anti-Mycobacterium Tuberculosis Research Articles

Synthesis of novel (-)-Camphene-based thiosemicarbazones and evaluation of anti-Mycobacterium tuberculosis activity

In this work the aim of study was the synthesis and evaluation of in vitro anti-Mycobacterium tuberculosis activity as well as the cytotoxicity in VERO cells of a series of 17 novel thiosemicarbazones derived from the natural monoterpene (-)-camphene by REMA and MTT methods. Overall, the majority of tested compounds exhibited considerable inhibitory effects on the growth of M. tuberculosis H37Rv, especially the derivatives 3, 4a–c, 4f, 4i, 4k, 5 and 6a–b. MIC values of 20 tested compounds ranged from 3.9 to > 250 μg/mL. It was found that when inserting new nitrogenous groups to the (-)-camphene increased the anti-M. tuberculosis activity of some compounds. The SI was calculated for all compounds that showed highly potent anti-M. tuberculosis activity and the best SI values were 21.36, 26.92 and 31.62 (4b, 6a and 6b), and may be considered potential candidates for future antituberculosis drugs.

Anti-Mycobacterium tuberculosis activity of essential oil and 6,7-dehydroroyleanone isolated from leaves of Tetradenia riparia (Hochst.) Codd (Lamiaceae)

BackgroundThe global resurgence of tuberculosis (TB) and the development of drug resistance, as multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis isolates, are a threat to TB control and have created a need for new and more effective anti-TB drugs. AimThe current study evaluated the in vitro cytotoxicity and activity of Tetradenia riparia essential oil (TrEO) and 6,7-dehydroroyleanone pure compound against M. tuberculosis H37Rv and susceptible and resistant clinical isolates. MethodsThe in vitro activities of TrEO and 6,7-dehydroroyleanone were determined by Resazurin Microtiter Assay Plate (REMA). The cytotoxicity was evaluated in murine peritoneal macrophages by Alamar Blue assay. The cytotoxic effects were expressed as median concentration cytotoxicity (CC50) and the selectivity index (SI) was calculated. ResultsTrEO and 6,7-dehydroroyleanone showed activity against M. tuberculosis H37Rv with minimum inhibitory concentration (MIC) 62.5 µg/ml and 31.2 µg/ml, respectively. Both of them exhibited activities against resistant and susceptible M. tuberculosis clinical isolates with MIC values between 31.2 and 62.5 µg/ml. Cytotoxicity assays showed SI 1.9 and 7.9 for TrEO and 6,7-dehydroroyleanone, respectively. ConclusionThese results revealed that TrEO isolated from leaves of T. riparia and the pure compound 6,7-dehydroroyleanone display good activity against M. tuberculosis clinical isolates, including MDR isolates, with low cytotoxicity to murine macrophages. The 6,7-dehydroroyleanone compound is a potential candidate for anti-TB drug.

Metabolism profiling of nevadensin in vitro and in vivo by UHPLC-Q-TOF-MS/MS

Nevadensin is major constituents of Lysionotus pauciflorus Maxim. (Chinese name: Shidiaolan), which has a variety of pharmacological effects such as anti-mycobacterium tuberculosis activities, antitussive, anti-inflammatory and anti-hypertensive. In this paper, we investigated the metabolism of nevadensin in vitro and in vivo. A strategy was firstly developed to identify the metabolites of nevadensin by using ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). An on-line data acquisition method a multiple mass defect filter (MMDF) combined with dynamic background subtraction (DBS) was developed to trace all probable metabolites. Furthermore, some assistant tools, such as key fragment ions (KFI), were employed for compound hunting and identification. Based on the proposed method, 23 metabolites were structurally characterized in vivo including 16 phase I and 7 phase II metabolites, and 12 metabolites were detected in vitro containing 10 phase I and 2 phase II metabolites. The results indicated that oxidation, hydrolysis, demethylation, methylation, sulfate conjugation and glucuronide conjugation were main metabolic pathways of nevadensin. In a word, this study maybe can provide reference and valuable evidence for further investigation of the metabolic mechanism of nevadensin.

