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Gupta MK, Gouda G, Sultana S, Punekar SM, Vadde R, Ravikiran T. Structure-related relationship: Plant-derived antidiabetic compounds. STUDIES IN NATURAL PRODUCTS CHEMISTRY 2023:241-295. [DOI: 10.1016/b978-0-323-91294-5.00008-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
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Khaled DM, Elshakre ME, Noamaan MA, Butt H, Abdel Fattah MM, Gaber DA. A Computational QSAR, Molecular Docking and In Vitro Cytotoxicity Study of Novel Thiouracil-Based Drugs with Anticancer Activity against Human-DNA Topoisomerase II. Int J Mol Sci 2022; 23:11799. [PMID: 36233102 PMCID: PMC9570267 DOI: 10.3390/ijms231911799] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/16/2022] [Accepted: 09/18/2022] [Indexed: 11/30/2022] Open
Abstract
Computational chemistry, molecular docking, and drug design approaches, combined with the biochemical evaluation of the antitumor activity of selected derivatives of the thiouracil-based dihydroindeno pyrido pyrimidines against topoisomerase I and II. The IC50 of other cell lines including the normal human lung cell line W138, lung cancer cell line, A549, breast cancer cell line, MCF-7, cervical cancer, HeLa, and liver cancer cell line HepG2 was evaluated using biochemical methods. The global reactivity descriptors and physicochemical parameters were computed, showing good agreement with the Lipinski and Veber's rules of the drug criteria. The molecular docking study of the ligands with the topoisomerase protein provides the binding sites, binding energies, and deactivation constant for the inhibition pocket. Various biochemical methods were used to evaluate the IC50 of the cell lines. The QSAR model was developed for colorectal cell line HCT as a case study. Four QSAR statistical models were predicted between the IC50 of the colorectal cell line HCT to correlate the anticancer activity and the computed physicochemical and quantum chemical global reactivity descriptors. The predictive power of the models indicates a good correlation between the observed and the predicted activity.
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Affiliation(s)
- Doaa M. Khaled
- Histology and Cytology Department, Faculty of Medicine, Helwan University, Cairo 11795, Egypt
| | - Mohamed E. Elshakre
- Chemistry Department, Faculty of Science, Cairo University, Cairo 12613, Egypt
| | - Mahmoud A. Noamaan
- Mathematics Department, Faculty of Science, Cairo University, Cairo 12613, Egypt
| | - Haider Butt
- Department of Mechanical Engineering, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Marwa M. Abdel Fattah
- Histology and Cytology Department, Faculty of Medicine, Misr University for Science & Technology, Cairo P.O. Box 77, Egypt
| | - Dalia A. Gaber
- Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Helwan University, Cairo 11795, Egypt
- Department of Biomedical Sciences, College of Medicine, Gulf Medical University, Ajman 4184, United Arab Emirates
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Elshakre ME, Noamaan MA, Moustafa H, Butt H. Density Functional Theory, Chemical Reactivity, Pharmacological Potential and Molecular Docking of Dihydrothiouracil-Indenopyridopyrimidines with Human-DNA Topoisomerase II. Int J Mol Sci 2020; 21:E1253. [PMID: 32070048 PMCID: PMC7072893 DOI: 10.3390/ijms21041253] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 01/25/2020] [Accepted: 01/27/2020] [Indexed: 01/31/2023] Open
Abstract
In this work, three computational methods (Hatree-Fock (HF), Møller-Plesset 2 (MP2), and Density Functional Theory (DFT)) using a variety of basis sets are used to determine the atomic and molecular properties of dihydrothiouracil-based indenopyridopyrimidine (TUDHIPP) derivatives. Reactivity descriptors of this system, including chemical potential (µ), chemical hardness (η), electrophilicity (ω), condensed Fukui function and dual descriptors are calculated at B3LYP/6-311++ G (d,p) to identify reactivity changes of these molecules in both gas and aqueous phases. We determined the molecular electrostatic surface potential (MESP) to determine the most active site in these molecules. Molecular docking study of TUDHIPP with topoisomerase II α and β is performed, predicting binding sites and binding energies with amino acids of both proteins. Docking studies of TUDHIPP versus etoposide suggest their potential as antitumor candidates. We have applied Lipinski, Veber's rules and analysis of the Golden triangle and structure activity/property relationship for a series of TUDHIPP derivatives indicate that the proposed compounds exhibit good oral bioavailability. The comparison of the drug likeness descriptors of TUDHIPP with those of etoposide, which is known to be an antitumor drug, indicates that TUDHIPP can be considered as an antitumor drug. The overall study indicates that TUDHIPP has comparable and even better descriptors than etoposide proposing that it can be as effective antitumor drug, especially 2H, 6H and 7H compounds.
