Flavanones and dihydroflavonols as biosynthetic intermediates in Matthiola incana

In anthocyanin-producing flowers of Matthiola incana, the presence of naringenin, naringenin 7-glucoside, dihydrokaempferol and dihydrokaempferol 7-glucoside could be demonstrated. The four isolated compounds initiated anthocyanin synthesis after administration to acyanic flowers of genetically defined lines of Matthiola incana and Antirrhinum majus. Therefore, these compounds cannot be regarded as end-products but rather as intermediates in anthocyanin biosynthesis. Furthermore, naringenin 7-glucoside and dihydrokaempferol 7-glucoside most probably act as a pool for their aglycones, which serve as the actual substrates.     

Isolation and sequence analysis of a chalcone synthase cDNA ofMatthiola incana R. Br. (Brassicaceae)

A cDNA clone (pcM12) of the chalcone synthase (CHS) ofMatthiola incana R. Br. (Brassicacease) was isolated from a cDNA library, sequenced and analysed. It comprises the complete coding sequence for the CHS and 5 and 3 untranslated regions. The deduced amino acid sequence shows that theMatthiola incana CHS consists of 394 amino acid residues. Comparison with CHS amino acid sequences of other plants indicates more than 82% homology.     

Simulation of quantitative characters by genes with biochemically definable action. III. The components of genetic effects in the inheritance of anthocyanins in Matthiola incana R. Br.

Summary In a self-pollinated plant species, Matthiola incana R. Br., six groups of isogenic lines were developed which were ideally suited for investigating the properties of individual genes controlling a quantitative character. Each group consisted of four homozygous parents for two alleles at each of the two loci in a common genetic background. A complete 4 × 4 diallel cross was obtained in each group. Because of the identical genetic background each diallel set could be considered as a genetic system of two loci. The biochemical functions of the alleles at each locus modifying the structure of the anthocyanin molecule were known. The phenotypes of the nine possible genotypes were qualitatively distinguishable by their flower colour differences. A quantitative measure of the phenotypic value associated with a genotype is the concentration of anthocyanins in flower tissues. In these simplified genetic systems, the nine phenotypic values could be expressed in terms of nine biometrical quantities, eight of which are attributable to the genetic effects of the alleles at the two loci under consideration. An unique solution of the set of nine equations in nine unknowns provided direct estimates of the parameters specifying additive, dominance and epistatic effects. Thus the effects of individual genes in a well-defined genetic background could be estimated by the use of a simple additive genetic model. An extension of the model provided estimates of the genetic parameters in different years and genetic backgrounds.Dominance was found to be the most important type of gene action in the inheritance of anthocyanin content in the flower tissues of M. incana. There was considerable epistasis, but the effect was very unstable over years and genetic backgrounds. The relative magnitude of additive effect was most stable. Heterosis was observed and was found to be largely due to dominance and additive × dominance interactions.

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Zusammenfassung In der selbstbefruchtenden Gartenpflanze Matthiola incana wurde eine Reihe weitgehend isogener Linien entwickelt, die sich in idealer Weise zur Untersuchung der Beiträge einzelner definierter Gene und Genkombinationen zu einem quantitativen Merkmal eignen. Das Material wurde in 6 Gruppen eingeteilt. Jede Gruppe besteht aus 4 homozygoten Eltern, die sich aus der Variation zweier Loci mit je zwei Allelen vor einem gemeinsamen genetischen Hintergrund ableiten und nach dialleler Kreuzung alle kombinatorisch möglichen Genotypen ergeben. Jeder diallele Satz stellt somit ein genetisches System mit zwei Loci dar, dessen qualitative Beiträge zur Modifikation der Anthocyanmoleküle bekannt sind und dessen quantitative Beiträge zur Gesamtkonzentration der Anthocyane gemessen werden. In diesen vereinfachten genetischen Systemen können die Phänotypenwerte der 9 Genotypen durch 9 biometrische Quantitäten beschrieben werden, von denen 8 den genetischen Effekten der variierten Loci und einer dem Beitrag des genetischen Hintergrundes zugeschrieben werden könen. Anhand eines einfachen linearen Modells werden Parameter für die additiven, Dominanz- und Epistasieeffekte der einzelnen Gene aus einem Satz von 9 Gleichungen mit 9 Unbekannten direkt geschätzt. Eine Erweiterung des Modells erlaubt die Schätzung der Parameter in verschiedenen Jahren und mit wechselndem genetischem Hintergrund. Für die Ausbildung des quantitativen Merkmals Anthocyangehalt der Blüten von Matthiola incana erwiesen sich die Dominanzkomponenten als der entscheidende Typ der Genwirkung. Ferner wurde ein erheblicher Epistasieanteil geschätzt, jedoch waren diese Beiträge nicht konstant, da sie über die Jahre variierten und eine starke Abhängigkeit von der Art des genetischen Hintergrundes zeigten. Der relative Anteil der additiven Komponenten erwies sich dagegen zwar als gering, jedoch sehr stabil. Beobachtete Heterosiseffekte müssen zum Teil den Dominanzkomponenten, zum Teil der Interaktion zwischen additiven und Dominanzkomponenten zugeschrieben werden.

