RESUMO
Recently, liposomal formulations that target macrophages have been used to treat lung diseases. However, the detailed mechanism of the cellular uptake must be elucidated to identify a formulation with excellent cellular uptake efficiency to treat non-tuberculous mycobacterial lung disease. We studied the effect of lipid composition on the cellular uptake of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)/cholesterol (Chol) liposomes with a size of approximately 200 nm into THP-1-derived macrophages. The amount of DPPC/Chol liposomes (80/20 mol%) was greater than that of DPPC/Chol (60/40 mol%) and DPPC/Chol (67/33 mol%) liposomes. The anisotropy of 1,6-diphenyl-1,3,5-hexatriene indicated that the membrane fluidity of the DPPC/Chol (80/20 mol%) liposomes was higher than that of the other two liposomes. DPPC/Chol (80/20 mol%) and DPPC/Chol (67/33 mol%) liposomes were taken up via clathrin- and caveolae-mediated endocytosis and phagocytosis. However, proteins involved in cellular uptake through ligand-receptor interactions were adsorbed to a greater extent on DPPC/Chol (80/20 mol%) liposomes than on DPPC/Chol (67/33 mol%) liposomes. Pretreatment of cells with antibodies against the low-density lipoprotein receptor and scavenger receptor type B1 largely inhibited the uptake efficiency of DPPC/Chol (80/20 mol%) liposomes. Our results indicate that the membrane fluidity of DPPC/Chol liposomes, which is controlled by the Chol ratio, is an important factor in controlling protein adsorption and the subsequent uptake efficiency of liposomes.
Assuntos
Colesterol , Lipossomos , Fluidez de Membrana , Macrófagos/metabolismoRESUMO
Nectriatide 1a, a naturally occurring cyclic tetrapeptide, has been reported to a potentiator of amphotericin B (AmB) activity. In order to elucidate its structure-activity relationships, we synthesized nectriatide derivatives with different amino acids in solution-phase synthesis and evaluated AmB-potentiating activity against Candida albicans. Among them, C-and N-terminal protected linear peptides were found to show the most potent AmB-potentiating activity.
Assuntos
Anfotericina B , Antifúngicos , Anfotericina B/química , Antifúngicos/química , Candida albicans , Peptídeos , Testes de Sensibilidade MicrobianaRESUMO
In vivo-mimic silkworm infection models with Mycobacterium avium and Mycobacterium intracellulare were newly established to evaluate the therapeutic effects of anti-M. avium complex (MAC) antibiotics. Silkworms raised at 37°C died within 72 hours of an injection of M. avium or M.intracellulare (2.5 × 107 colony-forming unit (CFU)/larva·g) into the hemolymph. Clinical anti-mycobacterial (tuberculosis) antibiotics were evaluated under these conditions. Clarithromycin, kanamycin, streptomycin, amikacin, and ciprofloxacin exerted therapeutic effects in a dose-dependent manner, which was consistent with those in the mouse model. Furthermore, three effective actinomycete culture broths were selected in the screening program of our microbial broth library using the silkworm model, and four active metabolites, ohmyungsamycins A and B (1 and 2), chartreusin (3), and griseoviridin (4), were identified. Among these compounds, 1 showed the lowest 50% effective dose (ED50) value (8.5 µg/larva·g), while 3 had the best ED50/minimum inhibitory concentration (MIC) ratio (7.4). These results indicate that silkworm models are a useful tool for identifying anti-MAC antibiotics candidates with veritable therapeutic effects.
