Copper(II) complexes of a hydroxamic acid from maize

Hiriart, Maria V.; Corcuera, Luís J.; Andrade, Carlos; Crivelli, Irma

doi:10.1016/s0031-9422(00)83092-7

Cited by 17 publications

(6 citation statements)

References 18 publications

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“…In the following five measure- ments, plants released on average 43.5 ( 7.5% lower amounts of Bx (Figure 6). Diurnal rhythms are well-known for the phytosiderophores of poaceous species (37,62,63), and there might be a regulative link, since Bx can also act as a chelator for iron and copper (64,65). For the phytosiderophores, it is suggested that the diurnal rhythm indicates a controlled release mechanism (37).…”

Section: Resultsmentioning

confidence: 99%

Differential Exudation of Two BenzoxazinoidsOne of the Determining Factors for Seedling Allelopathy of Triticeae Species

Belz

Hurle

2004

J. Agric. Food Chem.

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Benzoxazinoids (Bx) are natural phytotoxins that function as chemical defense compounds in several species. The release of Bx by intact plant roots associated these compounds with root allelopathy in Triticeae species; however, the significance of exudate concentrations of Bx for plant-plant interactions is still a controversial question. A biological screening of 146 cultivars of four Triticeae species (Triticum aestivum L., Triticum durum Desf., Triticum spelta L., and Secale cereale L.) demonstrated a high cultivar dependence to suppress the root growth of Sinapis alba L. by root allelopathy in a dose-response bioassay. Only a few cultivars possessed a marked high or low allelopathic activity, whereby high-performance liquid chromatography-diode array detection analysis of root exudates revealed that these cultivars differed considerably in their ability to exude the two Bx aglucones, DIBOA [2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one] and DIMBOA [2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one]. The total amount of DIBOA and DIMBOA exuded showed a significant correlation to the growth inhibition in bioassay with a statistically estimated contribution to the overall allelopathic effect of 48-72%. In a bioassay with pure phytotoxins, Bx concentrations consistent with the amounts quantified in the screening bioassay caused detrimental effects on S. alba and almost reproduced the statistically estimated contribution. The observed causal association between the allelopathic activity under laboratory conditions and the exudate concentrations of Bx suggests that this association might have implications for the interference of Triticeae species in natural plant communities.

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Section: Resultsmentioning

confidence: 99%

Differential Exudation of Two BenzoxazinoidsOne of the Determining Factors for Seedling Allelopathy of Triticeae Species

Belz

Hurle

2004

J. Agric. Food Chem.

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“…The values in Table 1 are consistent with hydroxamic acid acidity in general, and they are also in good agreement with the related literature data. [31][32][33][34][35][36][37][38] Evaluation of the effects of C-and N-substituents on the acidity of the hydroxamic acid group leads to the conclusion that the pK a increases slightly in the series Aha > Pha > Hha. The differences in the electronics result in more definite changes in the acidity of the secondary hydroxamic acids.…”

Section: Resultsmentioning

confidence: 99%

Thermodynamic Studies on the Protonation Equilibria of Some Hydroxamic Acids in NaNO₃ Solutions in Water and in Mixtures of Water and Dioxane

Fazary¹

2005

J. Chem. Eng. Data

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The protonation equilibria for nine hydroxamic acids in solutions have been studied pH-potentiometrically via a modified Irving and Rossotti technique. The dissociation constants (pK a values) of hydroxamic acids and the thermodynamic functions (ΔG°, ΔH°, ΔS°, and δ) for the successive and overall protonation processes of hydroxamic acids have been derived at different temperatures in water and in three different mixtures of water and dioxane (the mole fractions of dioxane were 0.083, 0.174, and 0.33). Titrations were also carried out in water ionic strengths of (0.15, 0.20, and 0.25) mol dm-3 NaNO3, and the resulting dissociation constants are reported. A detailed thermodynamic analysis of the effects of organic solvent (dioxane), temperature, and ionic strength on the protonation processes of hydroxamic acids is presented and discussed to determine the factors which control these processes.

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“…Benzoxazinoid hydroxamic acids are strong chelating agents , . When DIMBOA-iron and DIBOA-iron chelates were supplied in the hydroponic growth medium of maize, rice and oat seedlings presenting iron-deficiency chlorotic symptoms, the chelates were taken up by plant tissues and the chlorotic symptoms eventually disappeared .…”

Section: Other Ecological Roles Of Benzoxazinoid Hydroxamic Acidsmentioning

confidence: 99%

Hydroxamic Acids Derived from 2-Hydroxy-2H-1,4-Benzoxazin-3(4H)-one: Key Defense Chemicals of Cereals

Niemeyer

2009

J. Agric. Food Chem.

389

436

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Many cereals accumulate hydroxamic acids derived from 2-hydroxy-2H-1,4-benzoxazin-3(4H)-one. These benzoxazinoid hydroxamic acids are involved in defense of maize against various lepidopteran pests, most notably the European corn borer, in defense of cereals against various aphid species, and in allelopathy affecting the growth of weeds associated with rye and wheat crops. The role of benzoxazinoid hydroxamic acids in defense against fungal infection is less clear and seems to depend on the nature of the interactions at the plant-fungus interface. Efficient use of benzoxazinoid hydroxamic acids as resistance factors has been limited by the inability to selectively increase their levels at the plant growth stage and the plant tissues where they are mostly needed for a given pest. Although the biosynthesis of benzoxazinoid hydroxamic acids has been elucidated, the genes and mechanisms controlling their differential expression in different plant tissues and along plant ontogeny remain to be unraveled.

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Copper(II) complexes of a hydroxamic acid from maize

Cited by 17 publications

References 18 publications

Differential Exudation of Two BenzoxazinoidsOne of the Determining Factors for Seedling Allelopathy of Triticeae Species

Differential Exudation of Two BenzoxazinoidsOne of the Determining Factors for Seedling Allelopathy of Triticeae Species

Thermodynamic Studies on the Protonation Equilibria of Some Hydroxamic Acids in NaNO₃ Solutions in Water and in Mixtures of Water and Dioxane

Hydroxamic Acids Derived from 2-Hydroxy-2H-1,4-Benzoxazin-3(4H)-one: Key Defense Chemicals of Cereals

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Copper(II) complexes of a hydroxamic acid from maize

Cited by 17 publications

References 18 publications

Differential Exudation of Two BenzoxazinoidsOne of the Determining Factors for Seedling Allelopathy of Triticeae Species

Differential Exudation of Two BenzoxazinoidsOne of the Determining Factors for Seedling Allelopathy of Triticeae Species

Thermodynamic Studies on the Protonation Equilibria of Some Hydroxamic Acids in NaNO3 Solutions in Water and in Mixtures of Water and Dioxane

Hydroxamic Acids Derived from 2-Hydroxy-2H-1,4-Benzoxazin-3(4H)-one: Key Defense Chemicals of Cereals

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Thermodynamic Studies on the Protonation Equilibria of Some Hydroxamic Acids in NaNO₃ Solutions in Water and in Mixtures of Water and Dioxane