Subclass of Amino Acids & Proteins

Amino Acids

The building blocks of proteins; several free amino acids (L-theanine, GABA) are directly bioactive.

Overview

About Amino Acids

Amino acids are the smallest nitrogen-bearing building blocks of life — compact molecules carrying both an amine and a carboxylic-acid group, which is what lets them link end to end into peptides and proteins.

Twenty standard amino acids assemble the proteins of every living thing, but plants also synthesize a wide range of non-protein amino acids found nowhere in animal biochemistry, and it is often these unusual ones that carry the most distinctive pharmacology.

Where They Occur

Most amino acids in a plant are bound up in protein, but a free pool always circulates as the currency of nitrogen transport and storage. Some plants concentrate a particular free amino acid to notable levels:

Tea (Camellia sinensis)

L-theanine

Griffonia simplicifolia

5-HTP

Velvet bean (Mucuna pruriens)

L-DOPA

Fermented foods and some fruits

GABA

Watermelon

citrulline

That free fraction is what interests a phytochemistry reference, because several of these molecules are directly bioactive rather than merely nutritional.

Pharmacological Importance

Several free amino acids sit one metabolic step from a major neurotransmitter, which is what gives the group its pharmacological reach. L-theanine is calming and cognition-supporting; GABA is the body's principal inhibitory neurotransmitter; 5-HTP is the immediate precursor to serotonin; and L-DOPA is the precursor to dopamine.

This precursor role is why so many are taken as isolated supplements in their own right, rather than as part of a whole-herb preparation.

Toxicity & Safety

As a group these are among the gentlest constituents in the materia medica, tending towards nourishing and settling effects.

The exceptions come from the non-protein side: a small number of plant amino acids are genuinely toxic, such as the hypoglycin of unripe ackee and the neurotoxic β-ODAP of grass pea. The rule of thumb is that the familiar protein amino acids are safe and the unfamiliar ones deserve a closer look.

Constituents

All Amino Acids

59 total Filter amino acids

4-Hydroxyisoleucine 1 herb 5-Aminolevulinic acid 5-Hydroxytryptophan 1 herb · 1 supp

acetyl-l-carnitine 1 supp Acetylcysteine Allenic norleucine 1 herb Alpha-alanine 1 herb Anthranilic acid Asparagine 3 herbs

beta-alanine 1 supp Betaine 4 herbs · 1 supp

Chlorocrotylglycine 1 herb creatine 1 supp Cysteine 1 herb · 1 supp

d-phenylalanine 1 supp Dencichine 1 herb

gaba 1 herb · 2 supps Gamma-aminobutyric acid 1 herb Glutamine 2 herbs glycine 3 supps

l-alanine 1 supp l-arginine 1 supp l-asparagine 1 supp l-aspartic-acid 1 supp

Open in filterable index

Source Plants

Herbs Containing Amino Acids

18 herbs

Plants in the materia medica documented to carry amino acids, with the compounds each one is listed for. The bar counts how many DISTINCT amino acids are on record for a plant, relative to the best-documented — it measures breadth of record, not potency, so a plant with one well-studied compound can outrank a richer source that has simply been analysed less. No concentration figures are on record for this class yet, so nothing here distinguishes a major source from a trace.