Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807042626/sj2348sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807042626/sj2348Isup2.hkl |
CCDC reference: 664194
Key indicators
- Single-crystal X-ray study
- T = 100 K
- Mean (C-C) = 0.002 Å
- R factor = 0.044
- wR factor = 0.116
- Data-to-parameter ratio = 14.2
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical . ? PLAT420_ALERT_2_C D-H Without Acceptor N1 - H1N1 ... ? PLAT432_ALERT_2_C Short Inter X...Y Contact O3 .. C18 .. 3.01 Ang. PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........ 3
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 4 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 2 ALERT type 2 Indicator that the structure model may be wrong or deficient 0 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
For background to the biological activity of alkaloids, flavonoids and coumarins, see, for example: Das et al. (1984); Ito et al. (2000); Nakahara et al. (2002); Rahmani et al. (2003); Sohrab et al. (2004); Tantishaiyakul et al. (1986); Tantivatana et al. (1983). For related structures, see, for example: Duan et al. (2005); Huang et al. (2005); Li et al. (2006). Bernstein et al. (1995) provide information on hydrogen bond motifs, and for reference structural data, see Allen et al. (1987).
Stem barks of M. minutum (12 kg) were extracted with hexane–EtOAc (1:1) over the period of 3 days at room temperature. The mixture was filtered and concentrated under reduced pressure to provide the crude extract (58.3 g). This crude extract was subjected to quick column chromatography (QCC) over silica gel and eluted with a gradient of EtOAc–hexane to afford 60 factions (A1–A60). Fractions A29–A30 (617 mg) was subjected to repeated CC using the gradient of CH2Cl2 (70% CH2Cl2 in hexane to 100% CH2Cl2) to give the title compound (15.2 mg). Colorless block-shaped single crystals of the title compound were obtained by recrystallization from CH2Cl2–hexane (2:1 v/v) solution, Mp 487–489 K.
Plants of the genus Micromelum (Rutaceae) are known to be rich sources of alkaloids (Nakahara et al., 2002), coumarins (Rahmani et al., 2003; Ito et al., 2000; Tantishaiyakul et al., 1986; Tantivatana et al., 1983) and flavonoids (Das et al., 1984; Sohrab et al., 2004). Some of these compounds show anti-cancer activity (Tantishaiyakul et al., 1986; Tantivatana et al., 1983). Micromelum minutum known locally in Thailand as "Hat-Sa-Khun", is a small to medium-sized tree or shrub found widespread in South-East Asian countries. The leaves of this plant are traditionally used in the treatment of fever and giddiness and a poultice of the boiled roots is used for ague (Rahmani et al., 2003). In our search for bioactive compounds from Thai medicinal plant, we herein report the crystal structure of the title compound, which was isolated from the stem barks of M. minutum collected from Nongkhai province in the northeasthern of Thailand.
In the structure of the title compound (Fig. 1), the carbazole ring system (C1–C12/N1) is essentially planar with the maximum deviation of -0.013 (1) Å for atom N1. The hydroxy and aldehyde substituent groups lie in the plane of the benzene ring and an intramolecular O1—H1O1···O2 hydrogen bond between the aldehyde and one of the hydroxy groups helps maintain the planarity of the structure. The orientation of the 3-methyl-2-butenyl substituent group with respect to the C1–C6 benzene ring is indicated by the torsion angle C2/C1/C13/C14 of 130.72 (13)°, showing an anti-clinal conformation. The dihedral angle between the 3-methyl-2-butenyl group and the mean plane of carbazole is 70.26 (7) Å. Bond lengths and angles in the title compound are within normal ranges (Allen et al., 1987) and comparable to related structures (Duan et al., 2005; Huang et al., 2005; Li et al., 2006). An O1—H1O1···O2 intramolecular interaction generates S(6) ring motif (Bernstein et al., 1995). In addition, the weak C13—H13B···O1 intramolecular interaction generates S(5) ring motif. O3—H1O3···O2 intermolecular interactions connect the molecules into dimers (Fig. 2). These dimers form chains along the [401] direction (Fig. 2). The crystal is stabilized by O—H···O hydrogen bonds and weak C—H···O intramolecular interaction. π–π interactions were also observed with the Cg1···Cg2 distances of 3.5901 (8) Å (symmetry code; 1 + x, y, z) and 3.5899 (8) Å (symmetry code; -1 + x, y, z), Cg1 and Cg2 are the centroids of C1–C6 and C6–C5–C12–C7–N1 rings.