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This work was carried out while the senior author held a research fellowship awarded by the Alexander von Humboldt-Stiftung of Bad Godesberg, Germany, which is gratefully acknowledged.

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Research supported by Deutsche Forschungsgemeinschaft.     

Plant regeneration from mesophyll protoplasts of Matthiola incana (L.) R. Br.

Summary A protocol for obtaining regenerated fertile plants from mesophyll protoplasts of three lines of Matthiola incana is described. Protoplasts were isolated from leaves of 21–28 days old Matthiola plants grown in controlled environment. Sustained divisions were achieved when protoplasts were embedded in sodium alginate. Up to 2.0 % of the protoplasts developed into colonies which could be transferred to shoot regeneration media. More than 25 % of the obtained calluses regenerated shoots. About 4 % of these shoots could be rooted and after transfer to soil phenotypically normal plants have been obtained.Abbreviations 2,4-D 2,4-dichlorphenoxyacetic acid - NAA naphthalene acetic acid - IAA indole-3-acetic acid - BAP 6-banzylaminopurine - IPA isopentenyladenine - IPAR isopentenyladenosine - MES (2-[N-morpholino]) ethanesulfonic acid     

Wechselwirkungen zwischen einem turnip-mosaik-Virus und dem Genom des Wirtes

Zusammenfassung BeiMatthiola incana R. Br. wird das Phänomen der sog. Blütenbrechung beobachtet, die sich in einer Weißstreifigkeit, Aufhellung oder Vertiefung der normalerweise rosa oder violett gefärbten Blüten äußert. Es wird gezeigt, daß die Blütenbrechung durch ein Virus der turnip-mosaik-Gruppe verursacht wird und daß hinsichtlich der Art der Manifestation eine Wechselwirkung mit dem Genotyp des Wirtes vorliegt. In die Wechselwirkung sind nur Gene einbezogen, die die Quantität der Anthocyanpigmente kontrollieren, während Gene, die die Molekülstruktur verändern, hiervon unberührt bleiben.

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Interactions between a turnip-mosaic virus and the genotype of the host

Summary InMatthiola incana R. Br. the phenomenon of so called breaking of flower color is observed which is manifested in white areas dilution or intensification of the normally pink or violet flower colors. This phenomenon is shown to be caused by a virus of the turnip-mosaic-type. There is an interaction between the virus and the genotype of the host, in which are involved only genes controlling the quantity of the anthocyanin pigments but not genes responsible for alteration of the molecule structure of the anthocyanins.

     

Simulation of quantitative characters by genes with biochemically definable action

Summary Six groups of genetic materials were developed in a cruciferous garden plant, Matthiola incana R. Br., to produce simplified genetic systems of a pair of loci in each group. There were only two alleles at each locus, which were directly involved in the modification of anthocyanins in the plant tissue. The parental lines and their F₁'s in each group constituted an ideal 4 × 4 diallel cross and satisfied all but one condition necessary for a valid diallel analysis. Nonallelic interaction was the only possible offending postulate.The diallel analysis of the data on anthocyanin content in the flower tissues and a comparison of the results with that of a relatively straightforward method of analysis indicated that in the presence of epistasis, the dominance ratio (H₁/D) ceases to be a reliable measure of the average degree of dominance. In such situations additional genetic information obtained from the diallel analysis are not in agreement with the expectations on the basis of the already available genetic information on the materials. The estimator H₂/4 H₁, a measure of average value of the product of alleles with positive and negative effects, seemed to remain unaffected by epistasis. The Wr/Vr regression analysis does not always permit the detection of nonallelic gene interactions. The results suggest that duplicate interaction may escape detection by the regression analysis.

