Hemoglobin as a binding substrate in the quantitative analysis of plant tannins

Schultz, Jack C.; Baldwin, Ian Thomas; Nothnagle, Philip J.

doi:10.1021/jf00106a036

Cited by 76 publications

(21 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A threshold concentration of extract for 3-glucosidase precipitation was apparently required for immature S. acuminata (0.50 and 1.0 mg emulsin/ml) and immature S. leprosula (1.0 mg emulsin/ml only) since their regression lines had y intercepts (Table 1) different from zero (two-tailed t-tests, P < 0.05). Similar threshold effects have been noted in previous studies with leaf extracts (Bate-Smith, 1973;Martin and Martin, 1982) and tannins (Haslam, 1974;Schultz et al, 1981). The linearity of the nonasymptotic regions of the curves in Figure 1A-E permitted general comparisons of protein-precipitating capacity among extracts based on the regression slopes.…”

Section: Resultssupporting

confidence: 82%

Protein-precipitating capacity of tannins inShorea (Dipterocarpaceae) seedling leaves

Becker

Martin

1982

J Chem Ecol

View full text Add to dashboard Cite

The protein-precipitating capacities of tanniferous extracts from immature and mature leaves of threeShorea spp. (Dipterocarpaceae) seedlings were measured by an adaptation of Goldstein and Swain's β-glucosidase precipitation assay. Protein precipitation by the extracts was not correlated with total phenolics (Folin-Denis assay) or proanthocyanidin content (BuOH-HCl assay) as measured in an earlier study. Extracts ofS. maxwelliana mature leaves had much lower protein-precipitating capacity than those ofS. acuminata andS. leprosula, but fewer insect species feed on and cause less damage to the foliage ofS. maxwelliana compared with the other species' foliage. Immature leaf extracts ofS. leprosula andS. acuminata had substantial protein-precipitating capacities which in the latter species exceeded that of its mature leaf extracts. Leaf extracts precipitated less protein when initial protein concentration was reduced, although not limiting, but no effect or the reverse effect occurred with quebracho tannin and tannic acid. Problems in the characterization of foliage astringency and the interpretation of its role as a potential antiherbivore defense are discussed.

show abstract

Section: Resultssupporting

confidence: 82%

Protein-precipitating capacity of tannins inShorea (Dipterocarpaceae) seedling leaves

Becker

Martin

1982

J Chem Ecol

View full text Add to dashboard Cite

show abstract

“…Phenolics were extracted with 70% acetone for 3 hr at 40~ The acetone was removed under reduced pressure, and the extracts were diluted to 10 ml with distilled water. Extracts were analyzed for proanthocyanidin condensed tannins (butanol-HC1 method; Bate-Smith, 1977), leucoanthocyanin condensed tannins (vanillin method; Broadhurst and Jones, 1978;Butler et al, 1982), and protein-binding capacity using hemoglobin as the substrate (Schultz et al, 1981). Relative concentrations are expressed as wattle tannin (Acacia sp.…”

Section: Chemical Analysesmentioning

confidence: 99%

Condensed tannins, attine ants, and the performance of a symbiotic fungus

Orians

1991

J Chem Ecol

View full text Add to dashboard Cite

Field experiments indicate that the foliar concentration of condensed tannin affects the selection of leaf material ofInga oerstediana Benth., a tropical legume tree, by leaf cutter ants. In one study an increase in tannin concentration was correlated with a decrease in the acceptability of leaves to leaf-cutter ants, except at low tannin concentrations. Protein concentration was not correlated with acceptability nor was the ratio of protein to tannin. Results from a second study suggest that when the concentration of tannin was low the ants appear to select leaves on the basis of nutrient availability. Laboratory assays with the ants indicated that quebracho tannin, a commercially available condensed tannin, inhibits foraging ants. Again, at lower concentrations, quebracho tannin appeared to have little affect on the ants. The fungus the ants cultivate is a wood-rotting Basidiomycete that produces enzymes, such as polyphenol oxidase (PPO), that are capable of inactivating tannins. The activity of these PPOs may explain why leaf-cutter ants are undeterred by low concentrations of condensed tannins. I hypothesized that PPO activity would be absent from fungal cultures without tannin and that only high concentrations of tannin would inhibit the fungus. Cultures with and without tannin showed similar PPO activity. Thus PPO activity is constitutive. In fact, as fungal biomass increased, so did PPO activity. As hypothesized, only high concentrations of quebracho tannin inhibited PPO activity and fungal growth. However, it is not clear whether the ants can discriminate between concentrations that do and do not inhibit the fungus.

