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In the title compound, 3β-(dimethylamino)-16α-hydroxy-14-methyl-4-methylene-9,19-cyclo-5α-pregnan-20-one monohydrate, C25H39NO2·H2O, the pentacyclo steroidal alkaloid is composed of three six-membered, one five-membered and one three-membered ring. The molecular dimensions are as expected. The structure is stabilized by hydrogen bonds involving H and O atoms of water and the alkaloid molecules, with strong N...O [2.829 (7) Å] and O...O [2.790 (6) and 2.949 (7) Å] interactions.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270199014420/da1099sup1.cif
Contains datablocks Global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270199014420/da1099Isup2.hkl
Contains datablock I

CCDC reference: 142770

Comment top

Buxus species have long been known as rich sources of new and biologically active triterpenoidal alkaloids. Previous phytochemical investigations have led to the isolation of 150 such compounds (Atta-ur-Rahman, 1990). The extracts of the genus Buxus are reported to be useful in the indigenous system of medicine, in various disorders such as malaria, rheumatism and skin infections (Cordell, 1980). In this article, we report the crystal structure of the title compound (I), an interesting steroidal alkaloid isolated from the leaves of B. hyrcana, collected from Tehran, Iran.

The crystal structure of (I) is presented in Fig. 1. It contains a pentacyclo steroidal alkaloid hydrogen bonded to a water molecule. The molecular dimensions in (I) are normal and lie within expected ranges for the corresponding bond distances and angles, with mean bond distances as follows: Csp3—Csp3 1.535 (7), Csp3—Csp2 1.514 (4), N—Csp3 1.469 (10), C—O 1.430 (6), CO 1.200 (7) and CC 1.317 (7) Å. The alkaloid is composed of three six-membered, one five-membered and one three-membered ring. The six-membered rings A, B and C adopt chair, half-chair and skew-boat conformations, respectively, with puckering parameters (Cremer & Pople, 1975) Q = 0.586 (6), 0.530 (6) and 0.638 (5) Å, θ = 3.9 (6), 47.1 (5) and 68.9 (4)° and ϕ = 263 (9), 91.2 (8) and 273.9 (5)°, respectively. The five-membered ring D has a C14-envelope conformation with C14 0.675 (7) Å out of the plane of the remaining four atoms of the ring.

The structure is stabilized by hydrogen bonds involving the alkaloid molecules and water of hydration, with strong N···O [2.829 (7) Å] and O···O [2.790 (6) and 2.949 (7) Å] interactions. The geometry of the intermolecular interactions is provided in Table 2.

Experimental top

The leaves of Buxus hyrcana were collected from Tehran, Iran, during March and April, 1997. The methanolic extract of the air-dried and crushed leaves was evaporated to a gum, which was then suspended in water. After defatting with hexane, the aqueous layer was extracted with chloroform at different pH values. The fraction obtained at pH 3 was subjected to column chromatography. Elution of the column with chloroform:methanol (9:1) afforded the crystals of (I). Crystals suitable for X-ray crystallography were grown from acetone:methanol (9:1) at room temperature by slow evaporation.

Refinement top

The space group P21 was determined from the systematic absences, packing considerations, a statistical analysis of intensity distribution, and the successful solution and refinement of the structure. Friedel opposites (2689) were collected and were not merged. H-atoms of the water of solvation and hydroxyl group were located from a difference map. H atoms of the alkaloid were included at riding positions. The water H atoms were left in fixed positions. An absolute configuration could not be established in this analysis. However, refinement of the inverted structure towards the end of the full-matrix least-squares calculations yielded a Flack (1983) parameter of 2(3) and was, therefore, rejected as the absolute structure present in the crystal.

Computing details top

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 1994); program(s) used to solve structure: SAPI91 (Fan, 1991); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).