Quantitative structure–activity relationship and molecular docking of 4-Alkoxy-Cinnamic analogues as anti-mycobacterium tuberculosis

Quantitative structure–activity relationship (QSAR) and molecular docking studies were carried out on 4-Alkoxy-Cinnamic derivatives as potent anti-mycobacterium tuberculosis. Chemical structures of the molecules were optimized by employing Density Functional Theory and utilizing (B3LYP) with the 6-31G∗ basis set. Four models were generated by Genetic Function Approximation (GFA). Model one was selected as the optimum model based on validation parameters which were found to be significant with correlation coefficient (R2) of 0.980921, adjusted correlation coefficient (R2 adj) value of 0.97547 and Cross validation coefficient (Qcv2) value of 0.965244. External validations were employed to validate the chosen model and the model was found to have (R2test) of 0.8756 and Coefficient of determination for Y-randomization (c Rp2) value of 0.867578. The Molecular docking studies showed that the ligand 1,2,3,4,5 and 6 with better activities have higher bind affinities ranging from (−6.4 and −10.4 kcal/mol) which formed H-bonds and hydrophobic interactions with amino acid residues of mycobacterum tuberculosis (M. tuberculosis) DNA gyrase receptor. This research has shown that the binding affinities of these inhibitors were found to be better than the commercially sold anti-mycobacterium tuberculosis; enthambutol (−5.8 kcal/mol) and isoniazid (−5.3 kcal/mol). QSAR model generated and molecular docking results propose the direction for the design of new anti-tubercular agents with better activities against DNA gyrase.

Evaluation of a synthetic peptide for the detection of anti-Mycobacterium tuberculosis curli pili IgG antibodies in patients with pulmonary tuberculosis

Tuberculosis (TB) remains a serious threat in underdeveloped areas. Mycobacterium tuberculosis curli pili (MTP), a virulence factor, is a potential biomarker for a reliable point of care (POC) test and was evaluated for its ability to react with Immunoglobulin G (IgG) in TB patients. An MTP synthetic peptide in a slot blot assay was used to screen serum/plasma samples (n = 65) in 3 separate cohorts, including 40 TB positive (16 HIV co-infected), 20 TB negative/HIV negative patients and 5 healthy volunteers. Forty samples were true positives (HIV positive, n = 16), 23 true negatives (HIV negative) and 2 false positives (HIV negative). The McNemar test demonstrated a 3.08% accuracy estimate (CI: −2.1% - 3.08%). This confirms that MTP is expressed during infection, including HIV-TB co-infection, is likely to be suitable for the design of a POC test and supports the validation of MTP for TB detection in larger patient populations.

QSAR Modeling and Molecular Docking Analysis of Some Active Compounds against Mycobacterium tuberculosis Receptor (Mtb CYP121).

A quantitative structure-activity relationship (QSAR) study was performed to develop a model that relates the structures of 50 compounds to their activities against M. tuberculosis. The compounds were optimized by employing density functional theory (DFT) with B3LYP/6-31G⁎. The Genetic Function Algorithm (GFA) was used to select the descriptors and to generate the correlation model that relates the structural features of the compounds to their biological activities. The optimum model has squared correlation coefficient (R2) of 0.9202, adjusted squared correlation coefficient (Radj) of 0.91012, and leave-one-out (LOO) cross-validation coefficient (Qcv2) value of 0.8954. The external validation test used for confirming the predictive power of the built model has R2pred value of 0.8842. These parameters confirm the stability and robustness of the model. Docking analysis showed the best compound with high docking affinity of −14.6 kcal/mol which formed hydrophobic interaction and hydrogen bond with amino acid residues of M. tuberculosis cytochromes (Mtb CYP121). QSAR and molecular docking studies provide valuable approach for pharmaceutical and medicinal chemists to design and synthesize new anti-Mycobacterium tuberculosis compounds.

Structural Sequencing of Oligopeptides Aided by 1H Iterative Full-Spin Analysis.

