Spirocaracolitone isolated from a new genus and species, Ruptiliocarpon caracolito. The first CD spiro-triterpenoid

Spirocaracolitones, CD-Spiro Triterpenoids from Ruptiliocarpon caracolito

“…Isolation of Purified Spirocaracolitones. The procedure given above is an improvement over that reported for the isolation of the first spirocaracolitone …”

“…Earlier work on the bark of R . caracolito resulted in the isolation of a unique CD-spirotrieterpenoid, compound 1 . To the best of our knowledge neither the CD spiro arrangement nor the 12-α-methyl group present in 1 have been previously observed in triterpenoids.…”

“…A major component of the most active fractions thus obtained was subsequently purified by preparative HPLC to yield a white crystalline compound, C 44 H 54 O 12 , mp 215−218 °C, in about 0.01% yield from dried bark. The structure of this compound, named spirocaracolitone, was established as 1 by single crystal X-ray structure determination (Figure ) . Subsequent repetitive fractionation of the other components of the most active fractions, using a recycling HPLC equipped with a reverse phase column, enabled us to isolate and identify five additional CD-spirotriterpenoids, each in approximately 0.05−0.008% yield.…”

Spirocaracolitone Triterpenoids from the Bark of Ruptiliocarpon caracolito

“…All of these compounds were active as insect-growth reducers using the European corn borer as the test insect. 1 The bioassay studies also demonstrated synergism between the various analogues. The production of a number of closely related analogues of varying potency appears to be another example of phytochemical redundancy in chemical defenses, a strategy whereby the plant protects itself against an easy adaptation by the pest by becoming resistant to a single entity defense compound.…”

“…;1 H NMR (500 MHz, CDCl3) δ 3.08 (1 H, m, H1ax), 2.50 (1 H, dd, J ) 3.5, 18.0 Hz, H1eq),1.50 (1 H, m, H6ax), 2.25 (1 H, m, H6eq), 5.45 (1 H, m, H7), 2.58 (1 H, d, J ) 12.0 Hz, H8), 2.25 (1 H, m, H10), 5.43 (1 H, m, H11), 3.08 (1 H, m, H12), 5.45 (1 H, brs, H15), 5.68 (1 H, m, H16), 2.09 (1 H, m, H19ax), 1.96 (1 H, m, H19eq), 2.35 (1 H, dd, J ) 3.0, 12.5 Hz, H21ax), 2.58 (1 H, d, J ) 12.0 Hz, H21eq), 5.34 (1 H, d, J ) 3.0 Hz, H22), 1.89 (3 H, s, H23), 1.23, 1.28 (H24, 2 s, and/or H28), 5.13 (1 H, d, J ) 13.0 Hz, H25eq), 4.50 (1 H, d, J ) 13.0 Hz, H25ax), 1.08 (3 H, d, J ) 7.5 Hz, H26), 1.89 (3 H, s, H27), 1.34 (3 H, s, H29), 3.61 (3 H, s, OMe), 1.82, 1.84, 2.12 (3 × s, 3 × MeCO), benzoyl groups: 8.0 (4 H, m, H2′/H2′′), 7.58 (2 H, m, H4′/H4′′), 7.46 (4 H, m, H3′/H3′′); ESIMS m/z 913 [M + NH 4] + (14.18), 895 [MH] + (100); HRESIMS m/z 895.38601 [MH] + (calcd for C51H58O14, 895.38206).…”