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1.
Molecules ; 24(15)2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31374818

RESUMO

Using nanotechnology to develop new formulations of pesticides is considered a possible option in enhancing the efficiency, safety, and photostability of pesticides under various climatic conditions. In the present study, two novel nanoformulations (NFs) were successfully prepared based on nano-delivery systems for emamectin benzoate (EMB) by loading it on cellulose nanocrystals (CNCs) and silicon dioxide nanoparticles (SNPs) as carriers through a freeze-drying method. The synthesized nanoformulations were examined using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and dynamic light scattering (DLS). The results showed that SNPs and CNCs had a loading efficiency of 43.31% and 15.04% (w/w) for EMB, respectively, and could effectively protect EMB from photolysis under UV radiation. The LC50 values for EMB + SNPs, EMB + CNCs, and EMB commercial formulation against Phenacoccus solenopsis were 0.01, 0.05, and 0.31 µg/mL, respectively, indicating that both NFs were more effective than the EMB commercial formulation. This work seeks to develop new nano-carriers for potential applications of pesticides in plant protection, which will reduce the recommended dose of pesticides and thereby decrease the amount of pesticide residue in food and the environment.


Assuntos
Hemípteros/efeitos dos fármacos , Ivermectina/análogos & derivados , Nanopartículas/química , Animais , Celulose/química , Hemípteros/patogenicidade , Ivermectina/síntese química , Ivermectina/química , Ivermectina/farmacologia , Microscopia Eletrônica de Transmissão , Nanopartículas/ultraestrutura , Controle de Pragas/métodos , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier
2.
Eur J Med Chem ; 121: 422-432, 2016 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-27318119

RESUMO

In an effort to discover new molecules with good insecticidal activities, more than 40 new avermectin derivatives were synthesized and evaluated for their biological activities against three species of arachnids, insects and nematodes, namely, Tetranychus Cinnabarinus, Aphis craccivora and Bursaphelenchus xylophilus. All the tested compounds showed potent inhibitory activities against three insect species. Notably, the majority of compounds exhibited high selectivity against T. cinnabarinus, some of which were much better in comparison with avermectin. Especially compounds 9j (LC50: 0.005 µM) and 16d (LC50: 0.002 µM) were 2.5- and 4.7-fold more active than avermectin (LC50: 0.013 µM), respectively, against T. cinnabarinus. Moreover, compounds 9b, 9d-f, 9h, 9j, 9l, 9n, 9p, 9r, 9v and 17d showed superior activities with LC50 values of 2.959-5.013 µM compared to that of 1 (LC50: 6.746 µM) against B. xylophilus. Meanwhile, the insecticidal activities of compounds 9f, 9g, 9h, and 9m against A. craccivora were 7-8 times better than that of avermectin, with LC50 values of 7.744, 5.634, 6.809, 7.939 and 52.234 µM, respectively. Furthermore, QSAR analysis showed that the molecular shape, size, connectivity degree and electronic distribution of avermectin analogues had substantial effects on insecticidal potency. These preliminary results provided useful insight in guiding further modifications of avermectin in the development of potential new insecticides.


Assuntos
Antinematódeos/síntese química , Antinematódeos/farmacologia , Ivermectina/análogos & derivados , Relação Quantitativa Estrutura-Atividade , Animais , Antinematódeos/química , Técnicas de Química Sintética , Ivermectina/síntese química , Ivermectina/química , Ivermectina/farmacologia , Camundongos , Nematoides/efeitos dos fármacos , Relação Estrutura-Atividade
3.
J Antibiot (Tokyo) ; 69(1): 31-50, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26350782

RESUMO

Avermectins were isolated as compounds possessing anthelmintic activity from the culture broth of Streptomycesavermitilis by Omura and co-workers. Owing to their potent anthelmintic and insecticidal activities, as well as their unique pentacyclic architecture, the avermectin family attracted keen interest from synthetic organic chemists. We have recently completed a more efficient and straightforward total synthesis of avermectin B1a, as compared with previous syntheses.


