Hydantoins spectra

Isothiazolinones are a class of broad-spectrum biocides used as preservatives in many household and industrial products. They are used in cosmetics and shampoos as a biocide to kill fungi and bacteria. Unlike the preservatives DMDM hydantoin and imidazolidinyl urea, also commonly used in these products, isothiazolinones do not release formaldehyde, to which some people are sensitive. On the other hand, some people are sensitive to isothiazolinones. 

DMDM HYDANTOIN Typical use concentrations 0.15 -0.4% Cheap Water soluble Low oil solubility Broad spectrum of activity Active at low concentrations Active between pH 4 -10 Non-volatile Good heat stability Formaldehyde donor... 

The two groups of enzymes discussed here have attracted attention because both offer a useful broad spectrum of substrate specificity. They are grouped together because in the context of amino acid synthesis they form a natural pair. Amino acid hydantoins are convenient from the standpoint of organic synthesis. The hydantoinases cleave the ring, producing the A-carbamoyl derivative of the amino acid. This must then be further hydrolyzed to obtain the free amino acid, and this step is likely to be strictly enantioselective (Equation (10)). 

One of the most widely used enzymatic methods for D-amino acid production is the hydantoinase process [4]. The great advantage of this process is that, potentially, any optically pure D-amino acid can be obtained using the corresponding substrate from a wide spectrum of D,L-5-monosubstituted hydantoins, which are readily accessible by chemical synthesis [5]. In this cascade of reachons the chemically synthesized D,L-5-monosubstituted hydantoin ring is first hydrolyzed by a stereoselective hydantoinase enzyme (D-hydantoinase). Further hydrolysis of the resulting N-carbamoyl D-amino acid to the free D-amino acid is catalyzed... 

Extensive MO calculations for bond lengths and angles of l-phenyl-2-thio-5-carbomethoxymethylhydantoin have been reported.218 He(I) excited photoelectron spectra of hydantoin and 1-methyl-hydantoin are assigned by comparison with the spectrum of succinimide and by INDO/S calculations.219... 

Glydant . [Lonza] DMDM hydantoin prods. ineservative, broad spectrum antimicrobial for cosmetics and toiletries. 

Figure 19 RP-HPLC and mass spectrum of a representative hydantoin.

The o.r.d. spectrum of 2-acetamido-N-(L-aspart-4-oyl)-y -D-glucopy-ranosylamine (11) has been reported to exhibit two positive Cotton-effects having extrema at 227 and 204 nm. Similar Cotton-effects were observed for 1-N-acyl (17) and 1-hydantoin (27) derivatives of 2-acet-amido-2-deoxy-)8-D-glucopyranosylamine. Shen and coworkers reported single peaks for 11 at 229 nm and for the 2,5-piperazinedione derivative 29 at 230 nm. The o.r.d. spectra of synthetic and natural 3-0-)3-D-xylopyranosyl-L-serine (140) were compared, in order to establish the identity of the compound isolated from hydrolyzates of heparin and cartilage fractions. 

Chem. Descrip. DMDM hydantoin in water CAS 6440-58-0 EINECS/ELINCS 229-222-8 Uses Preservative, antimicrobial for cosmetics, toiletries, household prods., coatings, pigment siurries, other industrial systems Features Broad spectrum effective against Gram-positive and Gramnegative bacteria, fungi, and yeast... 

Two widely used preservatives, DMDM hydantoin and imidazolidinyl urea, are found in many shampoos, to prevent fungal and bacterial spoilage. They release formaldehyde to kill germs. Other broad-spectrum biocide are isothiazolinone and the related methylisothiazolinone and methylchlo-roisothiazolinone. Sodium benzoate is another preservative used in shampoos. It kills bacteria, fungi, and yeasts, and works well in acidic mixtures. 

Monomethylol-dimethyl-hydantoin produces a spectrum of activity which is characteristic of formaldehyde releasing compoimds. The compound is proposed for the preservation of cosmetics and pharmaceutical products addition rate 0-2%. 

The biological performance illustrated above is remarkable for its speed, spectrum and potency, and offers many advantages in applications related to the principal needs for antimicrobial activity preservation, odor control, prevention of carriage and dissemination of disease agents, and wearer protection. These features differentiate hydantoin grafted cotton from all other treatments. The efficacy reflects the power of Cl, and extends to mammalian viruses, even in the presence of high bioburden levels (data not shown). 

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