Showing papers in "Journal of Agricultural and Food Chemistry in 1973"

A century of DDT.

Abstract: Wohl keine andere synthetische Verbindung hat das Leben des Menschen und seine Umwelt so stark beeinflust, wie das 1874 erstmals synthetisierte DDT (I) dessen insekticide Wirksamkeit erst 65 Jahre spater und dessen okologische Schadwirkungen erst in jungster Zeit erkannt wurden.

Chromium in plants: distribution in tissues, organelles, and extracts and availability of bean leaf Cr to animals

Abstract: Chromium-51-labeled Cr(III) or Cr(VI) was added in seven increments to plant nutrient solutions, to a final level of 0.044 ppm. The Cr was added over a 14-day period at flowering stage in bean and wheat plants. At maturity bean plants contained about 55% and wheat had removed 81% of the added /sup 51/Cr. Bean roots contained about 92% and wheat roots 95% of the total plant /sup 51/Cr. Seeds contained only 0.02 to 0.1% of the total plant /sup 51/Cr. Uptake and translocation of /sup 51/Cr differed only slightly between the Cr(III) and Cr(VI) sources. Most of the /sup 51/Cr in fresh bean leaves was present as a soluble low molecular weight anionic complex that was not associated with any subcellular organelle. Rats fed the /sup 51/Cr-labeled bean leaves retained less than 0.5% of the dose after 48 hr.

Relationship between tannin levels, rat growth, and distribution of proteins in sorghum.

Abstract: Three high tannin varieties of sorghum gave significantly lower growth responses in weaning rats when compared with three low tanning varieties. Whole kernel and hand-separated endosperms were fractionated by the Landry and Moureaux method to yield five soluble fractions...

Chromium in foods in relation to biological activity.

Abstract: Chromium was determined in foods and in extracts of selected samples of foods using modification of the colorimetric procedure to stabilize color development. Extracts were prepared both by hydrolysis of samples to obtain total chromium and by alcohol extraction. Biological activities of these extracts were determined using the glucose oxidation procedure in the presence of insulin. No significant relationship was found between total chromium and biological activity. However, there was a significant relationship for chromium in alcohol extracts of meats, fungi, seeds, and seafoods, excluding fruits and vegetables. A proposed evaluation of the foods was based on these data.

Atrazine metabolism in sorghum: catabolism of the glutathione conjugate of atrazine.

Abstract: The major pathway of atrazine metabolism in intact sorghum was shown to involve the following steps: atrazine 'right arrow' S-(4-ethylamino-6-isopropylamino-1,3,5-triazin-2-yl)glutathione 'right arrow' gamma -glutamyl-S-(4-ethylamino-6-isopropylamino-1,3,5-triazin-2-yl)cysteine 'right arrow' S-(4-ethylamino-6-isopropylamino-1,3,5-triazin-2-yl cysteine 'right arrow' N-(4-ethylamino-6-isopropylamino-1,3,5-triazin-2-yl)cysteine 'right arrow' N-(4-ethylamino-6-isopropylamino-1,3,5-triazin-2-yl)lanthionine. From 40 to 87% of the atrazine entering sorghum through the roots was estimated to be metabolized via this pathway. Evidence indicated that atrazine can also be metabolized via this route after first undergoing N-dealkylation. The step involving conversion from the S- to the N-cysteine conjugate was shown to be a non-enzymatic rearrangement. This is the first reported occurrence of S-(4-ethylamino-6-isopropylamino-1,3,5-triazin-2-yl)cysteine, the lanthionine conjugate, 2-hydroxy-4-amino-6-isopropylamino-1,3,5-triazine and 2-hydroxy-4,6-diamino-1,3,5-triazine (ammeline) in sorghum. Structural formulae for these compounds and the metabolic pathway are shown. From summary