For background to the biological activity of alkaloids, flavonoids and coumarins, see, for example: Das et al. (1984); Ito et al. (2000); Nakahara et al. (2002); Rahmani et al. (2003); Sohrab et al. (2004); Tantishaiyakul et al. (1986); Tantivatana et al. (1983). For related structures, see, for example: Duan et al. (2005); Huang et al. (2005); Li et al. (2006). Bernstein et al. (1995) provide information on hydrogen bond motifs, and for reference structural data, see Allen et al. (1987).
Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXTL (Sheldrick, 1998); program(s) used to refine structure: SHELXTL (Sheldrick, 1998); molecular graphics: SHELXTL (Sheldrick, 1998); software used to prepare material for publication: SHELXTL (Sheldrick, 1998) and PLATON (Spek, 2003).
C18H17NO3 | F(000) = 624 |
Mr = 295.33 | Dx = 1.374 Mg m−3 |
Monoclinic, P21/c | Melting point = 487–489 K |
Hall symbol: -P 2ybc | Mo Kα radiation, λ = 0.71073 Å |
a = 4.7749 (1) Å | Cell parameters from 3795 reflections |
b = 18.8511 (6) Å | θ = 1.7–29.0° |
c = 16.0164 (5) Å | µ = 0.09 mm−1 |
β = 97.931 (2)° | T = 100 K |
V = 1427.88 (7) Å3 | Block, colourless |
Z = 4 | 0.52 × 0.18 × 0.09 mm |
Bruker APEXII CCD area-detector diffractometer | 3795 independent reflections |
Radiation source: fine-focus sealed tube | 2840 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.033 |
Detector resolution: 8.33 pixels mm-1 | θmax = 29.0°, θmin = 1.7° |
ω scans | h = −6→6 |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | k = −24→25 |
Tmin = 0.953, Tmax = 0.992 | l = −21→21 |
15047 measured reflections |
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)] = 0.044 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.116 | All H-atom parameters refined |
S = 1.10 | w = 1/[σ2(Fo2) + (0.0537P)2 + 0.2314P] where P = (Fo2 + 2Fc2)/3 |
3795 reflections | (Δ/σ)max < 0.001 |
267 parameters | Δρmax = 0.32 e Å−3 |
0 restraints | Δρmin = −0.24 e Å−3 |
C18H17NO3 | V = 1427.88 (7) Å3 |
Mr = 295.33 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 4.7749 (1) Å | µ = 0.09 mm−1 |
b = 18.8511 (6) Å | T = 100 K |
c = 16.0164 (5) Å | 0.52 × 0.18 × 0.09 mm |
β = 97.931 (2)° |
Bruker APEXII CCD area-detector diffractometer | 3795 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | 2840 reflections with I > 2σ(I) |
Tmin = 0.953, Tmax = 0.992 | Rint = 0.033 |
15047 measured reflections |
R[F2 > 2σ(F2)] = 0.044 | 0 restraints |
wR(F2) = 0.116 | All H-atom parameters refined |
S = 1.10 | Δρmax = 0.32 e Å−3 |
