Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr...

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Cyclodextr ins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler

description

Utility to Humans Centered in the Torus shaped form, differing interior sizes allow for encapsulation of many target compounds. β-cyclo-dextrin

Transcript of Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr...

Page 1: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Cyclodextrins!

A powerpoint presentation- 4-05-05:evening

Presenting-Addison CarterAdvisor- Dr David Kammler

Page 2: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Cyclodextrins:

α-cyclodextrin- 5 sugar moleculesβ-cyclo-dextrin- 6 sugar moleculesγ-cyclodextrin- 7 sugar molecules

Simply cyclized α-d-1,4-glucopyranose sugar

Page 3: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Utility to HumansCentered in the Torus shaped form, differing interior sizes allow for encapsulation of many target compounds.

β-cyclo-dextrin

Page 4: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Nonpolar centralcavity

Secondary Hydroxyl rim

Primary Hydroxyl Rim

An ether-like central section creates ideal conditions forpreferential spacial arrangement of non-polar compoundsin the central section

The exterior wall retains polar (hydrophilic) sugar-likecharacter which allows for solubility of the cyclodextrin molecule both with and without a guest molecule

Page 5: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.
Page 6: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Bacillus CirculansCyclodextrin glucosyltransferase- Extracted v. in situ

In reaction vats at pH 6.0-7.0 at 35-40 °C.

The source of cyclodextrins

Within starch producing plants

Page 7: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Targets:

Page 8: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Real World AppsDrugs

-solubility-photostability-oxidation prevention-ease of handling

Synthesis-site-selective binding-chiral selectivity-general protecting group

Page 9: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Real World Apps II Environmental Problems

-well water contamination-hypothetically use for heavy metal contamination

Chemical Analysis with HPLC-selective complexation with different target substrates allows for different flow rates for the various target substrates

Enzyme Mimicry?

Page 10: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Polymerization

Terephthalic acid polymerization

Methyl MethacrylatePolymerization

Page 11: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Phase Typed Polymerization

Bulk Solution

Emulsion Dispersion

One Phase

Two Phase

Page 12: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Trouble with polymerization

Surfactants-used in emulsion polymerization, one of the main modes of plastic production-phosphate/sulphate anion base

The problem: Not many readily available natural break down paths

Page 13: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Alternative Mode to Emulsion PolymerizationDispersion Polymerization:

Non-polar Polar

Some small number of monomericunits move into the aqueous phaseto be polymerized.

-rate-polydispersity-phase separation

Essentially this is the question of how much monomer will transverse the interstitial zone between the oiland water layers

Page 14: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

A Potential Solution: Cyclodextrins as Phase

Transfer Agents

Non-Polar

Polar

Complexation

Polymerization

InitiatorIn this the cyclodextrin modulates the transverse activity of the monomer.

Page 15: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

So then, what's the next Question, Considering:-dispersion polymerization is well documented

-with many substrates-in many solvent pairs-with some phase transfer catalysts

-only one person will be working on this project as a four credit class over the course of a semester

-numbers on the equilibria of substrates/substrate-cyclodextrin pairs is not readily available

-we do not have an NMR available to examine complexation

however,

-we do have a Ultraviolet-Visible spectrophotometric machine -cyclodextrin doesn't absorb UV-Vis spectrum light

Page 16: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Thus,

-We can find concentrations of photo responsive chemicals in solution

-in the aqueous layer (as well as the organic layer)with and without Cyclodextrin for each of our targetmolecules

-partition coefficients for those solvated chemicals

AbsorptionMolar AbsorptionConstant

Length of Absorbing sample

Concentrationof absorbing sample

Page 17: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Substrate Choice

- UV-active- polymerizable- soluble- complexable- available from the local stock of chemicals

All these are either mono- or di- substitutedbenzene rings which are known to be quiteUV-active. They are also cheap and polymerizable

Styrene Terephthalic acid p-aminobenzoic acid

p-pentylstyrene

Page 18: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Para-amino benzoic acid(PABA)

-Locally available-PABA is very UV active-soluble in water-soluble in ethyl acetate

The problem

-Too UV active in Ether, Ethyl Acetate, Water, 1-Octanol.1 M?.01 M?.001 M?.0001 M?

Dilution to this level allowed for a scale within machine detection limits.- Not an effective use of time considering the interest was to study partitioning with an eye toward polymerization which would be served via other routes

Page 19: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Terephthalic Acid, the First alternateProblem:Solubility

.1 M

.01 M

.001 M

Styrene, the Second Alternative

Unfortunately past this molarity the accuracy of the scale would be called into question for the amount of solvent that was acceptable.

Problem: Time-Only preliminary testing at .01 M was conducted however absorbance was within the detection envelope for the instrument.-Much lower prep time would result in larger volume of data

Page 20: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

AKA: The 1.5 month time warp

AnInterlude

Concerning the Repair of a Certain Piece of Instrumentation

Vital!to the Continuation of Senior Project

Page 21: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Epsilon Values of PABA in Four SolventsDetermined at .0001M PABA in named solvent

E In Ether

EEE In Ethyl Acetate

In Water

In 1-octanol

20180 at 275 nm

11970 at 284 nm

15650 at 275 nm

13480 at 266 nm

Values taken at the most convenient location along the graph of absorptivity, λ max.

Page 22: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Partitioning Behavior Compared With and without cyclodextrin

.264 at 273nm

.268 at 273nm1 M equivalent CD

Page 23: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

Amount of Cyclodextrin the issue?

.202 at 276nm

10 Molar equivalents of cyclodextrin presentyields lower absorbancethan the previous 1 Molar equivalent system

-instead of complexing with the PABA the peak shifting right may be a sign of ethyl acetate complexation

Page 24: Cyclodextrins! A powerpoint presentation- 4-05-05:evening Presenting-Addison Carter Advisor- Dr David Kammler.

The Road from here:Choice in substrate

-late found resources have recipes in which pure substrate is used as the non-polar phase

example:styrene ON aqueous cyclodextrin mixed -mono-substituted benzene rings-biphenyl

Time to mix-late found materials point to time scale of days for complexation

Substituted cyclodextrin-better match