organic compounds
N-Methylisosalsoline from Hammada scoparia
aLaboratoire de Chimie des Substances Naturelles, Faculté des Sciences de Sfax, BP 1171, 3000 Sfax, Tunisia, and bLaboratoire des Sciences de Materiaux et d'Environnement, Faculté des Sciences de Sfax, BP 1171, 3000 Sfax, Tunisia
*Correspondence e-mail: mohamed.damak@fss.rnu.tn
The title compound (systematic name: 1,2-dimethyl-6-methoxy-1,2,3,4-tetrahydroisoquinolin-7-ol), C12H17NO2, is a major alkaloid isolated from Hammada scoparia leaves. It belongs to the isoquinoline family and it was characterized by NMR spectroscopy and X-ray crystallographic techniques. The could not be reliably determined. An intermolecular O—H⋯N hydrogen bond is present in the crystal structure.
Related literature
For related literature on Hammada scoparia and isoquinoline see: Baker (1996); Benkrief et al. (1990); Carling & Sandberg (1970); El-Shazly & Wink (2003); El-Shazly et al. (2005); Iwasa et al. (2001); Jarraya & Damak (2001); Vetulani et al. (2001, 2003).
Experimental
Crystal data
|
Refinement
|
Data collection: SMART (Bruker, 1998); cell SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supporting information
10.1107/S160053680802477X/zl2131sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S160053680802477X/zl2131Isup2.hkl
The title compound was extracted from Hammada scoparia leaves:
Plant material Hammada scoparia (Pomel) Iljin= (Haloxylon scoparium (Pomel) Bge. = Haloxylon articulatum ssp scorparium (Pomel) Batt. = Arthrophytum scoparium (Pomel) Iljin), belongs to Chenopodiaceae family and is locally known as "rimth" in Sfax, Tunisia.
Leaves were carefully detached from the fresh plant, collected in June 2007 in Sfax, Tunisia, and air-dried. Voucher specimens (LCSN101) have been deposited at the " Laboratoire de Chimie des Substances Naturelles", Faculty of Science, University of Sfax, Tunisia.
Extraction and isolation of the N-Methylisosalsoline from Hammada scoparia leaves:
Air-dried leaves of Hammada scoparia were extracted at room temperature during 48 h with a mixture (EtOH-H2O, 1–9, v-v). After filtration through folder filter paper Whatman N° 1, the ethanol was removed under reduced pressure and the remaining aqueous phase was acidified with HCl (pH = 3) and then defatted by extraction with CH2Cl2. The defatted mother liquor was made alkaline with an NH4OH solution (pH = 10) and immediately extracted with CH2Cl2 to exhaustion. The latter CH2Cl2 extract was concentrated to yield a reddish-brown residue (total alkaloids).
The total
(5 g) were separated, on over silica gel 60 (0.063–0.200 mm; 160 g), using a gradient of dichloromethane-methanol as eluents. Eleven fractions were isolated according to their similarity by thin layer analyses. Further purifications gave two major pure the first is oily: Carnegine (1050 mg; fraction 3 eluted with dichloromethane) and the second (white rosette crystals) is N-methylisosalsoline (545 mg; fraction 7 eluted with dichloromethane-methanol, 94–6, v-v). These were previously isolated from Hammada scoparia (Carling & Sandberg, 1970; Benkrief et al., 1990; Jarraya & Damak, 2001; El-Shazly & Wink, 2003). Their structures were determined on the basis of their spectral data such as UV, MS, 1H NMR and H—H COSY, 13C NMR (BB, DEPT and C—H COSY, HMQC, HMBC, NOESY) and confirmed by comparison with published spectra.N-Methylisosalsoline (1-Methylcorypalline), white rosette crystals (MeOH), mp 443 K, UV λmax (EtOH) nm = 207, 225, 285. λmax (EtOH + OH-) nm = 213, 245, 300. EIMS, m/z (rel. int.): [M+] 207 (15), 193 (30), 192 (100), 177 (45), 164 (10), 149 (15), 121 (5), 96 (6), 91 (5), 77 (5), 57 (5), 42 (4). IR: (CHCl3) νmax (cm-1): 3540, 2950, 2850, 2800, 1600, 1520.
