3.2. Chemistry

Oleanolic acid (1, 2.1 g, 4.5 mmol) and DMAP (54 mg, 0.42 mmol) were dissolved in anhydrous THF (40 mL) under nitrogen. Diisopropylethylamine (DIPEA, 1.14 mL, 6.54 mmol) was added followed by dropwise addition of chloroacetyl chloride (0.96 mL, 12.1 mmol). After stirring for 2 h, absolute ethanol (1.5 mL) was used to quench the reaction. The solvent was removed in vacuo and the resulting crude product was adsorbed onto silica gel, after dissolving in CH₂Cl₂ (20 mL), then purified by column chromatography to obtain the desired chloroacetate as a white solid 2 (2.13 g, 87%). ¹H-NMR (400 MHz, CDCl₃) δ 5.24 (t, J = 3.4 Hz, 1H), 4.69–4.50 (m, 1H), 4.12 (s, 1H), 4.05 (d, J = 2.4 Hz, 2H), 2.24–1.18 (m, 24H), 1.08 (s, 3H), 1.00–0.93 (m, 7H), 0.89 (s, 3H), 0.86 (d, J = 7.9 Hz, 6H), 0.77 (s, 3H). ¹³C-NMR (100 MHz, CDCl₃) δ 183.7, 167.3, 138.1, 125.9, 83.5, 55.4, 52.7, 48.1, 47.6, 42.1, 41.4, 39.6, 39.2, 39.0, 38.3, 38.1, 37.0, 36.8, 33.0, 33.0, 30.7, 28.2, 28.1, 24.2, 23.7, 23.6, 23.4, 21.3, 18.3, 17.1, 16.8, 15.7. HRMS (ESI) m/z for C₃₂H₄₈ClO₄ ([M-H]⁻) 531.3251, calc. 531.3247.

Chloroacetate 2 (2 g, 3.75 mmol) was dissolved in absolute ethanol (160 mL) along with NaI (1.82 g, 12.15 mmol) under nitrogen. After stirring at room temperature for 2 h, a solution of MeONH₂ in THF (2.4 M, 1.9 mL, 4.56 mmol; made by stirring CH₃ONH₂·HCl in a NaOH/THF slurry for 24 h) was added, the nitrogen line removed, the reaction mixture was heated to 60 °C and stirred for 2 h, then the reaction was cooled to room temperature and another aliquot of MeONH₂ in THF (2 eq.) was introduced followed by reheating to 60 °C. This additive process was repeated roughly every 2 h until the reaction had progressed sufficiently based upon TLC which occurred after ~24 h of total reaction time. The solvent was removed and the product purified by column chromatography (0.92 g, 45%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 4.93–4.63 (m, 1H), 3.92 (s, 2H), 3.63 (s, 3H), 3.32 (d, J = 11.3 Hz, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.96 (s, 3H), 0.91 (s, 3H), 0.84 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.5, 171.6, 145.2, 122.7, 81.7, 61.8, 55.9, 54.2, 48.3, 47.0, 46.8, 42.5, 42.4, 40.1, 38.5, 38.4, 37.5, 34.6, 33.7, 33.6, 33.4, 31.4, 28.7, 28.5, 26.6, 24.3, 24.2, 24.2, 24.1, 18.9, 17.7, 17.3, 15.7. HRMS (ESI) m/z for C₃₃H₅₂NO₅ ([M-H]⁻) 542.3851, calc. 542.3851.

Oleanolic acid (1, 2.75 g, 5 mmol) was dissolved in anhydrous CH₂Cl₂ (200 mL), stirred and ice-bathed for 30 min. Then N,O-dimethylhydroxylamine hydrochloride (0.6 g, 6 mmol) and N-methylmorpholine (0.8 mL, 6 mmol) were added in order. The 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDAC, 1.5 g, 6.25 mmol) was slowly added over 10 min. After reacting in an ice-bath for 2 h, 5% HCl aqueous solution (50 mL) was added to quench the reaction. The acidic aqueous layer was extracted with CH₂Cl₂ (3 × 100 mL). The organic layers were combined and washed with saturated NaHCO₃ solution and saturated NaCl solution, respectively. The organic layer was dried over anhydrous Na₂SO₄, then purified by column chromatography to obtain the desired white solid 5 (79%, 2.4 g). ¹H-NMR (500 MHz, C₅D₅N) δ 5.43 (t, J = 3.4 Hz, 1H), 3.62 (s, 3H), 3.44 (d, J = 6.1 Hz, 1H), 3.34 (dd, J = 13.7, 3.9 Hz, 1H), 3.20 (s, 3H), 1.26 (s, 3H), 1.25 (s, 3H), 1.04 (s, 3H), 0.96 (s, 3H), 0.93 (s, 9H). ¹³C-NMR (125 MHz, C₅D₅N) δ 178.4, 145.3, 122.4, 78.2, 60.4, 56.0, 48.3, 48.1, 46.8, 42.5, 42.3, 39.7, 39.5, 39.0, 37.5, 34.4, 34.2, 33.3, 33.3, 30.8, 29.6, 28.9, 28.6, 28.2, 26.4, 23.9, 23.9, 22.5,18.9, 17.4, 16.6, 15.7. HRMS (ESI) m/z for C₃₂H₅₄NO₃ ([M+H]⁺) 500.4090, calc. 500.4098.

Lithium aluminium hydride (LAH, 0.6 g, 5 eq) was dissolved in anhydrous THF (100 mL) under nitrogen. After in an ice-bath under nitrogen for 30 min, a solution of compound 5 in THF (1.5 g, dissolved in 30 mL anhydrous THF) was added dropwise. After another 30 min of ice-bath reaction, the reaction continued at room temperature for 4 h. The reaction was quenched with saturated NH₄Cl solution, and the aqueous layer extracted with EtOAc (3 × 100 mL). The combined organic layer was washed with saturated NaCl solution, and then was dried over anhydrous Na₂SO₄. The crude product was redissolved with MeOH/CH₂Cl₂ (4:1, 150 mL), followed by addition of methoxyamino hydrochloride (CH₃ONH₂·HCl, 5 eq.) and pyridine (5 eq.), respectively. The reaction was heated to 55 °C under reflux for 8 h. Then purified by column chromatography to obtain the desired compound as a white solid 6 (81%, 1.1 g). ¹H-NMR (500 MHz, C₅D₅N) δ 5.30 (t, J = 3.5 Hz, 1H), 3.92 (s, 3H), 3.48–3.40 (m, 1H), 2.52 (dd, J = 13.6, 4.0 Hz, 1H), 1.25 (s, 3H), 1.21 (s, 3H), 1.05 (s, 3H), 0.97 (s, 3H), 0.96 (s, 3H), 0.90 (s, 3H), 0.89 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 158.7, 144.4, 123.4, 78.3, 61.4, 56.0, 48.3, 46.3, 44.4, 42.1, 40.4, 39.9, 39.6, 39.2, 37.5, 34.2, 33.4, 33.3, 33.3, 31.0, 29.0, 28.3, 27.2, 26.5, 24.9, 24.0, 23.8, 19.0, 17.7, 16.8, 15.8. HRMS (ESI) m/z for C₃₁H₅₂NO₂ ([M+H]⁺) 470.3991, calc. 470.3993.

