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Green Chemistry
acid and 24 mmol of ethylene glycol were catalyzed by total weight of equivalent amount of behenic acid) in 10 mL
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Novozym 435 (6% of total weight of equivalent amount of t-BuOH for 24 h. White solid; Rf 0.31; m.p. 83.33 °C; H NMR
behenic acid) in 5 mL t-BuOH for 12 h. White solid; Rf 0.69; m. (400 MHz, CDCl3, 25 °C, TMS): δ = 4.15–4.06 (m, 2H, –CH2–O–
p. 70.59 °C; 1H NMR (400 MHz, CDCl3, 25 °C, TMS): δ = CvO), 3.90–3.84 (m, 1H, –CH–OH), 3.70–3.64 (m, 1H, –CH–
4.25–4.18 (m, 2H, –CH2–O–CvO), 3.87–3.79 (m, 2H, –CH2– OH), 3.62–3.55 (m, 2H, –CH2–OH), 3.53 (t, J = 3.5 Hz, 1H,
OH), 2.32 (t, J = 7.6 Hz, 2H, –CH2–CvO), 2.15 (bs, 1H, –OH), –CH–OH), 2.26 (t, J = 7.6 Hz, 2H, –CH2–CvO), 1.65–1.45
1.73–1.54 (m, 2H, –CH2–), 1.36–1.18 (m, 36H, –CH2–), 0.87 (m, 2H, –CH2–), 1.42–0.94 (m, 36H, –CH2–), 0.79 (t, J = 6.8 Hz,
(t, J = 6.7 Hz, 3H, –CH3); MS, m/z calcd for C24H48O: 384.360; 3H, –CH3); MS, m/z calcd for C27H54O6: 474.392; found:
found: 407.3483 (M + Na+).
497.3785 (M + Na+).
Synthesis of 1-O-docosanoylglycerol (glycerol–behenic acid
Synthesis of 1-O-docosanoylsorbitol (sorbitol–behenic acid
monoester, compound 2). 2 mmol of behenic acid and monoester, compound 5). 2 mmol of behenic acid and
24 mmol of glycerol were catalyzed by Novozym 435 (8% of 20 mmol of sorbitol were catalyzed by Novozym 435 (20% of
total weight of equivalent amount of behenic acid) in 5 mL total weight of equivalent amount of behenic acid) in 10 mL
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t-BuOH for 12 h. White solid; Rf 0.43; m.p. 83.57 °C; H NMR t-BuOH for 24 h. White solid; Rf 0.21; m.p. 110.29 °C; 1H NMR
(400 MHz, CDCl3, 25 °C, TMS): δ = 4.30–4.05 (m, 2H, –CH2–O– (400 MHz, CDCl3, 25 °C, TMS): δ = 4.34–4.05 (m, 2H, –CH2–O–
CvO), 3.96–3.91 (m, 1H, –CH–OH), 3.74–3.56 (m, 2H, –CH2– CvO), 3.80 (d, J = 5.3 Hz, 1H, –CH–OH), 3.76–3.67 (m, 2H,
OH), 2.78 (bs, 2H, 2 × –OH), 2.35 (t, J = 7.6 Hz, 2H, –CH2–), –CH2–OH), 3.67–3.52 (m, 3H, –CH–OH), 2.29 (t, 2H, –CH2–
1.68–1.55 (m, 2H, –CH2–), 1.37–1.15 (m, 36H, –CH2–), 0.87 CvO), 1.64–1.47 (m, 2H, –CH2–), 1.42–0.98 (m, 36H, –CH2–),
(t, J = 6.7 Hz, 3H, –CH3); MS, m/z calcd for C25H50O4: 414.371; 0.80 (t, J = 6.6 Hz, 3H, –CH3); MS, m/z calcd for C27H54O6:
found: 437.3576 (M + Na+).
504.403; found: 505.4091 (M + H+).