Assuntos
Anti-Helmínticos/síntese química , Ivermectina/análogos & derivados , Anti-Helmínticos/química , Ivermectina/síntese química , Ivermectina/química , Modelos Moleculares , Estrutura Molecular
5.
Microb Cell Fact ; 14: 152, 2015 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-26400541

RESUMO

BACKGROUND: Avermectin and milbemycin are important 16-membered macrolides that have been widely used as pesticides in agriculture. However, the wide use of these pesticides inevitably causes serious drug resistance, it is therefore imperative to develop new avermectin and milbemycin analogs. The biosynthetic gene clusters of avermectin and milbemycin have been identified and the biosynthetic pathways have been elucidated. Combinatorial biosynthesis by domain swap provides an efficient strategy to generate chemical diversity according to the module polyketide synthase (PKS) assembly line. RESULTS: The substitution of aveDH2-KR2 located in avermectin biosynthetic gene cluster in the industrial avermectin-producing strain Streptomyces avermitilis NA-108 with the DNA regions milDH2-ER2-KR2 located in milbemycin biosynthetic gene cluster in Streptomyces bingchenggensis led to S. avermitilis AVE-T27, which produced ivermectin B1a with high yield of 3450 ± 65 µg/ml. The subsequent replacement of aveLAT-ACP encoding the loading module of avermectin PKS with milLAT-ACP encoding the loading module of milbemycin PKS led to strain S. avermitilis AVE-H39, which produced two new avermectin derivatives 25-ethyl and 25-methyl ivermectin (1 and 2) with yields of 951 ± 46 and 2093 ± 61 µg/ml, respectively. Compared to commercial insecticide ivermectin, the mixture of 25-methyl and 25-ethyl ivermectin (2:1 = 3:7) exhibited 4.6-fold increase in insecticidal activity against Caenorhabditis elegans. Moreover, the insecticidal activity of the mixture of 25-methyl and 25-ethyl ivermectin was 2.5-fold and 5.7-fold higher than that of milbemycin A3/A4 against C. elegans and the second-instar larva of Mythimna separate, respectively. CONCLUSIONS: Two new avermectin derivatives 25-methyl and 25-ethyl ivermectin were generated by the domain swap of avermectin PKS. The enhanced insecticidal activity of 25-methyl and 25-ethyl ivermectin implied the potential use as insecticide in agriculture. Furthermore, the high yield and genetic stability of the engineered strains S. avermitilis AVE-T27 and AVE-H39 suggested the enormous potential in industrial production of the commercial insecticide ivermectin and 25-methyl/25-ethyl ivermectins, respectively.


Assuntos
Regulação Bacteriana da Expressão Gênica/genética , Ivermectina/análogos & derivados , Ivermectina/síntese química , Policetídeo Sintases/metabolismo , Animais , Inseticidas/metabolismo , Ivermectina/metabolismo , Modelos Moleculares
6.
Pestic Biochem Physiol ; 120: 82-90, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25987225

RESUMO

Glutamate-gated chloride channels (GluCls) are inhibitory neurotransmitter receptors that are present only in invertebrates such as nematodes and insects. These channels are important targets of insecticidal, acaricidal, and anthelmintic macrolides such as avermectins, ivermectin (IVM), and milbemycins. To identify the amino acid residues that interact with IVM in GluCls, three IVM B1a derivatives with different photoreactive substitutions at C-13 were synthesized in the present study. These derivatives displayed low- or subnanomolar affinity for parasitic nematode (Haemonchus contortus) and silkworm (Bombyx mori) GluCls expressed in COS-1 cells. The derivatives also activated homomeric H. contortus GluCls expressed in Xenopus oocytes. The results indicate that synthesized photoreactive IVM B1a derivatives have superior affinity and functionality for chemically labeling the macrolide-binding site in GluCls. .


