QSAR study on the toxicity of substituted benzenes to the algae (Scenedesmus obliquus)

Lu, Guanghua; Yuan, Xing; Zhao, Yun-Tao

doi:10.1016/s0045-6535(00)00214-9

Cited by 50 publications

(29 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Thus, when evaluating the environmental effects of substituted benzenes, mixtures also were considered in this study. Some researchers have reported the joint toxicity of the substituted benzene mixtures to luminescent bacteria, algae, water fleas and fish [22,23]. In this study, the joint toxicities of 19 substituted benzene mixtures were evaluated using TU, AI, MTI and λ.…”

Section: Discussionmentioning

confidence: 99%

Acute and joint toxicity of twelve substituted benzene compounds to Propsilocerus akamusi Tokunaga

Cao

Niu

et al. 2014

Open Life Sciences

View full text Add to dashboard Cite

This study investigated the toxic effects of 12 substituted benzenes exposed to Propsilocerus akamusi larvae singly and as mixtures. Their toxicities were quantified in terms of median effective concentration (EC50) killing 50% of the larvae. For individual substituted benzenes to 4th-instar P. akamusi larvae, the toxicity was in decreasing order of p-chlorophenol > nitrobenzene > phenol > 1,2-dimethylbenzene > 1,3-dimethylbenzene > chlorobenzene > p-phenylenediamine > 1,4-dimethylbenzene > m-phenylenediamine > methylbenzene > benzene > aniline. The order of toxicity among three isomers of dimethylbenzene was 1,2-dimethylbenzene > 1,3-dimethylbenzene > 1,4-dimethylbenzene while p-phenylenediamine > m-phenylenediamine. The binary substituted benzene compounds’ toxicities were evaluated by toxic unit (TU), additive index (AI), mixture toxicity index (MTI) and similarity parameter index (λ). The evaluation results of TU and MTI for 9 substituted benzene compounds were completely consistent while the results of AI were the same as the results of λ based on 24 h EC50 of binary substituted benzenes. The evaluation results of 10 substituted benzene compounds were consistent using TU, MTI, AI and λ evaluation methods. 52.63% and 47.37% of binary substituted benzene tests on P. akamusi larvae showed synergism and partial addition/antagonism, respectively, under mixtures of equal proportions. These results suggest that substituted benzenes indicate acute and binary joint toxicity to P. akamusi.

show abstract

Section: Discussionmentioning

confidence: 99%

Acute and joint toxicity of twelve substituted benzene compounds to Propsilocerus akamusi Tokunaga

Cao

Niu

et al. 2014

Open Life Sciences

View full text Add to dashboard Cite

show abstract

“…São muito utilizados para prever o potencial de bioacumulação de uma substância, pois quanto maior o valor de k ow , maior a hidrofobicidade dessa substância e maior a sua capacidade em se bioacumular nos organismos. Substâncias químicas com baixo valor de kow são prontamente solúveis e podem ser absorvidas por meio da ingestão pelos organismos, enquanto que substâncias químicas com alto valor de kow são descritas como hidrofóbicas e tendem a estar associada à matéria orgânica particulada, como por exemplo, adsorvidas aos sedimentos e/ou absorvida pelas membranas dos organismos aquáticos (Lu et al, 2001;Islam e Tanaka, 2004). Em ambas as situações estes poluentes orgânicos atingem a biota aquática podendo causar efeitos tóxicos.…”

Section: Figura 1 Exemplos De Contaminantes Aquáticosunclassified

“…Estas abordagens incluem diversos tipos de estudos como a utilização de modelos de relação quantitativa de estrutura e atividade (QSAR), os quais são baseados nas características físicas e químicas dos compostos (Lu et al, 2001;Lu et al, 2008) e modelos de relação quantitativa de atividade química inter-específica (QUICAR) em que prevê o efeito tóxico de um composto em um organismo específico baseado em dados de outras espécies relacionadas (Tremolada et al, 2004). …”

Section: Figura 1 Exemplos De Contaminantes Aquáticosunclassified

Aspectos oxidativos e de biotransformação do poluente fenol na microalga Minutocellus polymorphus