Compound 6 (1 g, 2.1 mmol) was dissolved in acetic acid (100 mL), NaCNBH₃ (10 eq.) was added. The reaction was stirred at room temperature for 10 h. Quench the reaction by adding saturated NaHCO₃ solution (100 mL), and then was extracted with CH₂Cl₂ (3 × 100 mL). The organic layer was washed with saturated NaHCO₃ solution, saturated NaCl solution, and was dried over anhydrous Na₂SO₄. Filtered, and the solvent was condensed under reduced pressure. The crude product was purified by column chromatography with PE/EtOAc (10: 1) to obtain desired product as a white solid 7 (83%, 0.83 g). ¹H-NMR (500 MHz, C₅D₅N) δ 5.25 (t, J = 3.4 Hz, 1H), 3.63 (s, 3H), 3.43 (d, J = 9.0 Hz, 1H), 3.25 (dd, J = 11.7, 8.5 Hz, 1H), 2.77 (dd, J = 11.8, 6.8 Hz, 1H), 2.17 (dd, J = 13.5, 3.8 Hz, 1H), 1.24 (s, 3H), 1.23 (s, 3H), 1.04 (s, 3H), 1.01 (s, 3H), 0.94 (s, 3H), 0.91 (s, 3H), 0.90 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.0, 122.9, 78.2, 61.3, 59.9, 55.9, 48.2, 46.8, 45.2, 42.0, 40.4, 39.6, 39.3, 37.4, 36.1, 34.7, 33.6, 33.2, 33.1, 31.3, 28.9, 28.3, 26.4, 26.3, 24.1, 23.9, 23.5, 19.0, 17.2, 16.8, 16.0. HRMS (ESI) m/z for C₃₁H₅₄NO₂ ([M+H]⁺) 472.4142, calc. 472.4149.

To a solution of neoaglycone 3 (typically 0.1 mmol, 54.2 mg) and reducing sugar (2 eq.) were dissolved in MeOH/CHCl₃ (6:1, 5 mL). Neoaglycon 7 (0.1 mmol, 47.2 mg) and reducing sugar (2 eq.) was dissolved in MeOH/CHCl₃ (4:1, 5 mL), external proton source AcOH (10 eq.) were added, and then reaction at 40 °C for 48 h on a rotary shaker at 250 rpm. The target neoglycosides was purified with MeOH/CH₂Cl₂ by silica gel column chromatography. The configuration of the glycosidic bond of all the neoglycosides was identified by the J value of J_H1′−_H2′.

(3S)-O-(N-Methoxy-N-d-glucosylglycyl) oleanolic acid (4a)

White solid (15.2 mg, 21%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.50 (t, J = 3.3 Hz, 1H), 4.86–4.77 (m, 2H), 4.58 (dd, J = 11.9, 2.2 Hz, 1H), 4.43–4.33 (m, 2H), 4.32–4.19 (m, 3H), 4.15 (d, J = 16.9 Hz, 1H), 4.05 (s, 3H), 4.00–3.94 (m, 1H), 3.33 (dd, J = 13.8, 4.0 Hz, 1H), 1.31 (s, 3H), 1.04 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.89 (s, 3H), 0.84 (s, 3H), 0.82 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.5, 170.7, 145.2, 122.8, 95.6, 81.4, 80.8, 80.2, 72.1, 71.9, 63.3, 62.8, 55.9, 55.7, 48.3, 47.0, 46.8, 42.5, 42.4, 40.1, 38.6, 38.3, 37.5, 34.6, 33.6, 33.6, 33.4, 31.3, 28.7, 28.5, 26.6, 24.3, 24.1, 24.1, 24.1, 18.8, 17.7, 17.3, 15.8. HRMS (ESI) m/z for C₃₉H₆₄NO₁₀ ([M+H]⁺) 706.4525, calc. 706.4525.

(3S)-O-(N-Methoxy-N-β-l-glucosylglycyl) oleanolic acid (4b)

White solid (11.0 mg, 16%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.50 (t, J = 3.1 Hz, 1H), 4.84 (d, J = 8.7 Hz, 1H), 4.81 (dd, J = 11.2, 5.4 Hz, 1H), 4.57 (dd, J = 11.8, 2.1 Hz, 1H), 4.40 (dd, J = 11.9, 5.4 Hz, 1H), 4.35–4.12 (m, 5H), 4.05 (s, 3H), 4.00–3.93 (m, 1H), 3.33 (dd, J = 13.7, 3.9 Hz, 1H), 1.30 (s, 3H), 1.04 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.92 (s, 3H), 0.84 (s, 3H), 0.83 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.0, 170.2, 144.7, 122.2, 94.9, 80.8, 80.2, 79.6, 71.6, 71.3, 62.7, 62.1, 55.3, 54.9, 47.7, 46.5, 46.3, 42.0, 41.8, 39.5, 38.0, 37.8, 37.0, 33.8, 33.1, 33.0, 32.8, 31.3, 28.1, 27.9, 26.0, 23.7, 23.6, 23.5, 22.7, 18.3, 17.2, 16.6, 15.2. HRMS (ESI) m/z for C₃₉H₆₄NO₁₀ ([M+H]⁺) 706.4533, calc. 706.4525.

(3S)-O-(N-Methoxy-N-(2-deoxy-d-glucosyl)glycyl) oleanolic acid (4c)

White solid (38.5 mg, 56%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 4.83–4.77 (m, 2H), 4.55 (dd, J = 11.8, 2.3 Hz, 1H), 4.45–3.99 (m, 5H), 3.88 (s, 3H), 3.86–3.82 (m, 1H), 3.32 (dd, J = 13.7, 3.8 Hz, 1H), 2.71–2.54 (m, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.92 (s, 3H), 0.85 (d, J = 4.0 Hz, 6H). ¹³C-NMR (125 MHz, C₅D₅N) δ 179.9, 170.0, 144.7, 122.2, 91.0, 80.9, 80.3, 73.2, 73.0, 62.8, 62.4, 55.5, 55.3, 47.7, 46.5, 46.3, 42.0, 41.8, 39.5, 38.0, 37.8, 37.5, 37.0, 34.0, 33.1, 33.0, 32.8, 30.8, 28.1, 27.9, 26.0, 23.7, 23.6, 23.6, 23.5, 18.3, 17.2, 16.8, 15.2. HRMS (ESI) m/z for C₃₉H₆₄NO₉ ([M+H]⁺) 690.4575, calc. 690.4576.

(3S)-O-(N-Methoxy-N-(3-O-methyl-d-glucosyl)glycyl) oleanolic acid (4d)

White solid (10.7 mg, 15%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.48 (s, 1H), 4.89–4.70 (m, 2H), 4.56–4.29 (m, 5H), 4.26–4.05 (m, 2H), 4.02 (s, 3H), 3.96 (s, 3H), 3.93–3.84 (m, 1H), 3.32 (d, J = 13.2 Hz, 1H), 1.30 (s, 3H), 1.02 (d, J = 9.6 Hz, 3H), 1.00 (d, J = 4.8 Hz, 3H), 0.98 (d, J = 2.4 Hz, 3H), 0.88 (s, 3H), 0.84 (s, 3H), 0.82 (d, J = 3.8 Hz, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.5, 168.2, 145.2, 122.7, 95.5, 82.0, 81.5, 80.6, 71.7, 71.1, 66.0, 63.0, 62.7, 55.9, 55.8, 48.3, 47.0, 46.8, 42.5, 42.3, 40.1, 38.5, 38.3, 37.5, 34.6, 33.6, 33.6, 33.4, 31.2, 28.7, 28.5, 26.5, 24.3, 24.1, 24.0, 23.3, 19.8, 17.7, 17.3, 14.1. HRMS (ESI) m/z for C₄₀H₆₆NO₁₀ ([M+H]⁺) 720.4678, calc. 720.4681.

(3S)-O-(N-Methoxy-N-d-galactosylglycyl) oleanolic acid (4e)

White solid (16.1 mg, 23%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.50 (d, J = 11.1 Hz, 1H), 5.34 (d, J = 5.7 Hz, 0.67H, αH1′), 4.87–4.81 (m, 0.67H), 4.78 (dd, J = 10.4, 5.7 Hz, 1H), 4.63–4.43 (m, 2H), 4.42–4.13 (m, 4H), 3.99 (s, 3H), 3.95–3.89 (m, 1H), 3.44–3.25 (m, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.83 (d, J = 2.0 Hz, 3H), 0.80 (s, 3H), 0.78 (d, J = 7.4 Hz, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 179.9, 170.1, 144.6, 122.2, 99.8, 95.3, 84.0, 81.0, 80.8, 78.7, 78.6, 77.5, 76.3, 74.1, 72.6, 69.0, 65.3, 64.3, 55.3, 54.5, 47.7, 46.5, 46.3, 42.0, 41.8, 39.5, 38.0, 37.7, 37.0, 34.0, 33.1, 33.0, 32.8, 30.6, 28.1, 27.9, 26.0, 23.7, 23.6, 23.5, 23.5, 19.1, 17.2, 15.2, 13.5. HRMS (ESI) m/z for C₃₉H₆₄NO₁₀ ([M+H]⁺) 706.4520, calc. 706.4525.

