Nitrogen-rich secondary

Nitrogen-rich secondary metaboiites at high elevation. 

Nitrogen-rich secondary metabolites at high elevation. 

Table I shows the amounts of secondary metabolites formed on days 11 and 33 (during an incubation of 63 days) for both nitrogen-poor (HC/LN) and nitrogen-rich (HC/HN) cultures (15). The initial C/N ratios of the two cultures were 240 and 24, respectively. Figure 3 shows the variations in the total amounts of the secondary metabolites produced, the weights of the fungal mycelium, and the nitrogen and glucose concentrations remaining in the HC-LN culture media during the incubation period shown.

The same authors (Parthasarathy et al. 1983) undertook also to examining the C and N abundances in the secondaries of the same two Algol systems, with application of the spetrum synthesis method. The result obtained suggests that in the two cases the late-type mass-losing components are carbon-deficient, Ip/Fej i-0.5, and nitrogen-rich,[N/FeJ v+0.5. 

Nitrate-rich secondary aerosol, mainly composed of ammonium nitrate, on the other hand, is predominantly formed on medium spatial scale and hence may have its major origin within Germany. Large sources for NH3, one of the aerosol precursor compounds, are located in the agricultural areas of north-western Germany ( Swine belt ). The other precursors, oxides of nitrogen, stem mainly from industrial and traffic-related combustion sources. 

The radical cation of cysteine, Cys, serves as an example of the first and third point.This amino acid contains two potential donor sites, sulphur and nitrogen, so electron transfer to an excited sensitizer could result in a sulphur-centred or a nitrogen-centred radical cation. Decarboxylation of Cys to give an a-amino alkyl radical occurs on a timescale slightly faster than 1 ns, so a direct observation by EPR is not feasible. However, the CIDNP spectrum with 4-carboxybenzophenone CB as the sensitizer exhibits polarizations of the starting amino acid, which can only be the product of reverse electron transfer of pairs Cys " CB but obviously not in any way the product of the radical pairs formed by the decarboxylation. Concentrating on the cysteine polarizations thus avoids all complication due to the rich secondary chemistry. ... 

The chemistry of elemental sulfur and sulfur-rich molecules including polysulfides in liquid ammonia [82] and in primary as well as secondary amines [83] is complex because of the possible formation of sulfur-nitrogen compounds. Therefore, polysulfide solutions in these solvents will not be discussed here. Inert solvents which have often been used are dimethylfor-mamide (DMF) [84-86], tetrahydrofuran (THF) [87], dimethylsulfoxide (DMSO) [87], and hexamethylphosphoric triamide (HMPA) [86, 88]. 

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