Journal of Medicinal Chem.
Specific food additives other than flavouring agents The Committee evaluated six food additives for the first time and reevaluated a number of others.
Information on the safety evaluations and on specifications is summarized in Annex 2. Details of further toxicological studies and other information required for certain substances are given in Annex 3.
LE a-amylase has not been evaluated previously by the Committee. The enzyme is thermostable and active at a relatively low pH and low calcium concentration. These characteristics make the enzyme particularly suitable for use in starch hydrolysis conducted at high temperatures, for example, for the liquefaction of starch used in the production of nutritive sweeteners.
LE a-amylase is produced by pure culture fermentation of a strain of B. The enzyme is subsequently partially purified and concentrated, resulting in a liquid enzyme concentrate LEC.
These modifications were accomplished by introducing appropriate mutations into the DNA sequence encoding the Termamyl LC a-amylase. The engineered gene, designated as the LE a-amylase gene, was introduced into the host strain SJ The host strain was developed from a parent strain DN, a derivative of a natural B.
The DN strain was genetically engineered to inactivate the following native genes: The inactivated amyL, xyl, and gnt genes were replaced with three copies of the 9 LE a-amylase gene. In a separate step, the gene encoding Ccomponent protease was deleted.
The resulting strain was designated as MOL and used as a production strain The aim of these genetic modifications was to produce the LE a-amylase, to prevent the synthesis of proteases that might hydrolyse the LE a-amylase, and to avoid the production of the Termamyl a-amylase. The genetic material introduced into the production strain has been well characterized and does not contain any sequences that would encode for proteins resulting in the production of toxic or undesirable substances.
The LE a-amylase gene is stably integrated into the B. The production strain does not contain genes encoding proteins that inactivate antibiotics.
The LE a-amylase was assessed for potential allergenicity by amino acid sequence comparison with known allergens listed in publicly-available protein databases.
No immunologically-significant sequence homology was detected. Toxicological studies were conducted on the LEC. Therefore this highest dose equivalent to 1.
The LEC was not mutagenic in an assay for mutagenicity in bacteria in vitro and was not clastogenic in an assay for chromosomal aberrations in mammalian cells in vitro. The a-amylase preparation is intended for use in starch liquefaction in the production of sweetener syrups, alcoholic beverages and beer.
The absence of the a-amylase protein in the final purified sweetener syrup has been confirmed experimentally. In the spirits industry, no LE a-amylase or other organic solids are expected to be carried over to the final product because ethanol is removed by distillation from the fermentation mash containing the enzyme preparation.
In the brewing of beer, the enzyme preparation is added during the mashing process and is denatured and inactivated during the subsequent wort-boiling stage. The beer filtration process is likely to remove the denatured enzymes along with other insoluble materials.
In conclusion, no residual LE a-amylase is expected to be present in food processed using this enzyme preparation. A toxicological monograph and a chemical and technical assessment CTA were prepared and specifications were established.
Annatto extracts are obtained from the outer layer of the seeds of the tropical tree Bixa orellana. The principal pigment in annatto extract is cis-bixin, which is contained in the resinous coating of the seed itself.
Processing primarily entails the removal of the pigment by abrasion of the seeds in an appropriate suspending agent. Traditionally, water or vegetable oil is used for this purpose, although solvent extraction is also employed to produce annatto extracts with a higher pigment content.
At its eighteenth meeting, the Committee considered the results of long-term and short-term tests in experimental animals fed an annatto extract containing 0.
A longterm study in the rat provided the basis for evaluation; the NOEL in this study was 0. The Committee re-evaluated annatto extract at its twenty-sixth meeting, when the results of the metabolic studies that had been requested became available.
Studies of mutagenicity, additional long-term 11 1-year studies in the rat, and observations of the effects of annatto extract in humans were also considered. Studies in both rats and humans showed that although annatto pigments are absorbed from the intestine into the blood, clearance from the plasma is rapid.
The NOEL in the original long-term rat study was determined as 0. In this re-evaluation, the Committee considered the highest concentration of bixin in the material tested i.
The following extracts were considered for evaluation: Annatto extract solvent-extracted bixin: Annatto B1 The seeds are extracted with solvent to dissolve the pigment. The extract is filtered to remove insoluble material.A convenient six step synthesis of N-BOC-D-diphenylalanine from L-serine methyl ester hydrochloride is described.
The preparation of a novel chiral auxiliary, an oxazolidinone derived from D-diphenylalaninol, is also described. The synthesis of acid methyl ester hydrochlorides is shown in Scheme 1. A series of amino acids, including natural amino acids, aromatic amino acids and aliphatic amino acids was transformed to.
"Dipeptide The Methyl Ester Of N Acetyl L Prolyl L Phenylalanine" Essays and Research Papers Dipeptide The Methyl Ester Of N Acetyl L Prolyl L Phenylalanine chemistry lab report esterification BY MOHAMED ALKHARUSI GRADE 12 BIL Introduction Esters have a very sweet fruity smell.
The present invention relates to new compounds having modulatory (inhibitory and stimulatory) activity on serine peptidases and proteases in general and dipeptidyl peptidase IV, prolyl oligopeptidase (PO), dipeptidyl peptidase II (DPP II), fibroblast activation protein α (FAPα), lysosomal Pro-X carboxypeptidase and elastase in particular.
Synthesis And Nmr Study Of Dipeptide The Methyl Ester Of N Acetyl L Prolyl L Phenylalanine experiment synthesized H-Gly-Phe-OH dipeptide using “Fmoc chemistry”. The first part of experiment was the synthesis of L - phenylalanine methyl ester hydrochloride.
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