Homo- and hetero-difunctionalized β-cyclodextrins: Short direct synthesis in gram scale and analysis of regiochemistry

Gábor Benkovics,
Mihály Bálint,
Éva Fenyvesi,
Erzsébet Varga,
Szabolcs Béni,
Konstantina Yannakopoulou and
Milo Malanga

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Published 18 Mar 2019

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1. Graphical Abstract
2. Figure 1: Schematic representation of β-CD with glucopyranose atom numbering and with alphabetic labeling of ...
  
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3. Scheme 1: Syntheses of 6^A,6^X-diazido-β-CDs as reference compounds using the “capping” literature method [11,12].
  
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4. Scheme 2: Syntheses of homo-difunctionalized β-CDs using different reaction conditions.
  
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5. Figure 2: HPLC chromatograms of the authentic 6^A,6^X-diazido-β-CDs with known regiochemistry (references 1–3, Scheme 1...
  
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6. Figure 3: NMR spectral regions of the three ditosyl regioisomers in D₂O (500 MHz). The signals of the tosylat...
  
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7. Scheme 3: Syntheses of 6^A-monoazido-6^X-monotosyl-β-CDs using starting materials obtained from different react...
  
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8. Figure 4: Reversed-phase HPLC chromatograms of 6^A-monoazido-6^X-monotosyl-β-CDs prepared through reactions 4–8....
  
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9. Figure 5: HPLC separation of regioisomers and pseudoenantiomers of 6^A-monoazido-6^X-monotosyl-β-CD prepared in...
  
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10. Figure 6: Reversed-phase HPLC chromatograms of 6^A_,6^X-diazido-β-CDs prepared in reactions 9–13.
  
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Beilstein J. Org. Chem. 2019, 15, 710–720, doi:10.3762/bjoc.15.66

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Novel β-cyclodextrin–eosin conjugates

Gábor Benkovics,
Damien Afonso,
András Darcsi,
Szabolcs Béni,
Sabrina Conoci,
Éva Fenyvesi,
Lajos Szente,
Milo Malanga and
Salvatore Sortino

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Published 15 Mar 2017

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1. Graphical Abstract
2. Figure 1: Reaction scheme for the synthesis of eosin Y (2) and eosin B (4).
  
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3. Figure 2: Reaction scheme for the synthesis of eosin-appended β-CDs, 2–β-CD and 4–β-CD (NMM: N-methylmorpholi...
  
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4. Figure 3: TLC analysis of the composition of the crude coupling reaction mixtures.
  
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5. Figure 4: ¹H NMR spectrum of 2–β-CD with partial assignment (DMSO-d₆, 600 MHz, 298 K).
  
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6. Figure 5: Size distributions of 1 mM aqueous solutions of conjugates 4–β-CD (a) and 2–β-CD (b) at 25.0 °C (pH...
  
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7. Figure 6: Normalized absorption spectra of aqueous solutions of (a) eosin Y (2) and (b) conjugate 2–β-CD and ...
  
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8. Figure 7: Time-resolved fluorescence observed for aqueous solutions of (a) eosin Y (2) and (b) the 2–β-CD con...
  
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9. Figure 8: ¹O₂ luminescence detected upon 528 nm light excitation of D₂O solutions of (a) eosin Y (2) and (b) 2...
  
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Beilstein J. Org. Chem. 2017, 13, 543–551, doi:10.3762/bjoc.13.52

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New synthetic strategies for xanthene-dye-appended cyclodextrins

Milo Malanga,
Andras Darcsi,
Mihaly Balint,
Gabor Benkovics,
Tamas Sohajda and
Szabolcs Beni

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Published 17 Mar 2016

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1. Graphical Abstract
2. Figure 1: Structures of fluorescent xanthene dyes. Rhodamine B·HCl 1 and fluorescein disodium salt 2.
  
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3. Figure 2: Reaction scheme for the synthesis of rhodamine-appended β-CD.
  
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4. Figure 3: TLC plates at different development stages for monitoring the composition of Rho-β-CD crude (left p...
  
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5. Figure 4: ¹H NMR spectrum of Rho-β-CD with partial assignments (D₂O, 500 MHz, 298 K).
  
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6. Figure 5: Expansion of DEPT-ed-HSQC spectrum of Rho-β-CD with partial assignments (D₂O, 500 MHz, 298 K).
  
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7. Figure 6: Cartoon models for the possible intermolecular inclusion mode of Rho-β-CD in solution (3D perspecti...
  
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8. Figure 7: ¹H NMR spectrum of Flu-β-CD with partial assignments (D₂O, 500 MHz, 298 K).
  
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9. Figure 8: Cartoon models for the possible intermolecular inclusion mode of Flu-β-CD in solution (3D perspecti...
  
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Beilstein J. Org. Chem. 2016, 12, 537–548, doi:10.3762/bjoc.12.53

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Supramolecular structures based on regioisomers of cinnamyl-α-cyclodextrins – new media for capillary separation techniques

Gabor Benkovics,
Ondrej Hodek,
Martina Havlikova,
Zuzana Bosakova,
Pavel Coufal,
Milo Malanga,
Eva Fenyvesi,
Andras Darcsi,
Szabolcs Beni and
Jindrich Jindrich

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Published 19 Jan 2016

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1. Graphical Abstract
2. Figure 1: Example of elucidation of 2D NMR spectra of 2-O-Cin-α-CD.
  
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3. Figure 2: 2D ROESY spectrum of 2-O-Cin-α-CD in D₂O at 25 °C at 24 mM concentration.
  
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4. Figure 3: Expansion of the 2D ROESY spectrum of 2-O-Cin-α-CD indicating the geometric arrangement.
  
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5. Figure 4: ¹H NMR spectra of 2-O-Cin-α-CD in D₂O at 25 °C at different concentrations.
  
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6. Figure 5: ¹H NMR spectra of 3-O-Cin-α-CD in D₂O at 25 °C recorded at various concentrations.
  
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7. Figure 6: Diffusion coefficients of 2-O-Cin-α-CD (black) and, 3-O-Cin-α-CD (red) in D₂O at various concentrat...
  
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8. Figure 7: Effect of solvent on the size distribution of aggregates formed by 2-O-Cin-α-CD at 25 °C (the appli...
  
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9. Figure 8: Effect of a solvent on the size distribution of aggregates formed by 3-O-Cin-α-CD at 25 °C (the app...
  
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10. Figure 9: Aggregate sizes (diameter) of 2-O-Cin-α-CD (black) and 3-O-Cin-α-CD (red) in water at various tempe...
  
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11. Figure 10: Schematic representation of the DLS experiment proving the host–guest nature of the aggregate forma...
  
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12. Figure 11: The effect of competitive additives on the size distribution of aggregates formed by 3-O-Cin-α-CD a...
  
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13. Figure 12: Expansion of the 2D ROESY spectrum of 2-O-Cin-α-CD in the presence of CioOK as competitive guest mo...
  
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14. Figure 13: ¹H NMR spectrum of 2-O-Cin-α-CD before (up) and after (down) the addition of CioOK in 5-fold molar ...
  
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15. Figure 14: The influence of 5 mM 2-O-Cin-α-CD in BGE (right column) on the decrease of the effective electroph...
  
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