ch chit itosa san Antonio J. Galera-Carrillo, Elizabeth - - PowerPoint PPT Presentation

Heter eroa

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romati matic poly lyphen henol

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ic syste tems s based d on n ch chit itosa san

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Antonio J. Galera-Carrillo, Elizabeth Torres-Párraga, Antonio Franconetti, Francisca Cabrera-Escribano

Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Apartado de Correos No. 1203, 41071 Sevilla, Spain. Fax: +34954624960; Tel: +34954556868; E-mail: agalera@us.es

Aims

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Chitosan

Polyphenolic compounds POLYPHENOLIC SYSTEMS BASED ON CHITOSAN Compounds with expected…

• High biological activity
• High photophysical properties
• Multivalent presentation of polpyphenolic systems through chitosan

Synthesis of polyhydroxysubstituted heteroaromatic complexes

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 Methodology used was previously optimized for this laboratory to obtain p-substituted pyrylium salts  First aim was the synthesis of polyphenolic pyryliums salts, but the presence of any other kind of compounds was detected in some cases by RMN and HRMS: 3-desoxyanthocyanins and flavonoids

Expected

1) Pyrylium salts

Franconetti, A., Contreras-Bernal, L., Jatunov, S., Gómez-Guillén, M., Angulo, M., Prado-Gotor, R., Cabrera-Escribano, F., Physical Chemistry Chemical Physics 2014, 16 (34), 18442-18453

Synthesis of polyhydroxysubstituted heteroaromatic complexes

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2) 3-desoxyanthocyanins

Intramolecular reaction occurs due to the presence of an hydroxy group in ortho- possition of benzaldehyde

Synthesis of polyhydroxysubstituted heteroaromatic complexes

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3) Flavonoids

Intramolecular reaction occurs due to the presence of an hydroxy group in ortho- possition of acetophenone

Chitosan Cromylium and Pyrylium derivates

6 60 ºC 60 ºC

• 4. Franconetti, A., Contreras-Bernal, L., Prado-Gotor, R., Cabrera-Escribano, F. RSC Advances, 2015 5 (91), 74274-74283.

Pyridium Quinolinium

Degree of Substitution (DS)

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H-Aromáticos H1 H3,H4,H5,H6 y H6´ H2 NCOCH3

𝐸𝑇 (%)=

𝐽 𝐼−𝐵𝑠𝑝𝑛𝑏𝑢𝑗𝑑 𝑜 𝐵𝑠𝑝𝑛𝑏𝑢𝑗𝑑 𝐽 𝐼2−𝐼6 6

DS (%) (Example) = 10,3 %

1H-RMN (500 MHz) of chitosan derivate solved in CD3COOD/D2O:

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Conclusion and future work

 Reaction of polyhydroxysubstituted acetophenones with substituted benzaldehydes not only lead to pyrylium salts as expected, but 3- desoxyanthocyanins and flavonoids are also obtained.  Benzaldehydes with an hydroxy group in ortho possition lead to 3- desoxhyanthocyanins while acetophenones with an hydroxy group in same situation originate flavonoids. On the other hand, when there is no exist ortho hydroxy group neither in benzaldehyde nor acetophenone, chalcone or pyrylium salt is obtained.  New quaternized derivatives of chitosan have been synthesized, specifically pyrydinium and quinolinium salts derived from chitosan by reaction of the biopolymer with the corresponding salts of pyrylium and cromylium, respectively.  Photophysical properties and antioxidant capacity of these new compounds must be studied.