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Zusammenfassung Anhand der Crucifere Matthiola incana wurde ein genetisches Material aufgebaut, das es erlaubt, in 6 verschiedenen Gruppen je 2 Loci in allen Kombinationen systematisch zu variieren. Je Locus liegen 2 Allele vor, die in die Modifikation der Anthocyane eingreifen.Die Elterlinien und ihre F₁-Nachkommen bilden ein ideales 4 × 4-Diallel und erfüllen bis auf eine alle für eine gültige Diallelanalyse erforderlichen Bedingungen. Die einzige nicht erfüllte Voraussetzung ist die Abwesenheit nichtalleler Interaktionen.Die diallele Analyse der Daten über den Anthocyangehalt der Petalen und ein Vergleich der Resultate mit den aufgrund einer sehr direkten und detaillierten Untersuchungsmethode erhaltenen zeigten, daß das Dominanzverhältnis (H₁/D) bei Vorliegen von Epistasie keine brauchbare Messung des durchschnittlichen Dominanzgrades mehr ist. In derartigen Situationen stimmen auch die zusätzlich aus der diallelen Analyse zu erhaltenden Informationen nicht mit den Erwartungen überein, die auf der bereits vorliegenden Kenntnis der Genetik des Materials beruhen.Der Schätzwert H₂/4 H₁ als Messung des Durchschnittswertes des Produktes der Allele mit positiven und negativen Effekten scheint dagegen durch Epistasie unbeeinflußt zu bleiben.Die W _r /V _r , Regressionsanalyse führt nicht in allen Fällen zum Nachweis nichtalleler Interaktionen. Die Ergebnisse zeigen, daß eine duplicate gene action dem Nachweis durch die Regressionsanalyse entgeht.

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This work was carried out while the senior author held a research fellowship awarded by the Alexander von Humboldt-Stiftung, Bad Godesberg, Germany, which is gratefully acknowledged.Research supported by Deutsche Forschungsgemeinschaft.     

Simulation of quantitative characters by genes with biochemically definable action

Summary An experimental system has been developed which allows the application of the mathematical model given in Part I of this series. It consists of all possible genotypic combinations of four loci involved in the modification of the anthocyanin molecule structure by oxydation, glycosidation, and acylation in the annual cruciferous garden plantMatthiola incana. These genes are varied against a background which is nearly isogenic with respect to the concentration of flower pigments. The qualitative actions and interactions of the genes and the composition and isogenisation of the genetic background are described.As a simulated quantitative character the total concentration of anthocyanins per petal fresh weight is used and measured in a reading spectrophotometer.The genetic structure of the material is a prerequisite for the analysis by means of the earlier given model, and the knowledge of the qualitative actions and interactions of the involved genes may be useful in the interpretation of the estimations of the parameters and possibly facilitate an improvement of the model.

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Zusammenfassung Es wird ein experimentelles Material entwickelt, auf das das im Teil I dieser Reihe beschriebene mathematische Modell angewandt werden kann. Es besteht aus allen kombinatorisch realisierbaren genotypischen Variationen 4 verschiedener Loci, die in die Modifikation des Anthocyanmoleküls durch Oxydation, Glykosidierung und Acylierung bei der einjährigen CrucifereMatthiola incana R. Br. einbezogen sind.Diese Gene werden vor einem hinsichtlich der Intensität der Blütenfarbstoffe weitgehend isogenen Hintergrund variiert, ihre qualitativen Wirkungen und Wechselwirkungen werden ebenso wie die Zusammensetzung und Isogenisierung des genetischen Hintergrundes beschrieben. Als simuliertes quantitatives Merkmal dient die Gesamtkonzentration der Anthocyane/Petalenfrischgewicht, die im registrierenden Spektralphotometer gemessen wird.Die genetische Struktur dieses Materials ist Voraussetzung für die Anwendung des früher beschriebenen Modells, die Kenntnis der qualitativen Wirkungen und Wechselwirkungen der experimentell variierten Gene kann die Interpretation der Parameter-schätzungen und die Verbesserung des Modells erleichtern.