Campos¹

View full text Add to dashboard Cite

incondicional, pelo exemplo de força e vontade, pelo incentivo, pelo empenho na minha educação, pelas palavras sábias... A vocês devo tudo o que consegui hoje. Obrigada por tudo!!! Ao meu querido Jô Jô Jô Jô, um presente em minha vida, por todo o amor, paciência, compreensão e carinho. Por estar presente nos meus momentos mais difíceis, mas principalmente pela paz que me traz. AGRADECIMENTOSAo meu querido orientador Prof. Dr. Pio Colepicolo, pelos ensinamentos, pela amizade e por me proporcionar um amadurecimento científico.A minha querida mestra Profª. Dra. Maísa Ribeiro Pereira Lima Brigagão, por me iniciar nesse maravilhoso mundo da bioquímica.Ao Prof. Dr. Ernani Pinto, pela amizade e ajuda inicial no trabalho.Ao Prof. Dr. Maurício Yonanime, pela amizade, pela grande disposição e interesse no trabalho, pela colaboração nas análises de CG/MS.Ao Prof. Dr. Frank Hebert Quina e ao Prof. Dr. Cláudio Augusto Oller do Nascimento pela confiança e auxílio na conquista da bolsa.A amiga Daniela M. L. de Paula pela preciosa ajuda ao trabalho e pelo auxílio na operação do CG/MS.Aos amigos e companheiros de laboratório: Adriana, Ana, Anderson, Ângela, Diogo, Douglas, Eloísa, Fabyana, Humberto, João, Karina, Lígia, Luiza, Marcelo, Meron, Moacir, Paula, Patrícia, Sidnei, Tereza, Thaís, Tona, Vanessa Falcão, Vanessa, Vânia, pela convivência, pela amizade e pelo auxílio na utilização de aparelhos, além de diversas discussões muito produtivas.Ao técnico e amigo Ed, pela amizade e pela preciosa ajuda.A querida Sandrinha, pelo cuidado ao laboratório e pelas palavras amigas.A minha grande e querida amiga Amandinha, uma pessoa doce e companheira, pelo carinho e pela força nos momentos mais difíceis.A minha grande e querida amiga Paulinha, anjo em minha vida, pela força, pelo companheirismo, pela ajuda nos experimentos, pela enorme ajuda na fase final desse doutorado. Fico sem palavras para expressar minha enorme gratidão por vc.Obrigada pela linda amizade! Aos meus grandes amigos Sabrina, Fabiana, Henrique e Ingrid que mesmo apesar da distância continuam muito presentes em minha vida. Nossa amizade e nossos momentos de alegria sempre são lembrados com muito carinho.Aos amigos candangos, Simone e Fábio e Camila e Natanael, por tornar os nossos dias mais alegres.As professoras de bioquímica da EFOA, Terezinha e Denise, pelo carinho, ensinamentos e incentivo.Aos meus queridos e amados irmãos, Junior e Diego, pelo amor e companheirismo.Aos meus queridos avôs, João e Alzira (sempre presente em meu coração), José e Maria, pelo amor, carinho e orações.A minha segunda família, D. Edna, Sr. Zezé e Netinho, pelo carinho, amor e amizade.A Capes, CNPq, FAPESP e ao CEPEMA (Centro de Capacitação e Pesquisa em Meio Ambiente) pelo apoio financeiro.A todos que contribuíram direta ou indiretamente para a realização deste trabalho."Só existem duas maneiras de você viver sua vida. Uma é como se "Só existem duas maneiras de você viver sua vida. Uma é como se "Só existem duas maneiras de você viver sua vida. Uma é como se "Só existem duas maneiras de vo...

show abstract

“…Figure 6.1 shows that, for each of the 4 chemicals groups, E LUMO is a good descriptor in explaining the toxicity for most aromatic compounds except chlorinated nitrophenol. Similarly, Lu et al (2001) investigated the toxicity of nitrobenzenes to P. phosphoreum and developed QSARs with E LUMO and logK ow , and concluded also that the toxicity of substituted nitrobenzenes is controlled mainly by electronic factors (E LUMO ). Model 6.9 indicates that the relationship between log(1/IGC 50 ) and independent predictors is quite good and is capable of explaining variation in data (R 2 =0.92).…”

