SUPPLEMENTARY DATA FOR:

Valorization of monosaccharides towards fructopyrazines in a new sustainable and efficient eutectic medium

Svitlana Filonenko*, Antje Foelkel and Markus Antonietti

Max Planck Institute of Colloids and Interfaces Research Campus Golm14424 PotsdamGermany

Corresponding Author E-mail: svitlana.filonenko@mpikg.mpg.de

Electronic Supplementary Material (ESI) for Green Chemistry.This journal is © The Royal Society of Chemistry 2019

Materials

Saccharides arabinose (Alfa Aesar, 99%), xylose (Roth, 99%), glucose (Roth, 99%), fructose (Sigma-Aldrich, 99%), mannose (Alfa Aesar, 99%), galactose (Roth, 97%), sucrose (Sigma-Aldrich, 99%), maltose (Roth, 99%) were used without further purification. Due to the high hydrophobicity, ammonium formate (Alfa Aesar, 98%) was dried in the vacuum oven at room temperature for 24 hours prior the use in reaction.

Table S1. Composition of the eutectic mixtures

Entry Sample Type of saccharide Saccharides used as HBD component

Ratio saccharide /ammonium formate

1 EM-A arabinose 1:1

2 EM-Xpentoses

xylose 1:1

3 EM-G glucose 1:0.5, 1:0.75, 1:1, 1:1.2, 1:1.5

4 EM-F fructose 1:1

5 EM-Man mannose 1:1

6 EM-Gal

hexoses

galactose 1:1

7 EM-S sucrose 1:2

8 EM-Maldisaccharides

maltose 1:2

2.53.03.54.04.55.05.56.06.57.07.58.08.5δ/ ppm

6.43

1.01

1.00

8.14

8.27

8.40

8.55

2.53.03.54.04.55.05.56.06.57.07.58.08.5δ/ ppm

4.26

1.03

1.00

8.13

8.20

8.45

8.63

0102030405060708090100110120130140150160170180190200210δ/ ppm

0102030405060708090100110120130140150160170180190200210δ/ ppm

Fig. S1. 1H and 13C NMR spectra (D2O) of reaction mixture of ammonium formate with glucose, representing formation of 2,6-DOF (A and C, respectively), and ammonium formate with fructose, representing 2,5-DOF formation (B and D, respectively). The signals in 1H are not allowing distinguishing between the formation of 2,5-DOF and 2,6-DOF, while 13C NMR spectra give a different signals.

C

D

A

B

Pyrazine ring carbons

Pyrazine ring carbons

2.53.03.54.04.55.05.56.06.57.07.58.08.5δ/ ppm

2.50

DM

SO

8.25

0102030405060708090100110120130140150160170180190200210δ/ ppm

N

N OOO

O

O

O

O

H H

HH

HH

H H

HH

HH HH

H

H

H

H

H

Fig. S2. 1H and 13C NMR spectra (d6-DMSO) of crude reaction mixture of ammonium formate with glucose after freeze drying, representing formation of 2,6-DOF (A and B, respectively); the signal at 8.25 ppm corresponds to protons of formate anions ionically bonded to 2,6-DOF; 1H spectrum (D) predicted for the structure of 2,6-DOF (C). 1-3

C

D

A

B

0 day 1 day 2 day 3 day 4 day 5 day 7 day 14 day

Fig. S3. Physical occurrence of the ammonium formate / glucose mixture kept at room temperature over time

2.53.03.54.04.55.05.56.06.57.07.58.08.5δ/ ppm

0102030405060708090100110120130140150160170180190200δ/ ppm

2.53.03.54.04.55.05.56.06.57.07.58.08.5δ/ ppm

0102030405060708090100110120130140150160170180190200δ/ ppm

Fig. S4. 1H and 13C NMR spectra of the mixture of ammonium formate with glucose kept at room temperature for five days (A and B, respectively) and two weeks (C and D, respectively) representing different degree of 2,6-DOF formation.

C

D

A

B

2.53.03.54.04.55.05.56.06.57.07.58.08.59.0δ/ ppm

8.08.18.28.38.48.58.68.78.88.99.0δ/ ppm

Fig. S5. In situ 1H NMR spectra as a function of reaction time for the fructose transformation in eutectic medium in isochoric process at 80 °C.