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Affiliation(s)
- Mohamed E. Elshakre
- Chemistry Department, College of Science, Cairo University, Cairo 12613, Egypt;
| | - Mahmoud A. Noamaan
- Chemistry Department, College of Science, Cairo University, Cairo 12613, Egypt;
| | - Hussein Moustafa
- Chemistry Department, College of Science, Cairo University, Cairo 12613, Egypt;
| | - Haider Butt
- Department of Mechanical Engineering, Khalifa University, Abu Dhabi 127788, UAE;
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Piras AM, Zambito Y, Burgalassi S, Monti D, Tampucci S, Terreni E, Fabiano A, Balzano F, Uccello-Barretta G, Chetoni P. A water-soluble, mucoadhesive quaternary ammonium chitosan-methyl-β-cyclodextrin conjugate forming inclusion complexes with dexamethasone. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2018; 29:42. [PMID: 29603020 DOI: 10.1007/s10856-018-6048-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 03/15/2018] [Indexed: 06/08/2023]
Abstract
The ocular bioavailability of lipophilic drugs, such as dexamethasone, depends on both drug water solubility and mucoadhesion/permeation. Cyclodextrins and chitosan are frequently employed to either improve drug solubility or prolong drug contact onto mucosae, respectively. Although the covalent conjugation of cyclodextrin and chitosan brings to mucoadhesive drug complexes, their water solubility is restricted to acidic pHs. This paper describes a straightforward grafting of methyl-β-cyclodextrin (MCD) on quaternary ammonium chitosan (QA-Ch60), mediated by hexamethylene diisocyanate. The resulting product is a water-soluble chitosan derivative, having a 10-atom long spacer between the quaternized chitosan and the cyclodextrin. The derivative is capable of complexing the model drug dexamethasone and stable complexes were also observed for the lyophilized products. Furthermore, the conjugate preserves the mucoadhesive properties typical of quaternized chitosan and its safety as solubilizing excipient for ophthalmic applications was preliminary assessed by in vitro cytotoxicity evaluations. Taken as a whole, the observed features appear promising for future processing of the developed product into 3D solid forms, such as controlled drug delivery systems, films or drug eluting medical devices.
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Affiliation(s)
- Anna Maria Piras
- Department of Pharmacy, University of Pisa, via Bonanno 33, 56126, Pisa, Italy.
| | - Ylenia Zambito
- Department of Pharmacy, University of Pisa, via Bonanno 33, 56126, Pisa, Italy
| | - Susi Burgalassi
- Department of Pharmacy, University of Pisa, via Bonanno 33, 56126, Pisa, Italy
| | - Daniela Monti
- Department of Pharmacy, University of Pisa, via Bonanno 33, 56126, Pisa, Italy
| | - Silvia Tampucci
- Department of Pharmacy, University of Pisa, via Bonanno 33, 56126, Pisa, Italy
| | - Eleonora Terreni
- Department of Pharmacy, University of Pisa, via Bonanno 33, 56126, Pisa, Italy
| | - Angela Fabiano
- Department of Pharmacy, University of Pisa, via Bonanno 33, 56126, Pisa, Italy
| | - Federica Balzano
- Department of Chemistry and Industrial Chemistry, University of Pisa, via Moruzzi 13, 56124, Pisa, Italy
| | - Gloria Uccello-Barretta
- Department of Chemistry and Industrial Chemistry, University of Pisa, via Moruzzi 13, 56124, Pisa, Italy
| | - Patrizia Chetoni
- Department of Pharmacy, University of Pisa, via Bonanno 33, 56126, Pisa, Italy
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Schoenborn A, Schmid P, Bräm S, Reifferscheid G, Ohlig M, Buchinger S. Unprecedented sensitivity of the planar yeast estrogen screen by using a spray-on technology. J Chromatogr A 2017; 1530:185-191. [PMID: 29146425 DOI: 10.1016/j.chroma.2017.11.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 11/04/2017] [Accepted: 11/06/2017] [Indexed: 11/26/2022]
Abstract
The planar yeast estrogen screen (p-YES) can serve as a highly valuable and sensitive screening tool for the detection of estrogenic compounds in various sample matrices such as water and wastewater, personal care products and foodstuff. The method combines the separation of sample constituents by thin layer chromatography with the direct detection of estrogenic compounds on the surface of the HPTLC-plate. The previous protocol using the immersion of a normal phase silica HPTLC-plate in a cell suspension for bio-autography resulted in blurred signals due to the accelerated diffusion of compounds on the wet surface of the HPTLC-plate. Here, the application of the yeast cells by spraying on the surface of the HPTLC-plate is described as an alternative approach. The presented method for the hyphenation of normal phase thin layer chromatography with a yeast estrogen screen results in much sharper signals compared to reports in previous publications. Satisfying results were achieved using cultures with cell densities of 1000 FAU. Due to the reduced signal broadening, lower limits of quantification for estrogenic compounds were achieved (Estrone (E1)=2pg/zone, 17β-estradiol (E2)=0.5pg/zone, 17α-ethinylestradiol (EE2)=0.5pg/zone and Estriol (E3)=20pg/zone). As demonstrated, it is possible to characterize profiles of estrogenic activity of wastewater samples with high quality and reproducibility. The improved sensitivity opens the stage for applications using native samples from waste- or even surface water directly applied on HPTLC-plates without the need for prior sample treatment by e.g. solid phase extraction.
