Japanese soil was the origin of one of the most important drugs of the world: ivermectin. No other drug has such importance for the health of millions of people, particularly in the poor regions of the world. The discovery of the parent compounds of the avermectines is described first hand by S. Ōmura.

Ivermectin (MK-0933, 22, 23-dihydroderivative of amvermectin B1) is a synthetic derivative of a broadspectrum antiparasitic class of macro cyclic lactones known as avermectins. Avermectin B was first isolated by fermentation of a soil microorganism, the actinomycete Streptomyces avermitilis. Ivermectin has a structure similar to that of macrolide antibiotics, but without antibacterial activity ...

The 2015 Nobel Prize in Physiology or Medicine has been awarded to William C. Campbell, Satoshi Omura, and Youyou Tu for the discovery of avermectins and artemisinin, respectively, therapies that revolutionized the treatment of devastating parasite diseases. With the recent technological advances, a New Golden Age of natural products drug discovery is dawning.

1. Ivermectin belongs to the macrocyclic lactone class of endectocides and consists of a mixture of two homologous compounds, 22,23-dihydroavermectin B1a (H2B1a, not less than 80%) and 22,23-dihydroavermectin B1b (H2B1b, not more than 20%). Avermectins are potent anthelmintic, insecticidal and acaracidal compounds which, by increasing the membrane permeability to chloride ions, mediate the para...

Our chemical syntheses and related scientific investigations of natural products with complex architectures and powerful biological activities are described, focusing on the very large 3 nm-long polycyclic ethers called the ciguatoxins, highly strained and labile chromoprotein antitumor antibiotics featuring nine-membered enediyne cores, and extremely potent anthelmintic macrolides called the a...

Parasitic diseases are widespread, currently affecting about 3 x 109 people and innumerable domestic animals.0 Nematodes (round worms) are a group of most important parasitic organisms. Many attempts have been made to find potent nematocidal substances, however, only a few antibiotics are available in practice.^ Recently, avermectins, which have a potent nematocidal activity and are used in the...