Assuntos
Canais de Cloreto/metabolismo , Proteínas de Helminto/metabolismo , Proteínas de Insetos/metabolismo , Ivermectina/análogos & derivados , Ivermectina/farmacologia , Animais , Bombyx , Células COS , Canais de Cloreto/genética , Feminino , Haemonchus , Proteínas de Helminto/genética , Proteínas de Insetos/genética , Ivermectina/síntese química , Oócitos/metabolismo , Xenopus laevis
7.
Org Lett ; 16(15): 3864-7, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25025525

RESUMO

A stereodivergent approach to the spiroketal fragment of the avermectins is described. The strategy utilizes a sequence of three aldol reactions directed by the tris(trimethylsilyl)silyl "super silyl" group. Central to this strategy is that each aldol reaction can be controlled to allow access to either diastereomer in high stereoselectivity, thereby affording 16 stereoisomers along the same linear skeleton. The aldol products can be transformed into spiroketals, including an advanced intermediate in the total synthesis of avermectin A1a.


Assuntos
Aldeídos/química , Ivermectina/análogos & derivados , Compostos de Trimetilsilil/química , Ivermectina/síntese química , Ivermectina/química , Estrutura Molecular , Estereoisomerismo
8.
Biotechnol J ; 9(3): 316-25, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24478271

RESUMO

Natural products are still key sources of current clinical drugs and innovative therapeutic agents. Since wild-type microorganisms only produce natural products in very small quantities, yields of production strains need to be improved by breaking down the precise genetic and biochemical circuitry. Herein, we use avermectins as an example of production improvement and chemical structure diversification by synthetic biology. Avermectins are macrocyclic lactones produced by Streptomyces avermitilis and are well known and widely used for antiparasitic therapy. Given the importance of this molecule and its derivatives, many efforts and strategies were employed to improve avermectin production and generate new active analogues. This review describes the current status of synthetic strategies successfully applied for developing natural-product-producing strains and discusses future prospects for the application of enhanced avermectin production.


Assuntos
Antiparasitários/síntese química , Ivermectina/análogos & derivados , Biologia Sintética , Antiparasitários/química , Antiparasitários/uso terapêutico , Humanos , Ivermectina/síntese química , Ivermectina/química , Ivermectina/uso terapêutico , Lactonas/química , Streptomyces/química
9.
Colloids Surf B Biointerfaces ; 83(1): 148-54, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21131183

RESUMO

Stable and even microcrystals of Avermectin (AVM) were produced by recrystallization in presence of a stabilizer. Sequential layer growth was achieved by the layer-by-layer (LbL) self-assembly of biocompatible polyelectrolytes (PEs). The coated colloids were characterized using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The in vitro release of Avermectin from microcapsules was studied under the simulated insect midgut conditions. W-doped TiO(2) photocatalysts were synthesized by a simple hydrothermal method, and characterized by Brunauer-Emmett-Teller (BET) surface area measurements and SEM. The photocatalytic activities of photocatalysts, which were undoped with TiO(2) and W-doped TiO(2), were evaluated by the photocatalytic oxidation degradation of AVM microcapsules in aqueous solution under UV illumination. The toxicity of the photodegradable insecticide was evaluated by the adult stage Martianus dermestoides. The results showed that AVM microcrystals which were obtained by association had a mean length of 13.8µm and a zeta potential of -34.7mV. The drug loading and encapsulation efficiency were 65.57±0.96% and 46.15±0.96%, respectively. The in vitro release experiments revealed that the polyelectrolytes prolonged the release time of the encapsulated AVM microcrystals. The sample which was prepared at 120°C with 4.0mol% W-doped amount had the highest photocatalytic activity. Toxicity of the novel photodegradable insecticide was higher in the adult stage compared to the 95% AVM as indicated by the lower LC(50) value.