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Affiliation(s)
- Andreas Schoenborn
- ZHAW Life Sciences und Facility Management, Grüental, 8820 Wädenswil, Switzerland.
| | - Pascal Schmid
- ZHAW Life Sciences und Facility Management, Grüental, 8820 Wädenswil, Switzerland
| | - Sarah Bräm
- ZHAW Life Sciences und Facility Management, Grüental, 8820 Wädenswil, Switzerland
| | | | - Marina Ohlig
- Federal Institute of Hydrology, Am Mainzer Tor 1, D-56068 Koblenz, Germany
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Pan S, Gupta AK, Subramanian V, Chattaraj PK. Quantitative Structure-Activity/Property/Toxicity Relationships through Conceptual Density Functional Theory-Based Reactivity Descriptors. PHARMACEUTICAL SCIENCES 2017. [DOI: 10.4018/978-1-5225-1762-7.ch058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Developing effective structure-activity/property/toxicity relationships (QSAR/QSPR/QSTR) is very helpful in predicting biological activity, property, and toxicity of a given set of molecules. Regular change in these properties with the structural alteration is the main reason to obtain QSAR/QSPR/QSTR models. The advancement in making different QSAR/QSPR/QSTR models to describe activity, property, and toxicity of various groups of molecules is reviewed in this chapter. The successful implementation of Conceptual Density Functional Theory (CDFT)-based global as well as local reactivity descriptors in modeling effective QSAR/QSPR/QSTR is highlighted.
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Affiliation(s)
- Sudip Pan
- Indian Institute of Technology Kharagpur, India
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Svennebring AM. Investigation of the prerequisites for the optimization of specific plasma protein binding as a strategy for the reduction of first-pass hepatic metabolism. Xenobiotica 2014; 45:286-301. [PMID: 25364858 DOI: 10.3109/00498254.2014.978413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
1. It is hypothesized that the deliberate structural tailoring of compounds designed for drug use to increase the specific plasma protein binding can be used to reduce first-pass hepatic metabolism. To test the feasibility of this hypothesis, a dataset of drugs with plasma protein binding of 90% or above divided into three classes including 50 acids, 44 bases and 69 neutrals was analyzed. 2. Among the drugs with ≥99% plasma protein binding, the fraction of the total dose existing in free form in vivo (free dose fraction) decreased in the following order: acids (0.55%) > neutrals (0.16%) > bases (0.08%). The order was different for the fraction of the total dose that existed in plasma protein bound form (plasma protein bound dose fraction): acids (58%) > neutrals (17%) = bases (18%). 3. The free fraction was poorly correlated with the partition coefficient (Log P). The lower aqueous solubility associated with high plasma protein binding was explained by differences in Log P and not by the plasma protein binding per se. The logarithm of the extrarenal clearance was correlated with Log P. For acids and bases, extrarenal clearance was also correlated with fu. For neutrals, plasma protein binding had no protective effect.
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Affiliation(s)
- Andreas Mats Svennebring
- Department of Pharmaceutical Biosciences, Uppsala Biomedical Center, Uppsala University , Uppsala , Sweden
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Rawat S, Bruce ED. Designing quantitative structure activity relationships to predict specific toxic endpoints for polybrominated diphenyl ethers in mammalian cells. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 2014; 25:527-549. [PMID: 24738916 DOI: 10.1080/1062936x.2014.899512] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are known as effective flame retardants and have vast industrial application in products like plastics, building materials and textiles. They are found to be structurally similar to thyroid hormones that are responsible for regulating metabolism in the body. Structural similarity with the hormones poses a threat to human health because, once in the system, PBDEs have the potential to affect thyroid hormone transport and metabolism. This study was aimed at designing quantitative structure-activity relationship (QSAR) models for predicting toxic endpoints, namely cell viability and apoptosis, elicited by PBDEs in mammalian cells. Cell viability was evaluated quantitatively using a general cytotoxicity bioassay using Janus Green dye and apoptosis was evaluated using a caspase assay. This study has thus modelled the overall cytotoxic influence of PBDEs at an early and a late endpoint by the Genetic Function Approximation method. This research was a twofold process including running in vitro bioassays to collect data on the toxic endpoints and modeling the evaluated endpoints using QSARs. Cell viability and apoptosis responses for Hep G2 cells exposed to PBDEs were successfully modelled with an r(2) of 0.97 and 0.94, respectively.
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Affiliation(s)
- S Rawat
- a Department of Environmental Science , Baylor University , Waco , TX , USA
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Chakraborty A, Pan S, Chattaraj PK. Biological Activity and Toxicity: A Conceptual DFT Approach. STRUCTURE AND BONDING 2013. [DOI: 10.1007/978-3-642-32750-6_5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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10
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Myint KZ, Xie XQ. Recent advances in fragment-based QSAR and multi-dimensional QSAR methods. Int J Mol Sci 2010; 11:3846-66. [PMID: 21152304 PMCID: PMC2996787 DOI: 10.3390/ijms11103846] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 09/17/2010] [Accepted: 09/23/2010] [Indexed: 12/13/2022] Open
Abstract
This paper provides an overview of recently developed two dimensional (2D) fragment-based QSAR methods as well as other multi-dimensional approaches. In particular, we present recent fragment-based QSAR methods such as fragment-similarity-based QSAR (FS-QSAR), fragment-based QSAR (FB-QSAR), Hologram QSAR (HQSAR), and top priority fragment QSAR in addition to 3D- and nD-QSAR methods such as comparative molecular field analysis (CoMFA), comparative molecular similarity analysis (CoMSIA), Topomer CoMFA, self-organizing molecular field analysis (SOMFA), comparative molecular moment analysis (COMMA), autocorrelation of molecular surfaces properties (AMSP), weighted holistic invariant molecular (WHIM) descriptor-based QSAR (WHIM), grid-independent descriptors (GRIND)-based QSAR, 4D-QSAR, 5D-QSAR and 6D-QSAR methods.
