LOW MOLECULAR NITROGEN COMPOUNDS OF MARINE ALGAE
摘要
l\\1any studies devoted to the isolation of the constitutions of plants and to the determination of the structures of natural products have been conducted from thc latter part of the last century. Since Tswett succeeded in the separation of leaf pigments using column chromatographic techniques at the beginning of this century, chromatographic methods prevailing at present such as paper chromato-graphy, ion-exchange chromatography and thin-layer chromatography have been developed and established. These methods have come to be among the most potent tools the biological chemist possesses. They allow the components of a complex mixture of natural products to be resolved from each other with speed and precision, and thus can be used to detect promptly unknown substances. With the advance of these chromatographic procedures which facilitated the discovery of additional plant products, other new physicochemical methods have been developed and applied to the structure determination. The following four techniques are of outstanding importance: infrared and ultraviolet spectroscopy, nuclear magnetic resonance spectroscopy and mass spectrometry. By using these