Assuntos
Actinobacteria/química , Antibacterianos/administração & dosagem , Bombyx/microbiologia , Complexo Mycobacterium avium/patogenicidade , Infecção por Mycobacterium avium-intracellulare/tratamento farmacológico , Animais , Antibacterianos/farmacologia , Benzopiranos/administração & dosagem , Benzopiranos/farmacologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Glicosídeos/administração & dosagem , Glicosídeos/farmacologia , Testes de Sensibilidade Microbiana , Complexo Mycobacterium avium/efeitos dos fármacos , Complexo Mycobacterium avium/crescimento & desenvolvimento , Peptídeos/administração & dosagem , Peptídeos/farmacologia , Peptídeos Cíclicos/administração & dosagem , Peptídeos Cíclicos/farmacologiaRESUMO
A new cytotoxic agent designated as 2-epi-anthracimycin (1) was isolated along with anthracimycin and anthracimycin B (2-demethylanthracimycin) from the culture broth of the marine-derived actinomycete Streptomyces sp. OPMA00631. The structure of 1 was elucidated based on spectroscopic analyses (1D and 2D NMR data and ROESY correlations). Compound 1 exhibited cytotoxicity against Jurkat cells with an IC50 value of 50.5 µM in 20 h. The effect of 1 on the cell cycle distribution of Jurkat cells was investigated. Compound 1 (7.80 µM) increased G1 phase cells from 51.1 to 62.0% and conversely, decreased G2 and M phase cells from 30.7 to 19.3 % in 20 h. At a higher concentration, 1 (250 µM) markedly increased subG1 phase cells (1.9% at 0 h to 16.5% at 20 h), while the proportion of G1 phase cells was maintained (62.3%). These results suggest that 1 exhibits cytotoxicity against Jurkat cells by arresting the cell cycle at the G1 phase.
Assuntos
Actinobacteria/química , Organismos Aquáticos/química , Citotoxinas/química , Citotoxinas/farmacologia , Policetídeos/química , Policetídeos/farmacologia , Streptomyces/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Células JurkatRESUMO
The marine actinomycete strain OPMA02852, identified as the genus Streptomyces, was found to produce anti-mycobacterial compounds against Mycobacterium avium complex (MAC). One new compound, designated as steffimycin E (1), was isolated together with three known steffimycins (steffimycin (2), 10-dihydrosteffimycin (3), and 8-demethoxysteffimycin (4)) from the culture broth of this producing microorganism by solvent extraction, ODS column chromatography, and preparative HPLC. Compound 1 has a tetracyclic quinone structure with a sugar moiety. Compound 1 exhibited anti-mycobacterial activity against M. intracellulare, M. bovis BCG, and M. smegmatis.
Assuntos
Antraciclinas/farmacologia , Antituberculosos/farmacologia , Complexo Mycobacterium avium/efeitos dos fármacos , Mycobacterium avium/efeitos dos fármacos , Streptomyces/química , Antraciclinas/química , Antituberculosos/química , Linhagem Celular Tumoral , Células HeLa , Humanos , Infecção por Mycobacterium avium-intracellulare/tratamento farmacológicoRESUMO
Hydroxyoctadecadienoic acids (HODEs) are generated by oxidation of linoleic acid in vivo and thought to mediate various pathophysiological responses. In this study, we examined the effects of HODEs on EL4 mouse lymphoma cell growth and found that 9-(E,Z)-HODE inhibited EL4 cell growth in a dose-dependent manner, whereas no such growth inhibition was observed with other isomers (9-(E,E)-, 13-(Z,E)-, or 13-(E,E)-HODE), suggesting that the growth-inhibitory effect of HODEs was stereospecific. Analysis by flow cytometry (FACS) with annexin V and propidium iodide (PI) staining showed that 9-(E,Z)-HODE induced apoptosis with G2/M phase arrest. We next examined the growth inhibition profile of 9-(E,Z)-HODE against a panel of 39 human cancer cell lines (JFCR39). The fingerprint of growth inhibition by 9-(E,Z)-HODE exhibited a high degree of similarity to that by MLN4924, an inhibitor of NEDD8-activating enzyme. The intracellular NEDD8 (ubiquitin-like protein) expression in EL4 cells was decreased by the treatment with 9-(E,Z)-HODE as assessed by immunoblotting and flow cytometry. In conclusion, 9-(E,Z)-HODE specifically induced G2/M phase arrest and apoptosis, and the decrease of NEDD8 expression might be involved in this effect.
