Rapid determination of oxindole alkaloids in cat's claw by HPLC using ionic liquid‐based microwave‐assisted extraction and silica monolithic column

Abstract

Cat's claw is a large woody vine with hook-like thorns, and has been traditionally used to treat inflammatory disorders in South and Central America. In this study, a rapid, validated high-performance liquid chromatographic (HPLC) method using a silica monolithic column was developed for the simultaneous determination of oxindole alkaloids, namely rhynchophylline, pteropodine, isomitraphylline and isopteropodine, in cat's claw. The ionic liquid-based microwave-assisted extraction (ILMAE), considered as an environmentally friendly and powerful tool, was first applied in the extraction of oxindole alkaloids. To optimize the HPLC method, the stationary phases, pH values of mobile phase and flow rates were investigated. The validated HPLC method using a Monolithic RP column (100 × 4.6 mm) enables these analytes to be separated almost twice as fast as with a conventional particulate column (~16 vs ~30 min) with limits of quantification and detection of 0.5 and 0.15 μg/mL, respectively. The ILMAE conditions were optimized by the Taguchi orthogonal array design. In comparison with conventional water boiling extraction, ILMAE offers almost four times higher yields within an extremely short extraction time. The developed HPLC coupled with ILMAE method could be efficient and practical for rapid determination of oxindole alkaloids in cat's claw.

Isolation of mitraphylline from Uncaria tomentosa (Willd. ex Schult.) DC. barks and development of spectrophotometric method for total alkaloids determination in Cat's Claw samples

“…The singularity of the reference analytical standards and the usual methods based on HPLC to quantify total alkaloids in U. tomentosa impact the cost of the quality control process and, consequently, the final products available for patients and the public health sector . Therefore, this work proposes the isolation of mitraphylline from U. tomentosa barks to use the purified alkaloid as an analytical standard in the development of a simple and low cost spectrophotometric method for determination of total alkaloids in U. tomentosa samples.…”

Fabrication of an ionic‐liquid‐based polymer monolithic column and its application in the fractionation of proteins from complex biosamples

“…ILs are usually composed of organic cations and inorganic anions. ILs possess some fascinating properties, including good solubility, good stability in thermal and chemical conditions, tunable chemical groups, and nonflammability , which have made ILs more unique and useful as green solvent for chromatographic separation in recent years . So far, ILs‐based monoliths have shown excellent chromatographic properties in separating proteins.…”

Rapid and cost-effective method for the simultaneous quantification of seven alkaloids in Corydalis decumbens by microwave-assisted extraction and capillary electrophoresis

“…Microwaves can pass into the plant tissues and rapidly produce heat to break cells. Heating by microwaves is instantaneous and occurs in the interior of the sample . MAE has some advantages over conventional extraction methods, such as reduced extraction solvent volume and extraction time, increased extraction proficiency and sample throughput.…”