3795 reflections | Δρmin = −0.24 e Å−3 |
267 parameters |
Experimental. The low-temparture data was collected with the Oxford Cyrosystem Cobra low-temperature attachment. |
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 | ||
O1 | −0.1526 (2) | 0.39677 (5) | 0.42061 (6) | 0.0216 (2) | |
H1O1 | −0.288 (4) | 0.3808 (11) | 0.3755 (13) | 0.057 (6)* | |
O2 | −0.43458 (19) | 0.31436 (5) | 0.30620 (6) | 0.0224 (2) | |
O3 | 1.1123 (2) | 0.23309 (6) | 0.69986 (6) | 0.0229 (2) | |
H1O3 | 1.265 (5) | 0.2095 (11) | 0.7341 (13) | 0.059 (6)* | |
N1 | 0.6366 (2) | 0.28325 (6) | 0.58847 (7) | 0.0174 (2) | |
H1N1 | 0.695 (4) | 0.3170 (10) | 0.6218 (11) | 0.035 (5)* | |
C1 | 0.2402 (3) | 0.34865 (7) | 0.50719 (8) | 0.0167 (3) | |
C2 | 0.0161 (3) | 0.33985 (7) | 0.44266 (8) | 0.0167 (3) | |
C3 | −0.0384 (3) | 0.27355 (7) | 0.40085 (8) | 0.0174 (3) | |
C4 | 0.1316 (3) | 0.21427 (7) | 0.42481 (8) | 0.0173 (3) | |
H4A | 0.093 (3) | 0.1682 (8) | 0.3955 (10) | 0.021 (4)* | |
C5 | 0.3561 (3) | 0.22080 (7) | 0.48859 (7) | 0.0164 (3) | |
C6 | 0.4046 (3) | 0.28848 (7) | 0.52797 (7) | 0.0162 (3) | |
C7 | 0.7370 (3) | 0.21414 (7) | 0.59080 (8) | 0.0175 (3) | |
C8 | 0.9687 (3) | 0.18691 (8) | 0.64334 (8) | 0.0189 (3) | |
C9 | 1.0343 (3) | 0.11657 (8) | 0.63314 (8) | 0.0218 (3) | |
H9A | 1.198 (3) | 0.0965 (8) | 0.6684 (10) | 0.025 (4)* | |
C10 | 0.8714 (3) | 0.07462 (8) | 0.57257 (9) | 0.0230 (3) | |
H10A | 0.923 (3) | 0.0249 (9) | 0.5670 (10) | 0.026 (4)* | |
C11 | 0.6392 (3) | 0.10177 (8) | 0.52068 (8) | 0.0202 (3) | |
H11A | 0.524 (3) | 0.0717 (8) | 0.4791 (9) | 0.021 (4)* | |
C12 | 0.5716 (3) | 0.17311 (7) | 0.52989 (8) | 0.0174 (3) | |
C13 | 0.3057 (3) | 0.41821 (8) | 0.55191 (8) | 0.0211 (3) | |
H13A | 0.480 (3) | 0.4407 (8) | 0.5317 (10) | 0.027 (4)* | |
H13B | 0.147 (3) | 0.4527 (9) | 0.5336 (10) | 0.030 (4)* | |
C14 | 0.3473 (3) | 0.41179 (8) | 0.64689 (8) | 0.0213 (3) | |
H14A | 0.218 (3) | 0.3766 (9) | 0.6707 (10) | 0.027 (4)* | |
C15 | 0.5236 (3) | 0.44972 (8) | 0.70103 (8) | 0.0210 (3) | |
C16 | 0.5300 (4) | 0.44116 (10) | 0.79470 (9) | 0.0302 (4) | |
H16A | 0.462 (4) | 0.4849 (10) | 0.8203 (11) | 0.036 (5)* | |
H16B | 0.399 (3) | 0.4005 (9) | 0.8061 (10) | 0.029 (4)* | |
H16C | 0.730 (4) | 0.4325 (10) | 0.8242 (12) | 0.046 (5)* | |
C17 | 0.7187 (3) | 0.50577 (9) | 0.67578 (9) | 0.0258 (3) | |
H17A | 0.727 (4) | 0.5072 (9) | 0.6130 (12) | 0.041 (5)* | |
H17B | 0.652 (4) | 0.5541 (10) | 0.6914 (11) | 0.037 (5)* | |
H17C | 0.913 (4) | 0.4996 (10) | 0.7068 (11) | 0.044 (5)* | |
