DIMBOA glucoside

Effects of Gramine, DIMBOA and DIMBOA-Glucoside on ScfUzaph-Ci gAxmcnum feeding on artificial diets... 

Oikawa, A., Ebisui, K., Sue, M., Ishihara, A., and Iwamura, H. 1999. Purification and characterization of a p-glucosidase specific for 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) glucoside in maize. Z. Naturforsch. C Biosci. 54, 181-185... 

Both DIMBOA and DIMBOA glucoside inhibit photo-phosphorylation by spinach chloroplasts (Queirolo et al., 1981). DIMBOA is a potent inhibitor of cyanide-insensitive respiration in potato mitochondria (Hediger and Seigler, unpublished data). 

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... 

Hence, the plant own defensive system is able to liberate a toxic, bioactive weapon from a non-toxic precursor very rapidly and in appreciable amounts, because of the benzoxazinone glucoside content in seedlings can reach concentrations between 1-10 mmoles per kg of fresh weight [85,86]. E.g., 530 mg of DIMBOA have been isolated from 1 kg of frozen maize shoots [79]. 

As a result of the chemical degradation accompanied by the loss of formic acid (substituted) benzoxazolin-2(3/i)-ones are formed in a ring contraction reaction. The half life of DIMBOA in the juice of injured maize cells is about one day [74]. In fact, it was from this end of the cascade that benzoxazinoid acetal glucosides were detected starting with the discovery of benzoxazolin-2(3/f)-one (BOA) from rye [87]. Meanwhile, several substituted benzoxazolin-2(3/7)-ones (Fig. (5)) have been found in plants. 

Methoxybenzoxazolinone has been used pharmacologically too. In China, roots of Coix lachryma jobi L. var. ma-yuen Stapf were applied to therapy inflammation, rheumatism and neuralgia. From the roots, MBOA, DIMBOA and DIMBOA-glc have been isolated [51]. MBOA and DIMBOA, but not the glucoside were found to possess anti-inflammatory properties. ConA-stimulated histamine release by rat mast cells was... 

A series of hydroxamic acid derivatives with 4-hydroxy-l,4-benzoxazin-3-one structures occur in a number of cereal grain species (Poaceae or Gramineae) (Fig. 7.8) (Niemeyer, 1988). These compounds usually occur in plants as the 2-3-(9-D-glucosides enzymes that hydrolyze the compounds usually co-occur. DIBOA [2,4-dihydroxy-1,4(2H)-benzoxazin-3-one] (22) is the major compound in rye and DIMBOA [2,4-dihydroxy-7-methoxy-1,4(2H)-benzoaxa-... 

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