0 min

60 min

30 min

90 min

120 min

150 min

180 min

210 min

270 min

Fig. S6. Identification of reaction products by UHPLC-MS method: representative UHPLC chromatogram of reaction mixture of ammonium formate with mannose (A), galactose (B), arabinose (C), xylose (D) incubated at 90 °C for 4 hours, and product ion scans (MS/MS spectra) corresponding to respective pyrazine derivatives formed.

C

D

A

B

Fig. S7. Identification of reaction products by UHPLC-MS method: representative UHPLC chromatogram of reaction mixture of ammonium formate with sucrose (A), maltose (B), incubated at 90 °C for 4 hours, and product ion scans (MS/MS spectra) corresponding to respective pyrazine derivatives formed

A

B

Hexoses

Pentoses

Disaccharides

Fig. S8. Formulas of corresponding saccharides and the 1H NMR spectrum of bare mixture after reaction with ammonium formate for 4h at 90 °C: glucose (A), fructose (B), mannose (C), galactose (D), arabinose (E), xylose (F), sucrose (J), maltose (K).

mannose galactosefructose

arabinose

maltosesucrose

xylose

A

A

A

B

C

D

E

F

J

K

Fig. S9. TGA–MS weight loss and derivative of weight loss curves for ammonium formate / glucose mixture (A); mass spectra from thermal dermal decomposition of ammonium formate / glucose mixture (B)

100 200 300 4000

10

20

30

40

50

60

70

80Mass fragments m/z = 16 m/z = 17 m/z = 18 m/z = 29 m/z = 44

Temperature, °C

Ion

curr

ent,

10-1

0 A

20

40

60

80

100

Mas

s lo

ss, %

100 200 300 400

0,05

0,10

0,15

0,20

0,25

0,30

0,35

0,40

0,45Mass fragments m/z = 12 m/z = 30 m/z = 15 m/z = 45 m/z = 19 m/z = 46 m/z = 20

Temperature, °C

Ion

curr

ent,

10-1

0 A

20

40

60

80

100

Mas

s lo

ss, %

50 100 150 200 250 300 350 40020

40

60

80

100

TGA

Temperature, °C

TGA %

DTG mg/min

-0,30

-0,25

-0,20

-0,15

-0,10

-0,05

0,00

DTG

A

B

Fig. S10. DSC measurement of fructose / ammonium formate mixture in temperature range from -90 to 60 °C, heating/cooling rate is 10.0 °C/min; sample was heated from room temperature to 60 °C in order to form the eutectic mixture and cooled down immediately to avoid the reaction between the components

200 300 400 500 600

0,0

0,5

1,0

reaction temperature 60 C reaction temperature 80 C reaction temperature 90 C reaction temperature 100 C

N

N

R1,R2Ab

sorb

ance

/ a.

u.

Wavelength / nm

275

Fig. S11. UV-vis spectra of eutectic mixture solutions after reaction showing formation of (polyhydroxyalkyl)pyrazines formation.

4000 3500 3000 2500 2000 1500 100070

80

90

100

90

Tran

smitt

ance

/ %

50

100Tr

ansm

ittan

ce /

%

c

b

Tran

smitt

ance

/ %

/ cm-1

aC N N

N

R

Fig. S12. FTIR spectra of eutectic mixture of glucose with ammonium formate after reaction (a), pristine glucose (b) and ammonium formate (c).

References

1. Banfi, D.; Patiny, L. www.nmrdb.org: Resurrecting and processing NMR spectra on-line Chimia, 2008, 62(4), 280-281. 2. Andrés M. Castillo, Luc Patiny and Julien Wist. Fast and Accurate Algorithm for the Simulation of NMR spectra of Large Spin Systems. Journal of Magnetic Resonance 2011. 3. Aires-de-Sousa, M. Hemmer, J. Gasteiger, “ Prediction of 1H NMR Chemical Shifts Using Neural Networks”, Analytical Chemistry, 2002, 74(1), 80-90.