Assuntos
Eletrólitos/química , Inseticidas/síntese química , Ivermectina/análogos & derivados , Nanocompostos/química , Fotólise , Titânio/química , Tungstênio/química , Alginatos/química , Animais , Bioensaio , Catálise/efeitos dos fármacos , Catálise/efeitos da radiação , Quitosana/química , Besouros/efeitos dos fármacos , Cristalização , Eletroforese , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Inseticidas/efeitos da radiação , Inseticidas/toxicidade , Ivermectina/síntese química , Ivermectina/efeitos da radiação , Ivermectina/toxicidade , Nanocompostos/ultraestrutura , Tamanho da Partícula , Fotólise/efeitos dos fármacos , Fotólise/efeitos da radiação , Soluções , Propriedades de Superfície/efeitos dos fármacos , Propriedades de Superfície/efeitos da radiação , Testes de Toxicidade , Raios Ultravioleta
10.
Org Biomol Chem ; 8(1): 29-38, 2010 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-20024126
11.
Bioorg Med Chem ; 17(12): 4085-95, 2009 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-19168364

RESUMO

An overview is given on recent work towards new avermectin derivatives of extremely high insecticidal and acaricidal activity. These compounds were prepared from commercially available abamectin (avermectin B1) 1. For the synthesis, many novel entries have been opened up, making use of modern synthetic methods and applying them, for the first time, to the chemistry of avermectins. Several types of avermectin derivatives can be regarded as key innovations in the field. These are, in particular, 4''-deoxy-4''-(S)-amino avermectins 3, 4'-O-alkoxyalkyl avermectin monosaccharides 5, 4''-deoxy-4''-C-substituted 4''-amino avermectins 6 and 2''-substituted avermectins 7. 4''-Deoxy-4''-(S)-amino avermectins 3 were obtained by the consecutive application of the Staudinger and Aza-Wittig reaction. 4'-O-Alkoxyalkyl avermectin monosaccharides 5 were prepared by alkoxyalkylation of 5-O-protected avermectin monosaccharide. For the synthesis of 4''-deoxy-4''-C-substituted 4''-amino avermectins 6, several methods were used to construct the fully substituted 4''-carbon centre, such as a modified Strecker synthesis, the addition of organometallics to a 4''-sulfinimine and a modified Ugi approach. In order to prepare 2''-substituted avermectins 7, 5-O-protected avermectin monosaccharide was coupled with carbohydrate building blocks. An alternative synthesis involved the hitherto unknown enol ether chemistry of 4''-oxo-avermectin and the conjugate addition of a cuprate to an avermectin 2'',3''-en-4''-one. In addition, a number of other highly potent derivatives were synthesised. Examples are 4''-O-amino avermectins 8, as well as products arising from intramolecular rhodium catalysed amidations and carbene insertions. A radical cyclisation led to an intriguing rearrangement of the avermectin skeleton. Many of the new avermectins surpassed the activity of abamectin 1 against insects and mites.


Assuntos
Inseticidas/química , Ivermectina/análogos & derivados , Produtos Agrícolas/crescimento & desenvolvimento , Dissacarídeos/química , Inseticidas/síntese química , Inseticidas/farmacologia , Ivermectina/síntese química , Ivermectina/química , Ivermectina/farmacologia , Relação Estrutura-Atividade
12.
Bioorg Med Chem ; 17(2): 496-502, 2009 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-19114308

RESUMO

In the present study a family of macrocyclic and acyclic analogues as well as seco-analogues of avermectins were prepared from commercial Ivermectin (IVM) and their antileishmanial activity assayed against axenic promastigote and intracellular amastigote forms of Leishmania amazonensis. Contrarily to the filaricidal activity, the leishmanicidal potentiality of avermectin analogues does not appear to depend on the integrity of the non-conjugated Delta(3,4)-hexahydrobenzofuran moiety. Conjugated Delta(2,3)-IVM or its corresponding conjugated secoester show higher anti-leishmania activity than the parent compound. Surprisingly, the diglycosylated northern sub-unit exhibits the same anti-amastigote potentiality as the southern hexahydrobenzofuran. As expected for compounds derived from the widely used Ivermectin antibiotic, little toxicity has been noticed for most of the novel analogues prepared.


