycobacterium smegmatis and against slow-growing M. marinum, M. tuberculosis non-hazardous test models. In addition, the last three compounds of the above-mentioned showed insignificant cytotoxicity to primary porcine monocyte-derived macrophages.     

N-苯甲酰基苯并异噻唑-3-酮硫代甲酰胺类化合物的合成及生物活性

通过1,2-苯并异噻唑啉-2(3H)-酮和硫代异氰酸苯甲酸酐类化合物反应,合成了7种N-苯甲酰基苯并异噻唑-3-酮硫代甲酰胺类化合物,用IR、MS、1HNMR、13CNMR对其结构进行了表征;活性测试表明,浓度为0.005mol/L的该类化合物溶液对鳗孤菌、拟态孤菌、溶藻弧菌、大肠杆菌和嗜水性单胞菌的抑菌率达40.5%~100%。     

Antimicrobial and Hypoglycemic Activities of Novel N-Mannich Bases Derived from 5-(1-Adamantyl)-4-substituted-1,2,4-triazoline-3-thiones

The reaction of 5-(1-adamantyl)-4-ethyl or allyl-1,2,4-triazoline-3-thione with formaldehyde solution and various 1-substituted piperazines yielded the corresponding N-Mannich bases. The newly synthesized N-Mannich bases were tested for in vitro inhibitory activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Six compounds showed potent antibacterial activity against one or more of the tested microorganisms, while two compounds exhibited moderate activity against the tested Gram-positive bacteria. None of the newly synthesized compounds were proved to possess marked activity against Candida albicans. The oral hypoglycemic activity of six compounds was determined in streptozotocin (STZ)-induced diabetic rats. Four compounds produced significant strong dose-dependent reduction of serum glucose levels, compared to gliclazide at 10 mg/kg dose level (potency ratio > 75%).     

Phenanthroline derivatives with improved selectivity as DNA-targeting anticancer or antimicrobial drugs

Phenanthroline derivatives are of interest due to their potential activity against cancer, and viral, bacterial, and fungal infections. In a search for highly specific antitumor and antibacterial compounds, we report the activities of 1,10-phenanthroline-5,6-dione (phendione or L(1)), dipyrido[3,2-a:2',3'-c]phenazine (dppz or L(2)), and their corresponding platinum complexes ([PtL(1)Cl2] and [PtL(2)Cl2]), and provide the solid-state 3D structure for [PtL(1)Cl2]. It is generally known that a toxic metal ion coordinated to an active organic moiety leads to a synergistic effect; however, we report herein that the platinum complexes [PtL(1)Cl2] and [PtL(2)Cl2] have weaker activities relative to those of the free ligands, especially against bacteria. Testing these agents against a variety of human cancer cell lines revealed that L(1) and [PtL(1)Cl2] were at least as active as cisplatin against several of the cell lines (including a cisplatin-resistant cell line). The absence of antibacterial activity of [PtL(1)Cl2] removes the detrimental effect of phenanthrolines toward intestinal flora, suggesting a highly promising new strategy for the development of anticancer drugs with reduced side effects.     

Physicochemical and Theoretical Characterization of a New Small Non-Metal Schiff Base with a Differential Antimicrobial Effect against Gram-Positive Bacteria

Searching for adequate and effective compounds displaying antimicrobial activities, especially against Gram-positive bacteria, is an important research area due to the high hospitalization and mortality rates of these bacterial infections in both the human and veterinary fields. In this work, we explored (E)-4-amino-3-((3,5-di-tert-butyl-2-hydroxybenzylidene)amino) benzoic acid (SB-1, harboring an intramolecular hydrogen bond) and (E)-2-((4-nitrobenzilidene)amino)aniline (SB-2), two Schiff bases derivatives. Results demonstrated that SB-1 showed an antibacterial activity determined by the minimal inhibitory concentration (MIC) against Staphylococcus aureus, Enterococcus faecalis, and Bacillus cereus (Gram-positive bacteria involved in human and animal diseases such as skin infections, pneumonia, diarrheal syndrome, and urinary tract infections, among others), which was similar to that shown by the classical antibiotic chloramphenicol. By contrast, this compound showed no effect against Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, and Salmonella enterica). Furthermore, we provide a comprehensive physicochemical and theoretical characterization of SB-1 (as well as several analyses for SB-2), including elemental analysis, ESMS, ¹H and ¹³C NMR (assigned by 1D and 2D techniques), DEPT, UV-Vis, FTIR, and cyclic voltammetry. We also performed a computational study through the DFT theory level, including geometry optimization, TD-DFT, NBO, and global and local reactivity analyses.     

