INTRODUCTION
Naturally occurring medicines are drugs that that are used most extensively before science and technology advanced fast enough to identify the compounds effectively. It was later when people were able to isolate the active pharmalogical compounds and identification techniques were available.
Modern medicine can come from various sources, such as natural sources like plants and animals; it may also be synthesized chemically. Some of the medicines obtained from total synthesis are still described as naturally occurring medicines because the substances synthesized are available from natural sources. Some of the naturally occurring medicines include pain killer aspirin (acetylsalicylic acid) and insulin (although synthesized in human body, it is also administered as medicine to insulin-deficient patients.).
Even as science and technology advanced, the use of traditional medicine (that originated from the use of naturally occurring medicines) has not ceased. Many traditional medicine practitioners advocate the use of the medicine in its most natural form for the best results.
Despite that, it has always been scientists’ insatiable curiosity to find out the structures of naturally occurring medicines. With the help of today’s modern technology and methods in science, scientists are able to do so quite effectively.
Some of these methods are employed in organic chemistry analytical identification as well, because these naturally occurring medicines should come from an organic source (i.e. plants and animals).
SPECTROSCOPY & MAGNETIC RESONANCE
The methods encompass the use of spectrometry and spectroscopy methods, which measures the interaction of the substances with electromagnetic waves or frequencies of certain species (e.g. mass) in the spectrometric method. Another method is also to use nuclear magnetic resonance (NMR) which makes use of the fact that all atoms have an intrinsic quantum property of nuclear spin.
COMBINATION OF METHODS
The methods employed are analytical methods, that is, the structures are not known instantly; further analysis or more than one analytical method are necessary and further tests are required to test the analysis findings. For example, the NMR spectra may signal the existence of a certain functional group (alkyl, amine, carboxylic acid, or alcohol), the other spectra would probably be used to confirm this.
X-RAY DIFFRACTION
Some of the biological medicines are not exactly a chemical compound, but a macro molecule, such as a protein. The use of the methods above cannot be used to gain appreciable value, as some of these proteins are folded into specific shapes to give site-specific active sites. Hence sometimes scientists want to retain the folded structures of these macromolecules so they have to use non-invasive methods that do not break up the molecules into smaller fragments.
For biological molecules, x-ray diffraction is often used to observe the structures of these macromolecules, so that the interactions with the molecules with the specific sites may be investigated more effectively. Many of the molecule structures of the proteins and enzymes available in the protein data bank (www.rcsb.org) are obtained via x-ray diffraction methods at high resolutions.
