Chemical Data :

IUPAC: N-(Adamantan-1-yl)-1-(5-fluoropentyl)-1H-indole-3-carboxamide

CAS: 1354631-26-7

ChemSpider: 28189067

Molecular Weight: 382.51

Molecular Formula: C24H31FN2O

STS-135, also known as 5F-APICA, is a potent synthetic cannabinoid of the indole class.

It has the formal and systematic IUPAC name N-(adamantan-1-yl)-1-(5-fluoropentyl)-1H-indole-3-carboxamide. STS-135 has a molar mass of 382.51 grams and empirical formula C24H31FN2O.

The chemical structure of this STS-135 centres on a substituted indole. The R1 nitrogen of the indole is substituted with a fluoropentyl side chain. This substitution has been seen in many synthetic cannabinoids such as THJ-2201, 5F-AKB-48 and 5F-PB-22.

At R3 of the indole a carboxamide is substituted. The terminal amine of this carboxamide is attatched to an adamantine. This saturated structure consists of four fused cyclohexane rings making a unique three dimensional shape known as a diamondoid.

STS-135 is a structural analogue of 5F-AKB48, containing the same structural motifs, including the adamantine, but having an indole core as opposed to an indazole in the latter.

In vitro, STS-135 has been shown to be a potent full agonist at human cannabinoid receptor CB1 with and EC50 value of 13 nM. It has an EC50 value of 51 nM for CB2. It produces hypothermia and bradycardia in rats at doses ranging from 1-10 mg/ kg, which is a further indication of its cannabinoid like activity.

As STS-135 is a fluorinated synthetic cannabinoid one should be careful with the mode of ingestion used. Owing to the electronegativity of fluorine, these compounds form strong crystals with boiling points for the fluorinated cannabinoids in excess of 500 oC. In fact on heating, some of the compound is likely to combust rather than being released as vapour. The thermal degradation products of the fluorinated cannabinoids like STS-135 are likely to include highly reactive and toxic fluorocarbons.

These by-products will be noxious to the fine mucosal membrane of the respiratory tissue and the lungs and are likely to have further toxic effects if absorbed systemically. For this reason it is advised that if STS-135 is to be ingested at all, it should be done by a cold manner, such as ingestion or cold vaporisation. It is important to note that virtually all of the “E-Cigarette” vaporisers currently on the market produce their vapour by heat and so should be avoided.

The fluorinated indole and indazole cannabinoids are also known to be extremely potent. Their use has been linked to seizures, hospitalisations and deaths around the world. This is in part due to their full agonist action at CB1. It is also due to the fact that very little is required to have an effect, often 1 mg or less. This makes error in dose very easy, and accounts for the danger of these compounds.

The effects of long term or even short term recreational use of STS-135 on human health is not known. There have been no formal toxicological studies of this compound.

STS-135 is not fit for human consumption.

Unverifiable online reports give us some indication of the effects of STS-135.

It is reported as being heavily sedating with a strong “stoning” effect produced.

These compounds are known to be addictive with a high potential for abuse.

Other names and synonyms for STS-135:

1H-Indole-3-carboxamide, 1-(5-fluoropentyl)-N-tricyclo[,7]dec-1-yl- [ACD/Index Name]
N-(Adamantan-1-yl)-1-(5-fluoropentyl)-1H-indole-3-carboxamide [ACD/IUPAC Name]
N-(Adamantan-1-yl)-1-(5-fluoropentyl)-1H-indole-3-carboxamide [French] [ACD/IUPAC Name]
N-(Adamantan-1-yl)-1-(5-fluorpentyl)-1H-indol-3-carboxamid [German] [ACD/IUPAC Name]
1354631-26-7 [RN]