RESUMO
The biosynthesis of 2-methylisoborneol was reconstituted by elongation of dimethylallyl diphosphate (DMAPP) with (S)- and (R)-2-methylisopentenyl diphosphate (2-Me-IPP) using farnesyl diphosphate synthase (FPPS), followed by terpene cyclisation. The stereochemical course of the FPPS reaction was studied in detail using stereoselectively deuterated 2-Me-IPP isotopomers.
Assuntos
Canfanos , Geraniltranstransferase , Canfanos/síntese química , Difosfatos/metabolismo , Geraniltranstransferase/metabolismo , Terpenos/química , Terpenos/metabolismoRESUMO
A series of novel cannabinoid-type derivatives were synthesized by the coupling of (1S,4R)-(+) and (1R,4S)-(-)-fenchones with various resorcinols/phenols. The fenchone-resorcinol derivatives were fluorinated using Selectfluor and demethylated using sodium ethanethiolate in dimethylformamide (DMF). The absolute configurations of four compounds were determined by X-ray single crystal diffraction. The fenchone-resorcinol analogs possessed high affinity and selectivity for the CB2 cannabinoid receptor. One of the analogues synthesized, 2-(2',6'-dimethoxy-4'-(2â³-methyloctan-2â³-yl)phenyl)-1,3,3-trimethylbicyclo[2.2.1]heptan-2-ol (1d), had a high affinity (Ki = 3.51 nM) and selectivity for the human CB2 receptor (hCB2). In the [35S]GTPγS binding assay, our lead compound was found to be a highly potent and efficacious hCB2 receptor agonist (EC50 = 2.59 nM, E(max) = 89.6%). Two of the fenchone derivatives were found to possess anti-inflammatory and analgesic properties. Molecular-modeling studies elucidated the binding interactions of 1d within the CB2 binding site.
Assuntos
Canfanos/química , Canfanos/farmacologia , Agonistas de Receptores de Canabinoides/química , Agonistas de Receptores de Canabinoides/farmacologia , Desenho de Fármacos , Norbornanos/química , Norbornanos/farmacologia , Receptor CB2 de Canabinoide/química , Canfanos/síntese química , Agonistas de Receptores de Canabinoides/síntese química , Técnicas de Química Sintética , Relação Dose-Resposta a Droga , Humanos , Ligantes , Modelos Moleculares , Estrutura Molecular , Norbornanos/síntese química , Ligação Proteica , Receptor CB2 de Canabinoide/agonistas , Análise Espectral , Relação Estrutura-AtividadeRESUMO
Substituting natural products for traditional poison-killing antifouling agents is an efficient and promising method to alleviate the increasingly serious ecological crisis and aggravate the loss due to marine biofouling. Herein, the successful synthesis of poly(methyl methacrylate-co-ethyl acrylate-co-hexafluorobutyl methacrylate-co-isobornyl methacrylate) copolymer (PBAF) with borneol monomers and fluorine by a free radical polymerization method is reported. The PBA0.09F coating exhibits outstanding antibacterial and antifouling activity, achieving 98.2% and 92.3% resistance to Escherichia coli and Staphylococcus aureus, respectively, and the number of Halamphora sp. adhesion is only 26 (0.1645 mm2) in 24 h. This remarkable antibacterial and antifouling performance is attributed to the incorporation of fluorine components into the copolymer, which induces a low surface energy and hydrophobicity and the complex molecular structure of the natural nontoxic antifouling agent borneol. In addition, the results showed that the contents of the adhesion-related proteins mfp-3, mfp-5, and mfp-6 were significantly reduced, which proved that natural substances affect the secretion of biological proteins. Importantly, the PBAF coating exhibits excellent environmental friendliness and long-term stability. The antifouling mechanism is clarified, and an effective guide for an environmentally friendly antifouling coating design is proposed.