show abstract

“…The comparative manual assay was based on the method proposed by Schultz et al, 8 with a few modifications. Commercial bovine hemoglobin was used, instead of fresh blood.…”

Section: Manual Assaymentioning

confidence: 99%

“…7 Bate-Smith 6 proposed the use of hemoglobin for tannin determination as a chromoprotein in a spectrophotometric methodology. Later, Schultz et al 8 suggested this reaction for quantitative analysis of tannins and described some advantages (water soluble and some buffering ability) in using hemoglobin, compared to other proteins. On the other hand, these methods were considered difficult for routine application because they require large amounts of fresh blood and some colored compounds from samples or blood J. Braz.…”

Section: Introductionmentioning

confidence: 99%

“…10 The proposed methodology intended to reexamine the advantages of using hemoglobin for tannin precipitation, as described by Schultz et al. 8 The use of commercial hemoglobin improved the method, reducing the manual steps, because it is easily diluted in Tris/HCl buffer and more stable than that extracted from fresh blood. The detector used (FAAS) allowed the analysis of colored extracts, which is difficult to perform using methods with spectrophotometric detection.…”

mentioning

confidence: 99%

See 1 more Smart Citation

FIA-FAAS method for tannin determination based on a precipitation reaction with hemoglobin

Ferreira¹,

Souza²,

Nogueira³

2003

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Um sistema em fluxo acoplado a espectrômetro de absorção atômica com chama (FIA-FAAS) foi desenvolvido para determinação de taninos em amostras de feijão guandu, explorando a reação de precipitação entre os taninos e proteínas. Extratos obtidos pela sonicação das amostras com solução de metanol 50% (v/v), foram introduzidos no sistema e induzidos à reação com hemoglobina, sendo o precipitado produzido pela reação retido em um filtro localizado no percurso analítico. Solução 1% (m/v) dodecil sulfato de sódio, fluindo em sentido inverso ao fluxo de filtração, foi empregado para solubilizar e conduzir o complexo tanino-hemoglobina ao detector, espectrômetro de absorção atômica com chama, para quantificação dos íons ferro presentes na estrutura da hemoglobina. Uma solução de ácido tânico foi utilizada para construção da curva analítica. O método proposto apresentou freqüência analítica de 30 amostras por hora, desvio padrão relativo de 9,7 % (n=10) e limite de quantificação 0,27 mg L -1 de ácido tânico.A flow system, coupled with flame atomic absorption spectrometry (FIA-FAAS), was developed for tannin determination in pigeon pea samples, exploring the precipitation reaction between tannins and proteins. Sample extracts obtained by sonication with a 50% (v/v) methanol solution were introduced into the system and induced to react with a hemoglobin solution. The precipitate produced was retained on a filter located in the analytical flow. A reversed flow of 1% (w/v) sodium dodecyl sulfate solution was used for solubilization of the precipitate from the filter and to conduct the tanninhemoglobin complex to the FAAS, to quantify the iron ions present in the hemoglobin structure. A tannic acid solution was used to prepare the analytical curve. The proposed method allowed determination of 30 samples per hour, a standard deviation of 9.7% (n=10), and a quantification limit of 0.27 mg L -1 for tannic acid.Keywords: tannin-protein complexes, hemoglobin, FIA, flame atomic absorption spectrometry IntroductionThe term tannin originated from "tanning", an expression which refers to tan animal skin. 1 This is possible because tannins link to collagen, which is the protein present in animal skin. 2 Thus, the ability to link and precipitate proteins is a property that defines tannins. For this reason, the reaction between tannins and protein has been used in many analytical methods for tannin determination, 3-6 especially when results that measure the correlation with the nutritional value of food are desired. 7 Moreover, this reaction is very specific, which minimizes interference effects in an analytical method.Tannin-protein complexes are dissolved by detergents, that break hydrophobic interaction between them, or by high pH values that ionize hydroxyphenolic groups so that it becomes unable to maintain the hydrogen bonding. 4 Usually tannin-protein precipitates are dissolved using sodium dodecyl sulfate. 7 Bate-Smith 6 proposed the use of hemoglobin for tannin determination as a chromoprotein in a spectrophotometric methodology...

show abstract

Hemoglobin as a binding substrate in the quantitative analysis of plant tannins

Cited by 76 publications

References 7 publications

Protein-precipitating capacity of tannins inShorea (Dipterocarpaceae) seedling leaves

Protein-precipitating capacity of tannins inShorea (Dipterocarpaceae) seedling leaves

Condensed tannins, attine ants, and the performance of a symbiotic fungus

FIA-FAAS method for tannin determination based on a precipitation reaction with hemoglobin

Contact Info

Product

Resources

About