Pyrazole Derived Cationic Surfactants and their Tin and Copper Complexes: Synthesis,Surface Activity,Antibacterial and Antifungal Efficacy

Five membered heterocyclic cationic 3-pyrazolium surfactants namely: 2-[2-(alkyloxy)-2-oxoethyl]-3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-3-pyrazolium bromide (decyl-; dodecyl-) and their copper and tin complexes were synthesized, their structures were confirmed using different spectroscopic tools. The IR spectra of the metal complexes showed that these compounds exhibit a tetrahedron structure with the transition metal ion (M²⁺) at the center and the cationic ligands arranged in the apexes, while the halide ions in the center. The synthesized compounds were evaluated as biocides against different types of bacteria and fungi. The biological activity data showed that the cationic surfactants exhibit moderate to high efficacy against the tested microorganisms (either bacteria or fungi). While, complexation of these cationic surfactants with Cu (II) and Sn (II) ions the antimicrobial activity was strongly increased. The surface activity of these compounds were discussed and correlated to their chemical structure and the type of substituents on the heterocyclic moiety. Meanwhile, the antimicrobial assay was correlated to the surface activities of the synthesized compounds.     

含噻二唑环吡唑并[3,4-d]嘧啶类含氟衍生物的合成及抗菌活性

通过5-氨基-4-氰基-1-苯基-1H-吡唑与三氟乙酸、三氯氧磷反应"一锅法"制得1-苯基-6-三氟甲基-4-氯-1H-吡唑并[3,4-d]嘧啶,收率为61%,再与5-芳基-2-巯基-1,3,4-噻二唑发生芳香族亲核取代反应合成8种含噻二唑环吡唑并[3,4-d]嘧啶类含氟衍生物,收率为79%～87%。目标化合物的结构经红外光谱、核磁共振氢谱、质谱与元素分析表征。并将其用于两种细菌(金黄色葡萄球菌和大肠埃希菌)的抑菌实验研究。结果表明,该类化合物对金黄色葡萄球菌均有抑制作用,其中化合物Ⅳb和Ⅳh的抑制活性相对较高。     

Reactions of hydrazonoyl halides 44 [1]: synthesis of some new 1,3,4-thiadiazolines, 1,3,4-selenadiazolines and triazolino[4,3- a ]pyrimidines

1,3,4-Thiadiazolines, 1,3,4-selenadiazolines and triazolino[4,3-a]pyrimidines have been synthesized from 3-aza-[2,4-dimethyl(1,3-thiazol-5-yl)-2-bromo-3-substituted-amino]prop-2-en-1-ones with potassium thiocyanate, potassium selenocyanate, alkyl carbodithioates and 6-methyl-2-methylthio-4-substituted 3,4-dihydropyrimidine-5-carboxylates. Structures of the newly synthesized compounds have been established by elemental analysis, spectral data and alternative synthesis whenever possible. Some of products have been tested towards bacteria.     

几个含噻二唑环芳甲酰基脲的合成及生物活性

通过2-氨基-5-(3-吡啶基)-1,3,4-噻二唑与取代苯甲酰基异氰酸酯反应,得到相应的芳甲酰基脲:N-[5-(3-吡啶基)-1,3,4-噻二唑-2-基]-N′-(2-氯苯甲酰基)脲(Ⅲa)、N-[5-(3-吡啶基)-1,3,4-噻二唑-2-基]-N′-(2-溴苯甲酰基)脲(Ⅲb)、N-[5-(3-吡啶基)-1,3,4-噻二唑-2-基]-N′-(4-溴苯甲酰基)脲(Ⅲc)、N-[5-(3-吡啶基)-1,3,4-噻二唑-2-基]-N′-(2-甲基苯甲酰基)脲(Ⅲd)和N-[5-(3-吡啶基)-1,3,4-噻二唑-2-基]-N′-(4-三氟甲基苯甲酰基)脲(Ⅲe),收率分别为69.5%、67.2%、73.1%、66.8%和71.6%.产物的结构经红外光谱、核磁共振氢谱、质谱与元素分析表征.并对目标化合物进行了植物生长调节活性测试,初步的测试结果表明,目标化合物在10 mg/L表现出一定程度的生长素活性和较好的细胞分裂素活性,其中Ⅲc和Ⅲe的细胞分裂素活性超过40%.     

