Esters from Ferula samarcandica
In continuation of research on terpenoid plants of the Ferula L. genus (Apiaceae), we studied components of the roots of Samarkand ferula ( Ferula samarcandica Korov.) collected in Tashkent district. The terpenoid coumarins samarcandin and samarcandone were isolated previously from Samarkand ferula [1]. Later, a study of Samarkand ferula misidentified as mogoltav ferula ( F. mogoltavica Lipsky ex Korov.) isolated the terpenoid coumarins samarcandin, samarcandone, mogoltadone, gummosin, and farnesiferol A [2-4]. Air-dried ground roots were extracted with ethanol. The alcohol extract was evaporated, diluted with water (1:2), and treated with ethylacetate. The combined ethylacetate extract was distilled to produce a thick extract that was placed on a col umn of KSK silica gel (d = 3 cm, h = 80 cm) and eluted by benzine:ethylacetate (9:1) with a subsequent increase of ethylace tate concentration. Fractions of 100 mL were collected. The separation of the total terpenoids was monitored using TLC (hydrocarbons:ethylacetate, 4:1; developer, 1% vanillin in conc. H 2SO4). Four terpenoid esters were isolated: 1, C17H22O3, mp 155-156°C; 2, C18H24O4, mp 84-85°C; 3, C18H24O4, [α]D 22 -30 (c 0.5, ethanol); 4, C22H28O5, mp 129-130°C. Comparison of the PMR, UV, IR, and mass spectra of 1 and 2 with those in the literature identified them as tschimgin and tschimganin [5]. The IR spectrum (KBr, ν, cm) of 3 exhibited absorption bands typical of hydroxyl (3534), ester carbonyl (1693), and an aromatic ring (1598, 1514) [6]. The mass spectrum of 3 was similar to that of esters of monoterpene alcohols and had peaks for ions with m/z 304 [M]+, 168 (C8H8O4), 148, 123, 95, 93. The PMR spectrum (100 MHz, DMSO-d 6, δ, ppm, J/Hz) of 3 exhibited signals at 0.70, 0.80, and 1.02 (each 3H, s), 3.65 (3H, s, OCH 3), 7.10 (1H, d, J = 9.0, H-3 ′), 7.72 (1H, d, J = 2, H-6 ′), 7.75 (1H, q, J 1 = 9.0, J2 = 2, H-2′), 4.90 (1H, d, J1 = J2 = 7.5) and 5.15 (1H, br.d, J = 10). The two signals at 4.90 and 5.15 ppm in the range of geminal protons indicate that 3 is a natural mixture of tschimganin and iso-tschimganin. Similar mixtures of tschimgin/ iso-tschimgin and tschimganin/ isotschimganin were isolated from F. dshizakensis Korov. and F. angreni Korov. [7, 8]. The neutral part of the hydrolysate from base hydrolysis of 3 by aqueous KOH (5%) afforded a monoterpene alcohol of composition C10H18O with mp 201-202 °C that was identified as borneol [5]. Comparison of the PMR, IR, and mass spectra of 4 with those of known carotane esters showed that this compound was lancerodiol p-hydroxybenzoate, which was isolated earlier from F. lancerottensis [9]. Thus, it is found for the first time that Samarkand ferula contains esters of terpenoid alcohols in addition to terpenoid coumarins.
The stereochemistry of two monoterpenoid diastereomers from Ferula dissecta
Two diastereomeric monoterpene benzoates, tschimganin and iso-tschimganin, were isolated from the roots of Ferula dissecta. The absolute stereochemistry of the compounds was determined by chemical-related methods and ab initio calculations of electronic circular dichroism and 13C-NMR shifts. The antitumor activities of the diastereomers were also tested.
Studies in sesquiterpenes—XLIX: Sesquiterpenes from Ferula jaeschkeana vatke (part 1): jaeschkeanadiol—structure, stereochemistry
Abstract A new sesquiterpene diol, now named jaeschkeanadiol, has been isolated from the roots of Ferula jaeschkeana Vatke and is shown to possess structure1. Its stereochemistry has been established by a direct chemical correlation with laserol (9).