Assuntos
Antibacterianos/farmacologia , Incrustação Biológica/prevenção & controle , Canfanos/farmacologia , Polímeros de Fluorcarboneto/química , Metilmetacrilatos/química , Animais , Antibacterianos/síntese química , Bivalves/efeitos dos fármacos , Canfanos/síntese química , Diatomáceas/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Polímeros de Fluorcarboneto/síntese química , Interações Hidrofóbicas e Hidrofílicas , Metilmetacrilatos/síntese química , Staphylococcus aureus/efeitos dos fármacos , MolhabilidadeRESUMO
A series of (-)-borneol derivatives containing 2-aryl-thiazole scaffold were designed, synthesized, and characterized by 1H NMR, 13C NMR, and HRMS. The fungicidal activities of these novel compounds against Fusarium oxysporum, Magnaporthe grisea, Botrytis cinerea, and Penicillium digitatum were evaluated. The results indicated that (1S,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl(Z)-4-oxo-4-(((2-phenylthiazol-4-yl)methyl)amino)but-2-enoate (6a) displayed potential fungicidal activities with broad spectrum. Especially, 6a exhibited an IC50 value of 48.5 mg/L against P. digitatum, which has higher fungicidal activity than commercial products hymexazol and amicarthiazol. Moreover, (1S,2R,4S)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-yl-4-oxo-4-(((2-phenylthiazol-4-yl)methyl)amino)butanoate (5a) possesses an IC50 value of 24.3 mg/L against B. cinerea, comparable to hymexazol and far superior to amicarthiazol. Furthermore, the superficial structure-activity relationship was discussed, which might be helpful for discovering novel fungicides.
Assuntos
Antifúngicos/farmacologia , Canfanos/farmacologia , Desenho de Fármacos , Fungicidas Industriais/farmacologia , Penicillium/efeitos dos fármacos , Tiazóis/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Canfanos/síntese química , Canfanos/química , Relação Dose-Resposta a Droga , Fungicidas Industriais/síntese química , Fungicidas Industriais/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade , Tiazóis/químicaRESUMO
This work presents the design and synthesis of camphor, fenchone, and norcamphor N-acylhydrazone derivatives as a new class of inhibitors of the Hantaan virus, which causes haemorrhagic fever with renal syndrome (HFRS). A cytopathic model was developed for testing chemotherapeutics against the Hantaan virus, strain 76-118. In addition, a study of the antiviral activity was carried out using a pseudoviral system. It was found that the hit compound possesses significant activity (IC50 = 7.6 ± 2 µM) along with low toxicity (CC50 > 1000 µM). Using molecular docking procedures, the binding with Hantavirus nucleoprotein was evaluated and the correlation between the structure of the synthesised compounds and the antiviral activity was established.
Assuntos
Antivirais/farmacologia , Canfanos/farmacologia , Vírus Hantaan/efeitos dos fármacos , Hidrazonas/farmacologia , Isoindóis/farmacologia , Norbornanos/farmacologia , Animais , Antivirais/síntese química , Antivirais/metabolismo , Canfanos/síntese química , Canfanos/metabolismo , Proteínas do Capsídeo/metabolismo , Cães , Desenho de Fármacos , Células HEK293 , Humanos , Hidrazonas/síntese química , Hidrazonas/metabolismo , Isoindóis/síntese química , Isoindóis/metabolismo , Células Madin Darby de Rim Canino , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Norbornanos/síntese química , Norbornanos/metabolismo , Ligação Proteica , Proteínas do Core Viral/metabolismoRESUMO
Although the World Health Organisation had announced that smallpox was eradicated over 40 years ago, the disease and other related pathogenic poxviruses such as monkeypox remain potential bioterrorist weapons and could also re-emerge as natural infections. We have previously reported (+)-camphor and (-)-borneol derivatives with an antiviral activity against the vaccinia virus. This virus is similar to the variola virus (VARV), the causative agent of smallpox, but can be studied at BSL-2 facilities. In the present study, we evaluated the antiviral activity of the most potent compounds against VARV, cowpox virus, and ectromelia virus (ECTV). Among the compounds tested, 4-bromo-N'-((1R,4R)-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ylidene)benzohydrazide 18 is the most effective compound against various orthopoxviruses, including VARV, with an EC50 value of 13.9 µM and a selectivity index of 206. Also, (+)-camphor thiosemicarbazone 9 was found to be active against VARV and ECTV.