Antibiotic and Nematocidal Metabolites from Two Lichen Species Collected on the Island of Lampedusa (Sicily)

The antibiotic and nematocidal activities of extracts from two coastal lichen species collected on Lampedusa Island (Sicily), Ramalina implexa Nyl. and Roccella phycopsis Ach., were tested. Methyl orsellinate, orcinol, (+)-montagnetol, and for the first time 4-chlororcinol were isolated from Roccella phycopsis. (+)-Usnic acid was obtained from Ramalina implexa. The crude organic extract of both lichen species showed strong antibiotic activity against some bacterial species and nematocidal activity. Among all the pure metabolites tested against the infective juveniles (J2) of the root-knot nematode (RKN) Meloydogine incognita, (+)-usnic acid, orcinol, and (+)-montagnetol had significant nematocidal activity, comparable with that of the commercial nematocide Velum^® Prime, and thus they showed potential application in agriculture as a biopesticide. On the contrary, methyl orsellinate and 4-chlororcinol had no nematocidal effect. These results suggest that the substituent pattern at ortho-para-position in respect to both hydroxyl groups of resorcine moiety, which is present in all metabolites, seems very important for nematocidal activity. The organic extracts of both lichens were also tested against some Gram-positive and Gram-negative bacteria. Both extracts were active against Gram-positive species. The extract of Ramalina implexa showed, among Gram-negative species, activity against Escherichia coli and Acinetobacter baumannii, while that from Roccella phycopsis was effective towards all test strains, with the exception of Pseudomonas aeruginosa. The antimicrobial activity of (+)-usnic acid, methyl orsellinate, and (+)-montagnetol is already known, so tests were focused on orcinol and 4-chlororcinol. The former showed antibacterial activity against all Gram positive and Gram-negative test strains, with the exception of A. baumannii and K. pneumoniae, while the latter exhibited a potent antibacterial activity against Gram-positive test strains and among Gram-negative strains, was effective against A. baumannii and K. pneumonia. These results suggest, for orcinol and 4-chlororcinol, an interesting antibiotic potential against both Gram-positive and Gram-negative bacterial strains.     

1-[2-(2,4-二氯苯基)-4-烃氧基甲基-1,3-二氧戊环-2-基]甲基-1H-1,2,4-三氮唑类化合物的合成及杀菌活性研究

2,4-二氯苯乙酮经溴化得ω-溴-2,4-二氯苯乙酮,该化合物与丙三醇在对甲基苯磺酸催化下脱水,得2-(2,4-二氯苯基)-2-溴甲基-4-羟甲基-1,3-二氧戊环,该中间体与苯甲酰氯在常温下反应,合成了2-(2,4-二氯苯基)-2-溴甲基-4-苯甲酰氧基甲基-1,3-二氧戊环,然后与三氮唑钠盐在130℃反应36 h,之后在碱性条件下水解,获得1-[2-(2,4-二氯苯基)-4-羟甲基-1,3-二氧戊环-2-基]甲基-1H-1,2,4-三氮唑,再以吡啶为缚酸剂继续与甲磺酰氯反应,合成了1-[2-(2,4-二氯苯基)-4-甲磺酰氧基甲基-1,3-二氧戊环-2-基]甲基-1H-1,2,4-三氮唑,最后在碱性条件下,与12个不同结构的酚缩合成标题化合物1-[2-(2,4-二氯苯基)-4-烃氧基甲基-1,3-二氧戊环-2-基]甲基-1H-1,2,4-三氮唑。标题化合物的结构用GC-MS、FTIR进行了表证。生物活性实验结果表明,12个标题化合物对水稻稻瘟病菌的抑菌率均在88.0%以上,其中,1-[2-(2,4-二氯苯基)-4-间甲基苯氧基甲基-1,3-二氧戊环-2-基]甲基-1H-1,2,4-三氮唑达100%。1-[2-(2,4-二氯苯基)-4-苯氧基甲基-1,3-二氧戊环-2-基]甲基-1H-1,2,4-三氮唑和1-[2-(2,4-二氯苯基)-4-对硝基苯氧基甲基-1,3-二氧戊环-2-基]甲基-1H-1,2,4-三氮唑对油菜菌核病菌的抑菌率分别为100%和97.8%;1-[2-(2,4-二氯苯基)-4-间甲基苯氧基甲基-1,3-二氧戊环-2-基]甲基-1H-1,2,4-三氮唑对小麦赤霉病菌的抑制活性为91.2%。     