Section: Chlorinated Aromatics Containing a Nitro-or Cyano Groupmentioning

confidence: 99%

“…Molecular descriptors derived from quantum chemical computation have obvious advantages, because first they are not restricted to closely related compounds and can be easily obtained; secondly, they can clearly describe defined molecular properties. For these reasons, there have been many examples of the use of quantum chemical molecular descriptors (Lu et al, 2001;Zhang et al, 2007;and Wang et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Chlorine Contribution to Quantitative Structure and Activity Relationship Models of Disinfection By-Products' Quantum Chemical Descriptors and Toxicities

Wang¹

View full text Add to dashboard Cite

Quantitative Structure-Activity Relationship (QSAR) has been applied extensively in predicting toxicity of Disinfection By-Products (DBPs) in drinking water. Among many toxicological properties, acute and chronic toxicities of DBPs have been widely used in health risk assessment of DBPs. These toxicities are correlated with molecular properties, which are usually correlated with molecular descriptors. The primary goals of this thesis are: 1) to investigate the effects of molecular descriptors (e.g., chlorine number) on molecular properties such as energy of the lowest unoccupied molecular orbital (E LUMO ) via QSAR modelling and analysis; 2) to validate the models by using internal and external cross-validation techniques; 3) to quantify the model uncertainties through Taylor and Monte Carlo Simulation. One of the very important ways to predict molecular properties such as E LUMO is using QSAR analysis. In this study, number of chlorine (N Cl ) and number of carbon (N C ) as well as energy of the highest occupied molecular orbital (E HOMO ) are used as molecular descriptors.vii There are typically three approaches used in QSAR model development: 1) Linear or Multi-linear Regression (MLR); 2) Partial Least Squares (PLS); and 3) Principle Component Regression (PCR). In QSAR analysis, a very critical step is model validation after QSAR models are established and before applying them to toxicity prediction. The DBPs to be studied include five chemical classes: chlorinated alkanes, alkenes, and aromatics. In addition, validated QSARs are developed to describe the toxicity of selected groups (i.e., chloro-alkane and aromatic compounds with a nitro-or cyano group) of DBP chemicals to three types of organisms (e.g., Fish, T. pyriformis, and P.pyosphoreum) based on experimental toxicity data from the literature.The results show that: 1) QSAR models to predict molecular property built by MLR, PLS or PCR can be used either to select valid data points or to eliminate outliers; 2) The Leave-One-Out Cross-Validation procedure by itself is not enough to give a reliable representation of the predictive ability of the QSAR models, however, Leave-Many-Out/K-fold cross-validation and external validation can be applied together to achieve more reliable results; 3) E LUMO are shown to correlate highly with the N Cl for several classes of DBPs; and 4) According to uncertainty analysis using Taylor method, the uncertainty of QSAR models is contributed mostly from N Cl for all DBP classes. ix IntroductionDuring water treatment processes, the disinfection is commonly used to destroy pathogenic organisms and prevent the outbreak of waterborne infectious diseases.Although the benefits of water disinfection are well documented, there is an undesirable side effect of producing various Disinfection By-Products (DBPs) when disinfectants such as chlorine react with natural inorganic and organic matters in the water. Quantitative Structure-Activity Relationship (QSAR)QSAR analysis is a promising tool based on the assumption that t...

show abstract

QSAR study on the toxicity of substituted benzenes to the algae (Scenedesmus obliquus)

Cited by 50 publications

References 4 publications

Acute and joint toxicity of twelve substituted benzene compounds to Propsilocerus akamusi Tokunaga

Acute and joint toxicity of twelve substituted benzene compounds to Propsilocerus akamusi Tokunaga

Aspectos oxidativos e de biotransformação do poluente fenol na microalga Minutocellus polymorphus

Chlorine Contribution to Quantitative Structure and Activity Relationship Models of Disinfection By-Products' Quantum Chemical Descriptors and Toxicities

Contact Info

Product

Resources

About