Assuntos
Canfanos , Cânfora , Isoindóis , Orthopoxvirus/efeitos dos fármacos , Animais , Antivirais/síntese química , Antivirais/química , Antivirais/farmacologia , Canfanos/síntese química , Canfanos/química , Canfanos/farmacologia , Cânfora/análogos & derivados , Cânfora/química , Cânfora/farmacologia , Células Cultivadas , Humanos , Isoindóis/síntese química , Isoindóis/química , Isoindóis/farmacologia , Orthopoxvirus/classificação , Orthopoxvirus/patogenicidade , Orthopoxvirus/fisiologia , Infecções por Poxviridae/tratamento farmacológico , Infecções por Poxviridae/virologia , Tiossemicarbazonas/química , Tiossemicarbazonas/farmacologiaRESUMO
BACKGROUND AND PURPOSE: Tanshinol borneol ester (DBZ) is a novel synthetic compound derived from Dantonic® , a botanical drug approved in 26 countries outside the United States for angina pectoris and currently undergoing FDA Phase III clinical trial. Here, we investigated the angiogenic effects of (S)-DBZ and (R)-DBZ isomers in vitro and in vivo. EXPERIMENTAL APPROACH: A network pharmacology approach was used to predict molecular targets of DBZ. The effects of DBZ isomers on proliferation, migration, and tube formation of human endothelial cells were assessed. For in vivo approaches, the transgenic Tg (vegfr2:GFP) zebrafish and C57BL/6 mouse Matrigel plug models were used. ELISA and western blots were used to quantitate the release and expression of relevant target molecules and signalling pathways. KEY RESULTS: DBZ produced a biphasic modulation on proliferation and migration of three types of human endothelial cells. Both DBZ isomers induced tube formation in Matrigel assay and a 12-day co-culture model in vitro. Moreover, DBZ promoted Matrigel neovascularization in mice and partially reversed the vascular disruption in zebrafish induced by PTK787. Mechanistically, DBZ enhanced the cellular levels of VEGF, VEGFR2, and MMP-9, as well as activating Akt and MAPK signalling in endothelial cells. Selective inhibition of PI3K and MEK significantly attenuated its angiogenic effects. CONCLUSIONS AND IMPLICATIONS: These data reveal, for the first time, that DBZ promotes multiple key steps of angiogenesis, at least in part through Akt and MAPK signalling pathways, and suggest it may be potentially developed further for treating myocardial infarction and other cardiovascular diseases.
Assuntos
Angina Pectoris/tratamento farmacológico , Canfanos/farmacologia , Lactatos/farmacologia , Bibliotecas de Moléculas Pequenas/farmacologia , Angina Pectoris/metabolismo , Animais , Canfanos/síntese química , Canfanos/química , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Relação Dose-Resposta a Droga , Composição de Medicamentos , Humanos , Lactatos/síntese química , Lactatos/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Estrutura Molecular , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química , Estereoisomerismo , Relação Estrutura-Atividade , Cicatrização/efeitos dos fármacos , Peixe-ZebraRESUMO
Oxanorbornadiene dicarboxylate (OND) reagents were explored for the purpose of binding and releasing chemical cargos from endogenous circulating serum albumins. ONDs bearing gadolinium chelates as model cargos exhibited variable conjugation efficiencies with albumin in rat subjects that are consistent with the observed reactivity of each linker and their observed stability toward serum hydrolases in vitro. The terminal elimination rate from circulation was dependent on the identity of the OND used, and increased circulation time of gadolinium cargo was achieved for linkers bearing electrophilic fragments designed to react with cysteine-34 of circulating serum albumin. This binding of and release from endogenous albumin highlights the potential of OND linkers in the context of optimizing the pharmacokinetic parameters of drugs or diagnostic agents.
