2024 Author: Jasmine Walkman | [email protected]. Last modified: 2023-12-16 08:29
The general formula of isothiocyanates - R-N = C = S
Isothiocyanates (mustard oil) are organic compounds - antioxidantscontaining the functional group N = C = S and sulfur analogue isocyanates R - N = C = O1.
Reactivity of isothiocyanates
Isothiocyanates, like isocyanates, are heterocumulated with an electrophilic center on a carbon atom and are characterized by nucleophilic addition reactions:
R-N = C = S + NuH of R-NH-C (= S) Nu
(Nu = OR, Oar, SH, SR, NH2, NR1R2, RNHNH2, RH = NNH2, CN)
When isothiocyanates react with alcohols and phenols, thiocarbamates, dithiocarbamates with thiols, with amines - N, N - disubstituted thioureas with amines, thiosimicarbazides with hydrazines and thiosemicarbazones with aldehydes hydrazones are formed.
Upon interaction with C-nucleophiles, isothiocyanates form secondary amides, this addition proceeds as in the interaction of isothiocyanate with carbanions (Grignard reagents, carbanions of β-dicarbonyl compounds, etc.)
R-N = C = S + R1MgX to R-NH-C (= S) R1, And with regard to the Friedel-Crafts reaction:
R-N = C = S + ArH of R-NH-C (= S) Ar
Isothiocyanates are attached to carboxylic and thiocarboxylic acids, and carbon disulfide or carbon monoxide is cleaved by unstable intermediates, which also leads to the formation of secondary amides:
R = N = C = S + R1COXH on R-NH-C (= S) XCOR1
R-NH-C (= S) XCOR1 to R-NHCOR1 + CSX
(X = O, S)
Isothiocyanates are reduced with sodium borohydride to secondary thioformamides RNHC (S) H, lithium aluminum hydride to the corresponding methylamines RNHCH3, zinc in hydrochloric acid to primary amines RNH2.
Under the action of mercuric oxide, isothiocyanates form isocyanates:
R = N = C = S + HgO of R-N = C = O + HgS
The compounds cause apoptosis (death of cancer cells) and act selectively.
Sources of isothiocyanates are broccoli, cauliflower, horseradish and black mustard seeds, vegetables from the cabbage family. These plants contain sinigrin glycosylate, which during hydrolysis produces allyl isothiocyanate, which causes a burning taste of mustard and horseradish. Some isothiocyanates, such as phenethyl isothocyanate and sulforaphane, can inhibit carcinogenesis and tumor formation.
