Skatole

• 3-methyl
• β -methylindole

White to brownish crystals with unpleasant smell

Fixed

95 ° C.

265-266 ° C

Very poor in water ( 450 mg · l-1 at 20 ° C)

Attention

3450 mg · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

The skatole (from Greek σκώρ, gene. Σκατός " manure, litter ") is a very intense and unpleasant smelling indole compound. It forms white crystals.

Occurrence

Skatole found in human and animal feces, in the manure ( up to 0.1 %), the secretion of the civet and in very many plants as part of the floral scent before. Also the meat of uncastrated boar contains skatole.

Formation

Meat consists of proteins, the building blocks of proteins are amino acids. One of these amino acids is tryptophan, an essential amino acid that the human organism can not even be formed, but must be taken with food. The conversion of the amino acid, for example, during digestion into various degradation products, which partially absorbed by the body, are partly excreted, get enzymes. Skatole in addition to indole one of the degradation products of tryptophan. The relationship of tryptophan, indole and skatole can be seen on all three of the common ring structure. Since tryptophan especially common in animal proteins (ie also in the muscle ) occurs, skatole is available for frequent meat consumption in correspondingly larger amount in the chair.

Representation and extraction

Skatole can be produced chemically from indole. Since a direct methylation of indole, however, the 1- methylindole ( syn.: N- methylindole ) would provide, first, the N -H group must be provided with a protecting group. It is preferred, for example, trialkylsilyl protective groups, as they in the subsequent deprotonation (or lithiation ) are resistant with alkyllithium compounds. After reaction with methyl iodide, the protecting group is removed and you get skatole.

Properties

Skatole reacts violently with strong oxidants, strong acids, acid chlorides and acid anhydrides.

Use

Skatole is used in trace amounts in perfumery.

Physiology

The odor threshold for skatole in humans is a dilution of one milligram to 250,000 cubic meters, the volume of a 200 × 50 × 25 cubic meters large factory hall.

Proof

The substance gives with potassium hexacyanoferrate (II ) and sulfuric acid a red color.