Assuntos
Canfanos/química , Albumina Sérica/química , Animais , Canfanos/síntese química , Canfanos/farmacocinética , Interações Hidrofóbicas e Hidrofílicas , RatosRESUMO
During the last years, there has been a continuous interest in the development of cannabinoid receptor ligands that may serve as therapeutic agents and/or as experimental tools. This prompted us to design and synthesize analogues of the CB2 receptor antagonist N-fenchyl-5-(4-chloro-3-methyl-phenyl)-1-(4-methyl-benzyl)-1H-pyrazole-3-carboxamide (SR144528). The structural modifications involved the bioisosteric replacement of the pyrazole ring by a pyrrole ring and variations on the amine carbamoyl substituents. Two of these compounds, the fenchyl pyrrole analogue 6 and the myrtanyl derivative 10, showed high affinity (Ki in the low nM range) and selectivity for the CB2 receptor and both resulted to be antagonists/inverse agonists in [(35)S]-GTPγS binding analysis and in an in vitro CB2 receptor bioassay. Cannabinoid receptor binding data of the series allowed identifying steric constraints within the CB2 binding pocket using a study of Van der Waals' volume maps. Glide docking studies revealed that all docked compounds bind in the same region of the CB2 receptor inactive state model.
Assuntos
Canfanos/síntese química , Canfanos/farmacologia , Simulação de Acoplamento Molecular , Pirazóis/síntese química , Pirazóis/farmacologia , Receptor CB2 de Canabinoide/antagonistas & inibidores , Canfanos/química , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Estrutura Molecular , Pirazóis/química , Relação Estrutura-AtividadeRESUMO
Although tuberculosis (TB) continues to be one of the leading infectious disease killers globally, it is curable and preventable. Despite the existence of safe, well tolerated and effective drugs used in the TB treatment, the interest in new entities, combinations and regimens increases during the last 10 years. Recently, we reported for a new class of anti-TB agents - camphane-based derivatives with nanomolar activity against Mycobacterium tuberculosis strains. The quantitative structure-activity relationship (QSAR) study on 12 compounds revealed several structural requirements for antimycobacterial activity: two hydrogen bond donors, two or three rings and no large branched substituents. Here, we describe the design of a set of nine novel camphane-based derivatives following these requirements. The compounds were synthesized and tested against M. tuberculosis strain H37Rv. Four of them showed activities in the nanomolar range, significantly higher than the activities in the initial set. The QSAR study based on all 21 derivatives pointed to two main structural requirements for anti-TB activity: two hydrogen bond donors and a side chain with aromatic ring.
Assuntos
Antituberculosos/síntese química , Canfanos/síntese química , Mycobacterium tuberculosis/efeitos dos fármacos , Antituberculosos/farmacologia , Canfanos/farmacologia , Desenho de Fármacos , Ligação de Hidrogênio , Testes de Sensibilidade Microbiana , Relação Quantitativa Estrutura-AtividadeRESUMO
A series of six new amidoalcohols was designed and synthesized on the base of the camphor scaffold. Natural amino acids were transformed into their α-hydroxy analogues with retention of configuration, and attached to isobornylamine. The compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv. Some of the new compounds show 25 times higher activity than the classical anti-TB drug ethambutol. The activity shifts from micromolar to nanomolar inhibitory concentrations depending on the α-hydroxy acid moiety. Two of the most potent compounds exert low level of cytotoxic activity. These camphane-based amido-alcohols present promising potential lead compounds for further elaboration of antimycobacterial agents.
Assuntos
Antituberculosos/farmacologia , Canfanos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Antituberculosos/síntese química , Antituberculosos/química , Canfanos/síntese química , Canfanos/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
A series of new amidoalcohols and amidodiols were designed on the base of the camphor scaffold and evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv and MDR strain 43. Some of the new compounds show 25 times higher activity than the classical anti-TB drug ethambutol. Small structural changes in the side chain shift the activity from micromolar to nanomolar inhibitory concentrations. Quantitative structure-activity relationship (QSAR) model is derived to guide the further lead optimization. Two hydrogen bond donors and up to three rings in the molecules are optimal for nanomolar activity. The camphane-based amides present novel promising scaffolds for antimycobacterial agents.
