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PubMed1978

On the occurrence of the contact allergen primin and other quinoid compounds in species of the family of primulaceae.

82 different species of the Primulacea family have been investigated by a screening test. In 16 Primula species and 4 species of other genera the strong contact allergen primin could be detected by the Craven-test. Extracts of only 12 plants gave no color reaction. In the remaining species other quinoid components were detectable. From 4 species new quinoid substances were isolated. Primin itself was obtained from Primula elatior and from the petals (corollas) of Primula obconica. The results indicate that the presence of primin and other quinones is determined by their origin and seasonal variations. It is supposed that some of the detected quinones may function as allergens and therefore may be responsible for the contact dermatitis described in the literature due to several Primula species and some other species of the same family. Some indications point to the suspicion that primin occurs in the plant as a glycoside which is separated by extraction treatment to give its quinole and an unknown substance. The quinole oxidizes then to the quinhydrone and finally to primin itself.

Allergens↗
PubMed1999

Metabolism of D-glycero-D-manno-heptitol, volemitol, in polyanthus. Discovery Of a novel ketose reductase1

Volemitol (D-glycero-D-manno-heptitol, alpha-sedoheptitol) is an unusual seven-carbon sugar alcohol that fulfills several important physiological functions in certain species of the genus Primula. Using the horticultural hybrid polyanthus (Primula x polyantha) as our model plant, we found that volemitol is the major nonstructural carbohydrate in leaves of all stages of development, with concentrations of up to 50 mg/g fresh weight in source leaves (about 25% of the dry weight), followed by sedoheptulose (D-altro-2-heptulose, 36 mg/g fresh weight), and sucrose (4 mg/g fresh weight). Volemitol was shown by the ethylenediaminetetraacetate-exudation technique to be a prominent phloem-mobile carbohydrate. It accounted for about 24% (mol/mol) of the phloem sap carbohydrates, surpassed only by sucrose (63%). Preliminary 14CO2 pulse-chase radiolabeling experiments showed that volemitol was a major photosynthetic product, preceded by the structurally related ketose sedoheptulose. Finally, we present evidence for a novel NADPH-dependent ketose reductase, tentatively called sedoheptulose reductase, in volemitol-containing Primula species, and propose it as responsible for the biosynthesis of volemitol in planta. Using enzyme extracts from polyanthus leaves, we determined that sedoheptulose reductase has a pH optimum between 7.0 and 8.0, a very high substrate specificity, and displays saturable concentration dependence for both sedoheptulose (apparent Km = 21 mM) and NADPH (apparent Km = 0.4 mM). Our results suggest that volemitol is important in certain Primula species as a photosynthetic product, phloem translocate, and storage carbohydrate.

Journal Article↗
PubMed1999

DNA relatedness among the pathovars of Pseudomonas syringae and description of Pseudomonas tremae sp. nov. and Pseudomonas cannabina sp. nov. (ex Sutic and Dowson 1959).

A total of 48 pathovars of Pseudomonas syringae and eight related species were studied by DNA-DNA hybridization (S1 nuclease method) and ribotyping. The existence of nine discrete genomospecies was indicated. Genomospecies 1 corresponded to P. syringae sensu stricto and included P. syringae pathovars syringae, aptata, lapsa, papulans, pisi, atrofaciens, aceris, panici, dysoxyli and japonica. Genomospecies 2 included P. syringae pathovars phaseolicola, ulmi, mori, lachrymans, sesami, tabaci, morsprunorum, glycinea, ciccaronei, eriobotryae, mellea, aesculi, hibisci, myricae, photiniae and dendropanacis and nomenspecies Pseudomonas savastanoi, Pseudomonas ficuserectae, Pseudomonas meliae and Pseudomonas amygdali, which are thus synonymous. P. amygdali is the earliest valid name for this genomospecies. Genomospecies 3 included P. syringae pathovars tomato, persicae, antirrhini, maculicola, viburni, berberidis, apii, delphinii, passiflorae, philadelphi, ribicola and primulae. We recommend strain CFBP 2212 of P. syringae pv. tomato to serve as the type strain. Genomospecies 4 included 'Pseudomonas coronafaciens' and P. syringae pathovars porri, garcae, striafaciens, atropurpurea, oryzae and zizaniae and corresponds to 'P. coronafaciens'. Genomospecies 5 included P. syringae pv. tremae and corresponds to Pseudomonas tremae sp. nov. Genomospecies 6 included Pseudomonas viridiflava and the presently misidentified pathotype strains of P. syringae pv. ribicola and P. syringae pv. primulae and thus corresponds to P. viridiflava. Genomospecies 7 included P. syringae pv. tagetis and P. syringae pv. helianthi. We recommend strain CFBP 1694 of P. syringae pv. tagetis to serve as a reference strain. Genomospecies 8 included P. syringae pv. these and Pseudomonas avellanae and thus corresponds to P. avellanae. Genomospecies 9 included P. syringae pv. cannabina and corresponds to Pseudomonas cannabina sp. nov. Ribotyping (SmaI and HincII endonucleases) could separate seven of the nine genomospecies. The unnamed genomospecies 3 and 7 will be named when phenotypic data are available for identification. Two species are described, P. tremae sp. nov. and P. cannabina sp. nov. Other species will be named when phenotypic data are available for identification.

Bacterial Typing Techniques↗
PubMed1979

The sensitizing capacity of naturally occurring quinones. Experimental studies in guinea pigs. II. Benzoquinones.