Synthesis,Characterization, and Exploration of Antimicrobial Activity of Copper Complex of Diamide Derivative of p-tert-butylcalix[4]arene

Calixarenes are a versatile class of compounds, which possesses wide applications in various fields including biological as well as pharmaceutical sciences. In the present study, amide derivative of calix[4]arene (3) was synthesized and characterized by modern analytical techniques such as elemental analysis and Fourier transform infrared spectroscopy (FT-IR). Complexation property of 3 with essential metals was explored by UV-Vis spectroscopy. The results revealed that 3 shows good selectivity toward Cu²⁺. Job's plot analysis suggests that 3 forms complex with Cu²⁺ in 1:2 stoichiometric ratio. Antimicrobial activity of 3 and its Cu²⁺ complex was also determined and it was observed that 3 is more efficient against R. stolonifer as compared to its action against bacteria, because for fungus it shows “Minimum Inhibitory Concentration” (MIC) value equal to 1.5 µg/mL, while for bacteria MIC is 3 µg/mL. However, it was found that complex is more efficient in action than 3. Oxidation state of metal, overtone concept, and Tweedy's chelation theory justifies the increased activity of metal complex. Cu²⁺ complex shows higher antimicrobial activity toward Escherichia coli (E. coli) (Gram-negative) bacteria by showing MIC value 0.37 µg/mL. While for Staphylococcus albus (S. albus) (Gram-positive) bacteria and Rhizopus stolonifer (R. stolonifer) fungal species, it shows MIC value equal to 0.75 µg/mL.     

Synthesis,Surface Activity,and Antimicrobial Efficacy of Hydrogenated Cardanol-Derived Positively Charged Asymmetric Gemini Surfactants

Nine different hydrogenated cardanol-based quaternary ammonium compounds including one conventional single-tale single-head surfactant, one bicephalic single-tale double-head surfactant, and seven asymmetric Gemini surfactants were synthetized using a simple process with high yields. Their structures were characterized using ¹H NMR, ¹³C NMR, and high-resolution mass spectral studies. Their surface active properties were evaluated by the wilhelmy plate method at 25 °C and physical parameters like CMC, γ_CMC, π_CMC, C₂₀, τ_CMC, and A_min were calculated. The Krafft temperature values of C-BP-1, C-BP-4, and C-BP-6 are lower than 0 °C, suggesting high-potential industrial application. All synthesized compounds but C-BP-F exhibit great antimicrobial ability against Gram-positive bacteria (S. aureus [ATCC 25923] and C. glutamicum [ATCC 13032]) while inadequate antimicrobial ability against Gram negative strains (E. coli [ATCC 25922] and P. aeruginosa [ATCC 27853]).     

Triphenyltin ortho-aminophenyl- and 2-pyridyl-thiolates: synthesis and in vitro antitumour activity

The synthesis, spectroscopic characterization and in vitro antitumour activity of two triorganotin compounds, triphenyltin ortho-aminophenylthiolate (1) and triphenyltin 2-pyridylthiolate, compound (2) are reported. The structure of 1 is confirmed by X-ray diffraction, with the tin atom in a distorted tetrahedral geometry because of monodentate coordination, as a thiolate (Sn-S 2.431(2) A), of the ortho-aminophenylthiolate ligand. The in vitro antitumour activities of 1 and 2, against a number of cell lines, are comparable to those exhibited by methotrexate and doxorubicin, and higher than those of carboplatin and cisplatin.