Spectroscopic analysis, 1H NMR (300 MHz, CDCl3, p.p.m.): 1.34 (3H, d, J = 6.6 Hz, CH3–C1); 2.45 (3H, s, CH3–N); 2.63 (1H, ddd, J = 11.4, 6.9, 5.1 Hz, H–C3); 2.77 (2H, m, 2 H–C4); 3.02 (1H, ddd, J = 11.4, 6.9, 5.1 Hz,H–C3); 3.49 (1H, q, J = 6.6 Hz, H–C1); 3.83 (3H, s, CH3–O); 6.53 (1H,s, aromatic H, H–C5); 6.63 (1H, s, aromatic H, H–C8).
13C NMR (75.5 MHz, CDCl3, p.p.m.): 58.51, C1; 48.94, C3 ; 27.36, C4; 124.84, C4a; 112.96, C5; 145.31, C6; 144.00, C7; 110.57, C8; 131.95, C8a; 19.45, CH3–C1; 42.70, CH3–N; 55.77, CH3–O. The HMQC spectra showed correlations between 112.96 (C5) and 6.53 (1H, s,aromatic H, H–C5); 110.57 (C8) and 6.63 (1H, s, aromatic H, H–C8).
Suitable white X-ray quality crystals of this compound were obtained by recrystallization from methanol.
All H atoms attached to C atoms and O atom were fixed geometrically and treated as riding with C—H = 0.98 Å (Cmethine), 0.97 Å (Cmethylene), 0.96Å (Cmethyl), 0.93Å (Caromatic) and O—H = 0.84 Å with Uiso(H) = 1.2Ueq(Cmethylene, Cmethine, Caromatic) or Uiso(H) = 1.5Ueq (Cmethyl, O).
In the absence of significant
the could not be reliably determined and then the Friedel pairs were merged and any references to the were removed.Data collection: SMART (Bruker, 1998); cell
SAINT (Bruker, 1998); data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).C12H17NO2 | Dx = 1.264 Mg m−3 |
Mr = 207.27 | Melting point: 473 K |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 2100 reflections |
a = 7.5942 (6) Å | θ = 2.7–21.3° |
b = 10.8082 (8) Å | µ = 0.09 mm−1 |
c = 13.2716 (10) Å | T = 200 K |
V = 1089.33 (14) Å3 | Prism, colourless |
Z = 4 | 0.48 × 0.37 × 0.22 mm |
F(000) = 448 |
Bruker SMART CCD area-detector diffractometer | 3132 independent reflections |
Radiation source: sealed tube | 2870 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.030 |
ϕ and ω scans | θmax = 37.1°, θmin = 2.4° |
Absorption correction: multi-scan (Becker & Coppens, 1974) | h = −12→10 |
Tmin = 0.961, Tmax = 0.988 | k = −18→18 |
23859 measured reflections | l = −22→22 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.033 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.089 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0579P)2 + 0.028P] where P = (Fo2 + 2Fc2)/3 |
3132 reflections | (Δ/σ)max = 0.001 |
136 parameters | Δρmax = 0.44 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C12H17NO2 | V = 1089.33 (14) Å3 |
Mr = 207.27 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 7.5942 (6) Å | µ = 0.09 mm−1 |
b = 10.8082 (8) Å | T = 200 K |
c = 13.2716 (10) Å | 0.48 × 0.37 × 0.22 mm |