This report describes an approach using 1H NMR iterative full-spin analysis (HiFSA) to extract definitive structural information on unknown peptides from 1D 1H NMR data. By comparing the experimental data and HiFSA fingerprint of a known analogue, it is possible to isolate the characteristic 1H subspectrum of the different amino acids and, thus, elucidate the structure of the peptide. To illustrate this methodology, a comprehensive analysis of five new anti-Mycobacterium tuberculosis peptides (2-6), all analogues of ecumicin (1), was carried out. The method was validated by demonstrating congruence of the HiFSA-based structures with all available data, including MS and 2D NMR. The highly reproducible HiFSA fingerprints of the new ∼1600 amu peptides were generated in this process. Besides oligo-peptides, the HiFSA sequencing approach could be extended to all oligomeric compounds consisting of chains of monomers lacking H-H spin-spin coupling across the moieties. HiFSA sequencing is capable of differentiating complex oligomers that exhibit minor structural differences such as shifted hydoxyl or methyl groups. Because it employs the basic and most sensitive 1D 1H NMR experiment, HiFSA sequencing enables the exploration of peptide analogues up to at least 2000 amu, even with basic contemporary spectrometers and when only sub-milligram amounts of isolates are available.

Synthesis of acyl-hydrazone from usnic acid and isoniazid and its anti-Mycobacterium tuberculosis activity

Se evaluó el ácido úsnico (1), aislado del liquen Evernia prunastri (Cajamarca-Perú), producto natural conocido por sus actividades biológicas, y, del mismo modo, se evaluó la síntesis de su derivado acil-hidrazona (2), obtenido a partir de una reacción de condensación entre el ácido úsnico y la isoniazida en solución etanólica a reflujo, con un rendimiento global de 95%. Ambos compuestos fueron evaluados y comparados con la isoniazida según su actividad anti-Mycobacterium tuberculosis basada en el ensayo de susceptibilidad mediante el método TEMA. Los resultados mostraron que el compuesto 1 presenta valores de MIC de 16,0 μg/mL frente a las cepas H37Rv, TB DM 97 y MDR DM 1098, mientras que el compuesto 2 presenta valores de MIC de 2,0; 64,0 y 64,0 μg/mL respectivamente.

Antioxidant, anti-inflammatory, antiproliferative and antimycobacterial activities of the essential oil of Psidium guineense Sw. and spathulenol

Ethnopharmacological relevanceLeaves from Psidium guineense Sw. are used in popular medicine for the treatment of inflammatory disease. However, there is no scientific evidence demonstrating this activity. Aim of the studyTo evaluate the antioxidant, anti-inflammatory, antiproliferative and antimycobacterial activities of the essential oil of P. guineense and spathulenol (a major constituent). The study was conducted in part to provide evidence supporting the ethnobotanical use of the leaves of this species. Material and methodsThe essential oil (EOPG) was extracted from the leaves of P. guineense by hydrodistillation and analysed by gas chromatography-mass spectrometry (GC–MS). The major compound, spathulenol (PG-1), was isolated in a chromatographic column and characterized by nuclear magnetic resonance (NMR). EOPG and PG-1 were evaluated in vitro for antioxidant activity by DPPH, ABTS and MDA methods; anti-inflammatory potential was assessed using two models, including pleurisy and oedema, in mice. The impact of EOPG and PG-1 on cell proliferation was determined via spectrophotometric quantification of the cellular protein content using a sulforhodamine B assay, and anti-Mycobacterium tuberculosis activity was determined using the REMA method. ResultsA total of 38 components were identified from the EOPG, with the sesquiterpenic alcohol spathulenol (PG-1) (80.7%) being the major constituent. EOPG and PG-1 exhibited the highest antioxidant activities in the DPPH and MDA system compared with reference standard, with IC50 values ranging from 26.13 to 85.60μg/mL. Oral administration of EOPG and PG-1 showed significant inhibition in the Cg-induced mice paw oedema and pleurisy model. The EOPG (GI50 = 0.89μg/mL) and PG-1 (GI50 = 49.30μg/mL) were particularly effective against the ovarian cancer cell line. Both showed moderate antimycobacterial activity. ConclusionFor the first time, this study demonstrated the antioxidant, anti-inflammatory, antiproliferative and antimycobacterial properties of the essential oil of P. guineense (leaves were collected in Dourados-MS) and spathulenol, collaborating the etnhopharmacologycal use of this plant due to its an anti-inflammatory effect.