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Affiliation(s)
- Kyaw Zeyar Myint
- Department of Computational Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA; E-Mail:
| | - Xiang-Qun Xie
- Department of Computational Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15260, USA; E-Mail:
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA 15260, USA
- Pittsburgh Chemical Methodologies & Library Development (PCMLD) and Pittsburgh Drug Discovery Institute, University of Pittsburgh, Pittsburgh, PA 15260, USA
- * Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-412-383-5276; Fax: +1-412-383-7436
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Hansch C, Verma RP. Overcoming tumor drug resistance with C2-modified 10-deacetyl-7-propionyl cephalomannines: a QSAR study. Mol Pharm 2009; 6:849-60. [PMID: 19334723 DOI: 10.1021/mp800138w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The microtubule-stabilizing taxanes such as paclitaxel and docetaxel are the two most important anticancer drugs currently used in clinics for the treatment of various types of cancers. However, the major common drawbacks of these two drugs are drug resistance, neurotoxicity, substrate for drug transporter P-gp, cross-resistance with other chemotherapeutic agents, low oral bioavailability, and no penetration in the blood-brain barrier (BBB). These limitations have led to the search for new taxane derivatives with improved biological activity. In the present paper, we discuss the quantitative structure-activity relationship (QSAR) studies on a series of C2-modified 10-deacetyl-7-propionyl cephalomannines (IV) with respect to their binding affinities toward beta-tubulin and cytotoxic activities against both drug-sensitive and drug-resistant tumor cells, in which resistance is mediated through either P-gp overexpression or beta-tubulin mutation mechanisms, by the formulation of five QSARs. Hydrophobicity and molar refractivity of the substituents (pi(X) and MR(X)) are found to be the most important determinants for the activity. Parabolic correlations in terms of MR(X) (eqs 2 and 4 ) are encouraging examples in which the optimum values of MR(X) are well-defined. We believe that these two QSAR models may prove to be adequate predictive models that can help to provide guidance in design and synthesis, and subsequently yield very specific cephalomannine derivatives (IV) that may have high biological activities. On the basis of these two QSAR models, 10 cephalomannine analogues (IV-21 to IV-30) are suggested as potential synthetic targets. Internal (cross-validation (q(2)), quality factor (Q), Fischer statistics (F), and Y-randomization) and external validation tests have validated all the QSAR models.
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Affiliation(s)
- Corwin Hansch
- Department of Chemistry, Pomona College, Claremont, CA 91711, USA
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Verma RP, Hansch C. Taxane analogues against lung cancer: a quantitative structure-activity relationship study. Chem Biol Drug Des 2009; 73:627-36. [PMID: 19635054 DOI: 10.1111/j.1747-0285.2009.00816.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lung cancer is the second most common cancer in both men (after prostate cancer) and women (after breast cancer). The microtubule-stabilizing taxane such as docetaxel is the only agent currently approved for both first- and second-line treatment of advanced non-small cell lung cancer. Although docetaxel has made significant progress in the treatment of lung cancers either using alone or in combination with various novel targeted agents, its use often results in various undesired side-effects. These limitations have led to the search for new taxane derivatives with fewer side-effects, superior pharmacological properties, and improved anticancer activity to maximize the induced benefits for lung cancer patients. Herein, four series of taxane derivatives were used to correlate their inhibitory activities against lung cancer cells with hydrophobic and steric descriptors to gain a better understanding of their chemical-biological interactions. A parabolic correlation with MR(Y) is the most encouraging example, in which the optimum value of this parameter is well defined. On the basis of this quantitative structure-activity relationship model, six compounds (3-23 to 3-28) are suggested as potential synthetic targets. Internal (cross-validation (q(2)), quality factor (Q), Fischer statistics (F ) and Y-randomization) and external validation tests have validated all the quantitative structure-activity relationship models.
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Affiliation(s)
- Stefan Balaz
- Department of Pharmaceutical Sciences, College of Pharmacy, North Dakota State University, Fargo, North Dakota 58105, USA.
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14
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DiMaggio PA, McAllister SR, Floudas CA, Feng XJ, Li G, Rabinowitz JD, Rabitz HA. Enhancing molecular discovery using descriptor-free rearrangement clustering techniques for sparse data sets. AIChE J 2009. [DOI: 10.1002/aic.11986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Heidler J, Halden RU. Meta-analysis of mass balances examining chemical fate during wastewater treatment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:6324-32. [PMID: 18800497 PMCID: PMC2665886 DOI: 10.1021/es703008y] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Revised: 06/11/2008] [Accepted: 06/11/2008] [Indexed: 05/18/2023]
Abstract
Mass balances are an instructive means for investigating the fate of chemicals during wastewater treatment. In addition to the aqueous-phase removal efficiency (phi), they can inform on chemical partitioning, transformation, and persistence, as well as on the chemical loading to streams and soils receiving, respectively, treated effluent and digested sewage sludge (biosolids). Release rates computed on a per-capita basis can serve to extrapolate findings to a larger scale. This review examines over a dozen mass balances conducted for various organic wastewater contaminants, including prescription drugs, estrogens, fragrances, antimicrobials, and surfactants of differing sorption potential (hydrophobicity), here expressed as the 1-octanol-water partition coefficient (K(OW)) and the organic carbon normalized sorption coefficient (K(OC)). Major challengesto mass balances are the collection of representative samples and accurate quantification of chemicals in sludge. A meta-analysis of peer-reviewed data identified sorption potential as the principal determinant governing chemical persistence in biosolids. Occurrence data for organic wastewater compounds detected in digested sludge followed a simple nonlinear model that required only K(OW) or K(OC) as the input and yielded a correlation coefficient of 0.9 in both instances. The model predicted persistence in biosolids for the majority (> 50%) of the input load of organic wastewater compounds featuring a log10 K(OW) value of greater than 5.2 (log10 K(OC) > 4.4). In contrast, hydrophobicity had no or only limited value for estimating, respectively, phi and the overall persistence of a chemical during conventional wastewater treatment.