Bruker SMART CCD area-detector diffractometer | 3132 independent reflections |
Absorption correction: multi-scan (Becker & Coppens, 1974) | 2870 reflections with I > 2σ(I) |
Tmin = 0.961, Tmax = 0.988 | Rint = 0.030 |
23859 measured reflections |
R[F2 > 2σ(F2)] = 0.033 | 0 restraints |
wR(F2) = 0.089 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.44 e Å−3 |
3132 reflections | Δρmin = −0.24 e Å−3 |
136 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.05540 (10) | 0.85207 (7) | 0.13064 (6) | 0.01206 (13) | |
H1 | 0.0422 | 0.9013 | 0.0673 | 0.014* | |
C3 | 0.25806 (11) | 0.83001 (8) | 0.27194 (6) | 0.01586 (14) | |
H3A | 0.1557 | 0.8026 | 0.3124 | 0.019* | |
H3B | 0.3386 | 0.8766 | 0.3167 | 0.019* | |
C4 | 0.35296 (11) | 0.71807 (8) | 0.22912 (6) | 0.01475 (14) | |
H4A | 0.4694 | 0.7437 | 0.2029 | 0.018* | |
H4B | 0.3725 | 0.6567 | 0.2834 | 0.018* | |
C4A | 0.24733 (10) | 0.65931 (7) | 0.14534 (6) | 0.01156 (13) | |
C5 | 0.29165 (11) | 0.54034 (7) | 0.11057 (6) | 0.01275 (13) | |
H5 | 0.3867 | 0.4973 | 0.1412 | 0.015* | |
C6 | 0.19977 (11) | 0.48449 (7) | 0.03258 (6) | 0.01301 (13) | |
C7 | 0.05722 (11) | 0.54781 (7) | −0.01256 (6) | 0.01242 (13) | |
C8 | 0.01464 (10) | 0.66497 (7) | 0.02168 (6) | 0.01194 (13) | |
H8 | −0.0812 | 0.7078 | −0.0084 | 0.014* | |
C8A | 0.10928 (10) | 0.72232 (7) | 0.09969 (6) | 0.01059 (12) | |
C10 | 0.14695 (12) | 1.03330 (8) | 0.22797 (7) | 0.01802 (15) | |
H10A | 0.1079 | 1.0854 | 0.1718 | 0.027* | |
H10B | 0.2483 | 1.0720 | 0.2611 | 0.027* | |
H10C | 0.0507 | 1.0242 | 0.2766 | 0.027* | |
C11 | −0.12539 (11) | 0.85179 (8) | 0.18297 (7) | 0.01757 (15) | |
H11A | −0.1569 | 0.9365 | 0.2022 | 0.026* | |
H11B | −0.1200 | 0.7998 | 0.2434 | 0.026* | |
H11C | −0.2144 | 0.8189 | 0.1367 | 0.026* | |
C12 | 0.37900 (13) | 0.30406 (9) | 0.03586 (8) | 0.02182 (18) | |
H12A | 0.3910 | 0.2239 | 0.0020 | 0.033* | |
H12B | 0.3579 | 0.2908 | 0.1079 | 0.033* | |
H12C | 0.4874 | 0.3520 | 0.0269 | 0.033* | |
N1 | 0.19793 (9) | 0.91062 (6) | 0.18960 (5) | 0.01301 (12) | |
O1 | 0.23450 (9) | 0.37016 (6) | −0.00665 (5) | 0.01876 (13) | |
O2 | −0.02759 (9) | 0.49009 (5) | −0.08915 (5) | 0.01773 (13) | |
H2 | −0.1054 | 0.5372 | −0.1126 | 0.027* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0121 (3) | 0.0114 (3) | 0.0127 (3) | 0.0012 (2) | −0.0006 (2) | −0.0010 (2) |
C3 | 0.0162 (3) | 0.0185 (3) | 0.0128 (3) | −0.0004 (3) | −0.0017 (3) | −0.0026 (3) |
C4 | 0.0142 (3) | 0.0154 (3) | 0.0148 (3) | 0.0000 (3) | −0.0041 (3) | −0.0009 (3) |
C4A | 0.0107 (3) | 0.0121 (3) | 0.0119 (3) | −0.0005 (2) | −0.0007 (2) | 0.0007 (2) |