Figures top
[Figure 1] Fig. 1. ORTEPII (Johnson, 1976) drawing of (I) with the atomic numbering scheme. Displacement ellipsoids have been plotted at the 30% probability level and H-atoms assigned arbitrary radii.
3β-(Dimethylamino)-16α-hydroxy-14-methyl-4-methylene-9,19-cyclo-5α- pregnan-20-one monohydrate top
Crystal data top
C25H39NO2·H2OF(000) = 444
Mr = 403.59Dx = 1.172 Mg m3
Monoclinic, P21Mo Kα radiation, λ = 0.71069 Å
a = 6.1333 (8) ÅCell parameters from 25 reflections
b = 24.365 (3) Åθ = 10.0–25.0°
c = 8.0681 (6) ŵ = 0.08 mm1
β = 108.496 (8)°T = 293 K
V = 1143.4 (2) Å3Prismatic, colourless
Z = 20.38 × 0.29 × 0.25 mm
Data collection top
Rigaku AFC-6S
diffractometer
2901 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.038
Graphite monochromatorθmax = 27.6°, θmin = 2.7°
ω–2θ scansh = 07
Absorption correction: ψ scan
(North, Phillips & Mathews, 1968)
k = 3131
Tmin = 0.972, Tmax = 0.981l = 109
5848 measured reflections3 standard reflections every 200 reflections
5257 independent reflections intensity decay: 0.1%
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH atoms not refined
R[F2 > 2σ(F2)] = 0.059 w = 1/[σ2(Fo2) + (0.1023P)2 + 1.323P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.255(Δ/σ)max = 0.002
S = 1.07Δρmax = 0.22 e Å3
5257 reflectionsΔρmin = 0.24 e Å3
270 parametersExtinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
1 restraintExtinction coefficient: 0.009 (4)
Primary atom site location: structure-invariant direct methodsAbsolute structure: Flack (1983)
Secondary atom site location: difference Fourier mapAbsolute structure parameter: 1 (3)
Crystal data top
C25H39NO2·H2OV = 1143.4 (2) Å3
Mr = 403.59Z = 2
Monoclinic, P21Mo Kα radiation
a = 6.1333 (8) ŵ = 0.08 mm1
b = 24.365 (3) ÅT = 293 K
c = 8.0681 (6) Å0.38 × 0.29 × 0.25 mm
β = 108.496 (8)°
Data collection top
Rigaku AFC-6S
diffractometer
2901 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North, Phillips & Mathews, 1968)
Rint = 0.038
Tmin = 0.972, Tmax = 0.9813 standard reflections every 200 reflections
5848 measured reflections intensity decay: 0.1%
5257 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.059H atoms not refined
wR(F2) = 0.255Δρmax = 0.22 e Å3
S = 1.07Δρmin = 0.24 e Å3
5257 reflectionsAbsolute structure: Flack (1983)
270 parametersAbsolute structure parameter: 1 (3)
1 restraint
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.9274 (8)0.08845 (19)0.9604 (6)0.0750 (15)
H11.00120.06070.95690.113*
O20.5150 (9)0.02603 (19)0.7301 (7)0.0743 (13)