Assuntos
Antituberculosos/farmacologia , Canfanos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Antituberculosos/síntese química , Antituberculosos/química , Canfanos/síntese química , Canfanos/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Quantitativa Estrutura-AtividadeRESUMO
An efficient and general method for the synthesis of conjugated dienyl ketones via palladium(II) acetate catalyzed direct cross-coupling between simple alkenes and vinyl ketones is reported. This method has been successfully applied for the synthesis of Vitamin A1 and bornelone.
Assuntos
Alcenos/síntese química , Canfanos/síntese química , Cetonas/síntese química , Paládio/química , Compostos de Vinila/síntese química , Vitamina A/síntese química , Alcenos/química , Canfanos/química , Catálise , Cetonas/química , Estrutura Molecular , Compostos de Vinila/química , Vitamina A/químicaRESUMO
We report here for the first time the in vitro effects of (1S,2R,4S)-1,7,7-trimethyl-bicyclo[2·2·1]heptan-2-yl-3',4',5'-trimethoxy benzoate (1) and (1S,2R,4S)-1,7,7-trimethyl-bicyclo[2·2·1]heptan-2-yl benzoate (2) on the growth and ultrastructure of Trypanosoma cruzi. These two synthetic compounds exerted an antiproliferative effect on the epimastigote forms of the parasite. The ICs(50/72h) of two synthetic L-bornyl benzoates, 1 and 2, was 10·1 and 12·8 µg/ml, respectively. Both compounds were more selective against epimastigotes than HEp-2 cells. Ultrastructural analysis revealed intense cytoplasmic vacuolization and the appearance of cytoplasmic materials surrounded by membranes. The treatment of peritoneal macrophages with compounds 1 and 2 caused a significant decrease in the number of T. cruzi-infected cells. L-Bornyl benzoate derivatives may serve as a potential source for the development of more effective and safer chemotherapeutic agents against T. cruzi infections.
Assuntos
Antiprotozoários/farmacologia , Benzoatos/farmacologia , Canfanos/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Antiprotozoários/síntese química , Antiprotozoários/toxicidade , Benzoatos/síntese química , Benzoatos/toxicidade , Canfanos/síntese química , Canfanos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Citoplasma/ultraestrutura , Células Hep G2 , Humanos , Concentração Inibidora 50 , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/ultraestruturaRESUMO
(+)-syn-Benzotriborneol forms stable complexes with one molecule of water. This is due to the ability of the host to form three hydrogen bonds with water, to act simultaneously as a hydrogen-bond acceptor and donor, and to a perfect geometrical match between the pair. We report experimental (X-ray and neutron diffraction, VT NMR, DSC, TGA) and stereochemical studies carried out to elucidate and quantify the molecular and thermodynamic aspects of this supramolecular complex.
Assuntos
Canfanos/síntese química , Água/química , Ligação de Hidrogênio , Modelos Moleculares , Estrutura Molecular , Oxigênio/química , Soluções , Estereoisomerismo , TermodinâmicaRESUMO
CONTEXT: The destabilization of ß-amyloid (Aß) peptide aggregates and the protection of functional cells are the attractive therapeutic strategies for Alzheimer's disease (AD). Some active ingredients of Salvia miltiorrhiza f. alba C.Y.Wu & H.W.Li (Lamiaceae) (SM) have attracted increasing attention for the treatment of neurodegenerative diseases. OBJECTIVE: Salvianic borneol ester (SBE) is a new compound based on SM formulas. The present study was designed to examine the anti-amyloid effects and neuroprotection of SBE in vitro. MATERIALS AND METHODS: The destabilizing effects of SBE and its related compounds (salvianic acid A and borneol) on preformed Aß oligomers were measured by using fluorescence spectroscopy with thioflavin T (ThT) and the destabilizing effects of SBE were further confirmed visually by transmission electron microscopy (TEM). The neuroprotective effects of SBE against hydrogen peroxide (H(2)O(2))-induced toxicity in human neuroblastoma cells (SH-SY5Y) and motor neuron hybridoma cells (VSC 4.1) were shown by MTT assay and morphological observation. RESULTS: SBE showed the most significant destabilizing effect, though the mixture of salvianic acid A and borneol also destabilized Aß1-40 oligomers. The destabilizing activity of salvianic acid A or borneol alone was not significant. SBE destabilized Aß1-40 oligomers in dose- and time-dependent manners and the destabilizing effect could also be seen in the photographs of TEM. Furthermore, SBE could protect SH-SY5Y cells and VSC 4.1 cells against H(2)O(2)-induced toxicity in a dose-dependent manner. DISCUSSION AND CONCLUSION: SBE had the bifunctional activities of anti-amyloid and neuroprotection. It may have therapeutic potential for AD and be an alternative lead compound for developing new drugs against AD.