Assuntos
Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Ácidos Graxos Insaturados/farmacologia , Linfoma/metabolismo , Animais , Linhagem Celular Tumoral , Ácidos Graxos Insaturados/química , Linfoma/patologia , Camundongos , Proteína NEDD8/metabolismo , EstereoisomerismoRESUMO
Mycobacterium avium complex (MAC) is a serious disease mainly caused by M. avium and M. intracellulare. Although the incidence of MAC infection is increasing worldwide, only a few agents are clinically used, and their therapeutic effects are limited. Therefore, new anti-MAC agents are needed. Approximately 6600 microbial samples were screened for new anti-mycobacterial agents that inhibit the growth of both M. avium and M. intracellulare, and two culture broths derived from marine actinomycete strains OPMA1245 and OPMA1730 had strong activity. Nosiheptide (1) was isolated from the culture broth of OPMA1245, and griseoviridin (2) and etamycin (viridogrisein) (3) were isolated from the culture broth of OPMA1730. They had potent anti-mycobacterial activity against M. avium and M. intracellulare with minimum inhibitory concentrations (MICs) between 0.024 and 1.56 µg/mL. In addition, a combination of 2 and 3 markedly enhanced the anti-mycobacterial activity against both M. avium and M. intracellulare. Furthermore, a combination 2 and 3 had a therapeutic effect comparable to that of ethambutol in a silkworm infection assay with M. smegmatis.
Assuntos
Antibacterianos/farmacologia , Macrolídeos/farmacologia , Complexo Mycobacterium avium/efeitos dos fármacos , Peptídeos/farmacologia , Animais , Antibacterianos/química , Bombyx/microbiologia , Descoberta de Drogas , Macrolídeos/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Infecção por Mycobacterium avium-intracellulare/tratamento farmacológico , Infecção por Mycobacterium avium-intracellulare/microbiologia , Infecção por Mycobacterium avium-intracellulare/mortalidade , Peptídeos/química , Tiazóis/química , Tiazóis/farmacologiaRESUMO
Atropisomers with a biaryl dihydronaphthopyranone structure, dinapinones A1 (DPA1) (M position) and A2 (DPA2) (P position), were isolated from the fungus culture broth of Talaromyces pinophilus FKI-3864 as inhibitors of [14C]neutral lipid ([14C]triacylglycerol (TG) and [14C]cholesteryl ester (CE)) synthesis from [14C]oleic acid in Chinese hamster ovary-K1 (CHO-K1) cells. DPA2 inhibited [14C]TG and [14C]CE synthesis (IC50s, 0.65 and 5.6 µM, respectively), but DPA1 had no inhibitory activity on [14C]TG and [14C]CE synthesis even at 12 µM. However, a 1:1 mixture of DPA1 and DPA2 (DPAmix) had the most potent inhibitory activity on [14C]TG and [14C]CE synthesis (IC50s, 0.054 and 0.18 µM, respectively). The mechanism of action of DPAmix was investigated. DPAmix had no effects on the enzymes involved in neutral lipid synthesis, while DPAmix enhanced the degradation of [14C]neutral lipids with concomitant decrease in cytosolic lipid droplets accumulated in CHO-K1 cells. From analysis of autophagy marker proteins, DPAmix caused dose-dependent induction of microtubule-associated protein light chain 3-II (LC3-II) and degradation of p62. In the autophagic flux assay using bafilomycin A1, DPAmix upregulated autophagosome turnover. These results reveal that DPAmix enhances neutral lipid degradation together with induction of autophagy.