C18 | −0.2709 (3) | 0.26594 (8) | 0.33395 (8) | 0.0200 (3) | |
H18A | −0.292 (3) | 0.2171 (8) | 0.3105 (9) | 0.020 (4)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0183 (5) | 0.0200 (5) | 0.0242 (5) | 0.0030 (4) | −0.0051 (4) | 0.0011 (4) |
O2 | 0.0174 (5) | 0.0263 (6) | 0.0214 (5) | 0.0001 (4) | −0.0044 (4) | 0.0024 (4) |
O3 | 0.0193 (5) | 0.0265 (6) | 0.0202 (5) | 0.0007 (4) | −0.0066 (4) | 0.0016 (4) |
N1 | 0.0158 (5) | 0.0189 (6) | 0.0161 (5) | 0.0002 (5) | −0.0026 (4) | −0.0003 (5) |
C1 | 0.0151 (6) | 0.0187 (7) | 0.0156 (6) | −0.0006 (5) | −0.0002 (5) | 0.0012 (5) |
C2 | 0.0146 (6) | 0.0180 (7) | 0.0171 (6) | 0.0010 (5) | 0.0009 (5) | 0.0029 (5) |
C3 | 0.0141 (6) | 0.0228 (7) | 0.0147 (6) | −0.0022 (5) | −0.0001 (5) | 0.0014 (5) |
C4 | 0.0167 (6) | 0.0188 (7) | 0.0161 (6) | −0.0023 (5) | 0.0013 (5) | −0.0005 (5) |
C5 | 0.0152 (6) | 0.0190 (7) | 0.0150 (6) | −0.0001 (5) | 0.0016 (5) | 0.0010 (5) |
C6 | 0.0142 (6) | 0.0209 (7) | 0.0133 (5) | −0.0015 (5) | 0.0008 (5) | 0.0010 (5) |
C7 | 0.0160 (6) | 0.0203 (7) | 0.0164 (6) | 0.0007 (5) | 0.0029 (5) | 0.0022 (5) |
C8 | 0.0162 (6) | 0.0252 (8) | 0.0148 (6) | 0.0001 (5) | 0.0003 (5) | 0.0024 (5) |
C9 | 0.0188 (7) | 0.0268 (8) | 0.0194 (6) | 0.0057 (6) | 0.0018 (5) | 0.0063 (6) |
C10 | 0.0266 (7) | 0.0204 (8) | 0.0224 (6) | 0.0057 (6) | 0.0052 (6) | 0.0024 (6) |
C11 | 0.0215 (7) | 0.0212 (8) | 0.0176 (6) | 0.0008 (6) | 0.0021 (5) | 0.0007 (5) |
C12 | 0.0150 (6) | 0.0218 (7) | 0.0152 (5) | 0.0007 (5) | 0.0017 (5) | 0.0025 (5) |
C13 | 0.0234 (7) | 0.0194 (8) | 0.0190 (6) | 0.0003 (6) | −0.0028 (5) | 0.0000 (5) |
C14 | 0.0227 (7) | 0.0200 (8) | 0.0209 (6) | 0.0008 (6) | 0.0021 (5) | 0.0002 (5) |
C15 | 0.0229 (7) | 0.0206 (8) | 0.0187 (6) | 0.0038 (6) | −0.0004 (5) | −0.0017 (5) |
C16 | 0.0418 (10) | 0.0292 (9) | 0.0188 (7) | −0.0012 (8) | 0.0013 (6) | −0.0026 (6) |
C17 | 0.0265 (8) | 0.0260 (9) | 0.0232 (7) | −0.0029 (6) | −0.0027 (6) | −0.0025 (6) |
C18 | 0.0179 (7) | 0.0228 (8) | 0.0189 (6) | −0.0032 (6) | 0.0011 (5) | 0.0009 (5) |
O1—C2 | 1.3587 (16) | C9—C10 | 1.401 (2) |
O1—H1O1 | 0.95 (2) | C9—H9A | 0.974 (16) |
O2—C18 | 1.2433 (17) | C10—C11 | 1.389 (2) |
O3—C8 | 1.3698 (17) | C10—H10A | 0.977 (17) |
O3—H1O3 | 0.96 (2) | C11—C12 | 1.396 (2) |
N1—C6 | 1.3707 (16) | C11—H11A | 0.983 (15) |
N1—C7 | 1.3870 (18) | C13—C14 | 1.5115 (18) |
N1—H1N1 | 0.851 (18) | C13—H13A | 1.027 (16) |
C1—C2 | 1.3914 (17) | C13—H13B | 1.010 (17) |
C1—C6 | 1.3933 (18) | C14—C15 | 1.3305 (19) |
C1—C13 | 1.5062 (19) | C14—H14A | 1.015 (16) |
