Piriferine, a New Pyrrolidine Alkaloid from Aglaia pirifera Leaves

Chemistry and Biology of Rocaglamides (= Flavaglines) and Related Derivatives from Aglaia Species (Meliaceae)

“…These low molecular weight precursors, namely, odorine ( 103 ) (76, 77), odorinol ( 104 ) (19, 76), and piriferine ( 105 ) (78), are composed of cinnamic acid, the bifunctional amine 2-aminopyrrolidine, and 2-methylbutanoic acid (in odorine), 2-hydroxy-2-methylbutanoic acid (in odorinol) or 2-methylpropanoic acid (in piriferine). In 33 of the total of 37 aglain derivatives isolated so far, the bisamide side chain is directly analogous to a naturally occurring cinnamic acid bisamide, odorine ( 103 ), odorinol ( 104 ), or piriferine ( 105 ).…”

Bisamides from Aglaia Species: Structure Analysis and Potential to Reverse Drug Resistance with Cultured Cells

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The structure of pyramidatine [1], a new bisamide alkaloid from leaves of Aglaia pyramidata, was determined through extensive nmr studies, including homonuclear COSY, NOESY, APT, HETCOR, and selective INEPT techniques. Revision of the 13C-nmr assignment of piriforme [2], an alkaloid previously isolated from A. pirifera, was achieved by examination of several 2D nmr spectra (homonuclear COSY, NOESY, and HETCOR) and confirmed by selective INEPT nmr experiments.

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“…Pyramidatine [1} showed a molecular ion (hrms) at mlz 322.1677, indicating a molecular formula of C20H22N2O2 (caled 322.1681). The presence of a cinnamoyl moiety was suggested by the ion at mlz 131 in the mass spectrum (1), and the trans stereochemistry was confirmed by a pair of doublets (J = 15.8 Hz) at 6.63 (H-2") and 7.42 (H-3") in the 'H-nmr spectrum (Table 1) (1)(2)(3)(4). Ir absorptions at 3317, 1635, and 1621 cm-1 revealed the presence of two amide groups, and this was further supported by proton signals at 8.13 and 8.48 in the 'H-nmr spectrum and carbon resonances at 164.9 and 166.2 in the 13C-nmr spectrum.…”

“…On the basis of the above spectral evidence, it was proposed that pyramidatine has the structure 1. In order to confirm the structure, and also to obtain the complete 'Hand 13C-nmr spectral assignments of pyramidatine [1], a NOESY experiment was performed. From the NOESY spectrum, the resonance at 7.54 showed an nOe with H-2" and was therefore assigned to H-5"(9").…”

“…The assignments of C-2" and C-3" merit some discussion. The HETCOR spectrum of pyramidatine {1} indicated that C-2" ( 122.3) resonated at a higher field than C-3" ( 138.5), suggesting that possibly the chemical shifts of C-2" and C-3" in the cinnamoyl moiety of the bisamides in previous papers (1)(2)(3)(4) had been incorrectly reported and that the assignments for these two carbons should be reversed.…”