Biocatalysis

Dr. Mohamed Abd-Elhakeem

Faculty of Biotechnology

Organic Chemistry

Chapter 5

It is a fact organic synthesis change our

recent life. Each one use at least one

synthetic product every day

But the price was very high

Synthesis industry introduces contaminants into a natural environment that causes instability, disorder of brain, harm the ecosystem i.e.

components of pollution, can be either foreign substances or energies

World need a safe chemicals.

Need environmentally friendly

chemistry

Need Green Chemistry

Green chemistry, is the design of

chemical products and processes

that reduce or eliminate the use or

generation of hazardous substances.

The Green Chemistry program supports the invention of more environmentally friendly

1- chemical processes 2- Chemicals

This program works very closely with the of Green Chemistry.

twelve principles

Prevent Waste Design chemical syntheses to prevent waste, leaving no waste behind to clean up or treat.

Maximize Atom Economy Design syntheses so that the final product incorporates the maximum amount of raw material used to create it, leaving few or no atoms behind.

Design Less Hazardous Chemical Syntheses

Design syntheses to use and generate substances with little or no toxicity to human health or the environment whenever possible.

 

 

Create Safer Chemicals Design chemical products to be fully effective while minimizing or eliminating toxicity.

Use Safer Solvents and Auxiliaries Create processes that utilize innocuous auxiliary substances (such as water and eco-friendly materials) as solvents or separation agents. Otherwise, avoid using auxiliaries at all.

Design for Energy Efficiency Conduct chemical processes at ambient temperature and pressure whenever possible.

Use Renewable Feedstock Utilize renewable raw materials and feedstock whenever technically and economically practical, rather than depleting non-renewable materials.

Reduce Derivatives Minimize or avoid the use of blocking or protecting groups and avoid making temporary modifications when possible. Derivatives require additional reagents and generate waste.

Use Catalysts Instead of Reagents Minimize waste by using catalytic reactions that use small amounts of materials.

Design for Degradation Design chemical products that break down at the end of their use and do no persist in the environment.

Prevent Pollution in Real Time Make real-time, in-process monitoring, analysis and control part of your process to minimize or eliminate the formation of hazardous byproducts.

Minimize the Potential for Accidents Design chemicals and their forms (such as liquid, solid or gas) in such a way as they minimize the potential for chemical accidents including explosions, fires and toxic releases into the environment.

Classic Route to Ibuprofen

Ac2O

AlCl3

COCH3

HCl, AcOH, Al Waste

ClCH2CO2Et

NaOEt

OEtO2C

HCl

H2O / H+

OHC

AcOH

NH2OH

OHNN

H2O / H+

HO2C

NH3

H o e c h s t R o u t e T o I b u p r o f e n

O

H F

A c O H

A c 2 O

H 2 / N i

OH

C O , P d

H O 2 C

Biocatalysis

Biocatalysis is the use of enzymes as catalysts

to perform chemical transformations on

organic compounds.

HISTORY

Biocatalysis underpins some of the oldest chemical

transformations known to humans,

The oldest records of brewing are about 6000 years

old and refer to the Sumerians.

The employment of enzymes and whole cells have

been important for many industries for centuries.

The most obvious uses have been in the food and

drink businesses where the production of wine,

beer, cheese and yogurt.

More than one hundred years ago, biocatalysis

was employed to do chemical transformations on

non-natural man-made organic compounds

the last 30 years have seen a substantial increase

in the application of biocatalysts to produce fine

chemicals, especially for the pharmaceutical

industry.

Organic chemistry

Biochemistry

MicrobiologyMolecular biology

Biocatalysis

ADVANTAGESI- Selectivity/Specificity

Substrate selectivity – ability to distinguish a particular compound from among a mixture of chemically related compounds.

1-Chemo selectivity: Functional group selectivity – ability to act on one functional group selective even when other groups may be more chemically reactive

2- Regio selectivity: distinguish between functional groups which are chemically situated in different regions of the substrate molecule.

3- Stereo selectivity – ability to act on a substrate or produce a product of one Enantiomeric or diastereomeric form

II. Mild reaction conditions – most enzymes operate in aqueous solution, at mild temperatures and pH’s, and at atmospheric pressure. While

Chemical catalysts often require organic solvents, high temperatures, extremes of pH and high pressure. Enzymes can therefore result in lower energy and materials cost.

III. Environmentally friendly, ie, “green chemistry” proteins are naturally biodegradable, aqueous solution avoids solvent waste, lower energy costs = lower emissions IV. High catalytic efficiency high turnover numbers, ie, substrate molecules catalyzed per molecule of enzyme, resulting in less catalyst required to complete the conversion

1. Oxidoreductase (dehydrogenase) Catalyze redox reactions, usually NAD is used as a coenzyme

2. Transferases (acylase, phosphorylase) Catalyze transfer of a molecular group from one molecule to another

3. Hydrolases (esterase, lipase) Catalyze bond cleavage by the introduction of water

ENZYME CLASSIFICATION

4. Lyases!(a.k.a synthase - decarboxylase) Cleavage of C-Y (C or heteroatom) bonds to form double bonds or rings (or reverse rxn.)

5. Isomerases (racemase, epimerase) Catalyze reactions involving intramolecular rearrangements

6. Ligases (a.k.a. synthetase - DNA ligase) Formation or cleavage of C-Y (C or heteroatom) bonds with triphosphate (ATP) hydrolysis

importance inorganic synthesis

function Name Class

High Oxidations and reductions Oxidoreductases 1

Low Transfer of functional groups Transferases 2

Very high Hydrolysis and condensation reactions

Hydrolases 3

Medium Addition of small molecules to double bonds and eliminationReactions

Lyases 4

Low Isomerization reactions Isomerases 5

Low Formation of covalent bonds Ligases 6

The high value of hydrolase enzymes is due to

1- Their stability at different pH 2- they can be used in organic solvents 3- they don’t need cofactors from the

cell