Medicinal ChemistryUrgent need to study medicinal plants 1. To rescue knowledge in imminent danger of being lost Inventory by WHO found 20,000 plant species in use for medicine in 90 countries Only 250 of those species are commonly used or have been checked for main active chemical compounds Urgent need to study medicinal plants 2. The utility of plants in current therapy There has been a rush to develop synthetic medicines based on plant medicines, but often the synthetic medicines don’t work as well as the original plant medicines. For example – quinine and malaria .Efficacy of Quinine • Quinine is traditional and effective preventative of malaria • Synthetic preventatives such as chloroquine. maloprim. It is recommended that people do not take fansidar for more than 3 months due to potential liver damage. and fansidar have largely replaced the use of quinine • Many strains of Plasmodium have developed resistances to the synthetics and the synthetics are more toxic. Malaria Cycle . Anopheles freeborni mosquito – intermediate host and vector for Plasmodium sp. . Historical distribution of Malaria . Red areas show countries with malaria today . One of the sources of Quinine – Cinchona succirubra . Cinchona pubescens . Carl Linneaus named the tree genus Cinchona .Timeline of Quinine Use • 1633.use of the bark became so widespread that in the papal conclave of 1655 no one died of malaria • 1654 – English aware of use of quinine bark • 1735. a French botanist named Joseph de Jussieu journeyed to South America and found and described the tree that is the source of the bark .he sent samples to Sweden where in 1739. a Jesuit priest named Father Calancha described how to use quinine bark to cure fevers • 1645 Father Bartolome Tafur took some bark to Rome and many of the clergy used it • Cardinal John de Lugo wrote a pamphlet to be distributed with the bark . 97% of the world’s market . the Dutch orchards in Java produced 22 million pounds of quinine.Timeline of Quinine Use • 20 to 40 species of Cinchona . so the exact number of species is unknown – mostly understorey trees • 1820 the French chemists Joseph Pelletier and Joseph Caventou isolated the alkaloid quinine from the bark and identified it was the active ingredient in Peruvian bark • 1861. an Australian named Charles Ledger obtained seeds from an Aymara Indian named Manuel Incra • by 1930.the species are very hard to tell apart and the species will hybridize. Chemical structure of quinine . it is also used as a flavoring agent • Quinine prevents malaria by suppressing reproduction of the Plasmodium and also helps prevent some of the fevers and pain associated with malaria .Properties of Quinine • Quinine itself is an odorless white powder with an extremely bitter taste • It can be used to treat cardiac arrhythmias as well as malaria . Quinine fluoresces under UV light . Raymond Fosberg in the field in 1948 . Cinchona bark drying in the sun in Ecuador. 1944 . .Urgent need to study medicinal plants 3. To find new molecular models in plants Many times we can take a plant chemical and modify it or make synthetic copies of it that are very valuable to us. Lippia dulcis – sweetener from Pre-Columbian America . • In the 20th century. dulcis was chemically analyzed and a new sweetener was found. Verbenaceae – the verbenas). (F. . hernandulcin. L. that is 800 to 1000 times sweeter than sucrose.Lippia as a sweetener • In Pre-Columbian America. several plants of the genus Lippia were used as sweeteners. Urgent need to study medicinal plants 4. Another benefit is that most medicinal plants don’t have the kinds of harmful side effects seen with synthetic drugs. . The wide use of plants in folk medicine One positive aspect of the use of medicinal plants is their low cost compared to the high price of new synthetic drugs that are totally inaccessible to the vast majority of the world’s people. Plants and Human Cosmologies . Cosmologies Cosmologies are branches of philosophy which deal with the origins and structures of the universe .religions that explain how the universe formed and our place within it are one kind (a very powerful kind) of cosmology . The Oak of Guernica . Basque coat of arms with Oak of Guernica . . or April's tender shower? Stroke merciful and welcome would that be Which should extend thy branches on the ground. Guardians of Biscay's ancient liberty. The dews of morn.Oak of Guernica by Wordsworth . Or the soft breezes from the Atlantic sea. If never more within their shady round Those lofty-minded Lawgivers shall meet. what joy can sunshine bring to thee.1810 • THE OAK OF GUERNICA The ancient oak of Guernica. says Laborde in his account of Biscay. What other interest belongs to it in the minds of this people will appear from the following. under which they swore to the Biscayans to maintain their "fueros" (privileges). after hearing mass in the church of Santa Maria de la Antigua. in the year 1476. Peasant and lord. is a most venerable natural monument. in their appointed seat. Ferdinand and Isabella. repaired to this tree. SUPPOSED ADDRESS TO THE SAME OAK of Guernica! Tree of holier power Than that which in Dodona did enshrine (So faith too fondly deemed) a voice divine Heard from the depths of its aerial bower-How canst thou flourish at this blighting hour? What hope. Guernica by Picasso . The Fall by Michelangelo – detail from ceiling of the Sistine Chapel . Moses and The Burning Bush . The sacred Maori Waka Huia . The sacred Maori Waka Huia . Miro tree – Podocarpus ferruginea .