Effects-Directed Biological Detection

Separation, Identification, and Investigation of Antioxidant Ability of Plant Extract Components Using TLC, LC–MS, and TLC–DPPH•

“…Thin-layer chromatography -direct bioautography (TLC-DB) is a hyphenation in which the separation step is performed using (HP)TLC, while searching for compounds of given properties (antioxidant, enzymatic, antiestrogenic, antimutagenic, antibacterial or antifungal) is done using proper biological detection directly on the TLC plate. [30][31][32][33][34] This hyphenation affords several advantages, such as fast results, reduction in time-consuming sample preparation steps, and what is the most important, direct access to the separated target compounds on the (HP)TLC plate. TLC-DB plays an important role in identification of antioxidants and radical scavengers in natural samples.…”

Instrument platforms for thin-layer chromatography

“…Specific detectors for radioisotopes [56] and interfaces for direct evaluation by spectrosocopic instruments (mass spectrometry and infrared and Raman spectroscopy) [57][58][59][60][61] are also available. In recent years there has been a growing interest in biological detection using, among others, various luminescence reactions and conditions that facilitate instrumental detection [62,63]. This approach complements a long history of the use of in situ chemical reactions for selective and sensitive detection or visualization of thin-layer chromatograms (see Section 4).…”

“…There is growing interest in effect-directed detection in thinlayer chromatography employing various bioassays based on the inhibition/stimulation of growth or activity of an organism, such as bacteria, yeast cells, mold spores, cell organelles, enzymes, etc., for detection [62,63,[85][86][87][88]. Typically, after the separation step, the plate is dried and then dipped into a suspension of the test organism.…”

Hyphenated TLC as a Tool in the Effect-Directed Discovery of Bioactive Natural Products

“…TLC is a matrix tolerant method. Crude extracts can be directly applied on the plate with minimal or no sample preparation and possible loss of sample components [2]. Thus, all sample components separated on the plate can be directly evaluated using a bioassay, enabling sample bioactivity to be maintained and accurately assessed.…”