Assuntos
Ivermectina/análogos & derivados , Ivermectina/química , Tripanossomicidas/síntese química , Animais , Benzofuranos , Dissacarídeos , Ivermectina/síntese química , Ivermectina/farmacologia , Ivermectina/toxicidade , Leishmania mexicana/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/parasitologia , Camundongos , Testes de Sensibilidade Parasitária , Relação Estrutura-Atividade , Tripanossomicidas/farmacologia , Tripanossomicidas/toxicidade
13.
J Am Chem Soc ; 128(51): 16420-1, 2006 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-17177349

RESUMO

The glycosyltransferase AveBI, which is involved in the biosynthesis of the macrolide antihelmintic avermectin (AVM), was characterized in vitro. AveBI was confirmed to catalyze two separate iterative additions of l-oleandrose, and the reversibility of AveBI-catalyzed reaction was also demonstrated. Investigation of sugar nucleotide specificity revealed 10 unique sugar nucleotide substrates which, in combination with five distinct aglycones, led to the production of 50 differentially glycosylated AVM variants.


Assuntos
Glicosiltransferases/química , Ivermectina/análogos & derivados , Nucleotídeos/química , Catálise , Cromatografia Líquida de Alta Pressão , Ativação Enzimática , Ivermectina/síntese química , Ivermectina/química , Conformação Molecular , Sensibilidade e Especificidade , Estereoisomerismo
14.
Nat Chem Biol ; 1(3): 122-4, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16408011
15.
Pest Manag Sci ; 60(7): 697-702, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15260302

RESUMO

Four novel 5-acyloxyimino-5-deoxyavermectin B1 compounds have been synthesized from avermectin B1 by selective oxidization of the hydroxy group at C-5, followed by oximation and convenient esterification. Their structures were confirmed by IR, 1H NMR, 13C NMR and MS. Insecticidal activities of the intermediate oxime and the four new acyl derivatives were evaluated against Helicoverpa armigera, Spodoptera exigua and Musca domestica.


Assuntos
Inseticidas/toxicidade , Ivermectina/análogos & derivados , Ivermectina/toxicidade , Animais , Bioensaio , Isótopos de Carbono/metabolismo , Moscas Domésticas/efeitos dos fármacos , Inseticidas/síntese química , Ivermectina/síntese química , Dose Letal Mediana , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Mariposas/efeitos dos fármacos , Espectrofotometria Infravermelho , Spodoptera/efeitos dos fármacos
16.
Bioorg Med Chem Lett ; 14(16): 4135-9, 2004 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-15261257

RESUMO

Novel 4"-alkoxy avermectin derivatives were synthesized via rhodium carbenoid mediated O-H insertion reaction and tested for antiparasite activity against Artemia salina and Caenorhabditis elegans.


Assuntos
Ivermectina/análogos & derivados , Ivermectina/química , Animais , Caenorhabditis elegans/efeitos dos fármacos , Crustáceos/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Ivermectina/síntese química , Ivermectina/farmacologia
17.
Bioorg Med Chem Lett ; 13(22): 3943-6, 2003 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-14592480

RESUMO

Horner-Emmons reaction of 4"-dehydro-5-O-TBDMS-avermectin B(1a) with a variety of phosphorus ylides using LHMDS gave novel 4"-alkylidene avermectin derivatives in high yields. Further modifications led to derivatives bearing diverse functional groups. The new avermectin derivatives showed potent growth inhibitory activity against Artemia salina and Caenorhabditis elegans.


Assuntos
Inibidores do Crescimento/síntese química , Ivermectina/análogos & derivados , Ivermectina/síntese química , Animais , Artemia/efeitos dos fármacos , Artemia/crescimento & desenvolvimento , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/crescimento & desenvolvimento , Inibidores do Crescimento/farmacologia , Indicadores e Reagentes , Ivermectina/farmacologia , Conformação Molecular
18.
J Org Chem ; 67(3): 831-6, 2002 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-11856026