N10.0547 (9)0.39785 (19)0.0391 (6)0.0494 (12)
C10.3067 (10)0.2637 (2)0.0788 (7)0.0483 (13)
H1A0.30510.23030.01310.058*
H1B0.45920.27970.10840.058*
C20.1301 (12)0.3039 (2)0.0320 (7)0.0553 (15)
H2A0.17260.31370.13420.066*
H2B0.01860.28600.07200.066*
C30.1091 (10)0.3568 (2)0.0671 (7)0.0428 (12)
H30.26100.37420.10160.051*
C40.0631 (9)0.3416 (2)0.2352 (6)0.0386 (11)
C50.2451 (8)0.30313 (19)0.3467 (6)0.0344 (10)
H50.39230.32140.36090.041*
C60.2396 (10)0.2928 (2)0.5323 (6)0.0419 (12)
H6A0.09190.27750.52810.050*
H6B0.26080.32710.59650.050*
C70.4298 (9)0.2530 (2)0.6234 (6)0.0423 (12)
H7A0.57440.26620.61340.051*
H7B0.44450.25120.74650.051*
C80.3798 (8)0.19572 (19)0.5433 (6)0.0328 (10)
H80.23890.18320.56420.039*
C90.3270 (8)0.1963 (2)0.3415 (6)0.0349 (10)
C100.2510 (8)0.2504 (2)0.2454 (6)0.0362 (10)
C110.4589 (9)0.1557 (2)0.2610 (6)0.0434 (12)
H11A0.58970.17520.24660.052*
H11B0.35890.14640.14490.052*
C120.5485 (9)0.1018 (2)0.3571 (6)0.0438 (12)
H12A0.71190.09880.37440.053*
H12B0.47260.07130.28440.053*
C130.5086 (8)0.09750 (18)0.5351 (6)0.0334 (10)
C140.5673 (8)0.15371 (18)0.6329 (6)0.0326 (10)
C150.5748 (10)0.1375 (2)0.8192 (6)0.0426 (12)
H15A0.42060.13500.82720.051*
H15B0.66120.16430.90360.051*
C160.6941 (9)0.0812 (2)0.8527 (7)0.0470 (12)
H160.61390.05680.91070.056*
C170.6778 (9)0.0581 (2)0.6702 (7)0.0412 (12)
H170.82960.06240.65580.049*
C180.2601 (9)0.0792 (2)0.5063 (7)0.0491 (13)
H18A0.23670.04340.45420.074*
H18B0.23160.07800.61660.074*
H18C0.15640.10480.43030.074*
C190.0762 (8)0.2070 (2)0.2362 (6)0.0398 (11)
H19A0.03120.21310.30040.048*
H19B0.01300.18760.12650.048*
C200.6165 (10)0.0024 (2)0.6466 (7)0.0489 (13)
C210.6887 (14)0.0311 (3)0.5068 (9)0.075 (2)
H21A0.64770.06920.50340.113*
H21B0.61230.01450.39550.113*
H21C0.85200.02780.53260.113*
C220.1114 (10)0.3597 (2)0.2815 (8)0.0513 (13)
H22A0.12760.34900.38760.062*
H22B0.21850.38330.20810.062*
C230.8070 (9)0.1740 (2)0.6385 (7)0.0450 (12)
H23A0.85140.20430.71810.067*
H23B0.91620.14470.67720.067*
H23C0.80290.18560.52380.067*
C240.2753 (12)0.3756 (3)0.1430 (9)0.073 (2)
H24A0.32260.34780.07710.109*
H24B0.38770.40440.17250.109*
H24C0.26150.35970.24810.109*
C250.0499 (14)0.4287 (3)0.1517 (9)0.0691 (19)
H25A0.06040.45410.22250.104*
H25B0.18150.44850.08020.104*
H25C0.09660.40360.22570.104*
O30.1742 (9)0.00264 (19)0.9091 (8)0.0832 (16)
H310.28630.00240.87490.094*
H320.15390.03500.92800.094*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.072 (3)0.057 (3)0.068 (3)0.021 (2)0.018 (2)0.018 (2)