C5 | 0.0119 (3) | 0.0119 (3) | 0.0144 (3) | 0.0011 (2) | −0.0023 (2) | 0.0009 (2) |
C6 | 0.0132 (3) | 0.0100 (3) | 0.0159 (3) | 0.0018 (2) | −0.0021 (3) | −0.0005 (2) |
C7 | 0.0126 (3) | 0.0102 (3) | 0.0145 (3) | 0.0007 (2) | −0.0027 (3) | −0.0004 (2) |
C8 | 0.0116 (3) | 0.0107 (3) | 0.0135 (3) | 0.0009 (2) | −0.0023 (2) | 0.0000 (2) |
C8A | 0.0103 (3) | 0.0100 (3) | 0.0115 (3) | 0.0001 (2) | −0.0002 (2) | 0.0007 (2) |
C10 | 0.0179 (4) | 0.0149 (3) | 0.0212 (3) | 0.0006 (3) | 0.0022 (3) | −0.0053 (3) |
C11 | 0.0121 (3) | 0.0191 (3) | 0.0215 (3) | 0.0012 (3) | 0.0012 (3) | −0.0040 (3) |
C12 | 0.0231 (4) | 0.0173 (3) | 0.0250 (4) | 0.0099 (3) | −0.0070 (4) | −0.0022 (3) |
N1 | 0.0132 (3) | 0.0113 (3) | 0.0145 (3) | −0.0006 (2) | 0.0010 (2) | −0.0031 (2) |
O1 | 0.0199 (3) | 0.0113 (2) | 0.0251 (3) | 0.0056 (2) | −0.0085 (3) | −0.0043 (2) |
O2 | 0.0189 (3) | 0.0132 (2) | 0.0211 (3) | 0.0035 (2) | −0.0097 (2) | −0.0050 (2) |
C1—N1 | 1.4780 (10) | C7—O2 | 1.3555 (10) |
C1—C8A | 1.5174 (10) | C7—C8 | 1.3837 (10) |
C1—C11 | 1.5386 (12) | C8—C8A | 1.4045 (10) |
C1—H1 | 1.0000 | C8—H8 | 0.9500 |
C3—N1 | 1.4703 (11) | C10—N1 | 1.4722 (10) |
C3—C4 | 1.5185 (12) | C10—H10A | 0.9800 |
C3—H3A | 0.9900 | C10—H10B | 0.9800 |
C3—H3B | 0.9900 | C10—H10C | 0.9800 |
C4—C4A | 1.5110 (11) | C11—H11A | 0.9800 |
C4—H4A | 0.9900 | C11—H11B | 0.9800 |
C4—H4B | 0.9900 | C11—H11C | 0.9800 |
C4A—C8A | 1.3892 (10) | C12—O1 | 1.4257 (11) |
C4A—C5 | 1.4070 (11) | C12—H12A | 0.9800 |
C5—C6 | 1.3866 (11) | C12—H12B | 0.9800 |
C5—H5 | 0.9500 | C12—H12C | 0.9800 |
C6—O1 | 1.3665 (10) | O2—H2 | 0.8400 |
C6—C7 | 1.4139 (11) | ||
N1—C1—C8A | 109.97 (6) | C7—C8—C8A | 121.76 (7) |
N1—C1—C11 | 114.55 (6) | C7—C8—H8 | 119.1 |
C8A—C1—C11 | 111.16 (7) | C8A—C8—H8 | 119.1 |
N1—C1—H1 | 106.9 | C4A—C8A—C8 | 119.42 (7) |
C8A—C1—H1 | 106.9 | C4A—C8A—C1 | 122.58 (7) |
C11—C1—H1 | 106.9 | C8—C8A—C1 | 117.99 (7) |
N1—C3—C4 | 109.96 (7) | N1—C10—H10A | 109.5 |
N1—C3—H3A | 109.7 | N1—C10—H10B | 109.5 |
C4—C3—H3A | 109.7 | H10A—C10—H10B | 109.5 |
N1—C3—H3B | 109.7 | N1—C10—H10C | 109.5 |
C4—C3—H3B | 109.7 | H10A—C10—H10C | 109.5 |
H3A—C3—H3B | 108.2 | H10B—C10—H10C | 109.5 |
C4A—C4—C3 | 110.99 (7) | C1—C11—H11A | 109.5 |
C4A—C4—H4A | 109.4 | C1—C11—H11B | 109.5 |
C3—C4—H4A | 109.4 | H11A—C11—H11B | 109.5 |
C4A—C4—H4B | 109.4 | C1—C11—H11C | 109.5 |
C3—C4—H4B | 109.4 | H11A—C11—H11C | 109.5 |
H4A—C4—H4B | 108.0 | H11B—C11—H11C | 109.5 |
C8A—C4A—C5 | 119.05 (7) | O1—C12—H12A | 109.5 |
C8A—C4A—C4 | 121.03 (7) | O1—C12—H12B | 109.5 |
