Wavelength-Dependent Optical Response of Single Photosynthetic Antenna Complexes from Siphonous Green Alga .

The siphonaxanthin-siphonein-Chl-/-protein (SCP) complex from the siphonous green alga is the major light-harvesting complex (LHC) of these alga and is highly homologous to that of green plants (trimeric pigment-protein complex, LHCII). Interestingly, we find remarkable differences in the spectral response from individual SCP complexes when excited at 561 and 639 nm. While excitation in the green spectral range reproduces the common LHCII-like emission features for most of the complexes, excitation in the red spectral range yields a red-shifted emission and a significant reduction of the fluorescence decay time.

Preprocess dependence of optical properties of ensembles and single siphonaxanthin-containing major antenna from the marine green alga Codium fragile.

The siphonaxanthin-siphonein-Chl-a/b-protein (SCP) is the light-harvesting complex of the marine alga Codium fragile. Its structure resembles that of the major light-harvesting complexes of higher plants, LHC II, yet it features a reversed Chl a:Chl b ratio and it accommodates other variants of carotenoids. We have recorded the fluorescence emission spectra and fluorescence lifetimes from ensembles and single SCP complexes for three different scenarios of handling the samples.

Simultaneous purification of fucoxanthin isomers from brown seaweeds by open-column and high-performance liquid chromatography.

Simultaneous purification of fucoxanthin isomers from brown seaweeds by two steps of open-column chromatography (OCC) and reversed-phase (RP)-high-performance liquid chromatography (HPLC) is described. Analysis and identification of fucoxanthin isomers were performed by chromatographic and spectrophotometric properties such as retention time (t), spectral shape, maximal absorption wavelength (λ), Q-ratio, and mass spectrometry (MS) data including the ratio of fragment ions. The optimal conditions for a simultaneous separation and purification were examined by changing several parameters of HPLC, i.

Visible Light-Induced Antibacterial Activity of Pigments Extracted from Dregs of Green and Black Teas.

Chlorophyll and its derivatives are potential natural sensitizers frequently applied in antimicrobial photodynamic therapy. Chlorophyll derivatives are formed naturally during tea processing, but they do not contribute to the color of tea infusions and thus are presumably left in the tea dregs. The present study aimed to investigate (i) the chlorophyll remnants in the pigments recovered from dregs of green and black teas and (ii) the antibacterial activity of pigments extracted from the tea dregs upon illumination using a light-emitting diode (LED) as the light source.

Structures of Astaxanthin and Their Consequences for Therapeutic Application.

Reactive oxygen species (ROS) are continuously generated as a by-product of normal aerobic metabolism. Elevated ROS formation leads to potential damage of biological structures and is implicated in various diseases. Astaxanthin, a xanthophyll carotenoid, is a secondary metabolite responsible for the red-orange color of a number of marine animals and microorganisms.

An Indonesian Marine Bacterium, , Produces Antimicrobial Prodiginine Pigments.

Red pigmented marine bacteria, strains PS1 and SB14, were isolated from two sampling locations in different ecosystems on Alor Island, Indonesia, and cultured in the laboratory. We analyzed the 16S rRNA gene sequences and examined the pigment composition and found that both strains produced cycloprodigiosin (), prodigiosin (), and 2-methyl-3-hexyl-prodiginine () as major compounds. In addition, we detected three minor compounds: prodigiosin derivatives 2-methyl-3-propyl prodiginine (), 2-methyl-3-butyl prodiginine (), and 2-methyl-3-heptyl-prodiginine ().

Sulfur-Containing Carotenoids from A Marine Coral Symbiont Strain KJ5.

strain KJ5 (formerly called sp. strain KJ5) is a yellowish marine bacterium that was isolated from a hard coral in the Karimunjawa Islands, Indonesia. The complete genome sequence of the bacterium has been reported recently.

A comparative look at the first few milliseconds of the light reactions of photosynthesis.

This mini-review describes the current state of our understanding of the structure and function of the photosynthetic light-harvesting and reaction centres. A comparative approach is used in order to highlight the underlying principles that must be satisfied for efficient energy-transfer (light-harvesting) and electron transfer (charge separation in the reaction centres).