(3S)-O-(N-Methoxy-N-β-(2-deoxy-d-galactosyl)glycyl) oleanolic acid (4f)

White solid (29.8 mg, 43%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 4.79 (dd, J = 12.2, 5.2 Hz, 1H), 4.76 (d, J = 10.9 Hz, 1H), 4.52–4.01 (m, 6H), 3.99–3.90 (m, 1H), 3.85 (s, 3H), 3.33 (dd, J = 13.7, 3.7 Hz, 1H), 1.30 (s, 20H), 1.04 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.90 (s, 3H), 0.85 (s, 6H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.0, 170.1, 144.7, 122.2, 91.2, 80.9, 78.8, 70.2, 68.6, 62.5, 62.1, 55.3, 55.1, 47.7, 46.5, 46.3, 42.0, 41.8, 39.5, 38.0, 37.8, 37.0, 34.0, 33.1, 33.1, 33.0, 32.83, 30.18, 28.1, 27.9, 26.0, 23.7, 23.6, 23.5, 22.7, 18.3, 17.2, 16.8, 15.2. HRMS (ESI) m/z for C₃₉H₆₄NO₉ ([M+H]⁺) 690.4581, calc. 690.4576.

(3S)-O-(N-Methoxy-N-d-mannosylglycyl) oleanolic acid (4g)

White solid (17.2 mg, 24%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.50 (d, J = 12.8 Hz, 1H), 5.13 (dd, J = 38.5, 21.1 Hz, 2H), 4.93 (d, J = 1.7 Hz, 0.5H, αH1′), 4.82–4.54 (m, 3H), 4.53–4.28 (m, 3H), 4.25–4.18 (m, 0.5H), 3.96 (s, 3H), 3.79 (s, 1H), 3.44–3.25 (m, 1H), 1.03 (s, 3H), 1.00 (d, J = 1.6 Hz, 3H), 0.98 (s, 3H), 0.84 (d, J = 7.0 Hz, 3H), 0.82 (d, J = 2.8 Hz, 3H), 0.78 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.0, 170.1, 144.6, 122.2, 93.7, 92.1, 81.0, 81.0, 80.5, 77.9, 76.2, 74.1, 73.2, 72.2, 68.8, 65.3, 64.3, 55.6, 55.3, 55.3, 47.7, 46.5, 46.3, 42.0, 41.8, 39.5, 38.0, 37.7, 34.0, 34.0, 33.1, 33.0, 32.8, 30.6, 28.1, 27.9, 26.0, 23.8, 23.6, 23.5, 23.5, 19.1, 17.2, 15.2, 13.5. HRMS (ESI) m/z for C₃₉H₆₄NO₁₀ ([M+H]⁺) 706.4528, calc. 706.4525.

(3S)-O-(N-Methoxy-N-α-d-arabinosylglycyl) oleanolic acid (4h)

White solid (35.5 mg, 53%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 5.33 (d, J = 5.4 Hz, 1H), 4.81 (dd, J = 11.6, 4.7 Hz, 2H), 4.70–4.64 (m, 1H), 4.46–4.09 (m, 4H), 4.03–3.94 (m, 1H), 3.92 (s, 3H), 3.37–3.27 (m, 1H), 1.30 (d, J = 1.9 Hz, 3H), 1.03 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.93 (d, J = 4.0 Hz, 3H), 0.89 (s, 3H), 0.84 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.5, 170.5, 145.2, 122.8, 100.3, 85.7, 81.6, 79.4, 77.7, 63.1, 62.7, 55.9, 48.3, 47.0, 46.8, 42.5, 42.4, 40.1, 38.6, 38.4, 37.5, 34.6, 33.6, 33.6, 33.4, 31.9, 31.3, 30.7, 28.7, 28.5, 26.6, 24.3, 24.1, 24.1, 18.8, 17.7, 17.4, 15.7. HRMS (ESI) m/z for C₃₈H₆₂NO₉ ([M+H]⁺) 676.4413, calc. 676.4419.

(3S)-O-(N-Methoxy-N-l-arabinosylglycyl) oleanolic acid (4i)

White solid (13.7 mg, 20%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.50 (s, 1H), 5.32 (d, J = 5.4 Hz, 0.5H, αH1′), 4.86–4.72 (m, 2H), 4.70–4.66 (m, 0.5H), 4.64 (d, J = 9.0 Hz, 0.5H, βH1′), 4.52 (t, J = 8.9 Hz, 0.5H), 4.42–4.26 (m, 2H), 4.19 (ddd, J = 29.1, 11.0, 5.8 Hz, 2H), 3.96 (d, J = 32.9 Hz, 3H), 3.33 (dd, J = 13.8, 3.7 Hz, 1H), 1.30 (s, 3H), 1.04 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.88 (s, 3H), 0.86 (d, J = 5.8 Hz, 3H), 0.83 (d, J = 4.6 Hz, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 179.9, 170.2, 144.7, 122.2, 99.8, 95.5, 85.1, 81.0, 80.9, 78.9, 77.2, 75.6, 69.8, 69.1, 62.4, 62.2, 61.7, 55.6, 55.3, 47.7, 46.5, 46.3, 42.0, 41.8, 39.5, 37.8, 37.7, 37.0, 34.0, 33.1, 33.0, 32.8, 30.8, 28.1, 27.9, 26.0, 23.7, 23.6, 23.5, 18.3, 17.2, 16.8, 15.2. HRMS (ESI) m/z for C₃₈H₆₂NO₉ ([M+H]⁺) 676.4411, calc. 676.4419.

(3S)-O-(N-Methoxy-N-d-fucosylglycyl) oleanolic acid (4j)

White solid (19.4 mg, 28%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 5.29 (d, J = 5.3 Hz, 0.67H, αH1′), 4.70 (d, J = 9.1 Hz, 0.33H, βH1′), 4.53–4.09 (m, 3H), 3.99 (s, 3H), 3.93 (s, 3H), 3.85 (dd, J = 12.7, 6.1 Hz, 0.5H), 3.70–3.60 (m, 0.5H), 3.32 (d, J = 13.1 Hz, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.92 (d, J = 9.7 Hz, 3H), 0.87 (s, 3H), 0.84 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.5, 170.5, 145.2, 122.7, 100.2, 95.6, 88.0, 81.6, 81.5, 79.6, 78.4, 76.9, 73.6, 68.0, 62.8, 62.2, 56.0, 55.9, 52.3, 48.3, 47.0, 46.8, 42.5, 42.3, 40.1, 38.6, 38.3, 37.5, 34.6, 33.6, 33.6, 33.4, 31.3, 28.7, 28.5, 26.6, 24.3, 24.1, 24.1, 18.8, 17.7, 17.4, 17.3, 15.7, 14.6. HRMS (ESI) m/z for C₃₉H₆₄NO₉ ([M+H]⁺) 690.4585, calc. 690.4576.