The expressions and roles of different forms of IL-22 in Mycobacterium tuberculosis infection

Despite evidence suggesting an anti-Mycobacterium tuberculosis effector function of CD4+ T cells that produce and retain IL-22 in macaques, the general role of IL-22 in tuberculosis infection is still poorly characterized. To explore the immune mechanism in the pathogenesis of tuberculosis in humans, here we evaluated different forms of IL-22 in populations with different tuberculosis infection statuses. We enrolled 156 subjects including 49 patients with pulmonary tuberculosis, 27 patients with tuberculous pleurisy (TPE), 38 individuals with latent tuberculous infection (LTBI) and 42 healthy controls (HC). We found significantly higher IL-22 levels at the tuberculosis infection site than in the peripheral blood as well as higher antigen-specific IL-22 levels in the culture supernatant for patients with active tuberculosis than in healthy controls. The proportions of IL-22 + CD4+ T and IL-22 + CD8+ T cells in patients with active tuberculosis were significantly higher than those in the latent tuberculosis infection group and the healthy control group, based on intracellular cytokine staining. However, surprisingly, we found membrane-bound IL-22+ T cells, including CD4+ T cells and CD8+ T cells, by surface staining, especially in patients with active tuberculosis. Furthermore, the expression of membrane-bound IL-22 significantly decreased after drug therapy. In conclusion, our results suggest that IL-22 has various roles in tuberculosis immune responses. In particular, membrane-bound IL-22+ T cells may play important roles in the human immune response to Mycobacterium.

New cyrhetrenyl and ferrocenyl sulfonamides: Synthesis, characterization, X-ray crystallography, theoretical study and anti-Mycobacterium tuberculosis activity

A new series of cyrhetrenyl and ferrocenyl sulfonamides were designed, synthesized and characterized. The reactions of organometallic amines (P2 and P3) with the corresponding arylsulfonyl chlorides produced cyrhetrenyl (2a-c) and ferrocenyl (3a-c) sulfonamide derivatives. All the compounds were characterized by conventional spectroscopic techniques (FT-IR, 1H and 13C NMR and mass spectrometry). The proposed molecular structures of 2a and 3a were confirmed by single-crystal X-ray crystallography. Theoretical calculations at the DFT level were also carried out as an approximation to rationalize the influences of the electronic natures of the organometallic fragments into the sulfonamide skeleton. All the complexes were screened in vitro against Mycobacterium tuberculosis and exhibited only modest activities in the micromolar range.

Palladium(II)/N,N-disubstituted-N′-acylthioureas complexes as anti-Mycobacterium tuberculosis and anti-Trypanosoma cruzi agents

