https://abulafia.ciencias.uchile.cl/publicaciones/pdf/49-Phytochemistry-27-3349-1988.pdf

Hydroxamic acids (4-hydroxy-1,4-benzoxazin-3-ones), defence chemicals in the Gramineae

The biogeneration of green odour by green leaves

The synthesis of bacterial protein in the rumen of lactating cows fed on purified carbohydrates, with urea and ammonium salts as the sole sources of nitrogen, can be increased, through feed adaptation, to a level adequate not only for the maintenance of the cow but also for a relatively high milk production. The best annual milkyield per cow on the experimental feedhas, so far, been 4217 kilograms, calculated as standard milk (684 kilocalories per kilogram of milk). The composition of the test milk is similar to that of normal fat- and proteinrich milk. Fractionation of casein and serum proteins of test milk and normal milk by different methods demonstrated the similarity of the proteins of the two milks. The normal or higher concentrations of the water-solublevitamins in test milk show that the biosynthesis of these vitamins in the rumen is vigorous. The flavor of the two milks is very similar-proof that biosynthesis of the effective flavor compounds of milk occurs in the body of the cow. The only component of test milk whose composition, when small amounts of vegetable oil have been fed, has differed from that of normal milk is the fat. The studies of milk production on the experimental feed have opened up new possibilities for investigating the biosynthesis of different milk components. The studies are also of practical importance: Since the vigorous biosynthesis of proteins from simple nitrogen compounds in the rumen of test-feed-adapted cows has been demonstrated, there are greater possibilities for studying the replacement of protein by urea. In countries where there are plenty of forests, part of the feed of cows can be made up of certain wood products-for instance, hemicellulose and cellulose of low quality. The new findings may also be of value in the dry areas of the globe, where milk would be of vital significance for improving the nutrition of the population.

https://science.sciencemag.org/content/sci/153/3744/1603.full.pdf

Milk production of cows on protein-free feed.

Publisher Summary This chapter assembles data, which contribute to a physiological understanding of this pathway in insects, to appraise the role of ommochromes in insect life, and the relation of tryptophan metabolism to insect development. Tryptophan is an outstanding amino acid. It has the highest molecular weight of all amino acids occurring in proteins, and comprises, in its indolyl moiety, a system capable of donating electrons and; therefore, liable to form complexes with a range of other molecules. Molecular interactions have been observed between tryptophan and nucleic acids, and a variety of other molecules of biological importance. Organisms have taken advantage of the potentialities of this molecule and have transformed it into a wide range of biologically active compounds. In these, either the indole ring or its benzene nucleus are retained, the latter also being recast into the pyridine ring. In insects, a major product of tryptophan degradation is a group of 10 to 15 pigments, the ommochromes. Being brownish-yellow, bright red or dark violet-purple, these pigments produce the deep tinge of insect eyes and contribute to the brilliant coloration of many species.

The Tryptophan → Ommochrome Pathway in Insects

Strains of molds Aspergillus niger, A. ochraceus, A. oryzae, A. parasiticus, Penicillium chrysogenum, P. citrinum, P. funiculosum, P. raistrickii, P. viridicatum, Alternaria, Cephalosporium, and Fusarium sp. were grown on sterile coarse wheat meal at 26 to 28 C for 120 h. The volatiles from mature cultures were distilled at low temperature under reduced pressure. The distillates from traps -40 and -78 C were extracted with methylene chloride and subsequently concentrated. All the concentrates thus obtained were analyzed by gas-liquid chromatography, mass spectrometry, chemical reactions of functional groups, and olfactory evaluation. Six components detected in the culture distillates were identified positively: 3-methylbutanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and 2-octen-1-ol. They represented 67 to 97% of all the volatiles occurring in the concentrated distillate. The following 14 components were identified tentatively: octane, isobutyl alcohol, butyl alcohol, butyl acetate, amyl acetate, octyl acetate, pyridine, hexanol, nonanone, dimethylpyrazine, tetramethylpyrazine, benzaldehyde, propylbenzene, and phenethyl alcohol. Among the volatiles produced by molds, 1-octen-3-ol yielding a characteristic fungal odor was found predominant.

Volatile Flavor Compounds Produced by Molds of Aspergillus, Penicillium, and Fungi imperfecti

/pdf/the-mass-spectra-of-some-aliphatic-lactones-417a5va8m5.pdf

The Mass Spectra of Some Aliphatic Lactones.

/pdf/the-kinetics-and-mechanism-of-the-decomposition-of-2-4-h02o6xmo9g.pdf

The Kinetics and Mechanism of the Decomposition of 2,4-Dihydroxy-1,4-benzoxazin-3-one.

/pdf/the-synthesis-of-precursor-ii-of-benzoxazolinone-formed-in-44vt63mn2p.pdf

The Synthesis of Precursor II of Benzoxazolinone Formed in Rye Plants, and the Enzymic Hydrolysis of Precursor I, the Glucoside.

/pdf/studies-on-the-transfer-of-some-flavour-compounds-to-milk-1fb3msoduk.pdf

Studies on the transfer of some flavour compounds to milk.

/pdf/fungus-pigments-v-degradations-of-cinnabarin-4t19k2l5dr.pdf

Erkki Honkanen

Papers

The Mass Spectra of Some Aliphatic Lactones.

The Kinetics and Mechanism of the Decomposition of 2,4-Dihydroxy-1,4-benzoxazin-3-one.

The Synthesis of Precursor II of Benzoxazolinone Formed in Rye Plants, and the Enzymic Hydrolysis of Precursor I, the Glucoside.

Studies on the transfer of some flavour compounds to milk.

Fungus Pigments. V. Degradations of Cinnabarin.