RESUMO

A facile anionic cyclization approach toward stereocontrolled synthesis of the hexahydrobenzofuran subunit 3 of avermectin is described. As a model study, treatment of iodo compound 7 with n-BuLi at -100 degrees C effected metal-halogen exchange and subsequent anionic cyclization to afford perhydrobenzofuranone 8. For the total synthesis of subunit 3, compound 9 was dihydroxylated to give diol 10. Protection of the hydroxyl groups of diol 10 gave compound 11. Ketone 11 was then converted into the required enone 12 using Saegusa's protocol. On iodination followed by Luche reduction, enone 12 yielded alpha-iodo allylic alcohol 14, which on alkylation afforded ether 15. Conversion of the ester unit of 15 into a Weinreb amide group followed by anionic cyclization gave enone 17. 1,4-Addition of (MeOCH(2))(2)CuCNLi(2) to enone 17 followed by cleavage of the acetal unit afforded ketone 19. Preferential acetylation of the secondary alcoholic function of 19 afforded compound 20. The stereochemistry of 20 is confirmed by single-crystal X-ray analysis. Elimination of HOAc from 20 gave the crucial olefin 21. Hydrolysis of the acetate unit of 21 followed by protection of the resulting alcoholic function yielded tert-butyldimethylsilyl ether 23. Introduction of a hydroxyl group at the ring junction of 23, using Davis's procedure, finally afforded the hexahydrobenzofuran subunit 3.


Assuntos
Anti-Helmínticos/síntese química , Benzofuranos/química , Ivermectina/síntese química , Ânions , Anti-Helmínticos/química , Ivermectina/análogos & derivados , Ivermectina/química , Estrutura Molecular , Análise Espectral
19.
Nat Biotechnol ; 18(9): 980-3, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10973220

RESUMO

The side chain of the antifungal antibiotic ansatrienin A from Streptomyces collinus contains a cyclohexanecarboxylic acid (CHC)-derived moiety. This moiety is also observed in trace amounts of omega-cyclohexyl fatty acids (typically less than 1% of total fatty acids) produced by S. collinus. Coenzyme A-activated CHC (CHC-CoA) is derived from shikimic acid through a reductive pathway involving a minimum of nine catalytic steps. Five putative CHC-CoA biosynthetic genes in the ansatrienin biosynthetic gene cluster of S. collinus have been identified. Plasmid-based heterologous expression of these five genes in Streptomyces avermitilis or Streptomyces lividans allows for production of significant amounts of omega-cyclohexyl fatty acids (as high as 49% of total fatty acids). In the absence of the plasmid these organisms are dependent on exogenously supplied CHC for omega-cyclohexyl fatty acid production. Doramectin is a commercial antiparasitic avermectin analog produced by fermenting a bkd mutant of S. avermitilis in the presence of CHC. Introduction of the S. collinus CHC-CoA biosynthetic gene cassette into this organism resulted in an engineered strain able to produce doramectin without CHC supplementation. The CHC-CoA biosynthetic gene cluster represents an important genetic tool for precursor-directed biosynthesis of doramectin and has potential for directed biosynthesis in other important polyketide-producing organisms.


Assuntos
Anti-Helmínticos/síntese química , Coenzima A/química , Coenzima A/genética , Ácidos Cicloexanocarboxílicos/química , Ivermectina/análogos & derivados , Família Multigênica , Biotecnologia/métodos , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Ácidos Graxos/química , Cromatografia Gasosa-Espectrometria de Massas , Ivermectina/síntese química , Modelos Químicos , Modelos Genéticos , Plasmídeos/metabolismo , Ácido Chiquímico/análogos & derivados , Streptomyces/química , Streptomyces/genética
20.
Bioorg Med Chem ; 8(8): 2017-25, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11003146

RESUMO

Evaluation of a wide range of avermectin derivatives for flea activity in an in vitro feeding screen using the cat flea, Ctenocephalides felis, revealed a narrow structure-activity relationship (SAR) with activity surprisingly associated with monosaccharides and especially their C-5-oximes. We discovered commercially exploitable flea activity in a single compound, selamectin 33, which also possessed the necessary antiparasitic spectrum and margin of safety for development as a broad-spectrum companion animal endectocide.


Assuntos
Inseticidas/química , Inseticidas/farmacologia , Ivermectina/análogos & derivados , Ivermectina/química , Ivermectina/farmacologia , Sifonápteros , Animais , Gatos , Cães , Feminino , Inseticidas/síntese química , Ivermectina/síntese química , Espectroscopia de Ressonância Magnética , Masculino , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-Atividade
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