Natural Products as Antimicrobial Agents

Neanderthals living 60,000 years ago used plants such as hollyhock.

Currently, a significant percentage of pharmaceuticals dispensed in the United States are intended for use as antimicrobials.

Since the 1950s, the use of plant derivatives as antimicrobials has been common.

It is estimated that there are 250,000 to 500,000 species of plants on Earth.

Hippocrates mentioned a large number of medicinal plants in the late fifth century B.C.

Frankincense and myrrh were primarily valued for their medicinal properties.

During the Dark Ages, the Arab world continued to excavate their own older works and build upon them.

Natural products are not an important source of new drugs or templates for the development of new synthetic drugs.

Most of the aromatic substances synthesized by plants are phenols or their oxygen-substituted derivatives.

The Arab world played a significant role in preserving and building upon ancient medicinal knowledge during the Renaissance years.

People on all continents have long applied poultices and imbibed infusions of hundreds, if not thousands, of indigenous plants, dating back to ______.

Currently, of the onequarter to one-half of all pharmaceuticals dispensed in the United States having higher-plant origins, very few are intended for use as ______.

It is estimated that there are 250,000 to 500,000 species of plants on Earth. A relatively small percentage (1 to 10%) of these are used as foods by both humans and other animal species. It is possible that even more are used for ______ purposes.

Hippocrates (in the late fifth century B.C.) mentioned 300 to 400 ______ plants.

The Bible offers descriptions of approximately 30 healing ______.

During the Dark Ages, the Arab world continued to excavate their own older works and to build upon them. Of course, Asian cultures were also busy compiling their own ______.

Natural products are an important source of new drugs or serve as templates for the development of new synthetic drugs, from ______ therapies to antibiotics.

One of the main reasons for exploring natural products with antimicrobial activity is the ever-expanding plasmid transmitted antibiotic resistance genes and the presence of diseases (mainly respiratory and neurological) that are not covered by natural or plant-derived substances. The World Health Organization (WHO) promotes the use of medicinal herbs as remedies to support the absence of conventional treatment. Emphasis is placed on studies of bioactive compounds, their chemical composition, and the pharmacological potential of various plant species to produce compounds with lower toxicity than existing ______.

Due to their numerous benefits, natural compounds are now used to treat some diseases including microbial diseases, inflammatory processes and ______.

Major Groups of Antimicrobial Compounds From Plants Plants have an almost limitless ability to synthesize aromatic substances, most of which are phenols or their oxygen-substituted derivatives. Most are secondary metabolites, of which at least 12,000 have been isolated, a number estimated to be less than 10% of the total. In many cases, these substances serve as plant defense mechanisms against predation by microorganisms, insects, and herbivores. Some, such as terpenoids, give plants their odors; others (quinones and ______) are responsible for plant pigment.