6465. Neotame

Nomenclature

CAS number: 165450-17-9
N-(3,3-Dimethylbutyl)-l-α-aspartyl-l-phenylalanine 2-methyl ester; N-[N-(3,3-Dimethylbutyl)-l-α-aspartyl]-l-phenylalanine 1-methyl ester.
C20H30N2O5; mol wt 378.46.
C 63.47%, H 7.99%, N 7.40%, O 21.14%.

Description and references

Alkylated dipeptide reported to be 6000 to 10000 times sweeter than sucrose; structurally related to aspartame, q.v. Prepn: C. Nofre, J.-M. Tinti, FR 2697844; eidem, US 5480668 (1994, 1996); and sweetness evaluation: I. Prakash et al., Synth. Commun. 29, 4461 (1999). Crystal structure: D. J. Wink et al., Acta Crystallogr. C55, 1365 (1999). Analysis of polymorphic forms: B. E. Padden et al., Anal. Chem. 71, 3325 (1999). Review of discovery, properties, and utility: C. Nofre, J.-M. Tinti, Food Chem. 69, 245-257 (2000).

Chemical structure

Properties

Occurs as the monohydrate. White crystalline powder from ethyl acetate/hexane, mp 80-83°; also reported as mp 80.9-83.4° from aq MeOH. [α]D -54.84° (c = 1 in methanol); [α]D20 -39.8° (c = 0.5 in water). pKa1 3.01; pKa2 8.02. pI: 5.5. Caloric value: <1.2 kJ/g. Soly in water (g/l): 10.6 (15°), 12.6 (25°), 47.5 (60°); in ethyl acetate (g/l): 43.6 (15°), 77 (25°), >1000 (60°); in abs ethanol (g/l): ≈950 (25°).

Use

Non-nutritive sweetener.