Augmented Multivariate Image Analysis Applied to Quantitative Structure–Activity Relationship Modeling of the Phytotoxicities of Benzoxazinone Herbicides and Related Compounds on Problematic Weeds

Abstract

Two of major weeds affecting cereal crops worldwide are Avena fatua L. (wild oat) and Lolium rigidum Gaud. (rigid ryegrass). Thus, development of new herbicides against these weeds is required; in line with this, benzoxazinones, their degradation products, and analogues have been shown to be important allelochemicals and natural herbicides. Despite earlier structure-activity studies demonstrating that hydrophobicity (log P) of aminophenoxazines correlates to phytotoxicity, our findings for a series of benzoxazinone derivatives do not show any relationship between phytotoxicity and log P nor with other two usual molecular descriptors. On the other hand, a quantitative structure-activity relationship (QSAR) analysis based on molecular graphs representing structural shape, atomic sizes, and colors to encode other atomic properties performed very accurately for the prediction of phytotoxicities of these compounds against wild oat and rigid ryegrass. Therefore, these QSAR models can be used to estimate the phytotoxicity of new congeners of benzoxazinone herbicides toward A. fatua L. and L. rigidum Gaud.

Ten Years of the MIA-QSAR Strategy

“…These molecular descriptors (MDs) were successfully used in the modeling of numerous bioactivities such as: affinity to the dopamine D 2 receptor subtype (Freitas, Brown, & Martins, 2005), glycogen synthase kinase 3 (GSK-3) inhibitors (Goodarzi, Freitas, & Jensen, 2009), antimalarials (Cormanich, Freitas, & Rittner, 2011;Goodarzi & Freitas, 2011), anxiolytic agents receptor antagonists] (Bitencourt & Freitas, 2008), HIV reverse transcriptase inhibitors (Freitas, 2006;Goodarzi & Freitas, 2008;Goodarzi & Freitas, 2010a), phosphodiesterase type 5 (PDE-5) inhibitors (Antunes, Freitas, & Rittner, 2008), antifungals , peptides for treatment of dengue (Silla et al, 2011), anti-inflammatory agents (Lloret et al, 2009) and acetylcholinesterase inhibitors (Bitencourt, Freitas, & Rittner, 2012), among others. The traditional MIA-QSAR descriptors did not only find utility in the modeling of bioactivity endpoints; applications in spectroscopy (in the prediction of 13 C chemical shifts) (Goodarzi, Freitas, & Ramalho, 2009) and agrochemistry (in the modeling of the phytotoxicity and soil sorption profiles of herbicides) may be found in the literature (Bitencourt & Freitas, 2008;Freitas, Matias, Macedo, Freitas, & Venturin, 2013;Goodarzi & Freitas, 2010b). These results demonstrate the utility of these MDs in codifying relevant chemical structure information.…”

Coloured chemical image-based models for the prediction of soil sorption of herbicides

“…This is known as the aug-MIA-QSPR default approach and has been shown to adequately predict the phytotoxicity of some benzoxazinone herbicides and derivatives. 7 However, in this study, the atom colours were spotlighted to give a three-dimensional insight, causing a variation in the pixel values within the radius of the same atom. The presence of different pixel values for the same atom obliterates the one-toone correspondence of the colours to the atoms, thus making the interpretation of the ensuing models difficult.…”

Design, Synthesis, and Bioactivity of Eighteen Novel 2H‐1,4‐Benzoxazin‐3(4H)‐one Containing a Propanolamine Moiety

“…[8,9] The biological activity of heterocyclic compounds is an important focus in the exploration of new inhibitory backbone templates. Considerable research has been carried out on 2H-1,4-benzoxazin-3(4H)-one in the medical field, while related pesticides have exhibited antifungal, [10,11] antibacterial, [12 -14] herbicidal, [15,16] anticancer, [17,18] antitumor, [19] antileukaemia, [20] antagonist, [21] antioxidant, [22] and platelet aggregation inhibitor activities [23] (Figure 1). Moreover, many reports demonstrate that compounds containing propanolamine moiety have wide-ranging biological activities, including antifungal, [24] antibacterial, [25,26] anti-HIV, [27] anticancer [28] and antihypertensive [29] properties.…”