C2—C3 | 1.4249 (19) | C15—C17 | 1.501 (2) |
C3—C4 | 1.4034 (19) | C15—C16 | 1.5049 (19) |
C3—C18 | 1.4396 (18) | C16—H16A | 0.994 (18) |
C4—C5 | 1.3803 (17) | C16—H16B | 1.022 (17) |
C4—H4A | 0.993 (16) | C16—H16C | 1.02 (2) |
C5—C6 | 1.4279 (19) | C17—H17A | 1.012 (18) |
C5—C12 | 1.4550 (18) | C17—H17B | 1.007 (19) |
C7—C8 | 1.3922 (18) | C17—H17C | 0.996 (19) |
C7—C12 | 1.4005 (18) | C18—H18A | 0.993 (16) |
C8—C9 | 1.377 (2) | ||
C2—O1—H1O1 | 105.3 (13) | C9—C10—H10A | 118.7 (9) |
C8—O3—H1O3 | 110.8 (12) | C10—C11—C12 | 117.98 (13) |
C6—N1—C7 | 109.23 (11) | C10—C11—H11A | 121.2 (9) |
C6—N1—H1N1 | 123.5 (12) | C12—C11—H11A | 120.8 (9) |
C7—N1—H1N1 | 127.0 (12) | C11—C12—C7 | 119.30 (12) |
C2—C1—C6 | 115.52 (12) | C11—C12—C5 | 134.97 (12) |
C2—C1—C13 | 123.01 (12) | C7—C12—C5 | 105.72 (12) |
C6—C1—C13 | 121.47 (11) | C1—C13—C14 | 113.50 (12) |
O1—C2—C1 | 117.81 (12) | C1—C13—H13A | 109.5 (9) |
O1—C2—C3 | 120.49 (11) | C14—C13—H13A | 110.5 (9) |
C1—C2—C3 | 121.70 (12) | C1—C13—H13B | 108.9 (9) |
C4—C3—C2 | 120.58 (12) | C14—C13—H13B | 109.4 (9) |
C4—C3—C18 | 118.80 (12) | H13A—C13—H13B | 104.6 (12) |
C2—C3—C18 | 120.61 (12) | C15—C14—C13 | 126.62 (13) |
C5—C4—C3 | 119.48 (12) | C15—C14—H14A | 117.9 (9) |
C5—C4—H4A | 120.1 (9) | C13—C14—H14A | 115.3 (9) |
C3—C4—H4A | 120.4 (9) | C14—C15—C17 | 124.27 (13) |
C4—C5—C6 | 117.96 (12) | C14—C15—C16 | 121.07 (14) |
C4—C5—C12 | 135.20 (13) | C17—C15—C16 | 114.60 (12) |
C6—C5—C12 | 106.84 (11) | C15—C16—H16A | 111.0 (10) |
N1—C6—C1 | 126.95 (12) | C15—C16—H16B | 109.2 (9) |
N1—C6—C5 | 108.30 (11) | H16A—C16—H16B | 107.9 (13) |
C1—C6—C5 | 124.75 (12) | C15—C16—H16C | 111.5 (11) |
N1—C7—C8 | 127.28 (12) | H16A—C16—H16C | 106.2 (15) |
N1—C7—C12 | 109.89 (11) | H16B—C16—H16C | 110.9 (14) |
C8—C7—C12 | 122.83 (13) | C15—C17—H17A | 113.4 (10) |
O3—C8—C9 | 126.08 (12) | C15—C17—H17B | 110.0 (10) |
O3—C8—C7 | 116.65 (13) | H17A—C17—H17B | 106.3 (14) |
C9—C8—C7 | 117.26 (12) | C15—C17—H17C | 110.7 (11) |
C8—C9—C10 | 120.79 (13) | H17A—C17—H17C | 109.7 (14) |
C8—C9—H9A | 118.8 (9) | H17B—C17—H17C | 106.5 (14) |
C10—C9—H9A | 120.4 (9) | O2—C18—C3 | 125.11 (13) |
C11—C10—C9 | 121.84 (14) | O2—C18—H18A | 121.3 (9) |
C11—C10—H10A | 119.4 (9) | C3—C18—H18A | 113.6 (9) |
C6—C1—C2—O1 | 179.32 (11) | C12—C7—C8—O3 | 179.74 (11) |
C13—C1—C2—O1 | −1.14 (18) | N1—C7—C8—C9 | −178.43 (12) |
C6—C1—C2—C3 | −0.31 (17) | C12—C7—C8—C9 | 0.49 (19) |
C13—C1—C2—C3 | 179.23 (12) | O3—C8—C9—C10 | −179.66 (12) |
O1—C2—C3—C4 | −178.56 (11) | C7—C8—C9—C10 | −0.48 (19) |
