Lecture 10 Flashcards
(18 cards)
What is total synthesis?
Complete chemical synthesis of a complex natural product from simple, commercially available starting materials.
Often involves many steps (up to 100+), requires advanced synthetic chemistry skills, and is a competitive field.
What are the pros of total synthesis?
Can produce natural products without relying on scarce natural sources.
Useful for creating novel analogues that may be better drugs.
What are the cons of total synthesis?
Often time-consuming, costly, and complex.
What is semi-synthesis?
Combines biological production (biosynthesis) with chemical synthesis.
A precursor is biosynthesized in a natural source, then chemically converted into the final natural product or analogue.
What are the advantages of semi-synthesis compared to total synthesis?
Reduces the number of chemical steps and is often cheaper and more practical for commercial production.
Provide an example of semi-synthesis.
Paclitaxel semi-synthesis uses 10-Deacetylbaccatin (from yew needles), converted chemically to paclitaxel.
What is biosynthesis?
Natural enzymatic pathways inside organisms produce complex natural products from primary metabolites.
Enzymes assemble products using pathways like the mevalonate or shikimate pathways.
What is a key feature of biosynthesis?
Precise stereochemistry and complex structures formed naturally.
Give an example of a natural product produced through biosynthesis.
Artemisinin is biosynthesized in Artemisia annua via the mevalonate pathway.
What are the key challenges related to the extraction of natural products?
Natural products are often too complex or scarce for direct extraction on a large scale.
What is the significance of the case study on Paclitaxel?
Illustrates the low yield from natural sources and the application of both total and semi-synthesis for commercial use.
How is Paclitaxel produced semi-synthetically?
Uses 10-Deacetylbaccatin from renewable yew needles, which is converted chemically to paclitaxel.
What is the mechanism of action for artemisinin?
Endoperoxide reacts with iron in the parasite, generating radicals that kill the parasite without harming human cells.
What is the main takeaway regarding total synthesis?
Provides full chemical control but is resource-intensive.
What is the role of analogues in drug development?
Often required to improve drug-like properties such as bioavailability, toxicity, and cost.
True or False: Total synthesis is always the preferred method for drug development.
False. Semi-synthesis can be more practical and sustainable.
Fill in the blank: Semi-synthesis leverages nature’s _______ for precursors, then completes synthesis chemically.
biosynthetic machinery
What are the key processes that illustrate the interplay in natural product drug development?
Total synthesis, semi-synthesis, and biosynthesis.