The new complexes of Pd(II) with N,N-disubstituted-N′-acylthioureas:[(1) [Pd(dppf)(N,N-dimethyl-N′-benzoylthioureato-k2O,S)]PF6, (2) [Pd(dppf)(N,N-diethyl-N′-benzoylthioureato-k2O,S)]PF6, (3) [Pd(dppf)(N,N-dibuthyl-N′-benzoylthioureato-k2O,S)]PF6, (4) [Pd(dppf)(N,N-diphenyl-N′-benzoylthioureato-k2O,S)]PF6, (5) [Pd(dppf)(N,N-diethyl-N′-furoylthioureato-k2O,S)]PF6, (6) [Pd(dppf)(N,N-diphenyl-N′-furoylthioureato-k2O,S)]PF6, (7) [Pd(dppf)(N,N-dimethyl-N′- thiophenylthioureato-k2O,S)]PF6, and (8) [Pd(dppf)(N,N-diphenyl-N′-thiophenylthioureato-k2O,S)]PF6, were prepared and characterized by elemental analysis, and spectroscopic techniques. The structures of complexes (2), (3), (5), (6) and (8) had their structures determined by X-ray crystallography, confirming the coordination of the ligands with the metal through sulfur and oxygen atoms, forming distorted square-planar geometries. These complexes have shown antibacterial activity against anti-Mycobacterium tuberculosis H37Rv ATCC 27294. The complexes exhibited antiparasitic activity against Trypanosoma cruzi, while the metal-free thioureas did not. The results demonstrated that the compounds described here can be considered as promising anti-Mycobacterium tuberculosis and anti-T. cruzi agents, since in both cases their in vitro activity were better than reference drugs available for the treatment of both diseases.

Characterization of Mycobacterium marinum infections in zebrafish wounds and sinus tracts.

The impaired healing of Mycobacterium tuberculosis-infected wounds is a clinical challenge, and the mechanisms involved are still not clear. The zebrafish model of Mycobacterium marinum infection has provided surprising insights into the pathogenesis of tuberculosis in humans. Similarly, the major principles and phases of cutaneous wound healing are conserved among adult mammals and adult zebrafish. Here, we injected Mycobacterium marinum into the dorsal muscles of adult zebrafish and observed the development of chronic wound pathology. Deep sequencing showed that gene expression related to muscles was down-regulated, whereas expressions of the IL-1β, TNF-α, dram1 genes and the transcript of mir1-2 gene were up-regulated in infected wounds of zebrafish compared with control zebrafish. Muscles are immune-responsive tissues. Thus, muscles may play a role in the anti-Mycobacterium tuberculosis immunologic process, which leads to apoptosis of the infected muscle cell and formation of the subcutaneous sinus tract.

Organometallic tosyl hydrazones: Synthesis, characterization, crystal structures and in vitro evaluation for anti-Mycobacterium tuberculosis and antiproliferative activities

A series of new organometallic tosyl hydrazones of the general formula [{(η5-C5H4)-C(R)=NNHSO2C6H4CH3}]M(CO)3 (M=Re, Mn; R=H, CH3) were prepared by the reaction between formyl or acetyl organometallic precursors with p-toluenesulfonyl hydrazide. All compounds were characterized by conventional spectroscopic techniques (infrared, 1H and 13C NMR, mass spectrometry and elemental analysis). In addition, the molecular structures of the cymantrenyl hydrazones 2a and 2b have been determined by single-crystal X-ray diffraction. In the solid state, both compounds showed an E-configuration around the CN moiety. Evaluation of antitubercular activity, measured in vitro against Mycobacterium tuberculosis mc26230 strain, indicate that all organometallic tosyl hydrazones are considerably less active than the reference drug isoniazid. The antiproliferative activity against non-small cell lung cancer cells (H1299 cells) was also evaluated. Even though the IC50 measured for hydrazones 1–3 resulted 2–3-fold higher than cisplatin, biological results demonstrate that the electronic effects of the substituents on the hydrazone carbon are influencing factor in the anticancer activity.

Bis(diphenylphosphino)amines-containing ruthenium cymene complexes as potential anti-Mycobacterium tuberculosis agents

Several ruthenium complexes have been investigated regarding anti-Mycobacterium tuberculosis (anti-MTb) activity, with some diphosphine-containing ruthenium complexes comparable to first and second line drugs. However, to the best of our knowledge, there is no PNP-containing ruthenium complexes applied as metallodrugs. Thus, this study focused on the synthesis, characterization and anti-MTb activity of a new series of coordination compounds with general formula [RuCl(η6-p-cymene)(PNRP)]X (R=CH2Py (Py=pyridine)−[1a], CH2Ph (Ph=phenyl)−[1b], Ph−[1c] and p-tol (p-tol=p-tolyl)−[1d]; X=PF6− or BF4−). The complexes were fully characterized by NMR (1H, 31P{1H}), vibrational spectroscopy (FTIR), ESI-MS, molar conductance, elemental analysis and X-ray diffraction studies. The molecular structures of [1a]PF6, [1c]BF4 and [1d]PF6 were determined and confirm the spectroscopic and ESI-MS data. The complexes were used in anti-MTb trials, and the preliminary results are presented. The complexes are promising anti-MTb agents with MIC90 (Minimum Inhibitory Concentration of compounds required to inhibit the growth of 90% of MTb) values comparable with the Ethambutol, the reference drug used in this work, and complex [1a]BF4 presented the highest selectivity index.