Assuntos
Autofagossomos/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Cumarínicos/farmacologia , Lipogênese/efeitos dos fármacos , Lipólise/efeitos dos fármacos , Animais , Ascomicetos/química , Autofagossomos/metabolismo , Células CHO , Ésteres do Colesterol/biossíntese , Cumarínicos/química , Cumarínicos/isolamento & purificação , Cricetulus , Células HeLa , Células Hep G2 , Humanos , Gotículas Lipídicas/efeitos dos fármacos , Gotículas Lipídicas/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Estereoisomerismo , Triglicerídeos/biossínteseRESUMO
Atropisomeric dinapinonesâ A1 and A2 (DPA1 and DPA2) were isolated from a culture of Talaromyces pinophilus FKI-3864. Monapinone coupling enzyme (MCE), which dimerizes naphthopyranone monapinoneâ A (MPA), was purified from a cell-free extract of T.â pinophilus FKI-3864. MCE regioselectively dimerizes MPA at the 8,8'-positions to synthesize the atropisomers DPA1 and DPA2 in a ratio of approximately 1:2.5 without a cofactor. The optimal pHâ value and temperature for MCE were 4.0 and 50 °C, and the apparent Km and Vmax values for MPA were (72.7±23.2)â µm and (1.21±0.170)â µmol min-1 mg-1 protein. The MCE polypeptide is significantly homologous with multicopper oxidases. Heterologous expression of MCE and functional analysis confirmed that MCE catalyzes the regioselective coupling reaction of MPA to produce DPA. No fungal multicopper oxidase has previously been reported to catalyze regioselective intermolecular oxidative phenol coupling to produce naphthopyranone atropisomers.
Assuntos
Cobre/metabolismo , Cumarínicos/metabolismo , Naftalenos/metabolismo , Oxirredutases/metabolismo , Pironas/metabolismo , Talaromyces/enzimologia , Biocatálise , Cobre/química , Cumarínicos/química , Estrutura Molecular , Naftalenos/química , Oxirredutases/química , Pironas/química , EstereoisomerismoRESUMO
Autophagy is a cell survival process that represents a therapeutic target in cancer treatment. Many types of cytochalasins have been identified and some of them have been reported to interfere with the formation of the autophagosome, although only limited data are available to assess their potential effects. Therefore, in this study, we examined the effects of cytochalasins and structurally related compounds on cell survival and the regulation of autophagy in human lung A549 adenocarcinoma cells. Cytochalasin D (CD) and cytochalasin E (CE) prominently inhibited the growth of A549 cells in a dose-dependent manner. Following treatment with CE, F-actin filaments were disrupted, and the proportion of binucleated cells increased, whereas no such effects were observed with the seven other cytochalasins tested. We found that cytochalasin H (CH), CD, and especially CE could induce the up-regulation of autophagy-related protein (LC3-II) and SQSTM1/p62. Using bafilomycin A1, we demonstrated that CD, CE, and CH inhibited autophagosome turnover, resulting in a dysfunctional autophagic process. The results of this study reveal that CE is the most potent cytochalasin in terms of its ability to induce cell death and inhibit autophagy. CE may therefore be an effective therapeutic agent against lung cancer.
Assuntos
Antineoplásicos/administração & dosagem , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Citocalasinas/administração & dosagem , Células A549 , Antineoplásicos/classificação , Citocalasinas/classificação , Relação Dose-Resposta a DrogaRESUMO
An in vivo-mimic silkworm infection model with Mycobacterium smegmatis was established. When silkworms were raised at 37 °C following an injection of M. smegmatis cells (1.25 × 107 CFU larva-1 g-1) into the silkworm hemolymph, they died within 48 h. Under these conditions, four microbial peptides with anti-M. smegmatis activity, lariatin A, calpinactam, lysocin E and propeptin, exerted therapeutic effects in a dose-dependent manner, and these are also clinically used agents that are active against Mycobacterium tuberculosis. These results indicate that the silkworm infection model with M. smegmatis is practically useful for the screening of therapeutically effective anti-M. tuberculosis antibiotics.
Assuntos
Antibacterianos/farmacologia , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Mycobacterium smegmatis/efeitos dos fármacos , Peptídeos/farmacologia , Animais , Antituberculosos/administração & dosagem , Antituberculosos/farmacologia , Bombyx , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium tuberculosis/efeitos dos fármacos , Peptídeos/administração & dosagemRESUMO
Biseokeaniamides A, B, and C (1-3), structurally novel sterol O-acyltransferase (SOAT) inhibitors, were isolated from an Okeania sp. marine cyanobacterium. Their structures were elucidated by spectroscopic analyses and degradation reactions. Biseokeaniamide B (2) exhibited moderate cytotoxicity against human HeLa cancer cells, and compounds 1-3 inhibited both SOAT1 and SOAT2, not only at an enzyme level but also at a cellular level. Biseokeaniamides (1-3) are the first linear lipopeptides that have been shown to exhibit SOAT-inhibitory activity.
