Biotransformation of betulin by Mucor subtilissimus to discover anti-inflammatory derivatives

Design and Synthesis of Novel Betulin Derivatives Containing Thio-/Semicarbazone Moieties as Apoptotic Inducers through Mitochindria-Related Pathways

“…Melting points (mp) of all new derivatives were tested using a MP120 melting point apparatus (Haineng, Fujian, China). NMR spectra were tested using BrukerAvance DRX400 spectrometers 600 MHz for 1 H NMR and 150 MHz for 13 C NMR (Bruker, Berlin, Germany). The chemical shifts were expressed in ppm using tetramethylsilane as an internal standard.…”

“…The organic solvent was evaporated and then purified by silica gel column chromatography (ethyl acetate/petroleum ether = 1/50) to give 2 (2.95 g, 80%). White solid: mp 216.0-217.5 • C; 1 H NMR (600 MHz, CDCl 3 ) δ 4.69 (s, 1H, -C=CH), 4.59 (s, 1H, -C=CH), 4.47 (dd, J = 10.6, 5.7 Hz, 1H, AcO-CH), 4.25 (d, J = 10.9 Hz, 1H, CH 2 -O), 3.85 (d, J = 11.0 Hz, 1H, CH 2 -O), 2.44 (td, J = 11.1, 5.8 Hz, 1H), 2.07 (s, 3H, CH 3 -COO), 2.04 (s, 3H, CH 3 -COO), 1.68 (s, 3H, CH 3 -C=C), 1.03 (s, 3H, -CH 3 ), 0.97 (s, 3H, -CH 3 ), 0.87-0.82 (m, 9H, -CH 3 × 3), 0.78 (d, J = 9.3 Hz, 1H); 13 C NMR (150 MHz, CDCl 3 ) δ 171.6, 171.0, 150.2, 109.9, 80.9, 62.8, 55. 4, 50.3, 48.8, 47.7, 46.3, 42.7, 40.9, 38.4, 37.8, 37.6, 37.1, 34.5, 34.1, 29.7, 29.6, 27.9, 27.1, 25.2, 23.7, 21.3, 21.1, 20.8, 19.1, 18.2, 16.5, 16.2, 16.0, 14.7; MS (ESI) m/z: [M + H] + 527.4.…”

“…The crude product was purified by silica gel column chromatography to give 4 (240 mg, 80%). White solid: mp 270.2-271.8 • C; 1 H NMR (600 MHz, CDCl 3 ) δ 9.67 (d, J = 1.1 Hz, 1H, -CHO), 4.76 (d, J = 0.9 Hz, 1H, C=C-H), 4.63 (s, 1H, C=C-H), 4.47 (dd, J = 10.9, 5.5 Hz, 1H, AcO-CH), 2.86 (td, J = 11.2, 5.9 Hz, 1H), 2.04 (s, 3H, CH 3 -COO), 1.70 (s, 3H, -CH 3 ), 0.97 (s, 3H, -CH 3 ), 0.91 (s, 3H, -CH 3 ), 0.84 (d, J = 8.5 Hz, 9H, -CH 3 × 3); 13 The solution of 3-O-acetyl-betulinicaldehyde (4, 200 mg, 0.4 mmol) in 2% NaOH-MeOH (10 mL) was continuously stirred for 2 h at 80 • C. The solution was evaporated and then redissolved with CH 2 Cl 2 (100 mL), washed with brine twice and dried over anhydrous Na 2 SO 4 . The crude product was purified by silica gel column chromatography (ethyl acetate/petroleum ether = 1/10) to give 5 (116 mg, 65%).…”

“…The crude product was purified by silica gel column chromatography (ethyl acetate/petroleum ether = 1/10) to give 5 (116 mg, 65%). White solid: mp 285.3-287.2 • C; 1 H NMR (600 MHz, CDCl 3 ) δ 9.68 (d, J = 1.3 Hz, 1H, -CHO), 4.76 (s, 1H, C=C-H), 4.63 (s, 1H, C=C-H), 3.18 (dd, J = 11.5, 4.7 Hz, 1H, O-C-H), 2.86 (td, J = 11.2, 5.9 Hz, 1H, C=C-CH-), 1.70 (s, 3H, CH 3 -C=C), 0.97 (s, 3H, -CH 3 ), 0.95 (s, 3H, -CH 3 ), 0.92 (s, 3H, -CH 3 ), 0.82 (s, 3H, -CH 3 ), 0.75 (s, 3H, -CH 3 ); 13 To a solution of betulinicaldehyde (5, 1.55 g, 3.5 mmol) in ethanol (80 mL) was added hydrazine hydrate (85%, 2 mL). The reaction mixture was continuously stirred at 40 • C for 5 h. The solvent was evaporated, and crude product was purified by silica gel column chromatography (ethyl acetate/petroleum ether = 1/1) to give 6 (1.25 g, 70%).…”

“…Betulin (BE, lup-20(29)-ene-3β,28-diol, 1) is an important natural lupine-type triterpenoid widely distributed in plenty of plants, especially abundant in the bark of birch trees (Figure 1) [6]. Betulin has been shown to exert various biological and pharmacological activities, such as antibacterial [7,8], anti-HIV [9][10][11] and anti-inflammatory properties [12][13][14][15]. Recently, plenty of studies have reported that betulin and its derivatives have significant antitumor activities against many kinds of cancer cell lines, such as colorectal carcinoma (HT29, HCT116) [16,17], lung carcinoma (A549) [18], liver carcinoma (SK-HEP-1, HepG2) [19,20], breast carcinoma (MCF-7, MDA-MB231) [21], prostate carcinoma (PC3) [22] as well as cervical carcinoma (HeLa) [23] and leukemia (HL-60, K562, U937) [24][25][26].…”