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A Kelman

Publications and source records attributed to A Kelman.

23 records · Page 2Linked to original sources
PubMed1978

2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one, an Inhibitor from Zea mays with Differential Activity against Soft Rotting Erwinia Species.

[2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one] DIMBOA was extracted with ethyl acetate from acidified water homogenates of corn (Zea mays L.) seedlings. Pure DIMBOA or ethyl acetate extracts of corn tissue were added to bacterial growth medium at five concentrations (measured as hydroxamates). DIMBOA and corn extracts were more inhibitory to soft rot bacteria (Erwinia spp.) that are nonpathogenic to corn than to soft rot bacteria that are corn pathogens. The inhibitory activity of DIMBOA was similar to that of the ethyl acetate extracts. Both corn extracts and DIMBOA prolonged the lag phase of bacterial growth without significantly changing log phase growth rates. At various concentrations of the inhibitor, 50 to 100% of the activity of corn extracts inhibitory to different bacterial isolates was attributable to DIMBOA. Extracts of DIMBOA-deficient plants (genotype bxbx) were not inhibitory to Erwinia spp. It was concluded that DIMBOA is the major active component in those corn extracts which are inhibitory to soft rot Erwinia species.

Journal Article↗
PubMed1978

Factors That Influence the Activity of 2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one on Erwinia Species in Growth Assays.

Factors affecting the inhibitory activity of 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) against Erwinia carotovora, a nonpathogen of Zea mays L., and against a maize pathovar of Erwinia chrysanthemi (ECZ) were examined. Most experiments were performed with DIMBOA dissolved in a bacterial growth medium containing 10 g/liter of sucrose, inorganic salts, and 1 g/liter of casamino acids at pH 6.75. When temperature and pH were held constant, inhibition of E. carotovora varied linearly with the logarithm of the initial cell population. By altering temperatures, assays with constant pH and initial cell populations were performed under conditions of varying DIMBOA stability. When E. carotovora was grown at 24, 28, 32, and 36 C in the presence of 0.1 to 0.5 mm DIMBOA, the inhibition of bacterial growth was maintained long after DIMBOA had decomposed in the medium to levels which, if added initially, would not have been inhibitory. When assays were performed at pH 5.5, the pH of aqueous maize extracts, E. carotovora was more inhibited than at pH 6.75; however, ECZ was substantially less inhibited at the lower pH.

Journal Article↗
PubMed1977

Teratogenicity studies on late blighted potatoes in nonhuman primates (Macaca mulatta and Saguinus labiatus).

Female rhesus monkeys and marmosets were fed a diet containing blighted potatoes (Phytophthora infestans) at a level of 10g/kg per day for at least two weeks prior to breeding and six weeks following conception in order to gain additional information on the association of blighted potatoes and the development of anencephaly and spina bifida in primate species. There was an absence of either of these neural-tube defects in 32 rhesus and 14 marmoset infants whose mothers had received a blighted potato diet. In addition there were no cranial osseous defects. There were, however, two rhesus monkey infants with internal hydrocephalus whose mothers had consumed blighted potatoes.

Anencephaly↗