Polyenes

We work with polyenes: highly unsaturated conjugated compounds. Color and antioxidant (electron donator) activity are the predominant properties of polyenes. Polyenes occur, therefore, widespread in nature, e.g. as carotenoids. Polyenes function also as light harvesting antennas in photosynthesis and as molecular wires in nano-devices. Polyenic acids are employed in the synthesis of highly unsaturated lipids, which are used as nucleic acid carriers in gene therapy essays.

Group Members: 2 PhD candidates

Synthesis of polyenes

A microwave assisted Wittig reaction allowed the synthesis, in good yields, of the longest polyene so far recorded with 27 conjugated double bonds. The synthesis of this stable, well-soluble polyene represents a noteworthy step in the direction of ultimate max. The previous record (19 double bonds) was from 1951.
 


The longest polyene

Extending conjugation to the ultimate λmax

Molecular modelling

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Synthesis with polyenes

Polyene thioaldehydes are  not stable and trimerize  instantly to trithiocyclohexane.


Propeller molecule

Polyene thions are stable and form molecular wires on gold.

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Modification of polyenes

We have synthesized a new type of carotenoid with a 2H-pyran ring placed  in the polyene chain. This compound shows a significant increased max compared with carotenoids lacking the pyran ring. The pyranium ring is the distinctive feature of anthocyanidin dyes and has now become an internal part of carotenoids.

structural elements of carotenoids and anthocyanidin

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Polyene carrier molecules for gene therapy

Gene therapy transfers nucleic acids as pharmaceuticals into cells to change genes responsible for diseases. Gene transfer with cationic phospholipids is a rapidly developing branch of gene therapy. We synthesize the lipids and investigate  structure and activity relationship in collaboration with Weill Cornell Medical College, Doha, Qatar,- Stevens Institute of Technology, Hoboken, USA,-
Royal Holloway-University of London,- Center for Molecular and Structural Biomedicine, Faro, Portugal.

Test on genetic diseases:

  • Cervic cancer
  • Breast cancer
  • Ocular cancer
  • Muscular dystrophy

Polyene carrier with siRNA on cervic cancer cells

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Polyene lipids-highly unsaturated fats

Details about structure and morphology of lipids + nucleic acids (lipoplexes) are important parameters for cell penetration. Yet, shape and size of lipoplexes vary. We intend to prepare  nucleic acid carriers of defined size by forming monolayers from selenium lipids bound to gold-nanoparticles of predefined size.

Polyene-gold nanoparticles as gene carrier of defined size



Polyene on gold nanoparticles

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Polyene salts

The double bond chain in polyene - rare earth salts can act as a light antenna and might transfer the radiation energy to Europium (or other rare earth elements) thus possibly increasing its fluorescence.

Polyene as antenna for Europium (Eu) fluorescence

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Contact

Vassilia Partali - Leader Polyenes Group. Photo: Per Henning/NTNU

Vassilia Partali
Professor
E-mail: vassilia.partali@ntnu.no
More contact information