(3S)-O-(N-Methoxy-N-l-fucosylglycyl) oleanolic acid (4k)

White solid (17.3 mg, 25%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 5.31 (d, J = 5.3 Hz, 0.67H, αH1′), 4.72 (d, J = 9.0 Hz, 0.33H, βH1′), 4.49–4.04 (m, 3H), 3.99 (s, 3H), 3.93 (s, 3H), 3.86 (q, J = 6.4 Hz, 0.5H), 3.64 (dd, J = 9.3, 5.1 Hz, 0.5H), 3.32 (d, J = 13.6 Hz, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.94–0.91 (m, 3H), 0.88 (s, 3H), 0.84 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.0, 170.0, 144.7, 122.2, 99.6, 95.0, 87.5, 81.0, 80.8, 79.0, 77.8, 76.3, 73.0, 67.4, 62.2, 61.6, 56.1, 55.3, 47.7, 46.5, 46.3, 42.0, 41.8, 39.5, 38.0, 37.8, 37.0, 34.0, 33.1, 33.0, 32.8, 30.8, 28.1, 27.9, 26.0, 23.7, 23.6, 23.5, 22.7, 18.3, 17.2, 16.8, 16.7, 15.2, 14.1. HRMS (ESI) m/z for C₃₉H₆₂NO₉ ([M+H]⁻) 688.4434, calc. 688.4430.

(3S)-O-(N-Methoxy-N-β-d-xylosylglycyl) oleanolic acid (4l)

White solid (15.0 mg, 22%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 4.70 (d, J = 8.4 Hz, 1H), 4.53–4.29 (m, 2H), 4.27–4.12 (m, 2H), 4.04 (s, 3H), 3.77–3.58 (m, 1H), 3.32 (d, J = 13.3 Hz, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.00 (s, 3H), 0.98 (s, 3H), 0.91 (s, 3H), 0.89 (s, 3H), 0.83 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.7, 170.7, 145.2, 123.4, 96.2, 81.6, 80.3, 72.0, 71.3, 69.6, 62.7, 55.9, 55.6, 48.3, 47.0, 46.9, 42.5, 42.4, 40.1, 38.6, 38.4, 37.5, 34.6, 33.7, 33.6, 33.4, 30.8, 28.7, 28.5, 26.6, 24.3, 24.2, 24.1, 23.3, 18.8, 17.7, 17.3, 15.7. HRMS (ESI) m/z for C₃₈H₆₂NO₉ ([M+H]⁺) 676.4426, calc. 676.4419.

(3S)-O-(N-Methoxy-N-β-l-xylosylglycyl) oleanolic acid (4m)

White solid (8.6 mg, 13%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 4.72 (d, J = 8.2 Hz, 1H), 4.58–4.36 (m, 2H), 4.34–4.13 (m, 3H), 4.04 (s, 3H), 3.32 (d, J = 13.6 Hz, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.00 (s, 3H), 0.98 (s, 3H), 0.94 (s, 3H), 0.90 (s, 3H), 0.84 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 179.8, 170.2, 144.5, 122.9, 95.6, 80.9, 79.7, 71.4, 70.7, 69.0, 62.0, 55.3, 54.8, 47.7, 46.5, 46.3, 42.0, 41.8, 39.5, 38.0, 37.8, 37.0, 34.0, 33.1, 33.0, 32.8, 30.2, 28.1, 27.9, 26.0, 23.7, 23.6, 23.5, 22.7, 18.3, 17.2, 16.8, 15.2. HRMS (ESI) m/z for C₃₈H₆₂NO₉ ([M+H]⁺) 676.4430, calc. 676.4419.

(3S)-O-(N-Methoxy-N-β-l-lyxosylglycyl) oleanolic acid (4n)

White solid (40.2 mg, 59%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (t, J = 3.3 Hz, 1H), 5.18 (d, J = 8.2 Hz, 1H), 4.87–4.72 (m, 3H), 4.44–4.08 (m, 4H), 3.98 (s, 3H), 3.32 (dd, J = 13.9, 3.7 Hz, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.91 (s, 3H), 0.88 (s, 3H), 0.84 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 179.9, 170.2, 144.6, 122.2, 92.2, 81.0, 72.9, 70.5, 67.6, 66.9, 61.8, 55.3, 55.1, 47.7, 46.5, 46.3, 42.0, 41.8, 39.5, 38.0, 37.8, 37.0, 34.0, 33.1, 33.0, 32.8, 30.8, 28.1, 27.9, 26.0, 23.7, 23.6, 23.6, 23.5, 18.3, 17.2, 16.8, 15.2. HRMS (ESI) m/z for C₃₈H₆₂NO₉ ([M+H]⁺) 676.4417, calc. 676.4419.

(3S)-O-(N-Methoxy-N-l-rhamnosylglycyl) oleanolic acid (4o)

White solid (16.4 mg, 24%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 5.14-5.09 (m, 0.8H), 4.99 (s, 0.2H), 4.88 (s, 0.5H), 4.85–4.76 (m, 0.8H), 4.67 (d, J = 2.0 Hz, 0.2H, αH1′), 4.61 (dd, J = 8.8, 3.3 Hz, 0.5H), 4.47–4.38 (m, 0.6H), 4.38–4.24 (m, 1H), 4.20–4.08 (m, 0.4H), 3.97–3.77 (m, 2H), 3.74 (s, 3H), 3.31 (d, J = 13.2 Hz, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.00 (d, J = 3.7 Hz, 3H), 0.97 (s, 3H), 0.95 (d, J = 6.6 Hz, 3H), 0.93 (s, 3H), 0.87 (dd, J = 10.8, 5.1 Hz, 3H), 0.82 (d, J = 10.4 Hz, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.5, 170.4, 145.2, 122.7, 94.4, 92.4, 81.7, 81.1, 74.3, 74.0, 73.5, 72.9, 72.7, 70.4, 62.4, 61.8, 56.7, 55.9, 48.2, 47.0, 46.8, 42.5, 42.3, 40.1, 38.5, 38.3, 37.5, 34.6, 33.6, 33.6, 33.4, 31.3, 28.7, 28.6, 26.6, 24.3, 24.1, 24.1, 24.1, 19.2, 17.7, 17.4, 17.4, 15.7, 14.6. HRMS (ESI) m/z for C₃₉H₆₄NO₉ ([M+H]⁺) 690.4578, calc. 690.4576.

(3S)-O-(N-Methoxy-N-d-ribosylglycyl) oleanolic acid (4p)

White solid (42.1 mg, 62%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 5.41 (d, J = 2.9 Hz, 0.33H, αH1′), 5.08 (d, J = 8.2 Hz, 0.67H, βH1′), 4.86–4.72 (m, 2H), 4.67 (d, J = 4.9 Hz, 1H), 4.41–4.06 (m, 4H), 4.05 (s, 3H), 3.91 (d, J = 15.8 Hz, 1H), 3.32 (d, J = 12.9 Hz, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.94 (s, 3H), 0.91 (s, 3H), 0.83 (d, J = 4.4 Hz, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.3, 170.5, 145.0, 122.6, 100.7, 92.0, 85.6, 81.3, 73.2, 72.7, 72.5, 69.2, 68.8, 66.4, 63.9, 62.6, 62.5, 55.7, 48.1, 46.8, 46.6, 42.3, 42.2, 39.9, 38.4, 38.1, 37.3, 34.4, 33.4, 33.4, 33.2, 31.1, 28.5, 28.3, 26.4, 24.1, 23.9, 23.9, 23.9, 18.6, 17.5, 17.1, 15.5. HRMS (ESI) m/z for C₃₈H₆₂NO₉ ([M+H]⁺) 676.4423, calc. 676.4419.