C1—C2—C3—C4 | 1.07 (19) | C8—C9—C10—C11 | 0.0 (2) |
O1—C2—C3—C18 | 0.72 (18) | C9—C10—C11—C12 | 0.5 (2) |
C1—C2—C3—C18 | −179.66 (11) | C10—C11—C12—C7 | −0.47 (18) |
C2—C3—C4—C5 | −1.02 (18) | C10—C11—C12—C5 | 178.79 (13) |
C18—C3—C4—C5 | 179.70 (11) | N1—C7—C12—C11 | 179.07 (11) |
C3—C4—C5—C6 | 0.25 (18) | C8—C7—C12—C11 | −0.01 (19) |
C3—C4—C5—C12 | 179.63 (13) | N1—C7—C12—C5 | −0.38 (14) |
C7—N1—C6—C1 | 178.76 (12) | C8—C7—C12—C5 | −179.46 (11) |
C7—N1—C6—C5 | −1.12 (13) | C4—C5—C12—C11 | 1.0 (3) |
C2—C1—C6—N1 | 179.65 (11) | C6—C5—C12—C11 | −179.62 (14) |
C13—C1—C6—N1 | 0.10 (19) | C4—C5—C12—C7 | −179.72 (13) |
C2—C1—C6—C5 | −0.48 (18) | C6—C5—C12—C7 | −0.30 (13) |
C13—C1—C6—C5 | 179.97 (12) | C2—C1—C13—C14 | 130.72 (13) |
C4—C5—C6—N1 | −179.59 (10) | C6—C1—C13—C14 | −49.76 (17) |
C12—C5—C6—N1 | 0.87 (13) | C1—C13—C14—C15 | 146.11 (14) |
C4—C5—C6—C1 | 0.52 (19) | C13—C14—C15—C17 | −1.1 (2) |
C12—C5—C6—C1 | −179.02 (11) | C13—C14—C15—C16 | 175.88 (14) |
C6—N1—C7—C8 | 179.98 (12) | C4—C3—C18—O2 | −179.07 (12) |
C6—N1—C7—C12 | 0.94 (14) | C2—C3—C18—O2 | 1.6 (2) |
N1—C7—C8—O3 | 0.82 (19) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1O1···O2 | 0.95 (2) | 1.75 (2) | 2.6274 (13) | 151.4 (18) |
O3—H1O3···O2i | 0.96 (2) | 1.77 (2) | 2.7139 (14) | 166.9 (19) |
C13—H13B···O1 | 1.011 (16) | 2.391 (16) | 2.8469 (17) | 106.4 (11) |
Symmetry code: (i) x+2, −y+1/2, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | C18H17NO3 |
Mr | 295.33 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 100 |
a, b, c (Å) | 4.7749 (1), 18.8511 (6), 16.0164 (5) |
β (°) | 97.931 (2) |
V (Å3) | 1427.88 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.52 × 0.18 × 0.09 |
Data collection | |
Diffractometer | Bruker APEXII CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 2005) |
Tmin, Tmax | 0.953, 0.992 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 15047, 3795, 2840 |
Rint | 0.033 |
(sin θ/λ)max (Å−1) | 0.682 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.044, 0.116, 1.10 |
No. of reflections | 3795 |
No. of parameters | 267 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.32, −0.24 |
Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 1998) and PLATON (Spek, 2003).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1O1···O2 | 0.95 (2) | 1.75 (2) | 2.6274 (13) | 151.4 (18) |
O3—H1O3···O2i | 0.96 (2) | 1.77 (2) | 2.7139 (14) | 166.9 (19) |
C13—H13B···O1 | 1.011 (16) | 2.391 (16) | 2.8469 (17) | 106.4 (11) |
Symmetry code: (i) x+2, −y+1/2, z+1/2. |