Assuntos
Doença de Alzheimer/tratamento farmacológico , Antioxidantes/farmacologia , Canfanos/farmacologia , Descoberta de Drogas , Lactatos/farmacologia , Fármacos Neuroprotetores/farmacologia , Salvia , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/metabolismo , Antioxidantes/síntese química , Antioxidantes/uso terapêutico , Antioxidantes/toxicidade , Canfanos/síntese química , Canfanos/uso terapêutico , Canfanos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Feminino , Humanos , Lactatos/síntese química , Lactatos/uso terapêutico , Lactatos/toxicidade , Terapia de Alvo Molecular , Fármacos Neuroprotetores/síntese química , Fármacos Neuroprotetores/uso terapêutico , Fármacos Neuroprotetores/toxicidade , Síndromes Neurotóxicas/fisiopatologia , Síndromes Neurotóxicas/prevenção & controle , Oligonucleotídeos/metabolismo , Fragmentos de Peptídeos/metabolismo , FitoterapiaRESUMO
The resolution of the racemic ortho-isobornylphenol into enantiomers via diastereomeric camphanates was carried out. The absolute configuration ofchiral centers of synthesized compounds was established by the single crystal X-ray diffraction method. Antioxidant activity and membrane protective properties of individual enantiomers were studied on the model of H2O2-induced hemolysis of red blood cells.
Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Canfanos/síntese química , Canfanos/farmacologia , Fenóis/química , Fenóis/farmacologia , Animais , Membrana Celular/efeitos dos fármacos , Cristalografia por Raios X , Eritrócitos/efeitos dos fármacos , Hemoglobinas/química , Hemólise , Peróxido de Hidrogênio/química , Camundongos , Oxirredução , EstereoisomerismoRESUMO
A conserved threonine found in the majority of cytochromes P450 (P450s) has been implicated in the activation of dioxygen during the catalytic cycle. P450(cin) (CYP176A) has been found to be an exception to this paradigm, where the conserved threonine has been replaced with an asparagine. Prior studies with a P450(cin) N242A mutant established that the Asn-242 was not a functional replacement for the conserved threonine but was essential for the regio- and stereocontrol of the oxidation of cineole. To explore further how P450(cin) controls the activation of the dioxygen in the absence of the conserved threonine, two concurrent lines of investigation were followed. Modification of P450(cin) indicated that the Thr-243 was not involved in controlling the protonation of the hydroperoxy species. In addition, the N242T mutant did not enhance the rate and/or efficiency of catalytic turnover of cineole by P450(cin). In parallel experiments, the substrate cineole was modified by removing the ethereal oxygen to produce camphane or 2,2-dimethylbicyclo[2.2.2]octane (cinane). An analogous experiment with P450(EryF) showed that a hydroxyl group on the substrate was vital, and in its absence catalytic turnover was effectively abolished. Catalytic turnover of P450(cin) with either of these alternative substrates (camphane or cinane) revealed that in the absence of the ethereal oxygen there was still a significant amount of coupling of the NADPH-reducing equivalents to the formation of oxidised product. Again the substrate itself was not found to be important in controlling oxygen activation, in contrast to P450(EryF), but was shown to be essential for regio- and stereoselective substrate oxidation. Thus, it still remains unclear how dioxygen activation in the catalytic turnover of cineole by P450(cin) is controlled.