(3S)-O-(N-Methoxy-N-l-ribosylglycyl) oleanolic acid (4q)

White solid (40.8 mg, 60%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 5.42 (d, J = 3.7 Hz, 0.33H, αH1′), 5.10 (d, J = 8.6 Hz, 0.67H, βH1′), 4.86–4.70 (m, 2H), 4.67 (dd, J = 9.3, 4.7 Hz, 1H), 4.35–4.16 (m, 4H), 4.04 (s, 3H), 3.95 (s, 0.33H), 3.89 (s, 0.67H), 3.32 (d, J = 13.6 Hz, 1H), 1.30 (d, J = 2.8 Hz, 3H), 1.03 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.94 (s, 3H), 0.91 (d, J = 6.1 Hz, 3H), 0.83 (d, J = 4.6 Hz, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.5, 170.8, 145.2, 122.8, 100.9, 92.2, 85.8, 81.5, 73.4, 72.9, 72.7, 69.5, 69.0, 66.6, 64.0, 62.8, 62.7, 55.9, 48.3, 47.0, 46.8, 42.5, 42.4, 40.1, 38.6, 38.4, 37.5, 34.6, 33.6, 33.6, 33.4, 31.3, 28.7, 28.5, 26.6, 24.3, 24.1, 24.1, 24.1, 18.8, 17.7, 17.3, 15.7. HRMS (ESI) m/z for C₃₈H₆₂NO₉ ([M+H]⁺) 676.4413, calc. 676.4419.

(3S)-O-(N-Methoxy-N-(2-deoxy-d-ribosyl)glycyl) oleanolic acid (4r)

White solid (32.5 mg, 49%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.49 (s, 1H), 5.32 (d, J = 2.9 Hz, 0.8H, αH1′), 4.73–4.46 (m, 2H), 4.24–4.05 (m, 4H), 3.86 (s, 3H), 3.50 (d, J = 10.1 Hz, 1H), 3.35–3.29 (m, 1H), 1.30 (s, 3H), 1.03 (s, 3H), 1.01 (s, 3H), 0.98 (s, 3H), 0.93 (d, J = 7.5 Hz, 3H), 0.88 (d, J = 10.6 Hz, 3H), 0.84 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 180.5, 168.2, 145.2, 122.8, 106.2, 91.8, 82.3, 81.5, 72.5, 71.1, 70.8, 68.8, 68.6, 66.0, 63.3, 62.8, 62.5, 55.9, 48.3, 47.0, 46.8, 42.5, 42.4, 40.1, 38.6, 38.4, 37.5, 34.6, 33.6, 33.6, 33.4, 31.2, 28.7, 28.5, 26.6, 24.3, 24.2, 24.2, 24.1, 18.9, 17.7, 17.4, 15.8. HRMS (ESI) m/z for C₃₈H₆₀NO₈ ([M+H]⁻) 658.4326, calc. 658.4324.

28-N-Methoxyaminooleanane-β-d-glucoside (8a)

White solid (36.2 mg, 60%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.20 (d, J = 3.0 Hz, 1H), 4.61 (d, J = 7.9 Hz, 1H), 4.48 (dd, J = 11.8, 2.6 Hz, 1H), 4.36 (dd, J = 11.8, 4.9 Hz, 1H), 4.27–4.18 (m, 3H), 3.93–3.88 (m, 1H), 3.80 (s, 3H), 3.46–3.36 (m, 2H), 3.10 (d, J = 15.3 Hz, 1H), 2.27–2.09 (m, 1H), 1.21 (s, 3H), 1.20 (s, 3H), 1.05 (s, 3H), 1.02 (s, 3H), 0.89 (d, J = 1.3 Hz, 6H), 0.88 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.7, 123.7, 97.6, 81.1, 80.8, 78.8, 72.6, 72.5, 63.7, 56.5, 48.8, 48.0, 45.6, 42.6, 41.0, 40.2, 39.9, 38.0, 37.1, 35.6, 34.2, 33.7, 33.6, 32.3, 31.8, 31.1, 30.7, 29.5, 28.9, 27.2, 26.9, 24.8, 24.7, 19.6, 18.1, 17.3, 16.5. HRMS (ESI) m/z for C₃₇H₆₄NO₇ ([M+H]⁺) 634.4676, calc. 634.4677.

28-N-Methoxyaminooleanane-β-l-glucoside (8b)

White solid (32.2 mg, 51%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.19 (d, J = 3.0 Hz, 1H), 4.60 (d, J = 8.0 Hz, 1H), 4.48 (dd, J = 11.8, 2.5 Hz, 1H), 4.37 (dd, J = 11.8, 4.9 Hz, 1H), 4.30–4.22 (m, 3H), 3.86 (s, 1H), 3.81 (s, 3H), 3.44–3.38 (m, 2H), 3.22 (d, J = 14.9 Hz, 1H), 2.26–2.18 (m, 1H), 1.23 (s, 3H), 1.20 (s, 3H), 1.09 (s, 3H), 1.02 (s, 3H), 0.95 (s, 3H), 0.90 (s, 3H), 0.86 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.1, 123.0, 97.2, 80.5, 80.3, 78.2, 72.2, 71.9, 63.0, 55.9, 48.1, 47.4, 44.5, 42.0, 40.4, 39.5, 39.2, 37.3, 36.7, 35.0, 33.5, 33.2, 33.1, 31.6, 31.2, 30.5, 30.1, 28.9, 28.2, 26.4, 26.1, 24.0, 23.9, 18.9, 17.7, 16.7, 15.9. HRMS (ESI) m/z for C₃₇H₆₄NO₇ ([M+H]⁺) 634.4673, calc. 634.4677.

28-N-Methoxyaminooleanane-β-2-deoxy-d-glucoside (8c)

White solid (33.9 mg, 53%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.21 (t, J = 3.2 Hz, 1H), 4.72 (d, J = 10.5 Hz, 1H), 4.50 (dd, J = 11.6, 2.8 Hz, 1H), 4.39 (dd, J = 11.6, 4.9 Hz, 1H), 4.30–4.23 (m, 1H), 4.06 (t, J = 9.0 Hz, 1H), 3.86–3.80 (m, 1H), 3.66 (s, 3H), 3.44 (dd, J = 10.9, 4.8 Hz, 1H), 3.34 (d, J = 15.1 Hz, 1H), 2.96 (d, J = 15.2 Hz, 1H), 2.60–2.47 (m, 1H), 1.26 (s, 3H), 1.24 (s, 3H), 1.08 (s, 3H), 1.06 (s, 3H), 0.95 (s, 3H), 0.94 (s, 3H), 0.91 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.0, 123.2, 92.8, 80.5, 78.2, 73.9, 73.6, 63.3, 55.8, 48.2, 47.3, 45.0, 41.9, 40.4, 39.5, 39.2, 37.7, 37.3, 36.3, 34.9, 33.5, 33.0, 31.6, 31.1, 30.5, 30.1, 28.9, 28.2, 26.5, 26.1, 24.1, 24.0, 23.9, 18.9, 17.4, 16.6, 15.9. HRMS (ESI) m/z for C₃₇H₆₄NO₆ ([M+H]⁺) 618.4730, calc. 618.4728.

28-N-Methoxyaminooleanane-β-3-O-methyl-d-glucoside (8d)

White solid (25.2 mg, 39%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.27 (s, 1H), 4.63 (d, J = 8.9 Hz, 1H), 4.50 (dd, J = 11.8, 2.5 Hz, 1H), 4.39 (dd, J = 11.8, 4.8 Hz, 1H), 4.23 (q, J = 9.1 Hz, 2H), 3.95 (s, 3H), 3.85–3.77 (m, 4H), 3.50–3.41 (m, 2H), 3.13 (d, J = 15.3 Hz, 1H), 2.32–2.18 (m, 1H), 1.27 (s, 3H), 1.27 (s, 3H), 1.11 (s, 3H), 1.09 (s, 3H), 0.96 (s, 3H), 0.95 (s, 3H), 0.95 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 144.9, 122.9, 96.6, 90.0, 80.1, 78.1, 71.2, 70.8, 62.6, 60.9, 55.7, 48.0, 47.2, 44.7, 41.8, 40.2, 39.4, 39.1, 37.2, 36.3, 34.8, 33.4, 32.8, 32.8, 31.5, 31.0, 30.3, 28.7, 28.1, 26.4, 26.1, 24.1, 23.9, 23.8, 18.8, 17.3, 16.5, 15.7. HRMS (ESI) m/z for C₃₈H₆₆NO₇ ([M+H]⁺) 648.4825, calc. 648.4834.