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Affiliation(s)
| | - Rolf U. Halden
- Corresponding author phone: (480) 727-0893; fax (480) 727-0889; . Current mailing address: 1001 S. McAllister Avenue, P.O. Box 875701, Tempe, AZ 85287
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16
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Huang ZR, Hua SC, Yang YL, Fang JY. Development and evaluation of lipid nanoparticles for camptothecin delivery: a comparison of solid lipid nanoparticles, nanostructured lipid carriers, and lipid emulsion. Acta Pharmacol Sin 2008; 29:1094-102. [PMID: 18718178 DOI: 10.1111/j.1745-7254.2008.00829.x] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
AIM Camptothecin is an anticancer drug that acts against a broad spectrum of tumors. The clinical application of camptothecin is limited by its insolubility, instability, and toxicity problems. The aim of this study was to develop and characterize lipid nanoparticles with different lipid cores which can circumvent these problems. METHODS Lipid nanoparticles made of Precirol (solid lipid nanoparticles; SLN-P), Compritol (SLN-C), Precirol+squalene (nanostructured lipid carriers; NLC), and squalene (a lipid emulsion; LE) as the lipid core material were prepared. These systems were assessed and compared by evaluating the mean diameter, surface charge, molecular environment, camptothecin release, and cell viability against a melanoma. The safety and storage stability of these systems were also preliminarily examined. RESULTS The particle size ranged from 190 to 310 nm, with the NLC and LE showing the smallest and largest sizes, respectively. The in vitro drug release occurred in a sustained manner in decreasing order as follows: LE> NLC> SLN-P> SLN-C. It was found that varying the type of inner phase had profound effects on cell viability. The SLN-P generally showed higher cytotoxicity than the free control. The treatment of melanomas with the camptothecin-loaded SLN-C and NLC yielded cytotoxicity comparable to that of the free form. The percentage of erythrocyte hemolysis by all nanoparticles was < or =5%, suggesting a good tolerance to lipid nanoparticles. CONCLUSION The results collectively suggest that the SLN-P may have the potential to serve as a delivery system for parenteral camptothecin administration because of the sustained drug release, strong cytotoxicity, limited hemolysis, and good storage stability.
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Affiliation(s)
- Zih-rou Huang
- Pharmaceutics Laboratory, Chang Gung University, Taoyuan, Taiwan, China
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Singh J, Singh S, Shaik B, Deeb O, Sohani N, Agrawal VK, Khadikar PV. Mutagenicity of Nitrated Polycyclic Aromatic Hydrocarbons: A QSAR Investigation. Chem Biol Drug Des 2008; 71:230-43. [DOI: 10.1111/j.1747-0285.2008.00629.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Smith MD, Hill EM. Uptake and metabolism of technical nonylphenol and its brominated analogues in the roach (Rutilus rutilus). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2004; 69:359-369. [PMID: 15312719 DOI: 10.1016/j.aquatox.2004.06.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2004] [Revised: 06/09/2004] [Accepted: 06/20/2004] [Indexed: 05/24/2023]
Abstract
Alkylphenols have been implicated as one of the causative agents of oestrogenic contamination in fish. This study reports the fate of a technical mixture of secondary and tertiary isomers of the environmental contaminant 4-nonylphenol (NP) in mature female roach. Fish were exposed to a concentration of 4.9microg/l radio-labelled technical NP over a 4-day period in a flow-through aquarium. NP residues were extracted from all tissues and analysed by reverse phase radio HPLC. The concentration of NP residues was highest in bile and liver, with apparent bioconcentration factors (apparent BCFs) of 34,121 and 605, respectively. In other tissues, apparent BCF values were recorded between 13 and 250. NP was the only residue detected in brain, muscle and blood cells whereas an additional NP derivative was detected in other soft tissues, including gonads and liver, which was identified as the brominated derivative of technical NP, dibromo-4-nonylphenol. Traces of the dibrominated NP were also detected in aquarium water but only in the presence of NP, which suggested that bromination of the NP parent compound occurred in situ in the water due to the presence of trace amounts of oxidised bromine species in municipal water following disinfection. There was no evidence of further metabolism of the brominated derivative in roach, but a single major metabolite of NP was present in liver and bile, which was identified as the glucuronide conjugate of 4-(hydroxy-nonyl)-phenol. This detection of only one NP metabolite suggests that, in contrast to other fish species, the variety of metabolic pathways available for the deactivation of 4-alkylphenols in roach is limited. This study indicates that brominated alkylphenols bioconcentrate in a range of tissues and, as they have been detected in the aquatic environment, they could contribute to the body burden of alkylphenolics in fish. The formation of these brominated derivatives in aquarium water suggest that they could confound toxicity tests to assess the effects of alkyphenols to aquatic organisms.
