The Synthesis of Precursor II of Benzoxazolinone Formed in Rye Plants, and the Enzymic Hydrolysis of Precursor I, the Glucoside.

Honkanen, Erkki; Virtanen, Artturi I.; Tweit, Robert C.; Dodson, R. M.

doi:10.3891/acta.chem.scand.14-0504

Cited by 45 publications

(19 citation statements)

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“…The extinction coefficient of DIMBOA (E262 = 10,000) was determined in this study. The extinction coefficients for DIBOA (E2U = 8,500) and HBOA (E20 = 8,900) were those reported by Honkanen and Virtanen (9 RESULTS AND DISCUSSION Chromatograms of an extract from maize inbred Oh45 are shown in Figure I (DC-l 1) and Figure 2 (OV-17). Structural assignments for the peaks were made by GLC-MS and/or cochromatography (26 Id BSTFA, heated to 65 to 70 C for 20 min and 2-,ul portions were injected (Fig.…”

Section: Methodsmentioning

confidence: 94%

Quantitation of 1,4-Benzoxazin-3-ones in Maize by Gas-Liquid Chromatography

Woodward¹,

Corcuera²,

Helgeson³

et al. 1979

Plant Physiol.

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A gas-liquid chromatographic (GLC) procedure is reported for the quantitation of the trimethylsilyl (TMS) derivatives of substituted 2-hydroxy-2H-1,4-benzoxazin-3(4H)-ones (2-hydroxy-2H-1,4-benzoxazin-3(4H)-one(HBOAI; 2-hydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-onelHMBOAI;2,4dihydroxy-2H-1,4-benzoxazin-3(4H)-oneIDIBOAI;2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-onelDIMBOAI; and 2,4-dihydroxy-7,8-dimethoxy-2H-1,4-benzoxazin-3(4H)-oneIDIM2BOAI) Cyclic hydroxamic acids are known to occur in maize, wheat, and other members of the Gramineae (2,(6)(7)(8)23). The most abundant hydroxamate in aqueous extracts of maize is DIMBOA5 (11,13). This compound and its degradation product, MBOA, have been reported to be important in resistance of plants to insects (12, 14) and to some plant pathogens (4,16,17,22 The only procedure previously described for the direct quantitation of hydroxamates in plant extracts is based on the colorimetric absorption of a hydroxamic acid-ferric chloride complex (3,5,15,20). This procedure does not differentiate between the different hydroxamates in extracts, nor does it measure the structurally analogous lactams that also are present in maize extracts. We now report the development of a GLC procedure for the quantitation of individual cyclic hydroxamic acids and their lactam analogs in aqueous maize extracts. A preliminary report of this work has been presented (24). MATERIALS AND METHODSMost GLC analyses were performed with a Hewlett-Packard model 7620A gas chromatograph6 equipped with flame ionization detectors. Each column was all glass (2.0 m x 2 mm), contained 2% DC-l 1 as liquid phase on 80 to 100 mesh Gas-chrom Q, and was operated independently. The He carrier gas flow rate was 50 ml/min (measured at the detector). Air and H2 flow rates were 400 and 26 ml/min, respectively. The injection port and detector were maintained at 280 C. Oven temperature was 105 C for 15 min and then increased at 2 C/min to 165 C. Additional analyses were made with a Varian Aerograph series 1800 gas chromatograph also equipped with flame ionization detectors. Analyses were performed using a glass column (1.8 m x 2 mm) containing 3% OV-17 on 80-100 mesh Gas-chrom Q. The N2 carrier gas flow rate was 28 ml/min and the H2 and air flows were 27 and 400 ml/min, respectively. The injection port was maintained at 300 C and the detector at 290 C. Oven temperature was 170 C for 3 min followed by increases in 3 C/min for

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Section: Methodsmentioning

confidence: 94%

Quantitation of 1,4-Benzoxazin-3-ones in Maize by Gas-Liquid Chromatography

Woodward¹,

Corcuera²,

Helgeson³

et al. 1979

Plant Physiol.

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“…The compounds were eluted from the column with an acetic acid water mixture (1:9, v/v). Benzoxazinone concentrations were determined using extinction coefficients of E254 = 8850 for DIBOA and E5(0 = 8850 for HBOA (6). 5Mention of trademark, proprietary product, or vendor does not constitute a guarantee of warranty by the U.S. Department of Agriculture or the University of Missouri and does not imply approval to the exclusion of other products or vendors that may also be suitable.…”

Section: Standard and Reaction Product Identificationmentioning

confidence: 99%

“…The chemicals used were commercially available except for DIBOA which was extracted as previously described from Frederick rye (1) and HBOA which was synthesized using the methods of Honkanen and Virtanen (6).…”

Section: Chemicalsmentioning

confidence: 99%

Maize Microsomal Benzoxazinone N-Monooxygenase

Bailey

Larson²

1991

Plant Physiol.

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The benzoxazinones occur in hydroxamic acid and lactam forms in maize (Zea mays L.) tissue. The hydroxamic acid forms which possess a N-hydroxyl group are found in the highest concentration while the lactam members which lack the N-hydroxyl group occur in lower concentrations. The hydroxamic acid 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) has as its lactam counterpart 2-hydroxy-1,4-benzoxazin-3-one (HBOA). An enzyme has been identified in maize microsomal preparations which catalyzes the N-hydroxylation of HBOA to form DIBOA. The enzyme is initially observed in seedlings 2 days after imbibition which coincides with the onset of hydroxamic acid accumulation. The enzyme requires NADPH and is inhibited by sulfhydryl reagents, NADP, cytochrome c, cations, carbon monoxide, and nitrogen gas. The effect of nitrogen can be reversed by exposing the enzyme to air, while the effect of carbon monoxide can be reversed by exposing the enzyme to 450 nanometer light during the incubation period. The apparent Km values for HBOA and NADPH are 13 and 5 micromolar, respectively. The pH optimum is 7.5 and the temperature optimum for the enzyme is 35°C. A 450 nanometer absorbance peak is observed when reduced microsomal preparations are exposed to carbon monoxide which in combination with other data presented supports the hypothesis that the enzyme is a cytochrome P-450 dependent Nmonooxygenase.

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“…Some benzohydroxamic acids isolated from plants such as 2,4-dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one, known as DIBOA, and 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxacin-3(4H)-one, known as DIMBOA (Honkanen and Virtanen 1960;Hamilton et al 1962), exhibit a variety of interesting biological activities as phytotoxic properties, antimicrobial activity as well as antifeedant, antifungal and insecticidal properties (Duke 1986;Macías et al 2006aMacías et al , 2008Macías et al , 2009.…”

Section: Introductionmentioning

confidence: 99%