HPLC Analysis of Oxindole Alkaloids in <i>Uncaria Tomentosa</i>: Sample Preparation and Analysis Optimisation by Factorial Design

Bertol, Gustavo; Franco, Luzia; Oliveira, Brás Heleno de

doi:10.1002/pca.1335

Cited by 30 publications

(27 citation statements)

References 16 publications

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“…In addition, speciophylline (3), uncarine F (4), rhyncophylline (7), and isorhyncophylline (8) followed a similar elution order to that formerly reported by other authors. [20][21][22] Neither corynoxeine (9) nor isocorynoxeine (10) were detectable by HPLC-PDA or HPLC-MS/ MS, probably due to their low content in cat's claw bark. 19 …”

Section: Hplc-pda and Hplc-ms/ms Analysesmentioning

confidence: 99%

“…18 Given that mitraphylline (1) is the most suitable oxindole alkaloid for assaying total alkaloid content in cat's claw bark, 20 all content determinations were performed at 245 nm using mitraphylline (1) as the external standard. Exceptionally, isomitraphylline (2) was quantified as such, since it shows a very similar e-value to mitraphylline (1).…”

Section: Hplc-pda Validationmentioning

confidence: 99%

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Cat's claw oxindole alkaloid isomerization induced by common extraction methods

Kaiser¹,

Verza²,

Moraes³

et al. 2013

Quím. Nova

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Recebido em 31/8/12; aceito em 24/1/13; publicado na web em 14/5/13Cat's claw oxindole alkaloids are prone to isomerization in aqueous solution. However, studies on their behavior in extraction processes are scarce. This paper addressed the issue by considering five commonly used extraction processes. Unlike dynamic maceration (DM) and ultrasound-assisted extraction, substantial isomerization was induced by static maceration, turbo-extraction and reflux extraction. After heating under reflux in DM, the kinetic order of isomerization was established and equations were fitted successfully using a four-parameter Weibull model (R 2 > 0.999). Different isomerization rates and equilibrium constants were verified, revealing a possible matrix effect on alkaloid isomerization.

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Section: Hplc-pda and Hplc-ms/ms Analysesmentioning

confidence: 99%

Section: Hplc-pda Validationmentioning

confidence: 99%

Cat's claw oxindole alkaloid isomerization induced by common extraction methods

Kaiser¹,

Verza²,

Moraes³

et al. 2013

Quím. Nova

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“…There are numerous scientific reports on U. tomentosa bioactivity, comprising anti-inflammatory and antioxidant properties, and protective effects against cancer, as well as positive effects in the cardiovascular, central nervous and locomotor systems [2]. These bioactive properties of U. tomentosa have been attributed mainly to its alkaloid contents [3], however it has been reported that some properties such as its antioxidant effect could be related to its phenolic contents [4]. …”

Section: Introductionmentioning

confidence: 99%

Proanthocyanidin Characterization and Bioactivity of Extracts from Different Parts of Uncaria tomentosa L. (Cat’s Claw)

et al. 2017

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Apart from alkaloids, bioactive properties of Uncaria tomentosa L. have been attributed to its phenolic constituents. Although there are some reports concerning low-molecular-weight polyphenols in U. tomentosa, its polymeric phenolic composition has been scarcely studied. In this study, phenolic-rich extracts from leaves, stems, bark and wood (n = 14) of Uncaria tomentosa plants from several regions of Costa Rica were obtained and analysed in respect to their proanthocyanidin profile determined by a quadrupole-time-of-flight analyser (ESI-QTOF MS). Main structural characteristics found for U. tomentosa proanthocyanidins were: (a) monomer composition, including pure procyanidins (only composed of (epi)catechin units) and propelargonidins (only composed of (epi)afzelechin units) as well as mixed proanthocyanidins; and (b) degree of polymerization, from 3 up to 11 units. In addition, U. tomentosa phenolic extracts were found to exhibit reasonable antioxidant capacity (ORAC (Oxygen Radical Absorbance Capacity) values between 1.5 and 18.8 mmol TE/g) and antimicrobial activity against potential respiratory pathogens (minimum IC50 of 133 µg/mL). There were also found to be particularly cytotoxic to gastric adenocarcinoma AGS and colon adenocarcinoma SW620 cell lines. The results state the particularities of U. tomentosa proanthocyanidins and suggest the potential value of these extracts with prospective use as functional ingredients.