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Affiliation(s)
- Michael D Smith
- Centre for Environmental Research, Chichester Building, University of Sussex, Brighton BN19QJ, UK
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19
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Tong W, Xie Q, Hong H, Shi L, Fang H, Perkins R. Assessment of prediction confidence and domain extrapolation of two structure-activity relationship models for predicting estrogen receptor binding activity. ENVIRONMENTAL HEALTH PERSPECTIVES 2004; 112:1249-1254. [PMID: 15345371 PMCID: PMC1277118 DOI: 10.1289/txg.7125] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2001] [Accepted: 07/15/2004] [Indexed: 05/24/2023]
Abstract
Quantitative structure-activity relationship (QSAR) methods have been widely applied in drug discovery, lead optimization, toxicity prediction, and regulatory decisions. Despite major advances in algorithms and software, QSAR models have inherent limitations associated with a size and chemical-structure diversity of the training set, experimental error, and many characteristics of structure representation and correlation algorithms. Whereas excellent fit to the training data may be readily attainable, often models fail to predict accurately chemicals that are outside their domain of applicability. A QSAR's utility and, in the case of regulatory decisions, justification for usage increasingly depend on the ability to quantify a model's potential for predicting unknown chemicals with some known degree of certainty. It is never possible to predict an unknown chemical with absolute certainty. Here we report on two QSAR models based on different data sets for classification of chemicals according to their ability to bind to the estrogen receptor. The models were developed by using a novel QSAR method, Decision Forest, which combines the results of multiple heterogeneous but comparable Decision Tree models to produce a consensus prediction. We used an extensive cross-validation process to define an applicability domain for model predictions based on two quantitative measures: prediction confidence and domain extrapolation. Together, these measures quantify the accuracy of each prediction within and outside of the training domain. Despite being based on large and diverse training sets, both QSAR models had poor accuracy for chemicals within the domain of low confidence, whereas good accuracy was obtained for those within the domain of high confidence. For prediction in the high confidence domain, accuracy was inversely proportional to the degree of domain extrapolation. The model with a larger training set of 1,092, compared with 232 for the other, was more accurate in predicting chemicals at larger domain extrapolation, and could be particularly useful for rapidly prioritizing potential endocrine disruptors from large chemical universe.
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Affiliation(s)
- Weida Tong
- Center for Toxicoinformatics, National Center for Toxicological Research, Food and Drug Administration, Jefferson, Arkansas 72079, USA.
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20
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Affiliation(s)
- Mark T D Cronin
- Liverpool John Moores University, School of Pharmacy and Chemistry, Byrom Street, Liverpool, L3 3AF, UK
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21
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SABA H, NAKANO M. Oxidation of Triacyiglycerol by Laccase-Natural Mediator and Laccase-Mediator Derived from Natural Compound Systems. J Oleo Sci 2003. [DOI: 10.5650/jos.52.159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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22
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Selassie CD, Garg R, Kapur S, Kurup A, Verma RP, Mekapati SB, Hansch C. Comparative QSAR and the radical toxicity of various functional groups. Chem Rev 2002; 102:2585-605. [PMID: 12105936 DOI: 10.1021/cr940024m] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Cynthia D Selassie
- Chemistry Department, Pomona College, 645 North College Avenue, Claremont, California 91711, USA
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Abstract
In this report we consider the effect of substituents on phenol toxicity and show how the parameters used in Quantitative Structure-Activity Relationships (QSAR) can be used to draw mechanistic inferences of value in understanding the reasons behind the various types of toxicity. In particular, we are interested in gaining clearer insight into mechanisms via the Hammett-type parameters sigma, sigma(-), sigma(+) and octanol/water parti tion coefficients. Particular attention is given to the role of radical reactions and their role in attacking DNA to cause cancer or estrogenic toxicity.
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Affiliation(s)
- R Garg
- Chemistry Department, Pomona College, Claremont, CA 91711, USA
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Hansch C, Kurup A, Garg R, Gao H. Chem-bioinformatics and QSAR: a review of QSAR lacking positive hydrophobic terms. Chem Rev 2001; 101:619-72. [PMID: 11712499 DOI: 10.1021/cr0000067] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- C Hansch
- Department of Chemistry, Pomona College, Claremont, California 91711, USA
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25
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Abstract
In this report we discuss some of the surprising ways phenols interact in vivo and how some of their toxic activity can be understood in terms of QSAR and in fact can be related via electronic terms to be similar to processes of simple chemical reactions. A simple two-term QSAR is found to be a good predictor of estrogenic toxicity. However, it is also shown that even the simplest of phenols can yield quite unexpected results than can be elucidated via QSAR. We still have a long way to go before we can predict under what conditions a phenol will produce toxic effects such as cancer and how much phytophenols one can consume before reaping a toxic reaction.