Antitumor and anti-Mycobacterium tuberculosis agents based on cationic ruthenium complexes with amino acids

Six new complexes of Ru(II)/phenanthroline/1,4-bis(diphenylphosphino)butane containing amino acids (Glycine, l-Alanine, l-Valine, l-Tyrosine, l-Methionine or l-Tryptophan) were synthesized and characterized by IR, 31P{1H}, 13C and 1H NMR spectroscopies and cyclic voltammetry experiments. These data suggest the presence of diastereoisomers, except for the complex with glycine, amino acid that does not exhibit chiral carbon. The compounds are active against the MDA-MB-231 tumor cells and against Mycobacterium tuberculosis. The cationic ruthenium complexes with amino acids, reported here, show similar cytotoxicity against the MDA-MB-231 tumor cells. When compared with analogs complexes containing 2,2′-bipyridine as ligands, instead of 1,10-phenatroline, the new complexes studied here are, in general, roughly twice more active than the 2,2′-bipyridine ones and their IC50 values comparable with the cisplatin. In addition, low MICs values were obtained against Mycobacterium tuberculosis compared with the reference drugs, cycloserine and ethambutol.

The Activity of Immunoglobulin Y Anti-Mycobacterium tuberculosis on Proliferation and Cytokine Expression of Rat Peripheral Blood Mononuclear Cells.

Objective:It has long been known that chickens, like mammals, are capable of producing antigen-specific immunoglobulin Y (IgY), which functions similar to IgG. The present study was performed to investigate the activity of IgY anti-Mycobacterium tuberculosis on proliferation, interleukin (IL)-2, and interferon (IFN)-γ expression of rat peripheral blood mononuclear cells (PBMCs).Materials and Methods:The activity of IgY anti-M. tuberculosis in different doses (25, 50, and 100 μg/ml) on rat PBMCs proliferation was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. The production of IL-2 and IFN-γ in the PBMC supernatant was determined using enzyme-linked immunosorbent assay. Investigation was performed on mRNA expression of IL-2 and IFN-γ by reverse transcription-polymerase chain reaction (RT-PCR).Results:IgY anti-M. tuberculosis significantly increased the proliferation of rat PBMC. Furthermore, IgY anti-M. tuberculosis dose dependently increased IL-2 and IFN-γ production in PBMC, suggesting that pharmacological activities of IgY anti-M. tuberculosis in PBMC may be mediated by regulating the production of cytokines. In the RT-PCR, expression of cytokines such as IL-2 and IFN-γ in PBMC cultures was increased by IgY anti-M. tuberculosis.Conclusions:We concluded that increasing IL-2 and IFN-γ productions in PBMC was related to IgY anti-M. tuberculosis, stimulating the mRNA transcription (gene expression) of these cytokines which can induce proliferation of PBMC.SUMMARY Lohman laying hens immunized intramuscularly with antigens of M. tuberculosis can produce specific IgY anti-Mycobacterium tuberculosis complexIgY anti-M. tuberculosis significantly increased the proliferation of rat peripheral blood mononuclear cell (PBMC)IgY anti-M. tuberculosis dose dependently increased interleukin 2 (IL-2) and interferon (IFN)-γ production in PBMCIn the reverse transcription-polymerase chain reaction, expression of cytokines such as IL-2 and IFN-γ in PBMC cultures was increased by IgY anti-M. tuberculosisThe increasing IL-2 and IFN-γ productions in PBMC were related to stimulation on mRNA transcription which can induce proliferation of PBMC. Abbreviations Used: IgY anti-M. tuberculosis: Immunoglobulin Y anti-Mycobacterium tuberculosis; IL-2: Interleukin-2; IFN-γ: Interferon-γ; PBMCs: Peripheral blood mononuclear cells.