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Plants of the genus Micromelum (Rutaceae) are known to be rich sources of alkaloids (Nakahara et al., 2002), coumarins (Rahmani et al., 2003; Ito et al., 2000; Tantishaiyakul et al., 1986; Tantivatana et al., 1983) and flavonoids (Das et al., 1984; Sohrab et al., 2004). Some of these compounds show anti-cancer activity (Tantishaiyakul et al., 1986; Tantivatana et al., 1983). Micromelum minutum known locally in Thailand as "Hat-Sa-Khun", is a small to medium-sized tree or shrub found widespread in South-East Asian countries. The leaves of this plant are traditionally used in the treatment of fever and giddiness and a poultice of the boiled roots is used for ague (Rahmani et al., 2003). In our search for bioactive compounds from Thai medicinal plant, we herein report the crystal structure of the title compound, which was isolated from the stem barks of M. minutum collected from Nongkhai province in the northeasthern of Thailand.
In the structure of the title compound (Fig. 1), the carbazole ring system (C1–C12/N1) is essentially planar with the maximum deviation of -0.013 (1) Å for atom N1. The hydroxy and aldehyde substituent groups lie in the plane of the benzene ring and an intramolecular O1—H1O1···O2 hydrogen bond between the aldehyde and one of the hydroxy groups helps maintain the planarity of the structure. The orientation of the 3-methyl-2-butenyl substituent group with respect to the C1–C6 benzene ring is indicated by the torsion angle C2/C1/C13/C14 of 130.72 (13)°, showing an anti-clinal conformation. The dihedral angle between the 3-methyl-2-butenyl group and the mean plane of carbazole is 70.26 (7) Å. Bond lengths and angles in the title compound are within normal ranges (Allen et al., 1987) and comparable to related structures (Duan et al., 2005; Huang et al., 2005; Li et al., 2006). An O1—H1O1···O2 intramolecular interaction generates S(6) ring motif (Bernstein et al., 1995). In addition, the weak C13—H13B···O1 intramolecular interaction generates S(5) ring motif. O3—H1O3···O2 intermolecular interactions connect the molecules into dimers (Fig. 2). These dimers form chains along the [401] direction (Fig. 2). The crystal is stabilized by O—H···O hydrogen bonds and weak C—H···O intramolecular interaction. π–π interactions were also observed with the Cg1···Cg2 distances of 3.5901 (8) Å (symmetry code; 1 + x, y, z) and 3.5899 (8) Å (symmetry code; -1 + x, y, z), Cg1 and Cg2 are the centroids of C1–C6 and C6–C5–C12–C7–N1 rings.