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“…The content of alkaloids in the organic solution was analyzed by high-performance liquid chromatography (HPLC) using a Merck Hitachi LaChrom Elite® HPLC system with a diode array detector L-2455 (Hitachi High Technologies America, Pleasanton, CA, USA), using a PerkinElmer C18 column (150 × 4.6 mm, 3 μm) (Waltham, MA, USA), flow rate of 0.8 mL/min, 245 nm for alkaloid detection, and a previously validated gradient method. 34 Six signs, with retention times (t R ) of 10, 13, 15, 20, 22, and 31 minutes, were found in the chromatogram obtained from the UT-extract analyses. The extract was standardized using mitraphylline (t R = 15 minutes) and isopteropodine (t R = 31 minutes) as markers, with concentrations of 14.1 and 7.1 mg/g, respectively.…”

Section: Preparation Of the Organic Solvent Containing Ut Extractmentioning

confidence: 99%

“…34 The sediment obtained from centrifugation of the NP suspension was resuspended in water and re-centrifuged to determine the amount of alkaloid adsorbed onto the NP surface.…”

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confidence: 99%

Poly ε-caprolactone nanoparticles loaded with Uncaria tomentosa extract: preparation, characterization, and optimization using the Box–Behnken design

Ribeiro¹,

Rezende²,

Cabral³

et al. 2013

IJN

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Purpose:The aim of this research was to develop and optimize a process for obtaining poly ε-caprolactone (PCL) nanoparticles loaded with Uncaria tomentosa (UT) extract. Methods: Nanoparticles were produced by the oil-in-water emulsion solvent evaporation method. Preliminary experiments determined the initial conditions of the organic phase (OP) and of the aqueous phase (AP) that would be utilized for this study. Ultimately, a three-factor three-level Box-Behnken design (BBD) was employed during the optimization process. PCL and polyvinyl alcohol (PVA) concentrations (X 1 and X 2 , respectively) and the AP/OP volume ratio (X 3 ) were the independent variables studied, while entrapment efficiency (Y 1 ), particle mean diameter (Y 2 ), polydispersity (Y 3 ), and zeta potential (Y 4 ) served as the evaluated responses. Results: Preliminary experiments revealed that the optimal initial conditions for the preparation of nanoparticles were as follows: OP composed of 5 mL ethyl acetate/acetone (3/2) mixture containing UT extract and PCL, and an AP of buffered PVA (pH 7.5) solution. Statistical analysis of the BBD results indicated that all of the studied factors had significant effects on the responses Y 1 , Y 2 , and Y 4, and these effects are closely described or fitted by regression equations. Based on the obtained models and the selected desirability function, the nanoparticles were optimized to maximize Y 1 and minimize Y 2 . These optimal conditions were achieved using 3% (w/v) PCL, 1% (w/v) PVA, and an AP/OP ratio of 1.7, with predicted values of 89.1% for Y 1 and 280 nm for Y 2 . Another batch was produced under the same optimal conditions. The entrapment efficiency of this new batch was measured at 81.6% (Y 1 ) and the particles had a mean size of 247 nm (Y 2 ) and a polydispersity index of 0.062 (Y 3 ). Conclusion: This investigation obtained UT-loaded nanoparticle formulations with desired characteristics. The BBD approach was a useful tool for nanoparticle development and optimization, and thus should be useful especially in the realm of phytotherapeutics, in which varied compositions may be assessed in quantitative and qualitative terms.

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HPLC Analysis of Oxindole Alkaloids in Uncaria Tomentosa: Sample Preparation and Analysis Optimisation by Factorial Design

Cited by 30 publications

References 16 publications

Cat's claw oxindole alkaloid isomerization induced by common extraction methods

Cat's claw oxindole alkaloid isomerization induced by common extraction methods

Proanthocyanidin Characterization and Bioactivity of Extracts from Different Parts of Uncaria tomentosa L. (Cat’s Claw)

Poly ε-caprolactone nanoparticles loaded with Uncaria tomentosa extract: preparation, characterization, and optimization using the Box–Behnken design

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HPLC Analysis of Oxindole Alkaloids in Uncaria Tomentosa: Sample Preparation and Analysis Optimisation by Factorial Design

Cited by 30 publications

References 16 publications

Cat's claw oxindole alkaloid isomerization induced by common extraction methods

Cat's claw oxindole alkaloid isomerization induced by common extraction methods

Proanthocyanidin Characterization and Bioactivity of Extracts from Different Parts of Uncaria tomentosa L. (Cat’s Claw)

Poly &epsilon;-caprolactone nanoparticles loaded with Uncaria tomentosa extract: preparation, characterization, and optimization using the Box&ndash;Behnken design

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Poly ε-caprolactone nanoparticles loaded with Uncaria tomentosa extract: preparation, characterization, and optimization using the Box–Behnken design