Terpenoids. XXII.¹ Triterpenes from Some Mexican and South American Plants²

The Biosynthesis of β-Amyrin and β-Sitosterol in Germinating Seeds of Pisum sativum*

“…A sample of this material failed to depress the melting point of an authentic specimen of 3-amyrin (m.p. 200-201°) (Djerassi et al, 1956). Infrared spectra (CS2) of our sample and of the authentic material were identical.…”

“…We have isolated /3-amyrin (XI) by chromatography of a saponified acetone extract. Professor Carl Djerassi kindly sent us a sample from Byrsonima species (Djerassi et al, 1956) which had been proved to be identical with a sample provided by Professor F. S. Spring, in whose laboratories much of the structural work on triterpenoids had been done. Our /3-amyrin (XI) was identical with that of Djerassi, as shown by a comparison of infrared spectra, melting point of a mixture, and optical rotation.…”

A Metalloproteinase Inhibitor from Doliocarpus verruculosus

“…I = 1.5 Hz and 4.29, J = 1.5 Hz) in the 'H NMR spectrum was also characteristic of a triterpene skeleton. Literature search and spectral comparison with those of known plant metabolites (Djerassi et al, 1956;Nozaki el al., 1990;Sung et al, 1991) led us to conclude that I is betulinic acid. All the spectral data of I were in agreement with those of an authentic sample of betulinic acid obtained from Aldrich.…”

An Improved Scalable Synthesis of α- and β-Amyrin

“…= 226–228 °C (lit. : 225–229 °C) [ 27 ]; = +75° ( c 0.325, CHCl 3 ) (lit. : +70°) [ 27 ]; R f = 0.24 (silica gel, chloroform/hexane/EtOAc, 10:8:2); IR (KBr): ν = 3444 br , 2946 w , 2866 w , 1636 m , 1460 w , 1384 w , 1044 w , 1004 w cm −1 ; 1 H NMR (500MHz, CDCl 3 ): δ = 5.19 ( dd , J = 3.6, 3.6 Hz, 1H, H-12), 3.55 ( d , J = 11.0 Hz, 1H, H-28a), 3.21 ( d , J = 11.0 Hz, 1H, H-28b), 3.28–3.15 ( m , 1H, H-3), 1.98 ( dd , J = 13.5, 4.6 Hz, 1H, H-18), 1.94–1.79 ( m , 3H, H-16a + H-2a + H-2b), 1.77–1.66 ( m , 2H, H-15a + H-19a), 1.65–1.46 ( m , 7H, H-1a + H-11a + H-11b + H-6a + H-9 + H-22a + H-7a), 1.46–1.37 ( m , 1H, H-6b), 1.37–1.25 ( m , 3H, H-22b + H-7b + H-21a), 1.22–1.13 ( m , 2H, H-16b + H-21b), 1.16 (s, 3H, H-27), 1.10–1.03 ( m , 1H, H-19b), 1.03–0.91 ( m , 2H, H-15b + H-1b), 0.99 ( s , 3H, H-23), 0.94 ( s , 3H, H-26), 0.93 ( s , 3H, H-24), 0.88 ( s , 3H, H-29), 0.87 ( s , 3H, H-30), 0.79 ( s , 3H, H-25), 0.75–0.71 ( m , 1H, H-5) ppm; 13 C NMR (125 MHz, CDCl 3 ): δ = 144.4 (C-13), 122.5 (C-12), 79.2 (C-3), 69.8 (C-28), 55.3 (C-5), 47.7 (C-9), 46.6 (C-19), 42.5 (C-18), 41.9 (C-14), 39.9 (C-8), 38.9 (C-4), 38.8 (C-1), 37.1 (C-10), 34.3 (C-21), 33.3 (C-29), 32.7 (C-7), 31.2 (C-22), 31.2 (C-20), 31.1 (C-17), 28.3 (C-23), 27.4 (C-11), 26.1 (C-27), 25.7 (C-15), 23.7 (C-2), 23.7 (C-30), 22.2 (C-16), 18.5 (C-6), 16.9 (C-26), 15.7 (C-24), 15.7 (C-25) ppm; MS (ASAP): m / z (%) = 425.6 ([M-H 2 O + H] + , 100), 443.6 ([M + H] + , 48).…”