Synthesis of 1-O-docosanoylerythritol (erythritol–behenic
acid monoester, compound 3a). 2 mmol of behenic acid and
Differential scanning calorimetry
20 mmol of erythritol were catalyzed by Novozym 435 (15% of The thermal properties were analyzed using differential scan-
total weight of equivalent amount of behenic acid) in 10 mL ning calorimetry on a Pyris 6 DSC system (Perkin-Elmer Cetus,
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t-BuOH for 24 h. White solid; Rf 0.34; m.p. 85.49 °C; H NMR Norwalk, USA). Approximately 8 mg of each sample was put
(400 MHz, CDCl3, 25 °C, TMS): δ = 4.25–4.06 (m, 2H, –CH2–O– into an aluminum pan and placed in the equipment under a
CvO), 3.74–3.67 (m, 1H, –CH–OH), 3.67–3.57 (m, 2H, –CH2– purging atmosphere of nitrogen (20 mL min−1), with an empty
OH), 3.54–3.46 (m, 1H, –CH–OH), 2.28 (t, J = 7.6 Hz, 2H, pan as an inert reference. The heating and cooling profile was:
–CH2–CvO), 1.60–1.47 (m, 2H, –CH2–), 1.29–1.09 (m, 36H, (1) initial temperature 20 °C; (2) ramp 20 K min−1 to 120 °C;
–CH2–), 0.80 (t, J = 6.8 Hz, 3H, –CH3); MS, m/z calcd for (3) isothermal for 5 min; (4) ramp −5 K min−1 to 60 °C; (5) iso-
C26H52O5: 444.381; found: 467.3696 (M + Na+).
thermal for 10 min; and (6) ramp 5 K min−1 to 120 °C. The
Synthesis of 1-O-docosanoylpentaerythritol (pentaerythritol– DSC scans were evaluated using MicroCal Origin 8.6 software.
behenic acid monoester, compound 3b). 2 mmol of behenic
Fourier transform infrared spectroscopy
acid and 30 mmol of pentaerythritol were catalyzed by
Novozym 435 (15% of total weight of equivalent amount of Fourier transform infrared spectroscopy (FT-IR) was used for
behenic acid) in 10 mL t-BuOH for 48 h. White solid; Rf 0.37; the detection and characterization of the lipid organization in
m.p. 78.37 °C; 1H NMR (400 MHz, CDCl3, 25 °C, TMS): δ = 4.15 the synthetic compounds. Samples were pressed onto a ZnSe
(s, 2H, –CH2–O–CvO), 3.58 (s, 6H, –CH2–OH), 2.29 (t, J = ATR crystal mounted in a trough plate and placed in a horizon-
7.6 Hz, 2H, –CH2–CvO), 1.64–1.49 (m, 2H, –CH2–), 1.29–1.10 tal ATR-FT-IR spectrometer (PIKE, Madison, WI; Bruker, Ettlin-
(m, 36H, –CH2–), 0.81 (t, J = 6.8 Hz, 3H, –CH3); MS, m/z calcd gen, Germany). The temperature of the ATR plate with loaded
for C27H54O5: 458.397; found: 459.4019 (M + H+).
sample was precisely controlled and monitored by a tempera-
Synthesis of 1-O-docosanoylarabitol (arabitol–behenic acid ture controller. Spectra in the ATR setup were acquired with
monoester, compound 4a). 2 mmol of behenic acid and 2 °C intervals from 40–80 °C. The spectra were collected with
20 mmol of arabitol were catalyzed by Novozym 435 (20% of an unpolarized beam at a resolution of 4 cm−1 with 4 scans,
total weight of equivalent amount of behenic acid) in 10 mL and a spectral window of 4000–600 cm−1. Background spectra
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t-BuOH for 24 h. White solid; Rf 0.30; m.p. 86.71 °C; H NMR of the clean ZnSe crystal disc were collected at initial tempera-
(400 MHz, CDCl3, 25 °C, TMS): δ = 4.15–4.06 (m, 2H, –CH2–O– tures and subtracted from the sample spectra. The FT-IR
CvO), 3.90–3.84 (m, 1H, –CH–OH), 3.70–3.64 (m, 1H, –CH– spectra were analyzed using MicroCal Origin 8.6 software.
OH), 3.62–3.55 (m, 2H, –CH2–OH), 3.53 (t, J = 3.5 Hz, 1H,
Critical micelle concentration
–CH–OH), 2.26 (t, J = 7.6 Hz, 2H, –CH2–CvO), 1.65–1.45
(m, 2H, –CH2–), 1.42–0.94 (m, 36H, –CH2–), 0.79 (t, J = 6.8 Hz, The critical micelle concentrations (CMCs) of the different
3H, –CH3); MS, m/z calcd for C27H54O6: 474.392; found: sugar alcohol behenic acid monoesters were determined with
497.3801 (M + Na+).
pyrene fluorescence33 using
a fluorescence spectrometer
Synthesis of 1-O-docosanoylxylitol (xylitol–behenic acid (Varian Cary Eclipse, Agilent Technology, California, USA).
monoester, compound 4b). 2 mmol of behenic acid and Sample solutions of different concentrations (1, 0.5, 0.1, 0.05,
20 mmol of xylitol were catalyzed by Novozym 435 (20% of 0.01, 0.005 and 0.001 mg mL−1) were prepared using water
Green Chem.
This journal is © The Royal Society of Chemistry 2015