28-N-Methoxyaminooleanane-d-galactoside (8e)

White solid (35.8 mg, 56%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.23 (t, J = 5.4 Hz, 1H), 5.11 (d, J = 6.2 Hz, 0.2H, βH1′), 4.67 (d, J = 2.8 Hz, 0.8H, αH1′), 4.62 (s, 1H), 4.56–4.46 (m, 1H), 4.43–4.33 (m, 2H), 4.24 (dt, J = 9.5, 4.7 Hz, 1H), 4.10 (t, J = 6.3 Hz, 1H), 3.83–3.78 (m, 3H), 3.70–3.60 (m, 1H), 3.45 (dd, J = 10.9, 5.1 Hz, 1H), 3.11 (dd, J = 15.2, 8.0 Hz, 1H), 1.28 (s, 3H), 1.25 (s, 3H), 1.14 (d, J = 6.5 Hz, 3H), 1.06 (s, 3H), 0.94 (s, 3H), 0.92 (s, 3H), 0.86 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.0, 122.8, 101.7, 97.1, 83.8, 78.7, 78.3, 78.2, 78.0, 76.9, 73.0, 70.2, 69.6, 64.9, 62.2, 61.6, 55.8, 48.2, 47.3, 45.4, 42.0, 40.4, 39.5, 39.2, 37.3, 36.5, 34.8, 33.5, 33.3, 33.0, 31.1, 30.5, 30.0, 28.8, 28.2, 26.5, 26.5, 26.2, 24.0, 18.9, 17.4, 16.6, 15.8. HRMS (ESI) m/z for C₃₇H₆₄NO₇ ([M+H]⁺) 634.4676, calc. 634.4677.

28-N-Methoxyaminooleanane-2-deoxy-d-galactoside (8f)

White solid (33.1 mg, 54%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.36 (d, J = 6.5 Hz, 0.33H, αH1′), 5.15 (t, J = 3.3 Hz, 1H), 4.69–4.62 (m, 1H), 4.52–4.35 (m, 3H), 4.32–4.28 (m, 0.67 H), 3.95 (t, J = 6.1 Hz, 1H), 3.67 (d, J = 8.1 Hz, 3H), 3.52–3.42 (m, 3H), 2.95 (d, J = 15.3 Hz, 1H), 1.28–1.25 (m, 6H), 1.12 (s, 3H), 1.07 (s, 3H), 0.95 (s, 6H), 0.88 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 144.8, 122.7, 98.0, 97.0, 92.8, 86.8, 86.3, 78.8, 78.0, 73.7, 73.1, 72.1, 71.8, 70.7, 68.6, 65.0, 64.7, 62.3, 55.7, 48.0, 48.0, 47.2, 45.1, 41.8, 41.8, 40.2, 39.3, 39.0, 37.2, 36.2, 34.7, 30.9, 28.7, 28.0, 26.3, 25.9, 23.8, 23.7, 23.6, 18.7, 17.3, 16.4, 15.7. HRMS (ESI) m/z for C₃₇H₆₄NO₆ ([M+H]⁺) 618.4739, calc. 618.4728.

28-N-Methoxyaminooleanane-d-mannoside (8g)

White solid (33.5 mg, 52%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.24 (t, J = 5.4 Hz, 1H), 5.00 (d, J = 2.5 Hz, 0.5H, αH1′), 4.77–4.70 (m, 0.5H), 4.67 (dt, J = 8.3, 4.0 Hz, 1H), 4.59–4.43 (m, 2H), 4.38–4.17 (m, 1H), 3.99–3.57 (m, 5H), 3.54–3.32 (m, 2H), 3.03 (dd, J = 20.5, 14.9 Hz, 1H), 1.28 (d, J = 3.1 Hz, 3H), 1.27 (d, J = 2.8 Hz, 3H), 1.07 (t, J = 3.1 Hz, 3H), 0.98 (t, J = 3.5 Hz, 3H), 0.95 (s, 3H), 0.93 (d, J = 2.8 Hz, 3H), 0.89 (d, J = 11.2 Hz, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.0, 122.9, 102.6, 96.1, 93.8, 82.0, 81.3, 78.2, 77.1, 73.4, 72.5, 71.5, 69.8, 65.2, 63.5, 62.3, 60.6, 55.9, 48.2, 47.3, 45.2, 42.0, 40.3, 39.5, 39.2, 37.3, 36.6, 35.0, 33.5, 31.6, 31.1, 30.5, 28.9, 28.2, 26.6, 26.4, 24.1, 24.0, 23.9, 18.9, 17.5, 16.6, 15.9. HRMS (ESI) m/z for C₃₇H₆₄NO₇ ([M+H]⁺) 634.4672, calc. 634.4677.

28-N-Methoxyaminooleanane-d-arabinoside (8h)

White solid (35.2 mg, 58%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.25 (t, J = 3.1 Hz, 1H), 5.18 (d, J = 5.5 Hz, 0.67H, αH1′), 4.67–4.63 (m, 1H), 4.61–4.50 (m, 1H), 4.46–4.34 (m, 2H), 4.29–4.21 (m, 1H), 4.16 (dd, J = 8.9, 3.4 Hz, 0.33H), 3.89–3.78 (m, 3H), 3.49–3.42 (m, 2H), 3.34 (dd, J = 50.9, 15.5 Hz, 1H), 2.28 (dd, J = 13.6, 3.8 Hz, 0.33H), 1.30 (s, 3H), 1.26 (d, J = 1.8 Hz, 3H), 1.08 (d, J = 2.8 Hz, 3H), 1.06 (s, 3H), 0.95 (d, J = 3.4 Hz, 3H), 0.93 (s, 3H), 0.90 (d, J = 5.7 Hz, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 144.8, 122.7, 102.0, 97.6, 84.3, 78.0, 77.7, 76.3, 70.2, 69.5, 69.4, 62.7, 61.9, 55.7, 48.0, 47.2, 45.1, 41.9, 40.2, 39.3, 39.1, 37.2, 36.5, 34.8, 33.3, 33.1, 33.0, 31.4, 30.9, 30.3, 29.9, 28.7, 28.1, 26.3, 26.0, 23.9, 23.7, 18.7, 17.5, 16.5, 15.7. HRMS (ESI) m/z for C₃₆H₆₂NO₆ ([M+H]⁺) 604.4581, calc. 604.4572.

28-N-Methoxyaminooleanane-l-arabinoside (8i)

White solid (37.3 mg, 62%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.18 (d, J = 5.9 Hz, 0.5H, αH1′), 5.14 (t, J = 3.2 Hz, 2H), 4.63–4.59 (m, 0.5H), 4.53–4.41 (m, 2H), 4.31–4.11 (m, 3H), 3.73 (d, J = 6.3 Hz, 3H), 3.42 (dd, J = 10.9, 4.9 Hz, 1H), 3.01 (d, J = 15.5 Hz, 1H), 2.17 (d, J = 10.6 Hz, 3H), 1.25 (s, 3H), 1.21 (s, 3H), 1.11 (s, 3H), 1.02 (s, 3H), 0.94 (s, 3H), 0.88 (s, 3H), 0.78 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 144.9, 122.6, 101.4, 97.0, 84.6, 78.1, 76.2, 70.2, 69.6, 69.5, 55.8, 55.7, 48.1, 48.1, 47.1, 45.6, 41.9, 41.9, 40.3, 40.2, 39.4, 39.1, 37.3, 36.4, 33.4, 33.0, 31.5, 31.0, 30.4, 30.0, 28.8, 28.1, 26.4, 26.1, 23.9, 23.9, 23.5, 18.8, 17.4, 16.5, 15.8. HRMS (ESI) m/z for C₃₆H₆₂NO₆ ([M+H]+) 604.4576, calc. 604.4572.

