Stereochemistry of malkanguniol and stereostructures of some other related polyalcohols from willd.

New sesquiterpene esters and alkaloids from Euonymus japonicus: the ‘Ejap’ series. X-Ray molecular structures of Ejap-2, -3, -4, -5, -6, and -10

“…Similarly to the central ring system of E ~e r -1 , ~ in Ejap-10 (9) one of the trans-fused six-membered carbocyclic rings deviates characteristically from the expected conformation. It is also sharpened at C( 6) and flattened at C(9) to accomodate the C(l1)-0(1) ether bridge formed between C(5) and C (7). The C-C bonds pertaining to C (10) [e.g.…”

Celangulin: A Nonalkaloidal Insect Antifeedant from Chinese Bittersweet, Celastrus angulatus

“…As celangulin has one benzoate, one free hydroxyl, and five acetate groups, the unesterified parent compound would be C1502608, in which seven of the eight oxygen atoms are in hydroxyl groups and the remaining one presumed to be an ether. Many polyhydroxylated sesquiterpenes based on dihydroagarofuran {3} esterified by one or two benzoic, nicotinic, or fiiroic acid groups and several HO Ac residues have been found in the genus CtUstrus (7,(12)(13)(14)(15)(16)(17). Where 13C-nmr data are reported for these compounds, C-5 has a value between 86.3 and 92.4 and C-13 between 80.1 and 83.7 (14,18).…”

“…Fractions 3 and 4, in which celangulin was detected by tic, were combined and subjected to flash chromatography on Woelm 40 µ Si gel (116 g, 15.2 cm X 45-mm i.d. column, 50-ml fractions) first with DCE-MTBE (90:10) as the eluent (fractions 1-9), then with DCE-MTBE (85:15) (fractions [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]• Celangulin appeared in fractions 16-21. Fraction 19 (42 mg), which contained the largest amount of celangulin, was purified by semipreparative hplc on a column (15 X 1 cm i.d.)…”

Structure of Sesquiterpenoids from Celastrus angulatus

“…Compound 2 analyzed for C28H3609 by hrms. The uv, ir, and mass and nmr spectral data suggested the presence of three acetate esters, one benzoate ester, and the 1,8,9,13-tetrasubstituted ß-dihydroagarofuran parent (8). In the 1Hnmr spectrum, the double doublet at 5.30 (1H,7 = 4.8, 12 Hz) was assigned to µ-1, the double doublet at 5.51 (1H,7 = 4, 5.3 Hz) to H-8, the doublet at 5.63 (1H,7 = 5.3 Hz) to H-9, and the AB quartet at 4.75 and 4.82 (7 = 13 Hz) to H-13 (other assignments are summarized in Table 2).…”