Experimental studies on the sensitizing capacity of naturally occurring benzoquinones, isolated from plants and woods have been carried out in guinea pigs of the Pirbright white strain. Seven compounds were available: primin, three dalbergiones, mansonia quinone (mansonone A), 2,6-dimethoxybenzoquinone and rapanone. With five of these substances (primin, mansonone A, three dalbergiones) guinea pigs could be sensitized. Primin, the allergen of Primula obconica Hance (primrose) proved to be the most effective one of all quinones tested in this and the preceding studies. As a similar but weaker sensitizer R-3, 4-dimethoxydalbergione from Machaerium scleroxylon Tul. (Pao ferro, Caviuna vermelha) could be identified. The results obtained with mansonone A, a sesquiterpenoid quinone from Mansonia altissima A. Chev. demonstrate that even naturally occurring orthoquinones are capable of inducing contact allergy. Allergic cross reactions could be obtained between all chemically related mansonones A-F. The results are in good accordance with the view that the sensitizing capacity of naturally occurring quinones depends on the fundamental quinoid structure and the length, position and configuration of the aliphatic side-chain.

Animals↗
PubMedDate not supplied

Profiles in genetics: George Wells Beadle and the origins of the gene-enzyme concept.

Beadle's success in establishing biochemical genetics on a firm foundation was due to a combination of several circumstances. These include the following: 1. Apt timing of his work, which Garrod's work clearly lacked, was important. Geneticists were receptive to his ideas and conclusions. As Beadle (1967, 1974) himself acknowledged, much ground was prepared earlier by Garrod and Haldane, who discussed gene action in terms of biochemical reactions, although it was largely ignored. The physiology of gene action was discussed and speculated on to a great extent in the preceding years by Bridges, Goldschmidt, Muller, and Wright. 2. Beadle's selection of Neurospora was most appropriate. It was a haploid organism (with no complications of dominance and recessivity) that could be grown and manipulated easily for isolating mutants to study their segregation and recombination within a short time. Its cytogenetics and the method of growing on chemically defined media were already worked out. It was devoid of the long generation time and more complex sex cycle (among other problems) that complicated the biochemical study of higher plants (e.g., Primula), which Haldane and Scott-Moncrieff had attempted earlier. 3. Beadle's striking ability to shift from one organism to another--from corn to Drosophila to Neurospora--must be acknowledged. He saw the limitations of existing methods and had the courage and skill to move on to more successful methods: from conventional breeding to tissue transplants to microbiological techniques. 4. Beadle's own curiosity about the biochemical nature of gene action and his good fortune in having had such outstanding teachers as Emerson, as well as his ability to collaborate with Ephrussi and Tatum, contributed largely to his success.

Enzymes↗
PubMed1980

Eosinophil chemotactic factor (ECF) in blister fluid of dermatological diseases.

The occurrence of low molecular weight (less than 500 dalton) eosinophil chemotactic factor (ECF) was studied in the blister fluid of patients with various dermatological diseases by an in vitro chemotaxis method. After chromatographic separation of the test substance on a small Sephadex G 25 column, ECF was demonstrated in blisters of five patients with bullous pemphigoid, in three patients with systemic drug reactions and in one patient with blisters are contact with primula. ECF was not found in blisters of patients with epidermolysis bullosa and herpes gestationis or in DNCB-induced blisters. Fluid obtained from suction blisters was negative in normal controls and in unaffected skin of patients with atopic eczema, but contained ECF in eczematous areas. The demonstration of ECF in tissue fluid suggests that this factor plays a role in the local accumulation of eosinophils at sites of certain inflammatory reactions.

Blister↗
PubMed1990

Primin standard patch testing: 5 years experience.

From 1 November 1984 to 1 November 1989. 3075 patients (1949 female and 1126 male) were patch tested with the European standard series, including primin 0.01% pet. 57 positive reactions were obtained (1.8%). About 95% of the patients with positive patch tests were female. 60% of the patch-test-positive patients were above age 60 and 35% above 70 years. The test was negative in all under the age of 20 and rarely positive under the age of 35 years. Only 2 patients had probable patch test sensitization observed 8 and 14 days after application of the test material. 41% of the patients with positive reactions had current primula dermatitis at the time of patch testing. The frequency and high degree of current relevance justify inclusion of primin in the standard series, at least in certain geographical regions. The patch test concentration of 0.01% pet. seems to be correct.

Adult↗
PubMed1995

Structure-activity relationships in allergic contact dermatitis (I). Studies on the influence of side-chain length with derivatives of primin.

Primin (2-methoxy-6-pentyl-1,4-benzoquinone) is a naturally-occurring strong sensitizer from Primula obconica (Primulacease). To determine the effect of side-chain length on sensitizing potency, 15 analogues with linear side chains from C1 to C15 and 4 C6-analogues with branched side chains were prepared synthetically and devoted to experimental sensitization in guinea pigs. The results showed an increase of the sensitizing capacity with increasing length of the alkyl side chain from C1 to C10, reaching a maximum at C11 and C12. On further elongation, the sensitizing potency decreased beyond C13, reaching values which finally were as low as those of the C1 and C3 derivatives. The results mirror findings which formerly have been obtained with other non-quinonoid compounds like catechols, phenols, hydroquinones and gallates. In the plant kingdom, compounds approximating an "ideal allergen" consisting of a quinonoid ring with a 10 or 11 carbon-membered side chain have been identified only once: 2,3-dimethoxy-geranyl-1,4-benzoquinone, a remarkably strong sensitizer found in Wigandia caracasana (Hydrophyllaceae).

Animals↗