Angustine and related alkaloids from species of Mitragyna, nauclea, uncaria, and Strychnos

Naucleactonin D, an Indole Alkaloid and other Chemical Constituents from Roots and Fruits of Mitragyna inermis

“…The molecular formula, C 19 H 14 N 2 O 3 , implying fourteen double bond equivalents, was deduced from NMR data and negative ion-mode HRESIMS. The broadband decoupled 13 C NMR spectrum (Table 1) , another aromatic proton at δ = 7.39 (s), two sets of methylene protons at δ = 3.07 (t, J = 6.6 Hz) and δ = 4.40 (t, J = 6.6 Hz), and one proton at δ = 11.82 (s), suggesting the presence of an NH or OH group. The 1 H-1 H COSY and HMBC spectra allowed the identification of the fragment C=C-CH 2 -CH 2 -N. The above 1 H and 13 C NMR data of 1 were similar to those of naucleactonin A [14], suggesting the same indolo[2,3-a]quinolizine skeleton in the two compounds.…”

“…2 and Experimental Section) and NOESY correlations between the methyl and formyl groups confirmed further their positions. On the basis of the above data, the structure of naucleactonin D (1) was elucidated as 6, The known compounds nauclefiline (2) [15], naucleficine (3) [16], nauclefidine (4) [17], angustoline (5) [18], angustine (6) [13,18], barbinervic acid (7) [19], quinovic acid 3-O-α-L-rhamnopyranoside (8) [20,21], betulinic acid (9) [22], a mixture of ursolic acid (10) [23,24] and oleanolic acid (11) [24], strictosamide (12) [18,28] (Fig. 3), a mixture of stigmasterol [25] and β -sitosterol [26], and β -sitosterol 3-O-β -D-glucopyranoside [27] were identified by comparison of their spectral and physical (melting points and/or optical rotations) data with published values.…”

“…The 1 H NMR spectra were recorded on Varian Mercury-300 (300.141 MHz), Varian VNMRS-300 (300.536 MHz), Varian Inova-500 (499.8 MHz), and Varian Inova-600 (599.743 MHz) spectrometers equipped with 3 mm probes; 13 C NMR spectra were measured at 75.575, 125.707 and 150.815 MHz relatively to TMS as internal standard; shifts are reported as δ values. UV/Vis spectra were recorded in MeOH on a Varian Cary 3E UV/Vis spectrophotometer.…”

“…In the continuing search for bioactive or new secondary metabolites from Cameroonian medicinal plants, we have investigated solvent extracts of the fruits and roots of M. inermis. In this article, we report on the isolation and structure elucidation of a new indole alkaloid, named naucleactonin D (1), and on 13 C NMR assignments for nauclefiline (2) and naucleficine (3). Compound 6 has been isolated and identified previously from Mitragyna javanica and Mitragyna parvifolia [13].…”

“…In this article, we report on the isolation and structure elucidation of a new indole alkaloid, named naucleactonin D (1), and on 13 C NMR assignments for nauclefiline (2) and naucleficine (3). Compound 6 has been isolated and identified previously from Mitragyna javanica and Mitragyna parvifolia [13]. The structure of compound 1 was elucidated on the basis of a detailed spectroscopic analysis, and by comparison with reported data.…”