The article contains sections titled: 1. Introduction and History 2. Properties 2.1. Physical Properties and Structure 2.2. Chemical Properties 2.3. Important Amino Acids 2.3.1. Proteinogenic Amino Acids 2.3.2. Other Important Amino Acids 3. Industrial Production of Amino Acids 3.1. General Methods 3.2. Production of Specific Amino Acids 3.2.1. l ‐Alanine 3.2.2. l ‐Arginine 3.2.3. l ‐Aspartic Acid and Asparagine 3.2.4. l ‐Cystine and l ‐Cysteine 3.2.5. l ‐Glutamic Acid 3.2.6. l ‐Glutamine 3.2.7. l ‐Histidine 3.2.8. l ‐Hydroxyproline 3.2.9. l ‐Isoleucine 3.2.10. l ‐Leucine 3.2.11. l ‐Lysine 3.2.12. d , l ‐Methionine and l ‐Methionine 3.2.13. l ‐Phenylalanine 3.2.14. l ‐Proline 3.2.15. l ‐Serine 3.2.16. l ‐Threonine 3.2.17. l ‐Tryptophan 3.2.18. l ‐Tyrosine 3.2.19. l ‐Valine 4. Biochemical and Physiological Significance 5. Uses 5.1. Human Nutrition 5.1.1. Supplementation 5.1.2. Flavorings, Taste Enhancers, and Sweeteners 5.1.3. Other Uses in Foodstuff Technology 5.2. Animal Nutrition 5.3. Pharmaceuticals 5.3.1. Nutritive Agents 5.3.2. Therapeutic Agents 5.4. Cosmetics 5.5. Agrochemicals 5.5.1. Herbicides 5.5.2. Fungicides 5.5.3. Insecticides 5.5.4. Plant Growth Regulators 5.6. Industrial Uses 6. Chemical Analysis 7. Economic Significance 8. Toxicology

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Amino acids are key components of human and animal nutrition, both as part of a protein-containing diet, and as supplemented individual products. In the last 10 years there has been a marked move away from the extraction of amino acids from natural products, which has been replaced by efficient fermentation processes using nonanimal carbon sources. Today several amino acids are produced in fermentation plants with capacities of more than 100,000 tonnes to serve the requirements of animal feed and human nutrition. The main fermentative amino acids for animal nutrition are L-lysine, L-threonine, and L-tryptophan. DL-Methionine continues to be manufactured for animal feed use principally by chemical synthesis, and a pharmaceutical grade is manufactured by enzymatic resolution. Amino acids play an important role in medical nutrition, particularly in parenteral nutrition, where there are high purity requirements for infusion grade products. Amino acids are also appearing more often in dietary supplements, initially for performance athletes, but increasingly for the general population. As the understanding of the effects of the individual amino acids on the human metabolism is deepened, more specialized product mixtures are being offered to improve athletic performance and for body-building.

Reaction of PtCl2(en) (en = ethane-1,2-diamine) with thallous pentafluorobenzoate in hot pyridine ( py ) or 4-methylpyridine ( mepy ) yields the [N,N′- bis (2,3,5,6-tetrafluorophenyl)ethane-1,2-diaminato(2-)]platinum(II) complexes, Pt[N(p-HC6F4)CH2]2( py )2 (1a) and Pt[N(p- HC6F4)CH2]2( mepy )2 (1b). The route to (1a) is considered to involve formation of [Pt(en)( py )2](O2CC6F5)2 (2), decarboxylation of (2) into Pt(NHCH2)2( py )2 (1c) and pentafluorobenzene, and nucleophilic attack of (1c) on C6F5H. Complex (1a) has also been prepared by decarboxylation of (2), reaction of PtI2(en) and TlO2CC6F5, and reaction of PtCl2(en), C6F5H, and TlO2CC6F4H-p in boiling pyridine. From reaction of PtCl2(en), TlO2CC6F4H-p, and the appropriate polyfluorobenzene (RF) in boiling pyridine or 4-methylpyridine, the organoamidoplatinum compounds Pt(NRCH2)2L2(R = C6F5, p-MeC6F4, p-ClC6F4, p-BrC6F4, p-IC6F4, 2,3,5-F3C6H2, or p-C6F5C6F4, L = py and R = C6F5, L = mepy ) have been prepared. Analogous reactions of PtCl2( pn )( pn = propane-1,3-diamine) give the complexes Pt[NR(CH2)3NR]( py )2 (R = C6F5 or p-HC6F4). Spectroscopic evidence for the structures is discussed. The polyfluorophenyl groups confer stability to water on ethane-1,2-diaminato(2-)platinum(II) complexes, and this is attributable to delocalization of non-bonded lone pairs from the amido nitrogens into the polyfluorophenyl rings.

Ketene dithioacetals undergo a Sharpless-type asymmetric oxidation using (+)-DET, Ti(O(i)()Pr)(4), and cumene hydroperoxide to give the trans bis-sulfoxides 4a-f with essentially complete control of enantioselectivity and diastereoselectivity. The high enantioselectivity is a consequence of carrying out two asymmetric processes on the same substrate. However, this should lead to the formation of a small amount of the meso isomer but none was isolated. From monitoring the enantioselectivity of the monoxide over time, it was concluded that small amounts of the meso isomer must be formed. The inability to isolate this compound could be because it acted as a ligand on titanium and remained tightly bound even upon workup.