28-N-Methoxyaminooleanane-d-fucoside (8j)

White solid (35.2 mg, 57%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.15 (s, 1H), 4.51 (dt, J = 17.5, 8.7 Hz, 2H), 4.18 (dd, J = 8.7, 3.4 Hz, 1H), 4.09 (d, J = 2.8 Hz, 1H), 3.88 (q, J = 6.0 Hz, 1H), 3.78 (s, 3H), 3.66 (t, J = 9.8 Hz, 1H), 3.47 (dd, J = 11.0, 4.9 Hz, 1H), 3.10–3.04 (m, 1H), 1.29 (s, 3H), 1.27 (s, 3H), 1.19 (s, 3H), 1.08 (s, 3H), 0.99 (s, 3H), 0.93 (s, 3H), 0.86 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.5, 123.3, 97.2, 87.6, 78.7, 77.4, 74.0, 73.5, 69.7, 56.4, 48.7, 47.8, 46.1, 42.5, 40.9, 40.0, 39.7, 37.9, 37.0, 35.3, 34.0, 33.9, 33.6, 32.1, 31.6, 31.0, 30.6, 29.4, 28.7, 27.0, 26.7, 24.5, 19.4, 18.1, 18.0, 17.1, 16.4. HRMS (ESI) m/z for C₃₇H₆₄NO₆ ([M+H]+)618.4733, calc. 618.4728.

28-N-Methoxyaminooleanane-β-l-fucoside (8k)

White solid (38.9 mg, 63%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.19 (d, J = 3.2 Hz, 1H), 4.49 (t, J = 8.8 Hz, 1H), 4.44 (d, J = 8.7 Hz, 1H), 4.10 (dd, J = 8.8, 3.4 Hz, 1H), 4.04 (d, J = 2.9 Hz, 1H), 3.80 (d, J = 6.9 Hz, 1H), 3.74 (s, 3H), 3.42 (dd, J = 10.9, 4.9 Hz, 1H), 3.35 (dd, J = 14.9, 3.9 Hz, 1H), 3.26 (d, J = 15.0 Hz, 1H), 2.26 (dd, J = 13.4, 3.9 Hz, 1H), 1.25 (s, 3H), 1.22 (s, 3H), 1.14 (s, 3H), 1.02 (d, J = 2.3 Hz, 3H), 0.97 (s, 3H), 0.91 (s, 6H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.0, 122.7, 96.9, 86.6, 78.0, 76.9, 73.3, 72.8, 68.9, 55.7, 48.0, 47.3, 44.3, 41.9, 40.2, 39.3, 39.1, 37.2, 37.2, 36.4, 34.8, 33.3, 33.0, 32.8, 31.0, 28.7, 28.0, 26.2, 25.9, 23.9, 23.8, 20.5, 18.7, 17.4, 17.4, 16.5, 15.7. HRMS (ESI) m/z for C₃₇H₆₄NO₆ ([M+H]⁺) 618.4732, calc. 618.4728.

28-N-Methoxyaminooleanane-β-d-xyloside (8l)

White solid (38.2 mg, 63%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.26 (t, J = 3.3 Hz, 1H), 4.57 (d, J = 6.7 Hz, 1H), 4.40 (dd, J = 10.8, 4.5 Hz, 1H), 4.19 (d, J = 13.9 Hz, 3H), 3.80 (s, 3H), 3.69 (t, J = 10.4 Hz, 1H), 3.52 (d, J = 15.3 Hz, 1H), 3.41 (t, J = 14.6 Hz, 1H), 3.03 (d, J = 15.4 Hz, 1H), 2.25–2.14 (m, 1H), 1.26 (s, 3H), 1.23 (s, 3H), 1.10 (s, 3H), 1.04 (s, 3H), 0.92 (s, 3H), 0.92 (s, 3H), 0.89 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 144.9, 122.7, 97.1, 80.1, 78.0, 71.7, 70.9, 69.2, 55.7, 48.0, 47.0, 45.3, 41.8, 40.2, 39.3, 39.0, 37.2, 36.2, 34.7, 33.3, 33.1, 32.8, 31.4, 31.0, 30.3, 28.7, 28.0, 26.3, 26.1, 23.8, 23.8, 23.6, 18.7, 17.2, 16.4, 15.7. HRMS (ESI) m/z for C₃₆H₆₂NO₆ ([M+H]⁺) 604.4572, calc. 604.4572.

28-N-Methoxyaminooleanane-β-l-xyloside (8m)

White solid (37.2 mg, 62%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.30 (t, J = 3.2 Hz, 1H), 4.55 (d, J = 8.7 Hz, 1H), 4.43 (dd, J = 11.1, 5.2 Hz, 1H), 4.28–4.18 (m, 3H), 3.85 (s, 3H), 3.70 (t, J = 10.7 Hz, 1H), 3.49–3.43 (m, 1H), 3.34 (d, J = 5.8 Hz, 2H), 2.29 (dd, J = 13.3, 3.8 Hz, 1H), 1.29 (s, 3H), 1.25 (s, 3H), 1.17 (s, 3H), 1.06 (s, 3H), 0.99 (s, 3H), 0.95 (s, 3H), 0.92 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.0, 122.8, 97.8, 80.2, 78.1, 71.7, 71.1, 69.3, 55.7, 49.6, 48.0, 47.2, 44.7, 42.0, 40.3, 39.4, 39.1, 37.2, 36.5, 34.8, 33.4, 33.1, 33.0, 31.5, 31.0, 30.3, 28.7, 28.1, 26.3, 26.0, 23.9, 23.8, 18.8, 17.5, 16.5, 15.7. HRMS (ESI) m/z for C₃₆H₆₂NO₆ ([M+H]⁺) 604.4578, calc. 604.4572.

28-N-Methoxyaminooleanane-l-lyxoside (8n)

White solid (34.2 mg, 57%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.88 (d, J = 3.5 Hz, 0.2H, αH1′), 5.22 (d, J = 3.2 Hz, 1H), 4.81 (d, J = 3.3 Hz, 1H), 4.78–4.72 (m, 1H), 4.72–4.65 (m, 0.8H), 4.49–4.42 (m, 1H), 4.35 (dd, J = 11.2, 4.2 Hz, 1H), 4.23 (dd, J = 18.4, 8.8 Hz, 1H), 3.97–3.78 (m, 3H), 3.60–3.43 (m, 2H), 3.09 (dd, J = 16.5, 15.1 Hz, 1H), 1.29–1.27 (m, 3H), 1.25 (d, J = 11.2 Hz, 3H), 1.16 (d, J = 5.4 Hz, 3H), 1.09–1.06 (m, 3H), 0.98 (d, J = 7.0 Hz, 3H), 0.95 (d, J = 3.8 Hz, 3H), 0.91 (d, J = 3.2 Hz, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.56, 123.23, 102.50, 96.98, 83.26, 78.68, 73.85, 73.61, 73.41, 71.79, 69.99, 68.58, 67.66, 56.35, 50.22, 48.67, 47.71, 46.17, 42.49, 40.87, 39.97, 39.69, 37.83, 36.97, 35.39, 34.02, 33.98, 33.79, 33.52, 31.59, 30.94, 29.33, 28.70, 26.97, 26.73, 24.49, 24.43, 19.39, 17.92, 17.11, 16.34. HRMS (ESI) m/z for C₃₆H₆₂NO₆ ([M+H]⁺) 604.4575, calc. 604.4572.

