Spectroscopic Study on the Interaction of Human Cytoglobin with Copper(â ¡) Ion.

Cytoglobin (Cygb), a recently discovered member of the vertebrate globin family, exhibits a traditional globin fold with a three-over-three α-helical sandwich. The interaction between copper(Ⅱ) ion (Cu2+) and Cygb has been investigated by UV-Vis, fluorescence, synchronous fluorescence and circular dichroism (CD) spectra. Results showed that the absorption intensity of Cygb at 280 nm increased and the intrinsic fluorescence of Cygb was quenched when Cu2+ was added. This fluorescence quenching of Cygb has been proven that it belongs to static quenching. The synchronous fluorescence spectra indicated that there were small changes about the microenvironment of tryptophan residues and tyrosine residues; furthermore, the binding site of Cu2+ is closer to tryptophan residues than tyrosine residues. No obvious change was observed about the secondary structure of Cygb with the addition of Cu2+ from the CD spectra.

Analysis and biological activities of anthocyanins.

Anthocyanins are naturally occurring compounds that impart color to fruits, vegetables, and plants. They are probably the most important group of visible plant pigments besides chlorophyll. Apart from imparting color to plants, anthocyanins also have an array of health-promoting benefits, as they can protect against a variety of oxidants through a various number of mechanisms. However, anthocyanins have received less attention than other flavonoids, despite this. This article reviews their biological functions and pre-clinical studies, as well as the most recent analytical techniques concerning anthocyanin isolation and identification.

Recent advances in traditional plant drugs and orchids.

The main objective of this paper is to review recent advances in plant drug research and developments in orchid study, in an attempt to provide useful references for plant drug studies. Plants have been used as medicine for millennia. Out of estimated 250 000 to 350 000 plant species identified so far, about 35 000 are used worldwide for medicinal purposes. It has been confirmed by WHO that herbal medicines serve the health needs of about 80 percent of the world's population; especially for millions of people in the vast rural areas of developing countries. Meanwhile, consumers in developed countries are becoming disillusioned with modern healthcare and are seeking alternatives. The recent resurgence of plant remedies results from several factors: 1) the effectiveness of plant medicines; 2) the side effect of most modern drugs; and 3) the development of science and technology. It has been estimated that in the mid-1990s over 200 companies and research organizations worldwide are screening plant and animal compounds for medicinal properties. Actually, several important drugs used in modern medicine have come from medicinal plant studies, eg, taxol/paclitaxel, vinblastine, vincristine, topotecan, irinotecan, etoposide, teniposide, etc. As for drugs derived from orchids, some novel discoveries, both in phytochemical and pharmacological properties, were reported by some universities. However, studies on plants are very limited. Only about a third of the million or so species of higher plants have been identified and named by scientists. Of those named, only a tiny fraction has been studied. Nowadays the linking of the indigenous knowledge of medicinal plants to modern research activities provides a new approach, which makes the rate of discovery of drugs much more effective than with random collection.