Assuntos
Citrobacter/enzimologia , Cicloexanóis/química , Cicloexanóis/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Monoterpenos/química , Monoterpenos/metabolismo , Oxigênio/metabolismo , Canfanos/síntese química , Canfanos/química , Canfanos/metabolismo , Citrobacter/genética , Cicloexanóis/síntese química , Eucaliptol , Monoterpenos/síntese química , Mutagênese , Mutação , NADP/metabolismo , Especificidade por SubstratoRESUMO
For decades, toxaphene had been used as a major chloropesticide. Degradation of the multicomponent mixture in the environment was mainly reported to be due to anaerobic dechlorination and hydrodechlorination. Little was known about oxidative transformation processes and the potential hydroxylated metabolites were not available as standard compounds. For this reason we synthesized hydroxylated polychlorobornanes by the UV-induced photochlorination of 2-endo-bornyl acetate with sulfuryl chloride followed by hydrolysis of the acetate moiety. The released polychlorinated 2-endo-hydroxybornanes were slightly higher chlorinated the longer the reaction was maintained. After 8h, the main products were pentachlorinated hydroxybornanes followed by hexa- and heptachlorinated homologues. Traces of octachlorinated hydroxybornanes were also observed. The GC/ECNI-MS spectra of the products were characterized by the molecular ions and the [M-Cl]â» fragment ions. The molecular ions of the polychlorinated hydroxybornanes are isobaric with those of polychlorinated biphenyls. E.g. hexachlorohydroxybornanes (C10H12Cl6O) and hexachlorobiphenyls (C12H4Cl6) show the molecular ion at m/z 358. Based on fractionation experiments on silica with the synthesis products it might be possible that OH-CTTs if present in samples will elute into a more polar fraction usually discarded or not collected. Both problems might explain why these compounds have not been more frequently described in the scientific literature.
Assuntos
Canfanos/síntese química , Poluentes Ambientais/química , Inseticidas/química , Toxafeno/química , Canfanos/química , Canfanos/metabolismo , Poluentes Ambientais/síntese química , Poluentes Ambientais/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hidroxilação , Inseticidas/metabolismo , Bifenilos Policlorados/química , Toxafeno/metabolismoRESUMO
OBJECTIVE: To observe the influence of natural borneol and synthetic borneol on mucosal permeability of Gardenia extract. METHOD: Taken frog skin as a vitro model to study the vitro mucosal permeation the impacts of the natural borneols and synthetic borneols on the P(app) of the Jasminoidin were studied, and the effect of different borneols on the stability of Jasminoidin were investigated. Compared the 10 h accumulated infiltration rate of each group the effects of influence factors,such as C(Ge), C(B) and rotation speed on P(app) were investigated by using response surface method. RESULT: The P(app) of Jasminoidin of natural borneol and synthetic borneol group were 1.44 fold and 1.77 fold of control group (P < 0.01). For two borneol groups, the results also showed a significant difference too (P < 0.05). Jasminoidin began to degrade about 8 h after the effect of frog skin for control group and synthetic borneol group, but was stable within 12 h for natural borneol group. The accumulated permeation rate of 10 h was same for different borneol groups. It was about 1.3 fold of control group. The C(Ge) had a salinence influence on the P(app) (P < 0.01) and C(B) had a salience influence on time-lag (P < 0.01). CONCLUSION: Both the natural borneol and synthetic borneol can accelerate the permeation of Jasminoidin and the synthetic borneol has stronger effect on the P(app). Both two different borneol can reduce the degradation effect of frog skin to Jasminoidin, but the natural borneol has a better protect effect on it. By using more natural borneol, the mucosal permeability of Gardenia extract can be increased, the time-lag can be reduced, and Jasminoidin has better stability.