Assuntos
Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Cianobactérias/química , Lipopeptídeos/isolamento & purificação , Lipopeptídeos/farmacologia , Esterol O-Aciltransferase/antagonistas & inibidores , Antineoplásicos/química , Caspase 3/metabolismo , Células HeLa , Humanos , Lipopeptídeos/química , Biologia Marinha , Estrutura Molecular , Ressonância Magnética Nuclear BiomolecularRESUMO
A new cytotoxic agent designated isomethoxyneihumicin (1 and 2), a mixture of lactam-lactim tautomers, was isolated along with methoxyneihumicin (3) from the culture broth of the marine Nocardiopsis alba KM6-1. The structures of 1 and 2 were elucidated in spectroscopic analyses (1D and 2D NMR data, and ROESY correlations). Isomethoxyneihumicin (15.0 µM) and 3 (15.0 µM) arrested the cell cycle of Jurkat cells at the G2/M phase (66 and 67%) in 12 h. Isomethoxyneihumicin and 3 exhibited cytotoxicity against Jurkat cells with IC50 values of 6.98 and 30.5 µM in 20 h, respectively. These results strongly suggest that isomethoxyneihumicin and 3 exhibit cytotoxicity against Jurkat cells by inhibiting the cell cycle at the G2/M phase.
Assuntos
Actinomycetales/metabolismo , Antineoplásicos/farmacologia , Lactamas/farmacologia , Pirazinas/farmacologia , Antineoplásicos/administração & dosagem , Antineoplásicos/isolamento & purificação , Relação Dose-Resposta a Droga , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Células Jurkat , Lactamas/administração & dosagem , Lactamas/isolamento & purificação , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Pirazinas/administração & dosagem , Pirazinas/isolamento & purificaçãoRESUMO
Cyslabdan was isolated from the culture broth of Streptomyces sp. K04-0144 as a new potentiator of imipenem activity against methicillin-resistant Staphylococcus aureus. We accomplished the synthesis of cyslabdan according to a previously reported structure. However, we subsequently found that this structure was incorrect; our analysis of natural cyslabdan showed that it possessed R stereochemistry at the C8 position, not S, as had previously been reported. Thus, we completed the protecting-group-free synthesis of the correct structure of cyslabdan, which is described herein.
Assuntos
Acetilcisteína/análogos & derivados , Diterpenos/química , Diterpenos/síntese química , Acetilcisteína/síntese química , Acetilcisteína/química , Conformação Molecular , Streptomyces/químicaRESUMO
Methicillin-resistant Staphylococuss aureus (MRSA) is a major nosocomial pathogen that has developed resistance to many antibiotics. New anti-infective drugs to prevent and treat MRSA infection are required. Four assay systems were conducted to screen microbial cultures for new anti-infective compounds active against MRSA. Nosokomycins, new members of the phosphoglycolipid family, were discovered from a culture of Streptomyces cyslabdanicus K04-0144 in an MRSA-silkworm infection assay. The target molecule of nosokomycins was suggested to be the transglycosylase of penicillin binding protein (PBP) involved in MRSA peptidoglycan biosynthesis. Spirohexaline, with a hexacycline structure, was isolated from a fungal culture of Penicillium brasilianum FKI-3368 in an enzyme assay of undecaprenyl pyrophosphate (UPP) synthase, which is needed for the synthesis and transport of GlcNAc-MurNAc-pentapeptides from the cytoplasmic membrane site to the external membrane site for peptidoglycan synthesis. Spirohexaline inhibited MRSA growth by the blockade of UPP synthase activity. Cyslabdan, with a cysteine-carrying labdan skeleton, was also discovered from the nosokomycin-producing actinomycete as a potentiator of imipenem activity against MRSA. The molecular target of cyslabdan was identified as FemA, which is involved in the synthesis of a pentaglycine interpeptide bridge in MRSA peptidoglycan. Citridone A with a unique 6-6/5/5-ring system containing a rare phenyl-R-furopyridone skeleton, originally isolated as a potentiator of antifungal miconazole activity, was found to inhibit MRSA yellow pigment production. These new microbial products will serve as lead compounds for developing new anti-infective drugs for combating MRSA.