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Affiliation(s)
- R Garg
- Department of Chemistry, Pomona College, 645N College Avenue, Claremont, CA 91711, USA
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26
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Abstract
Many different in vivo and in vitro tests are currently used to assess the toxicity of chemicals and complex mixtures such as cigarette smoke condensate. In vivo tests include assays in rodents to determine carcinogenicity, tumorigenicity and reproductive effects In vitro tests of mutagenicity are conducted with both bacterial and mammalian cell systems. A first step towards lowering the toxicity of cigarette smoke condensate is the identification of the relevant compound However, changing the concentration of a given smoke component may not linearly alter the biological activity of the complex mixture due to interactive effects. The "effective toxicity" of a chemical constituent is a function of the concentration, the metabolic fate, the potency in in vivo and in vitro assays, and the ability to reach the target tissues. The logarithm of the octanol-water partition coefficient (log P) is an important parameter since it affects metabolism, biological transport properties and intrinsic toxicity. Using concentration data from the International Agency for Cancer Research (IARC), biological activity data from the Registry of Toxic Effects of Chemical Substances (RTECS) database and measured and calculated log P values, we have rank ordered some of the important compounds in cigarette smoke condensate by their measured or potential toxicity. Condensates from different cigarette brands, tar categories and styles vary in their concentrations of these compounds. Chemicals of greater commercial or scientific interest may be toxicity tested more extensively, thereby increasing the probability of positive test results and highlighting the need for consideration of structure-activity relationships.
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Affiliation(s)
- C J Smith
- Research and Development, Bowman Gray Technical Center, R.J. Reynolds Tobacco Company, Winston-Salem, NC 27105, USA
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Hansch C, McKarns SC, Smith CJ, Doolittle DJ. Comparative QSAR evidence for a free-radical mechanism of phenol-induced toxicity. Chem Biol Interact 2000; 127:61-72. [PMID: 10903419 DOI: 10.1016/s0009-2797(00)00171-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Phenol and 14 substituted-phenols were tested for their ability to impair epithelial cell membrane integrity in WB rat liver cells as determined by an increase in lactate dehydrogenase release. Two quantitative structure-activity relationship (QSAR) regression equations were developed which showed that separate mechanisms of phenolic cytotoxicity are important - nonspecific toxicity due to hydrophobicity and formation of phenoxyl radicals. The equations most predictive of phenol toxicity are denoted as log1/C=-0. 98sigma(+)+0.77logP+0.23 or log1/C=-0.11BDE+0.76logP+0.21, respectively, where C is the minimum concentration of substituted-phenol required for a toxic response. P is the octanol-water partition coefficient, sigma(+) is the electronic Hammett parameter and BDE is the OH homolytic bond dissociation energy. In the literature, phenol toxicity correlated to sigma(+) is rare, but there is strong evidence that phenols possessing electron-releasing groups may be converted to toxic phenoxyl radicals. A common feature in a variety of cells is generation of elevated amounts of reactive oxygen species (ROS) associated with a rapid growth rate. The slightly elevated cancer risk associated with the use of Premarin may be due to phenoxyl-type radicals derived from one or more of its components.
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Affiliation(s)
- C Hansch
- Department of Chemistry, Pomona College, Claremont, CA, USA
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Selassie CD, DeSoyza TV, Rosario M, Gao H, Hansch C. Phenol toxicity in leukemia cells: a radical process? Chem Biol Interact 1998; 113:175-90. [PMID: 9717517 DOI: 10.1016/s0009-2797(98)00027-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The multiple functions of the phenol moiety that are widely present in disparate sources such as drugs, pesticides, teas, fuel additives and surfactants have not been clearly delineated. The differences in behavior of phenols, which run the gamut from aberrations in DNA/chromosomes to suppression of genotoxic activity of carcinogenic compounds, merit further attention. In this study, a through examination of the growth inhibition patterns of 37, simple 3- and 4-substituted phenols in mouse leukemia cells was carried out and the following quantitative structure-activity relationship (QSAR) was obtained for the 23 electron releasing substituents in X-phenols: log 1/IC50 = -1.58 sigma(+) +0.21 log P + 3.10. In this QSAR, IC50 is the concentration of phenol that induces 50% inhibition of growth. P is a measure of the hydrophobicity of each phenol and Brown's electronic parameter, sigma+, represents the electronic effect of the substituent. The negative dependence on sigma+ is strongly reminiscent of what is observed in the developmental toxicity of phenols on rat embryos as well as for the radical abstraction of a hydrogen atom from phenolic groups. The other 15 electron-attracting substituted X-phenols clearly show a linear dependence on hydrophobicity alone: Log 1/IC50 = 0.62 log P + 2.35. The bifurcation in mechanism of action of this large set of diverse phenols is novel and unusual. It suggests that two distinct processes are operative. In the case of electron releasing substituted phenols, the observations are not inconsistent with a radical mediated process while with electron attracting substituted phenols, non-specific toxicity as modulated by hydrophobicity, appears to predominate.
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Affiliation(s)
- C D Selassie
- Chemistry Department, Pomona College, Claremont, CA 91711, USA.