C5—C4A—C4 | 119.90 (7) | H12A—C12—H12B | 109.5 |
C6—C5—C4A | 121.49 (7) | O1—C12—H12C | 109.5 |
C6—C5—H5 | 119.3 | H12A—C12—H12C | 109.5 |
C4A—C5—H5 | 119.3 | H12B—C12—H12C | 109.5 |
O1—C6—C5 | 125.51 (7) | C3—N1—C10 | 111.00 (7) |
O1—C6—C7 | 115.09 (7) | C3—N1—C1 | 111.54 (6) |
C5—C6—C7 | 119.39 (7) | C10—N1—C1 | 112.10 (7) |
O2—C7—C8 | 123.81 (7) | C6—O1—C12 | 116.80 (7) |
O2—C7—C6 | 117.30 (7) | C7—O2—H2 | 109.5 |
C8—C7—C6 | 118.87 (7) | ||
N1—C3—C4—C4A | −48.19 (9) | C4—C4A—C8A—C1 | −0.30 (11) |
C3—C4—C4A—C8A | 15.68 (11) | C7—C8—C8A—C4A | −1.26 (12) |
C3—C4—C4A—C5 | −166.13 (7) | C7—C8—C8A—C1 | 178.70 (7) |
C8A—C4A—C5—C6 | −0.56 (12) | N1—C1—C8A—C4A | 16.96 (10) |
C4—C4A—C5—C6 | −178.78 (7) | C11—C1—C8A—C4A | −110.97 (8) |
C4A—C5—C6—O1 | 179.31 (8) | N1—C1—C8A—C8 | −163.01 (7) |
C4A—C5—C6—C7 | −0.60 (12) | C11—C1—C8A—C8 | 69.06 (9) |
O1—C6—C7—O2 | −0.54 (11) | C4—C3—N1—C10 | −165.48 (7) |
C5—C6—C7—O2 | 179.38 (7) | C4—C3—N1—C1 | 68.74 (8) |
O1—C6—C7—C8 | −179.10 (7) | C8A—C1—N1—C3 | −50.54 (8) |
C5—C6—C7—C8 | 0.82 (12) | C11—C1—N1—C3 | 75.49 (8) |
O2—C7—C8—C8A | −178.36 (8) | C8A—C1—N1—C10 | −175.71 (6) |
C6—C7—C8—C8A | 0.10 (12) | C11—C1—N1—C10 | −49.68 (9) |
C5—C4A—C8A—C8 | 1.47 (11) | C5—C6—O1—C12 | −0.82 (13) |
C4—C4A—C8A—C8 | 179.67 (7) | C7—C6—O1—C12 | 179.10 (8) |
C5—C4A—C8A—C1 | −178.50 (7) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···N1i | 0.84 | 1.90 | 2.6970 (10) | 159 |
Symmetry code: (i) x−1/2, −y+3/2, −z. |
Experimental details
Crystal data | |
Chemical formula | C12H17NO2 |
Mr | 207.27 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 200 |
a, b, c (Å) | 7.5942 (6), 10.8082 (8), 13.2716 (10) |
V (Å3) | 1089.33 (14) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.48 × 0.37 × 0.22 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (Becker & Coppens, 1974) |
Tmin, Tmax | 0.961, 0.988 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 23859, 3132, 2870 |
Rint | 0.030 |
(sin θ/λ)max (Å−1) | 0.848 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.033, 0.089, 1.07 |
No. of reflections | 3132 |
No. of parameters | 136 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.44, −0.24 |
Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997), WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···N1i | 0.84 | 1.90 | 2.6970 (10) | 159.0 |
Symmetry code: (i) x−1/2, −y+3/2, −z. |
Acknowledgements
The authors gratefully acknowledge Professor Jean-Claude Daran (Directeur de Recherche, Laboratoire de Chimie de Coordination, CNRS–Toulouse) for helpful comments regarding this paper.
