Picomole analyses of tryptophan by derivatization to 9-hydroxymethyl-beta-carboline.
Inoue. S S; Tokuyama. T T; Takai. K K
Key Findings
- A Pictet‑Spengler reaction can convert tryptophan into 9‑hydroxymethyl‑beta‑carboline, allowing detection of sub‑picomole levels.
- The method works on less than 1 µL of plasma ultrafiltrate or 1 mg of brain tissue.
- Peptides with an N‑terminal tryptophan (e.g., delta sleep‑inducing peptide) are converted to N‑(9‑hydroxymethyl‑beta‑carboline‑3‑carbonyl) derivatives, retaining all other residues.
Practical Outcomes
- For biohackers, there’s no direct actionable protocol or dosage guidance. The technique is useful only for specialized laboratory measurement of tryptophan, not for everyday health optimization or performance enhancement.
Summary
The paper describes a new lab technique for measuring extremely tiny amounts of the amino acid tryptophan by turning it into a fluorescent compound. It’s a chemistry method for researchers, not a study about how the peptide works in the body or how to use it for health.
Abstract
A new method specific for the determination of subpicomole quantities of tryptophan has been developed by elaboration of the Pictet-Spengler reaction. It permitted reproducible quantitation of tryptophan in less than 1 microliter of plasma ultrafiltrate or 1 mg of brain tissue. Samples deproteinized by trichloroacetic acid were boiled for 15 min with formaldehyde and potassium ferricyanide at controlled acidity, where tryptophan was converted to a single new product identified as 9-hydroxymethyl-beta-carboline. It was quantitated by either direct spectrofluorometry or a reversed-phase HPLC system developed for beta-carbolines. Under our conditions, peptides containing N-terminal tryptophan such as Trp-Leu and delta sleep-inducing peptide gave N-(9-hydroxymethyl-beta-carboline-3-carbonyl) peptides which retained all amino acid residues except tryptophan.
Study Information
pubmed
1983
1983-07-15T00:00:00.000Z
10.1016/0003-2697(83)90036-2
14
40