Chlorophyll enhancement

Plenary 3. Ronald E Hester et al, e-mail address reh York.ac.uk (SERS). Use of dioxane envelope to bring water insoluble cliromophores (chlorophylls) into contact with aqueous silver colloids for SERS enliancement. PSERRS— protected surface-enhanced resonance Raman spectroscopy . 

In recent years, metallo-chlorophylls and metaUo-chlorophyllins have been considered alternatives to their natural chlorophyll counterparts due to their enhanced color potency, and greater stability against moderate heat, dilute acids, and oxidative agents in general, not to mention their alleged biological activities. 

Xanthophyll distortion revealed by Raman spectroscopy may not only be an important binding fingerprint but may also be a key functional feature, associated with the altered photophysical behavior and lead to enhancement of excitation energy exchange with chlorophyll. 

Exposed for 35 days to 30, 250, or 3000 pg atrazine/L 100 pg/L, 3-4 weeks 1000 pg/L, 3-4 weeks The high concentration significantly enhanced peroxidase activity but did not affect growth or chlorophyll production (Lytle and Lytle 1998) Biomass reduction of 34% (Stevenson etal. 1982) Biomass reduction of 46% (Stevenson etal. 1982)... 

Many organic chemicals such as chlorophyll, benzophenone, rotenone, aromatic amines and FMN are known to sensitize and enhance photochemical reactions of xenobiotics 3, 4, 5 ). ... 

Ethylene coordinates the expression of genes responsible for enhanced respiratory metabolism, chlorophyll degradation, carotenoid synthesis, conversion of starch to sugars, increased activity of cell wall-degrading enzymes, aroma volatile production, and so on. All these events stimulate a series of biochemical, physiological, and structural changes making fruits mature and attractive to the consumer. 

Surface-enhanced resonance Raman spectra were observed from dye molecules spaced as distant as six spacer increments (ca. 16 nm = 16 A) from the silver surface. These studies suggested that an electromagnetic mechanism is operative in this assembly in contradistinction to a chemical mechanism that would require direct contact between the Raman-active species and the metal surface. These studies are of relevance in the study of chromophoric species in biological membranes (e.g., enzymes, redox proteins, and chlorophylls). 

The high concentration significantly enhanced peroxidase activity but did not affect growth or chlorophyll production (Lytle and Lytle 1998) Biomass reduction of 34% (Stevenson etal. 1982)... 

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