DIBOA

Ruiz, and P. Castanera. A high performance liquid chromatography method for quantification of diboa, dimboa and mboa from aqueous extracts of corn HV047 and winter cereal plants. J Liq Chro-matogr 1994 17(12) 2651-2665. 

HVlOl Barria, B. N., S. V. Cpaj, and H. M. HV113 Niemeyer. Occurrence of Diboa in wild Hordeum species and its relation to Aphid resistance. Phytochemistry 1992 31(1) 89-91. 

Enzymatic and chemical degradation of the benzoxazinoid acetal glucoside DIBOA-GIc. 

DIBOA-GIc H H Secale cereale (Poaceae)34 Triticum aestivum (Poaceae)41 Consolida orientaiis (Ranunculaceae)60 Acanthus mollis (Acanthaceae)84 Acanthus ebracteatus (Acanthaceae)43... 

DIBOA H H Secale cereale79 Saccharum officinale (Poaceae)48 Triticum aestivum16... 

Two reviews cover the whole synthetic literature in the field until 1997.1,67 Suitable syntheses for the main aglucones DIBOA68 and DIMBOA64 74 have been reported, as well as a general diastereoselective glucosidation method to form DIBOA-GIc, DIMBOA-GIc and other benzoxazinone glucosides.46... 

Adapted species may have developed, however, strategies which enable them to survive allelopathic attacks. One of those strategies certainly includes detoxification of absorbed allelochemicals by constitutive or inducible pathways. Metabolization and detoxification are known reactions in a number of crops upon application of diverse synthetic herbicides.38 Enhanced herbicide detoxification is an important factor in the development of nontarget-site cross-resistance and multiple resistance. It is reasonable to expect comparable strategies in plants that are relatively resistant to allelochemicals such as DIBOA, DIMBOA, and their derivatives. Especially in ecosystems where co-existing species have to be adapted to each other, detoxification of absorbed allelochemicals may play a crucial role under defined circumstances. 

Yenish, J. P., Worsham, A. D. and Chilton, W. S., 1995. Disappearance of DIBOA-glucoside, DIBOA, and BOA from rye (Secale cereale L.) cover crop residue. Weed Sci. 43, 18-20... 

Similar results were observed in a more recent work10 when BOA, DIBOA, and rye extract activities were studied. The results showed that BOA and DIBOA inhibit germination only in the small- to medium-seeded species Amaranthus palmeri, Digitaria sanguinalis, Echinochloa indica, Lactuca sativa, and Lycopersicon esculentum. Large-seeded crops, including cucurbits and Zea mays,... 

Focusing on the mechanisms of action of BOA into the plant cell, Barnes et al.7 suggested that the chlorotic seedlings observed in the presence of BOA and DIBOA could be the consequence of a benzoxazinone effect on the photophosphorylation and electron transport into the plant metabolism. In this way, Niemeyer et al.28 studied the effects of BOA on energy-linked reactions in mitochondria and reported an inhibition of the electron transfer between flavin and ubiquinone in Complex I, with complete inhibition of electron transport from NADH to oxygen in SMP. They could also detect an inhibition of BOA on ATP synthesis by acting directly on the ATPase complex at the F1 moiety. 

ATPase activity was also studied by Friebe et al. in 1997.17 They correlated the BOA and DIBOA effects on radicle elongation of Avena sativa seedlings with their effects on the activity of plasma membrane H+-ATPase from roots of Avena sativa cv. Jumbo and from Vida faba cv. Alfred. They hypothesized that an alteration in the plasma membrane ATPase activity could be the reason for an abnormal nutrient absorption in plants exposed to hydroxamic acids, because of the role that this enzyme plays in the ion gradient and, therefore, in the ionic transport through plasma membrane. The results of this experiment showed a strong inhibition in the activity of this enzyme in the plasma membrane of chloroplast and mitochondria when it was exposed to BOA and DIMBOA. This alteration implies early interactions with the assayed hydroxamic acids. 

GDIBOA DIBOA-GIc OH H H Secale cereale (Poaceae) [2,34-37] Triticum aesttvum (Poaceae) [3638-41] Consolida orienlalis (Ranunculaceae) [42] Acanthus mollis (Acanthaceae) (43]... 

DIBOA OH H H Secale cereale (Poaoeae) [1,34,35,65-67] Saccharum officinale (Poacea) [38] Triticum aeslivum (Poaceae) [16-18,39-41,68] Zea mays (Poaceae) [60,69] Hordeum vulgare (Poaceae) [25] Agropyron repens (Poaceae) [63,70] Acanthus mollis (Acanthaceae) [43] Aphelandra tetragona (Acanthaceae) [71] Consolida orientalis (Ranunculaceae) [42]... 

Due to the existence of additional four chiral centres to the anomeric centre a- and p-D-glucose are diastereomers and can be analytically distinguished and separated, easily. It shall be pointed out, that the same process has not been investigated yet on the level of enantiomeric cyclohemiacetals, which have no chiral centre besides the anomeric one. Therefore, hemiacetals like DIBOA or DIMBOA have also been of interest from the viewpoint of physical organic chemistry (Fig. (6)). 

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