     

Effect of 8-hydroxyquinoline on the uptake of uridine and incorporation into RNA

8-hydroxyquinoline has been previously used as an inhibitor in studies on porphyrin metabolism, where it is thought to act by chelating iron. It is shown that this compound also rapidly inhibits uridine uptake of seedlings or cotyledons of the crucifer Matthiola incana R.Br. RNA synthesis is also affected but the inhibition is not as severe as reported for fission yeast.Abbreviations oligo (dT)-cellulose cellulose with oligo-deoxythymidylic acid attached - poly (A) polyadenylic acid     

Phytochemical Profile and Antioxidant Activity of the Aerial Part Extracts from Matthiola incana subsp. rupestris and subsp. pulchella (Brassicaceae) Endemic to Sicily

As part of a project aimed at investigating the Matthiola taxa endemic to Sicily (Italy), this study focused on Matthiola incana, an edible species used in the traditional medicine of various countries. Herein, the characterization of phenolic and volatile compounds, the antioxidant capacity in vitro (1,1-diphenyl-2-picrylhydrazil (DPPH), reducing power and Fe²⁺ chelating activity assays) and the toxicity test (Artemia salina lethality bioassay) of the hydroalcoholic extracts from the aerial parts of M. incana subsp. rupestris from Mt. Pellegrino (Palermo) and Mt. Erice (Trapani), and of M. incana subsp. pulchella are reported. The results are compared with those previously shown for M. incana subsp. incana, to achieve a comprehensive overview of the three subspecies. The HPLC-PDA/ESI-MS and SPME-GC/MS analyses led to the identification of 13 phenolics and 54 volatile compounds. Differences in the qualitative-quantitative profile of these phytochemicals have been highlighted between the M. incana subspecies. The antioxidant tests showed different activity for the extracts, which were found to possess better chelating properties. At last, none of the tested extracts displayed toxicity against brine shrimp larvae. These findings enrich the knowledge on the Matthiola taxa growing wild in Sicily, both from the strictly systematic point of view and for the possible applications as sources bioactive compounds that can be used in the nutraceutical field.     

Stoffwechselprodukte von Mikroorganismen

Zusammenfassung Aus Kulturen zweier Streptomycetenstämme wurde das l-2,5-Dihydrophenylalanin (I) isoliert. Die antibiotische Wirkung dieser Verbindung kann durch Phenylalanin und Tyrosin aufgehoben werden.

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Metabolic products of microorganisms87. l-2,5-dihydrophenylalanine

Summary l-2,5-Dihydrophenylalanine has been isolated from cultures of two strains of Streptomyces. The antibiotic activity of this compound is antagonized by Phenylalanine and Tyrosine.

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86. Mitteilung: W. Keller-Schierlein und W. Richle: Antimicrobial Agents and Chemotherapy 1970 (im Druck).

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Jetzt: Gesellschaft für Molekularbiologische Forschung mbH., Stöckheim bei Braunschweig.     

Enzymatic reduction of (+)-dihydroflavonols to flavan-3,4-cis-diols with flower extracts from Matthiola incana and its role in anthocyanin biosynthesis

A cell-free extract from flowers of Matthiola incana catalyzes a NADPH-dependent stereospecific reduction of (+)-dihydrokaempferol to 3,4-cis-leucopelargonidin (5,7,4-trihydroxyflavan-3,4-cis-diol). The pH-optimum of this reaction is around 6. The rate of reaction with NADH was about 50% of that found with NADPH. (+)-Dihydroquercetin and (+)-dihydromyricetin were also reduced by the enzyme preparation to the corresponding flavan-3,4-cis-diols. Correlation between the genotype of M. incana and the presence of dihydroflavonol 4-reductase is strong evidence that this enzyme is involved in anthocyanin biosynthesis.     

Uridine 5′-diphosphate-xylose: anthocyanidin 3-O-glucose-xylosyltransferase from petals of Matthiola incana R.Br.

Petals of genetically defined lines of Matthiola incana R.Br. contain a glycosyltransferase which catalyzes the transfer of the xylosyl moiety of uridine 5-diphosphate-xylose to the glucose of cyanidin 3-glucoside. The enzyme also uses 3-glucosides of pelargonidin and delphinidin, cyanidin 3-(p-coumaroyl)-glucoside and 3-(caffeoyl)-glucoside as substrates. The xylosyltransferase exhibits a pH optimum of 6.5. The enzyme activity depends on the stage of bud and flower development. Accumulation of cyanidin 3-glucoside during flower development is correlated with xylosyltransferase activity.Abbreviations HPLC high-performance liquid chromatography - UDP uridine 5-diphosphate     

Nucleosides Having Quinolone Derivatives as Nitrogenated Base: Regiospecific and Stereospecific Ribosylation of 3-Carbethoxy-1,4-dihydro-4-oxoquinolines