Assuntos
Antibacterianos/farmacologia , Descoberta de Drogas , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estreptocócicas/tratamento farmacológico , Infecções Estreptocócicas/microbiologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Humanos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Estrutura MolecularRESUMO
Mammalian cells possess the molecular apparatus necessary to take up, degrade, synthesize, and release free d-aspartate, which plays an important role in physiological functions within the body. Here, biologically active microbial compounds and pre-existing drugs were screened for their ability to alter the intracellular d-aspartate level in mammalian cells, and several candidate compounds were identified. Detailed analytical studies suggested that two of these compounds, mithramycin A and geldanamycin, suppress the biosynthesis of d-aspartate in cells. Further studies suggested that these compounds act at distinct sites within the cell. These compounds may advance our current understanding of biosynthesis of d-aspartate in mammals, a whole picture of which remains to be disclosed.
Assuntos
Ácido Aspártico/antagonistas & inibidores , Benzoquinonas/farmacologia , Lactamas Macrocíclicas/farmacologia , Plicamicina/análogos & derivados , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Animais , Ácido Aspártico/biossíntese , Células HEK293 , Humanos , Células PC12 , Plicamicina/farmacologia , Ratos , Sesquiterpenos/farmacologia , EstereoisomerismoRESUMO
Genome mining of cyslabdan-producing Streptomyces cyslabdanicus K04-0144 revealed that a set of four genes, cldA, cldB, cldC, and cldD (the cld cluster), which formed a single transcriptional unit, were involved in the biosynthesis of cyslabdan that potentiates imipenem activity against methicillin-resistant Staphylococcus aureus. Experimental studies supported the heterologous expression of the cld cluster of S. cyslabdanicus K04-0144 in S. avermitilis SUKA22, and transformants carrying the cld cluster produced not only cyslabdan A (1), but also its new derivatives, 17-hydroxyl-1 (2) and 2-hydroxyl-1 (3), in the culture broth. An analysis of diterpene metabolites in the mycelia showed that a large amount of a novel intermediate had accumulated and its structure was elucidated as (7S, 8S, 12E)-8,17-epoxy-7-hydroxylabda-12,14-diene (4). The cld-like cluster (rmn cluster) was also detected in the genome of S. anulatus GM95 by searching our in-house genome databases, and the heterologous expression of the rmn cluster in S. avermitilis SUAK22 demonstrated that the rmn cluster was involved in the biosynthesis of the labdane-type bicyclic diterpene, raimonol (7). CldA/RmnA catalyzed the generation of geranylgeranyl diphosphate (GGPP) from dimethylallyl diphosphate and isopentenyl diphosphate. CldB/RmnB converted GGPP to (+)-copalyl diphosphate, and CldD/RmnD generated labda-8(17),12(E),14-triene (5). CldC introduced two oxygen atoms at C-7 and C-8,17 to generate 4, while RmnC hydroxylated 5 at C-7 to generate 7. The heterologous expression of the cld cluster suggested that four gene products catalyzed to generate 4, but not 1. The deletion mutant of the gene encoding the mycothiol (MSH)-S-conjugate amidase (mca) of S. avermitilis SUKA22 carrying the cld cluster failed to produce 1, but accumulated 4 in the mycelia, whereas S. avermitilis SUKA22 and its mca-deletion mutant carrying the cld cluster both produced the MSH-S-conjugate of 4. The intermediate 4 was converted into the MSH-S-conjugate with MSH, which was achieved through a non-enzymatic nucleophilic reaction. The MSH-S-conjugate of 4 generated was further hydrolyzed to generate the mercapturic acid derivative, 1, by MSH-S-conjugate amidase and 1 was excreted from the mycelia.