References
Baker, B. J. (1996). β-Carboline and isoquinoline alkaloids from marine organisms. In: Alkaloids: Chemical and Biological Perspectives, edited by W. S. Pelletier, vol. 10, pp. 357–407. New York: Pergamon. Google Scholar
Becker, P. J. & Coppens, P. (1974). Acta Cryst. A30, 129–147. CrossRef IUCr Journals Web of Science Google Scholar
Benkrief, R., Brum-Bousquet, M., Tillequin, F. & Koch, M. (1990). Ann. Pharm. Fr. 48, 219–224. CAS PubMed Google Scholar
Bruker (1998). SAINT-Plus and SMART. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Carling, C. & Sandberg, F. (1970). Acta Pharm. Suec. 7, 285–288. CAS PubMed Web of Science Google Scholar
El-Shazly, A. M., Dora, G. & Wink, M. (2005). Pharmazie, 60, 949–952. Web of Science PubMed CAS Google Scholar
El-Shazly, A. & Wink, M. (2003). Z. Naturforch. Teil C, 58, 477–480. CAS Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Iwasa, K., Moriyasu, M., Tachibana, Y., Kim, H. S., Wataya, Y., Wiegrebe, V., Bastow, K. F., Cosentino, L. M., Kozuka, M. & Lee, K. H. (2001). Bioorg. Med. Chem. 9, 2871–2884. Web of Science CrossRef PubMed CAS Google Scholar
Jarraya, R. & Damak, M. (2001). J. Soc. Chim. Tunis. 4, 941–948. CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Vetulani, J., Antkiewicz-Michaluk, L., Nalepa, I. & Sansone, M. (2003). Neurotox. Res. 5, 147–155. Web of Science CrossRef PubMed Google Scholar
Vetulani, J., Nalepa, I., Antkiewicz-Michaluk, L. & Sansone, M. (2001). J. Neurol. Transm. 108, 513–526. Web of Science CrossRef CAS Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Hammada scoparia has been reported to contain the alkaloids carnegine and N-methylisosalsoline as major tetrahydroisoquinoline alkaloids in addition to other minor alkaloids (Benkrief et al., 1990, Jarraya & Damak 2001; El-Shazly & Wink, 2003).
The tetrahydroisoquinoline alkaloids affect the vegetative nervous system (Vetulani et al., 2001 and 2003). Some of these alkaloids are known to be strong agonists at nicotinic acetylcholine receptors and it is thus likely that they serve as chemical defense compounds against insects and mammalian herbivores (El-Shazly et al., 2005). Other simple isoquinoline alkaloids display potent, and often selective cytotoxicity or exhibit potential antimicrobial, antimalarial, antiviral and anti-HIV activities (Baker, 1996; Iwasa et al., 2001).
The current study describes the isolation and the structure elucidation of N-methylisosalsoline. The structure of the title compound was established principally by two-dimensional NMR spectroscopy and through X-ray diffraction analysis although the absolute configuration could not be reliably determined.
The conformation of this compound is stabilized by an intermolecular hydrogen bond between the hydroxyl O2—H2 group and atom N1 (Table 1). The molecules are assembled by intermolecular O—H···N hydrogen bonds (Table 1, Fig. 2)