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.

Recent advances in traditional plant drugs and orchids.

Therapeutic orchids: traditional uses and recent advances--an overview.

Chemical constituents from Dendrobium densiflorum.

The fresh or dried stems of many Dendrobium species are well known as one of the most expensive tonics in traditional Chinese medicine Documented as a “superior grade” herbal medicine in the ancient text “Shen Nong’s Herbal Classic”, Dendrobium has been used for thousands of years and is now a popular health food worldwide The main chemical components of Dendrobium are alkaloids, aromatic compounds, sesquiterpenoids and polysaccharides, with multiple biological activities, including immunomodulatory, neuroprotective and anti-tumor effects, etc Various qualitative and quantitative methods have been developed for the quality evaluation of Dendrobium In this review, the research progress since the 1930s relating to the chemistry, bioactivity and quality control of Dendrobium is summarized, existing problems and prospects are also discussed

Chemistry, bioactivity and quality control of Dendrobium, a commonly used tonic herb in traditional Chinese medicine

A commercial aqueous smoke preparation was exhaustively extracted, using dichloromethane as solvent, until the carrier had totally lost its smoky odor. Qualitative and quantitative characterizations of the extract were performed by means of gas chromatography/mass spectrometry and gas chromatography with flame ionization detector, respectively. Carbonyl derivatives including aldehydes and ketones as well as acids and esters are almost absent; however, the high proportion of phenol, guaiacol, and syringol derivatives is noticeable. The presence of di-tert-butylhydroxytoluene, several hopanes, and a number of lignin dimers must be pointed out; these latter components had apparently not been detected before either in smoke flavorings or in wood smoke. The mass spectral data of the compounds considered as lignin dimers and of the unidentified components are given. The presence of lignin dimers is very interesting from the point of view of health and food technology for their therapeutic, organoleptic, and antioxidant properties.

P.L. Majumder

Papers

Moscatilin, a bibenzyl derivative from the orchid Dendrobium moscatum