Assuntos
Acetilcisteína/análogos & derivados , Cisteína/metabolismo , Diterpenos/química , Diterpenos/metabolismo , Diterpenos/farmacologia , Glicopeptídeos/metabolismo , Imipenem/farmacologia , Inositol/metabolismo , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Xenobióticos/metabolismo , Acetilcisteína/química , Acetilcisteína/metabolismo , Acetilcisteína/farmacologia , Amidoidrolases/genética , Amidoidrolases/metabolismo , Vias Biossintéticas/genética , Inativação Metabólica , Família Multigênica/genética , Micélio/metabolismo , Organofosfatos/metabolismo , Streptomyces/genética , Streptomyces/metabolismoRESUMO
INTRODUCTION: Acyltransferase (AT) catalyzes the transfer of an acyl moiety from acyl-coenzyme A (acyl-CoA) to an acceptor. ATs play important roles in the maintenance of homeostasis in the human body and have been linked to various diseases; therefore, several ATs have been proposed as potential targets for the treatment or prevention of such diseases. The AT family includes acyl-CoA:cholesterol AT (ACAT), diacylglycerol AT (DGAT), and monoacylglycerol AT (MGAT) for the metabolism of lipids. Furthermore, recent molecular biological studies revealed the existence of their isozymes with distinct functions in the body. AREAS COVERED: This review summarized patent filings published between 2010 and the present date that claimed isozyme-selective inhibitors of ACAT, DGAT and MGAT, which are involved in neutral lipid metabolism. EXPERT OPINION: Isozymes of ACAT, DGAT and MGAT play distinct functions in neutral lipid metabolism in the human body and have been considered as potential therapeutic targets. Accordingly, isozyme-selective inhibitors that could be used in the treatment or prevention of lipid metabolism disorders were searched for. Of these, pyripyropene A derivatives, ACAT2-selective inhibitors, may be potential therapeutics for the treatment of atherosclerosis, homozygous familial hypercholesterolemia and nonalcoholic fatty liver disease.
Assuntos
Aciltransferases/antagonistas & inibidores , Desenho de Fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Animais , Aterosclerose/tratamento farmacológico , Aterosclerose/enzimologia , Humanos , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Hiperlipoproteinemia Tipo II/enzimologia , Isoenzimas , Terapia de Alvo Molecular , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/enzimologia , Patentes como AssuntoRESUMO
A small molecule named habiterpenol produced by actinomycete Phytohabitans suffuscus 3787_5 was found to abrogate bleomycin-induced G2 arrest in Jurkat cells. Habiterpenol showed no cytotoxic effect on Jurkat cells even at 273 µM; however, the compound inhibited bleomycin-induced G2 arrest in Jurkat cells with an IC50 value of 3.55 µM, while it showed no effect on colchicine-induced M arrest even at 273 µM. These results indicated that habiterpenol selectively abrogated bleomycin-induced G2 arrest in Jurkat cells.
Assuntos
Antibióticos Antineoplásicos/farmacologia , Bleomicina/farmacologia , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Micromonosporaceae/metabolismo , Triterpenos/farmacologia , Colchicina/farmacologia , Humanos , Concentração Inibidora 50 , Células Jurkat , Pontos de Checagem da Fase M do Ciclo Celular/efeitos dos fármacos , Triterpenos/administração & dosagem , Triterpenos/isolamento & purificaçãoRESUMO
Although >100 thiopeptides have been discovered, the number of validated gene clusters involved in their biosynthesis is lagging. We use genome mining to identify a silent thiopeptide biosynthetic gene cluster responsible for biosynthesis of lactazoles. Lactazoles are structurally unique thiopeptides with a 32-membered macrocycle and a 2-oxazolyl-6-thiazolyl pyridine core. We demonstrate that lactazoles originate from the simplest cluster, containing only six unidirectional genes (lazA to lazF). We show that lazC is involved in the macrocyclization process, leading to central pyridine moiety formation. Substitution of the endogenous promoter with a strong promoter results in an approximately 30-fold increase in lactazole A production and mutagenesis of lazC precursor gene in production of two analogs. Lactazoles do not exhibit antimicrobial activity but may modulate signaling cascades triggered by bone morphogenetic protein. Our approach facilitates the production of a more diverse set of thiopeptide structures, increasing the semisynthetic repertoire for use in drug development.