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29
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Hansch C, Gao H. Comparative QSAR: Radical Reactions of Benzene Derivatives in Chemistry and Biology. Chem Rev 1997; 97:2995-3060. [PMID: 11851484 DOI: 10.1021/cr9601021] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Corwin Hansch
- Department of Chemistry, Pomona College, Claremont, California 91711
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30
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Ghanooni M, Mattison DR, Zhang YP, Macina OT, Rosenkranz HS, Klopman G. Structural determinants associated with risk of human developmental toxicity. Am J Obstet Gynecol 1997; 176:799-805; discussion 805-6. [PMID: 9125603 DOI: 10.1016/s0002-9378(97)70603-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES Identifying drugs or chemicals that represent hazards to human development is a continuous challenge. Of the approximately 60,000 chemicals in commercial use only 5% have been evaluated for developmental toxicity. Identification of inexpensive, rapid, validated techniques to demonstrate chemical hazards for the human embryo or fetus is the objective of this research. STUDY DESIGN This research explored identification of structure activity predictors associated with human developmental toxicity by means of MULTICASE (multiple computer-automated structure evaluation), an algorithm that evaluates associations between chemicals and their constituent fragments and a biologic response. This algorithm allows identification of chemicals (and specific substructures) that may be human developmental toxicants. Developmental toxicity data were compiled from two sources (the Teratogen Information System and Food and Drug Administration guidelines) and analyzed to identify structural determinants (biophores) associated with human developmental toxicity. RESULTS This analysis identified 17 biophores associated with human developmental toxicity. Testing the biophores against the learning set demonstrated 99% concordance, 100% sensitivity, and 98% specificity. Cross-validation studies were conducted, in which the original database was randomly separated into five learning and test sets; these demonstrated a mean concordance of 73%, with a mean sensitivity of 63% and a mean specificity of 79%. CONCLUSIONS The MULTICASE structure-activity model is useful for identifying potential human developmental toxicants, as well as serving as a starting point for mechanistic investigations.
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Affiliation(s)
- M Ghanooni
- Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, PA 15261, USA
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31
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Richard AM, Hunter ES. Quantitative structure-activity relationships for the developmental toxicity of haloacetic acids in mammalian whole embryo culture. TERATOLOGY 1996; 53:352-60. [PMID: 8910981 DOI: 10.1002/(sici)1096-9926(199606)53:6<352::aid-tera6>3.0.co;2-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Developmental toxicity in mouse whole embryo culture assay has been reported for acetic acid (AA) and a series of ten haloacetic acids, including mono-, di-, tri-fluoro (MFA, DFA, TFA), chloro (MCA, DCA, TCA), bromo (MBA, DBA, TBA), and monoiodo (MIA) acetic acids. Benchmark concentrations (BCm), calculated as the lower 95% confidence limit of molar acid concentration producing a 5% increase in embryos with neural tube defects, provided potency estimates for development of quantitative structure-activity relationships (QSARs). The best overall regression was obtained for the ten halo-acids (excluding AA) and related log (1/BCm) to the energy of the lowest unoccupied molecular orbital (Elumo) and acid dissociation constant (pKa) with a correlation coefficient of r = 0.97, and a sample size-adjusted r2 = 0.92. This QSAR suggested a common basis for the mechanism of HA activity, which would imply additivity for mixtures of these acids. Examination of QSARs for subsets of the total data set (e.g., monohaloacids) highlighted parameter relationships embedded in the total QSAR, helping to unravel the separate contributions of Elumo and pKa to the overall potency. The relevance of these parameters is discussed in terms of postulated mechanisms of developmental toxicity involving changes in intercellular pH and redox metabolism. The whole embryo assay results pertain to direct embryo exposure and toxicity without the confounding influence of maternal factors. The resulting QSAR model offers possible insight into the mechanism of embryo toxicity that will hopefully contribute to understanding of the more complex, in vivo teratogenicity problem.
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Affiliation(s)
- A M Richard
- National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA
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Karelson M, Lobanov VS, Katritzky AR. Quantum-Chemical Descriptors in QSAR/QSPR Studies. Chem Rev 1996; 96:1027-1044. [PMID: 11848779 DOI: 10.1021/cr950202r] [Citation(s) in RCA: 939] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mati Karelson
- Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, P.O. Box 117200, Gainesville, Florida 32611-7200
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33
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Hansch C, Hoekman D, Gao H. Comparative QSAR: Toward a Deeper Understanding of Chemicobiological Interactions. Chem Rev 1996; 96:1045-1076. [PMID: 11848780 DOI: 10.1021/cr9400976] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Corwin Hansch
- Department of Chemistry, Pomona College, Claremont, California 91711
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Hansch C, Zhang L. Comparative QSAR: radical toxicity and scavenging. Two different sides of the same coin. SAR AND QSAR IN ENVIRONMENTAL RESEARCH 1995; 4:73-82. [PMID: 8765903 DOI: 10.1080/10629369508029905] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
From an analysis of the toxicity of phenols to rat embryos and anilines to embryo fibroblast cells a new type of toxicity is postulated for these classes of compounds. Substituents which increase the electron density on the aromatic ring as estimated by sigma + or epsilon HOMO increase potency. It is postulated that it is the radical form of the phenols and the anilines that accounts for their toxicity. The results are compared with QSAR for radical scavengers and oxidoreductases acting on phenols, anilines and carbazoles.
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Affiliation(s)
- C Hansch
- Chemistry Department, Pomona College, Claremont, California 91711-6338, USA
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