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During the past fifty years, thousands of natural products have
been isolated from plants, fungi, and bacteria. Apart from intense
searches by pharmaceutical companies for medicinals and the
concentrated effort mounted by the National Cancer Institute, many
of these have not been tested in biological systems. The major
reasons for this appear to be, at least, twofold. First, individual
researchers looking for biologically active natural products will
often isolate only small amounts of material sufficient to
determine a structure and calculate the specific activity for their
particular bioassay systems: insufficient funds preclude
re-isolating the compound unless industrial potential is foreseen.
Second, the difficulty with which original structures were proved
prior to 1972. This required the isolation of relatively large
quantities of a natural product and there followed extensive
degradation, elemental analyses of the parent and its fragments,
then synthesis, piece by piece, of the molecule. All this took time
and energy. No wonder that when the structure was proved the
chemist was enervated. And coupled to this was the fact that many
chemists were not trained to test their materials in biological
systems. In contrast, today a natural product can be isolated, its
mass and molecular formula determined and, if there is some
serendipity, crystals may be obtained for single crystal x-ray
analysis. If conditions are near perfect, it is possible to isolate
and identify a novel compound in a month.
During the past fifty years, thousands of natural products have
been isolated from plants, fungi, and bacteria. Apart from intense
searches by pharmaceutical companies for medicinals and the
concentrated effort mounted by the National Cancer Institute, many
of these have not been tested in biological systems. The major
reasons for this appear to be, at least, twofold. First, individual
researchers looking for biologically active natural products will
often isolate only small amounts of material sufficient to
determine a structure and calculate the specific activity for their
particular bioassay systems: insufficient funds preclude
re-isolating the compound unless industrial potential is foreseen.
Second, the difficulty with which original structures were proved
prior to 1972. This required the isolation of relatively large
quantities of a natural product and there followed extensive
degradation, elemental analyses of the parent and its fragments,
then synthesis, piece by piece, of the molecule. All this took time
and energy. No wonder that when the structure was proved the
chemist was enervated. And coupled to this was the fact that many
chemists were not trained to test their materials in biological
systems. In contrast, today a natural product can be isolated, its
mass and molecular formula determined and, if there is some
serendipity, crystals may be obtained for single crystal x-ray
analysis. If conditions are near perfect, it is possible to isolate
and identify a novel compound in a month.
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