Abstract

Ribosylation reactions of previously silylated 3-carbethoxy-8-methyl-1,4-dihydro-4-oxoquinoline (6a) and 3-carbethoxy-6-methyl-1,4-dihydro-4-oxoquinoline (6b) with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (7), under Lewis acid catalysis, were studied. The method using hexamethyldisilazane (HMDS)/trimethylchlorosilane (TMCS) mixture for silylation and anhydrous stannic chloride as catalyst for ribosylation failed to give any nucleoside product. On the other hand, the protected nucleoside 3-carbethoxy-6-methyl-1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-1,4-dihydro-4-oxoquinoline (8b) was obtained in good yields using bis(trimethylsilyl)trifluoroacetamide (BSTFA) containing 1% of TMCS and the same catalyst. Compound 8b was more easily isolated in higher yields with an improvement of the later method by replacing stannic chloride with trimethylsilyl trifluoromethanesulfonate (TMSOTf).

De-O-benzoylation of 8b with methanolic sodium hydroxide solution afforded the free riboside 3-carbomethoxy-6-methyl-1-β-D-ribofuranosyl-1,4-dihydro-4-oxoquinoline (9b). The structures of the obtained products were confirmed by their LTV, MS, IR, ¹H and ¹³C-NMR data.     

The isolation of keratinophilic fungi from soil and wild animals in South Dakota

Hairs and skin scrapings from 224 wild animals representing 30 species were examined for the presence of keratinophilic fungi. Commercial agars and sterile soil plates moistened with water containing cycloheximide were utilized for culturing specimens. Keratinophilic fungi of the generaTrichophyton andChrysosporium were isolated from 26.8% of the specimens. Using the hair baiting technique of Vanbreuseghem, 54 soil samples were screened for keratinophilic fungi. Eighteen (33.3%) of the samples were positive for the genusTrichophyton. Microsporon spp. were not recovered from the animal hairs or soil samples.

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Zusammenfassung Haare und Haut von 224 wilden Tieren, von dreißig Arten, sind für das Vorkommen von keratinophilen Pilzen untersucht worden. Agar und sterile mit Wasser angefeuchtete Erdbodenplatten mit Cycloheximid sind für Kulturzwecke benützt worden. Keratinophile Pilze von den GattungenTrichophyton undChrysosporium sind von 26.8% der Proben isoliert worden. Mittels der Haarködermethode von Vanbreuseghem sind 54 Erdbodenproben für keratinophile Pilze untersucht worden. Achtzehn der Proben (33.3%) waren für die GattungTrichophyton positiv.Mikrosporon spp. wurden von Tierhaaren oder Erdbodenproben nicht erhalten.

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Approved by the director of the South Dakota Agricultural Experiment Station as Journal Series No. 916.

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Formerly was of the staff of the Bacteriology Department at South Dakota State University.     

Production and analysis of intergeneric somatic hybrids between <Emphasis Type="Italic">Brassica oleracea</Emphasis> and<Emphasis Type="Italic"> Matthiola incana</Emphasis>

The gene pool of Brassica oleracea was enriched via intergeneric somatic hybridization between B. oleracea (2n = 18) and Matthiola incana (2n = 14). One hundred and eighteen plants were obtained from 96 calli. Only four plants (H1, H2, H3 and H4) showed an intermediate phenotype from the parents; among these, H1 and H3 arose from the same callus. Random amplified polymorphic DNA (RAPD), sequence-related amplified polymorphism (SRAP), and cytological analyses confirmed that H1 and H3 were hybrids. The nuclear DNA content of the regenerated plants was determined by flow cytometry. More than half of the plants contained a nuclear DNA content of 1.3 to 3.9 pg/cell, which was higher than the content of B. oleracea but lower than that of M. incana. H1 contained 4.89 ± 0.02 pg of DNA per cell, while H3 nuclear DNA content was estimated at 4.87 ± 0.06 pg/cell. Cytological study of the root-tip cells revealed that the majority of the H1 and H3 hybrid cells contained 28 chromosomes.     

Die organischen Säuren im Cambialsaft von Larix decidua Mill

Summary The quantitatively most important organic acids in the cambial sap of Larix decidua have been isolated and characterised. Quinic acid predominated and smaller amounts of shikimic acid, malic acid, oxalic acid, amino acids and sugar phosphates were also present. It is shown by the aphid-technique that quinic acid is probably transported in the phloem from the young needles and shoots to the cambial zones of the tree.

