Neuroscience JoVE (Open Access) Citable · DOI

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

Name: Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
Uploaded: 2026-06-04
Duration: 14 min 22 s
Description: The involvement of free radicals in life sciences has constantly increased with time and has been connected to several physiological and pathological ...

DOI: 10.3791/50379-v

What you'll learn

✓ Synthesize cholesteryl ester and cyclopurine isomers as free radical markers
✓ Isolate oxidized lipids from human serum samples
✓ Identify DNA lesions from gamma radiolysis using enzymatic digestion
✓ Apply radical-based biomarkers to detect oxidative stress in biological systems

Protocol

Radical-based biomimetic chemistry has been applied to building-up libraries necessary for biomarker development.

Difficulty

advanced

Total time

~3–5 days (including organic synthesis, radiolysis, enzymatic digestion, and analytical characterization)

Biosafety

BSL-1

Steps

Synthesize mono-trans isomers of cholesteryl esters

Prepare mono-trans isomeric forms of cholesteryl esters through controlled radical-based organic synthesis. These isomers serve as reference standards and biomarker precursors for detecting lipid peroxidation.

▶ 03:05

Isolate cholesteryl esters fraction from human serum

Extract and separate the cholesteryl ester fraction from human serum samples using chromatographic or lipid extraction methods. This fraction contains endogenous oxidized lipid biomarkers.

▶ 04:34

Synthesize (5'R)- and (5'S)-5',8-cyclo-2'-deoxyadenosine isomers

Prepare both stereoisomers of 5',8-cyclo-2'-deoxyadenosine through radical chemistry. These cyclopurine lesions are DNA damage biomarkers resulting from free radical attack.

▶ 06:25

Synthesize (5'R)- and (5'S)-5',8-cyclo-2'-deoxyguanosine isomers

Prepare both stereoisomers of 5',8-cyclo-2'-deoxyguanosine using similar radical-based synthetic routes. These guanine-derived cyclopurines complement the adenosine lesion biomarkers.

▶ 08:02

Perform gamma radiolysis of DNA aqueous solutions

Expose DNA samples to gamma radiation in aqueous solution to generate free radicals and induce oxidative DNA damage. This creates lesion profiles representative of in vivo oxidative stress.

▶ 08:50

Digest irradiated DNA with enzymatic enzymes

Use nuclease digestion protocols to convert damaged DNA into constituent nucleotides and lesion products. This enables isolation and quantification of individual oxidative damage biomarkers.

▶ 09:38

Characterize biomarker profiles and oxidative stress signatures

Analyze synthesized standards and digested DNA samples to identify and validate free radical-induced biomarkers. Compare experimental lesion patterns against clinical or biological samples to detect oxidative stress.

▶ 10:43

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