体外评价29种中药的抗结核分枝杆菌活性

结核病是迄今为止最难控制的传染病之一，且近年来呈上升趋势。中药是新药发现的重要来源之一，且在我国储存量大。本试验选取29种中草药，分别对结核分枝杆菌H37Rv和牛分枝杆菌BCG菌株进行活性筛选，发现14种中草药具有抗结核杆菌作用，其中9种中草药与异烟肼和利福平存在协同抗菌作用，首次发现三角条具有抗结核杆菌活性。研究结果为发现新型抗结核杆菌分子骨架奠定了基础。 Tuberculosis is one of common infectious diseases that has been difficult to control so far and has been on the rise in recent years. Chinese herbal medicine is an important natural resource for the discovery of new drug, and China has a wealth of natural medicine resources. In this experiment, 29 traditional Chinese medicines were selected for the screening of anti-M tuberculosis H37Rv and BCG respectively. The results indicated that 14 kinds of herbs showed powerful activity against Myco-bacterium tuberculosis H37Rv and BCG. Among them, 9 kinds of Chinese herbal medicine exhibited synergistic antibacterial effect combined with isoniazid and rifampicin respectively. In addition, it was first discovered that the Sanjiaotiao (Chinese name) had anti-Myco bacterium tuberculosis activity. The study laid the foundation for the discovery of the new skeleton of anti-Mycobacterium tuberculosis drug.

Structure/Activity of PtII/N,N-Disubstituted-N’-acylthiourea Complexes: Anti-Tumor and Anti-Mycobacterium tuberculosis Activities

The syntheses, characterization, cytotoxicity against tumor cells and anti-Mycobacterium tuberculosis activity assays of PtII/PPh3/N,N-disubstituted-N'-acylthioureas complexes with general formulae [Pt(PPh3)2(L)]PF6, PPh3 = triphenylphosphine; L = N,N-disubstituted-N'-acylthiourea, are here reported. The complexes were characterized by elemental analysis, molar conductivity, infrared (IR), nuclear magnetic resonance (NMR) (1H, 13C{1H} and 31P{1H}) spectroscopy. The 31P{1H} NMR data are consistent with the presence of two PPh3 ligands cis to each other position, and one N,N-disubstituted-N'-acylthiourea coordinated to the metal through O and S, in a chelate form. The structures of the complexes were determined by X-ray crystallography, forming distorted square-planar structures. The complexes were tested in human cell lines carcinomas and also screened with respect to their anti-Mycobacterium tuberculosis activity (H37RvATCC 27294). It was found that complexes with N,N-disubstituted-N'-acylthiourea containing open and small chains as R2 groups show higher cytotoxic and higher anti-Mycobacterium tuberculosis activity than those containing rings in this position.

Design, synthesis and biological activity of pyrazinamide derivatives for anti-Mycobacterium tuberculosis

A total of 11 pyrazinamide derivatives were designed and synthesised using pyrazinamide as the lead compound, which was optimised by structural modification with alkyl chains, six-membered rings, and bioisosterism, respectively. The target compounds were synthesised using pyrazinecarboxylic acid as the starting material by acylation, amidation, and alkylation, respectively. Their structures were confirmed by 1H NMR, 13C NMR, HRESIMS, and elemental analysis, respectively. The bioactivities of derivatives were assayed using bacteriostatic experiment and minimum inhibitory concentration experiment. It was showed that the derivatives had good inhibitory effect on Mycobacterium tuberculosis. The biological activity of derivative 1f was the best among all compounds, its antibacterial activity was 99.6%, and the minimum inhibitory concentration was 8.0 µg/mL.