28-N-Methoxyaminooleanane-l-rhamnoside (8o)

White solid (34.7 mg, 56%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.33 (t, J = 3.3 Hz, 1H), 5.28 (d, J = 6.1 Hz, 0.2H, βH1′), 4.69 (d, J = 2.9 Hz, 0.8H, αH1′), 4.34–4.29 (m, 1H), 4.19 (t, J = 9.1 Hz, 1H), 4.07 (dd, J = 9.2, 3.0 Hz, 1H), 3.84 (d, J = 7.8 Hz, 3H), 3.76 (dq, J = 9.3, 6.1 Hz, 1H), 3.51–3.39 (m, 4H), 3.12 (d, J = 14.6 Hz, 1H), 1.18 (s, 3H), 1.08 (d, J = 3.1 Hz, 3H), 1.07 (s, 3H), 1.01 (s, 3H), 0.99 (s, 3H), 0.98 (s, 6H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.8, 123.2, 102.2, 95.3, 86.4, 78.7, 77.3, 76.9, 74.6, 72.5, 63.8, 62.3, 61.6, 56.4, 48.7, 48.0, 45.2, 42.5, 40.9, 40.0, 40.0, 39.7, 37.9, 37.1, 34.0, 32.1, 31.6, 31.6, 31.0, 30.6, 29.4, 29.3, 28.7, 27.0, 26.6, 24.5, 24.4, 19.4, 19.3, 18.3, 17.1, 17.1, 16.4. HRMS (ESI) m/z for C₃₇H₆₄NO₆ ([M+H]⁺) 618.4733, calc. 618.4728.

28-N-Methoxyaminooleanane-d-riboside (8p)

White solid (34.9 mg, 58%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.29 (t, J = 3.0 Hz, 1H), 5.23 (d, J = 3.4 Hz, 0.5H, αH1′), 4.80–4.62 (m, 2H), 4.35 (dd, J = 11.6, 3.7 Hz, 0.5H), 4.31–4.14 (m, 3H), 3.91–3.77 (m, 3H), 3.50–3.34 (m, 2H), 3.04 (dd, J = 38.0, 15.1 Hz, 1H), 1.28 (d, J = 2.7 Hz, 3H), 1.27 (s, 3H), 1.08 (d, J = 2.6 Hz, 3H), 0.97 (dd, J = 12.2, 3.2 Hz, 6H), 0.95 (d, J = 4.4 Hz, 3H), 0.93 (d, J = 3.9 Hz, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.3, 122.9, 103.6, 93.4, 84.7, 78.3, 73.0, 72.6, 69.3, 68.8, 66.4, 64.1, 62.2, 56.0, 55.9, 48.2, 47.3, 45.6, 42.1, 40.5, 39.6, 39.3, 37.4, 36.6, 33.6, 31.7, 31.3, 30.6, 29.0, 28.9, 28.3, 26.6, 26.5, 26.4, 24.1, 24.1, 24.0, 19.0, 17.4, 16.7, 15.9. HRMS (ESI) m/z for C₃₆H₆₂NO₆ ([M+H]⁺) 604.4580, calc. 604.4572.

28-N-Methoxyaminooleanane-l-riboside (8q)

White solid (33.2 mg, 55%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.24 (t, J = 3.2 Hz, 1H), 5.20 (d, J = 3.1 Hz, 0.5H, αH1′), 4.81–4.60 (m, 2H), 4.38 (dd, J = 11.7, 3.6 Hz, 0.5H), 4.31–4.18 (m, 3H), 3.84 (s, 3H), 3.46 (dd, J = 10.8, 5.1 Hz, 1H), 3.33 (dd, J = 14.9, 8.7 Hz, 1H), 2.98 (d, J = 14.8 Hz, 1H), 1.26 (s, 3H), 1.17 (s, 3H), 1.07 (s, 3H), 1.03 (s, 3H), 0.95 (s, 3H), 0.94 (d, J = 2.3 Hz, 3H), 0.93 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.0, 123.0, 104.3, 94.0, 84.3, 78.3, 73.1, 72.7, 69.2, 68.9, 64.0, 62.5, 55.9, 48.3, 47.3, 45.2, 44.9, 42.2, 42.1, 40.6, 40.4, 39.6, 39.3, 37.4, 37.4, 36.8, 36.7, 35.0, 33.6, 33.6, 31.2, 28.9, 28.3, 26.5, 26.5, 26.3, 24.1, 24.0, 23.8, 19.0, 17.6, 16.7, 15.9. HRMS (ESI) m/z for C₃₆H₆₂NO₆ ([M+H]⁺) 604.4575, calc. 604.4572.

28-N-Methoxyaminooleanane-2-deoxy-d-riboside (8r)

White solid (33.9 mg, 58%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.30 (d, J = 3.3 Hz, 0.8H, αH1′), 5.25 (s, 1H), 4.70–4.52 (m, 1H), 4.47–4.34 (m, 1H), 4.28 (d, J = 10.5 Hz, 0.2H), 4.26–4.07 (m, 3H), 3.66 (d, J = 10.0 Hz, 3H), 3.50–3.44 (m, 2H), 1.30 (s, 3H), 1.28 (d, J = 3.5 Hz, 3H), 1.27 (s, 3H), 1.08 (s, 3H), 0.98 (d, J = 6.0 Hz, 3H), 0.97 (t, J = 3.0 Hz, 3H), 0.95 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 145.6, 123.4, 98.5, 93.5, 88.3, 78.7, 72.8, 72.1, 68.9, 68.9, 67.2, 62.6, 61.7, 60.3, 56.3, 48.6, 47.7, 47.2, 46.0, 45.6, 42.5, 40.9, 39.99, 39.72, 37.8, 36.8, 34.0, 31.6, 31.0, 29.3, 28.7, 27.0, 26.8, 26.7, 24.5, 24.4, 24.4, 19.4, 17.8, 17.1, 16.4. HRMS (ESI) m/z for C₃₆H₆₂NO₅ ([M+H]⁺) 588.4616, calc. 588.4623.

Oleanolic acid-28-O-β-d-glucopyranoside (1a)

White solid (75.2 mg, 28%). ¹H-NMR (500 MHz, C₅D₅N) δ 6.34 (d, J = 8.0 Hz, 1H), 5.46 (s, 1H), 4.48–4.03 (m, 6H), 3.44 (dd, J = 10.9, 5.1 Hz, 1H), 3.22 (dd, J = 14.1, 4.4 Hz, 1H), 1.25 (s, 3H), 1.23 (s, 3H), 1.14 (s, 3H), 1.03 (s, 3H), 0.93 (s, 3H), 0.90 (s, 3H), 0.88 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 176.5, 144.2, 123.0, 95.8, 79.4, 78.9, 78.1, 75.7, 74.2, 62.3, 55.8, 48.2, 47.1, 46.3, 42.2, 41.8, 39.9, 39.4, 39.0, 37.4, 34.0, 33.2, 33.2, 32.6, 31.0, 29.1, 28.8, 28.3, 28.1, 26.1, 23.9, 23.5, 18.9, 17.6, 16.6, 15.7 HRMS (ESI) m/z for C₃₆H₅₈O₈Na ([M+Na]⁺) 641.4029, calc. 641.4024.

Erythrodiol-28-O-β-d-glucopyranoside (1b)

White solid (62.8 mg, 23%). ¹H-NMR (500 MHz, C₅D₅N) δ 5.24 (s, 1H), 4.92 (d, J = 7.7 Hz, 1H), 4.62 (d, J = 11.7 Hz, 1H), 4.48 (dd, J = 11.2, 4.4 Hz, 1H), 4.35–4.28 (m, 2H), 4.10 (dd, J = 17.3, 8.2 Hz, 2H), 3.86 (s, 2H), 3.51–3.41 (m, 1H), 1.26 (s, 6H), 1.08 (s, 3H), 1.02 (s, 3H), 0.97 (s, 3H), 0.92 (s, 3H), 0.88 (s, 3H). ¹³C-NMR (125 MHz, C₅D₅N) δ 144.7, 122.8, 105.9, 78.8, 78.6, 78.1, 77.2, 75.4, 71.8, 63.0, 55.8, 48.1, 46.7, 43.2, 42.0, 40.2, 39.5, 39.2, 37.3, 37.2, 34.5, 33.5, 32.9, 32.7, 31.2, 28.8, 28.2, 28.2, 26.3, 23.9, 23.9, 22.1, 18.9, 17.1, 16.6, 15.9. HRMS (ESI) m/z for C₃₆H₆₀O₇Na ([M+Na]⁺) 627.4231, calc. 627.4231.