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Zweite Mitteilung über den Cambialsaft von Larix decidua. Erste Mitteilung in Planta (Berl.) 73, 155–160 (1967).     

The B-ring hydroxylation pattern of intermediates of anthocyanin synthesis in pelargonidin-and cyanidin-producing lines of Matthiola incana

In flowers of Matthiola incana, the B-ring hydroxylation pattern of anthocyanins is controlled by the locus b. Recessive genotypes produce pelargonidin and genotypes with wild-type alleles cyanidin as the aglycone. Supplementation experiments on acyanic flowers using extracts of pelargonidin-and cyanidin-producing flowers, respectively, showed not only the presence of compounds with a precursor function for anthocyanin synthesis in the cyanic flowers but also differences in the B-ring hydroxylation pattern of these compounds. Chromatographic investigations proved that flavanones and dihydroflavonols occur in extracts of cyanic flowers. Naringenin, dihydrokaempferol, and their 7-glucosides could be demonstrated in all flower extracts, but in extracts of cyanidin-producing flowers, dihydroquercetin and a further 3, 4-hydroxylated dihydroflavonol, tentatively identified as dihydroquercetin 3-glycoside, were additionally found. In no case, however, could eriodictyol be detected. From these results and from the ready hydroxylation of dihydrokaempferol to dihydroquercetin in a white mutant line of Matthiola incana, it can be concluded that introduction of the 3-hydroxyl group of anthocyanins is not achieved by specific incorporation of caffeic acid during synthesis of the flavonoid skeleton, but by hydroxylation at the dihydroflavonol stage.     

Die Simulation quantitativer Merkmale durch Gene mit biochemisch definierbarer Wirkung

Summary With reference to the concentration of aglycones in carefully hydrolysed anthocyanin extracts of 16 genotypes of Matthiola incana R.Br. it was investigated whether the measurement of the optical density of qualitatively different anthocyanin extracts may pass as a suitable measurement of the total content of anthocyanin pigments. — The results obtained after acid hydrolysis of different anthocyanin extracts show that the qualitative change of the pigment pattern influences in some cases the extinction values considerably. Thus, 3-mono-sides and 3-biosides were underestimated, whereas 3, 5-glycosides were overestimated. The acylation of the anthocyanin molecule seems to have a detectable influence only on the 3, 5-triglycosides. — The results obtained could be confirmed largely by comparison with purchased preparations and are in accordance with the coefficients of extinction we measured and those found in literature. From these results correction factors may be derived which are suited to transforming the extinction values obtained by measurements of the optical density to the same scale. — The influence of this transformation on the distribution of measurements and on the estimates of the parameters of the genes involved was examined by means of a formerly investigated trifactorial system.Zusammenfassung Anhand der Konzentration des Aglycons in schonend hydrolysierten Anthocyanextrakten von 16 Genotypen der Sommerlevkoje, Matthiola incana R.Br. wurde untersucht, ob die Messung der optischenDichte qualitativ unterschiedlicher Anthocyanextrakte als geeignetes Maß für den Gesamtgehalt der Anthocyanpigmente gelten kann. — Die nach saurer Hydrolyse der verschiedenen Anthocyanextrakte erhaltenen Ergebnisse zeigen, daß qualitative Änderungen des Pigmentmusters in einigen Fällen die Extinktionswerte erheblich beeinflussen. So werden 3-Monoside und 3-Bioside bei Extinktionsmessungen in ihrer Konzentration unterbewertet wogegen 3, 5-Glycoside überbewertet werden. Die Acylierung der Anthocyanmoleküle scheint nur bei den 3, 5-Triglycosiden einen nachweisbaren Einfluß zu haben. — Die erhaltenen Ergebnisse konnten anhand von Handelspräparaten weitgehend bestätigt werden und stehen auch in guter Übereinstimmung mit selbst bestimmten und in der Literatur veröffentlichten molaren Extinktionskoeffizienten. — Aus den Ergebnissen lassen sich Korrekturfaktoren ableiten, die geeignet sind, die bei Messungen der optischen Dichte erhaltenen Extinktionswerte in eine miteinander vergleichbare Form zu überführen. — An den Meßwerten eines früher untersuchten trifaktoriellen Systems wurde die Auswirkung der Korrekturen auf die Verteilung der Meßwerte und auf die Parameterschätzwerte der beteiligten Gene geprüft.

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Angenommen durch W. Seyffert