O20.087 (3)0.045 (2)0.097 (4)0.009 (2)0.039 (3)0.007 (2)
N10.061 (3)0.045 (3)0.040 (2)0.001 (2)0.013 (2)0.0032 (19)
C10.068 (4)0.044 (3)0.040 (3)0.008 (3)0.028 (3)0.003 (2)
C20.082 (4)0.053 (4)0.033 (3)0.010 (3)0.020 (3)0.001 (2)
C30.054 (3)0.038 (3)0.038 (3)0.002 (2)0.016 (2)0.002 (2)
C40.043 (3)0.036 (3)0.038 (3)0.001 (2)0.014 (2)0.002 (2)
C50.040 (3)0.035 (2)0.032 (2)0.006 (2)0.016 (2)0.000 (2)
C60.056 (3)0.041 (3)0.033 (2)0.003 (2)0.020 (2)0.005 (2)
C70.056 (3)0.044 (3)0.027 (2)0.002 (2)0.014 (2)0.006 (2)
C80.035 (2)0.036 (2)0.032 (2)0.004 (2)0.0157 (19)0.0036 (18)
C90.036 (2)0.039 (3)0.031 (2)0.005 (2)0.0120 (19)0.006 (2)
C100.042 (3)0.040 (3)0.028 (2)0.001 (2)0.0140 (19)0.0023 (19)
C110.050 (3)0.049 (3)0.034 (2)0.005 (2)0.018 (2)0.009 (2)
C120.050 (3)0.043 (3)0.040 (3)0.007 (2)0.016 (2)0.006 (2)
C130.034 (2)0.031 (2)0.038 (2)0.002 (2)0.014 (2)0.004 (2)
C140.036 (3)0.029 (2)0.035 (2)0.002 (2)0.0137 (19)0.0070 (18)
C150.050 (3)0.043 (3)0.036 (2)0.006 (2)0.014 (2)0.001 (2)
C160.054 (3)0.041 (3)0.042 (3)0.004 (2)0.009 (2)0.005 (2)
C170.043 (3)0.038 (3)0.042 (3)0.002 (2)0.012 (2)0.004 (2)
C180.040 (3)0.044 (3)0.060 (3)0.006 (2)0.012 (2)0.005 (3)
C190.041 (3)0.035 (3)0.040 (3)0.003 (2)0.007 (2)0.005 (2)
C200.054 (3)0.032 (3)0.053 (3)0.003 (2)0.007 (3)0.000 (2)
C210.109 (6)0.046 (4)0.065 (4)0.014 (4)0.019 (4)0.011 (3)
C220.058 (3)0.049 (3)0.052 (3)0.009 (3)0.024 (3)0.006 (3)
C230.040 (3)0.042 (3)0.053 (3)0.008 (2)0.015 (2)0.006 (2)
C240.072 (5)0.071 (5)0.058 (4)0.002 (4)0.004 (3)0.003 (3)
C250.100 (6)0.051 (4)0.062 (4)0.006 (4)0.033 (4)0.011 (3)
O30.094 (4)0.045 (3)0.129 (4)0.007 (2)0.061 (3)0.013 (3)
Geometric parameters (Å, º) top
O1—C161.430 (6)C8—C91.556 (6)
O2—C201.200 (7)C9—C101.525 (7)
N1—C241.452 (8)C9—C191.526 (7)
N1—C251.473 (8)C9—C111.545 (7)
N1—C31.482 (7)C10—C191.490 (7)
C1—C21.522 (8)C11—C121.536 (7)
C1—C101.523 (7)C12—C131.535 (6)
C2—C31.543 (7)C13—C181.533 (7)
C3—C41.517 (7)C13—C141.565 (6)
C4—C221.317 (7)C13—C171.572 (7)
C4—C51.515 (7)C14—C231.538 (7)
C5—C61.529 (6)C14—C151.541 (7)
C5—C101.530 (6)C15—C161.539 (8)
C6—C71.514 (7)C16—C171.550 (7)
C7—C81.528 (7)C17—C201.517 (7)
C8—C141.538 (7)C20—C211.507 (9)
C24—N1—C25110.0 (5)C19—C10—C5118.9 (4)
C24—N1—C3114.7 (5)C1—C10—C5110.0 (4)
C25—N1—C3110.6 (5)C9—C10—C5120.6 (4)
C2—C1—C10109.8 (5)C12—C11—C9119.1 (4)
C1—C2—C3113.2 (4)C13—C12—C11113.1 (4)
N1—C3—C4113.4 (4)C18—C13—C12108.9 (4)
N1—C3—C2114.6 (4)C18—C13—C14112.9 (4)
C4—C3—C2109.2 (4)C12—C13—C14109.4 (4)
C22—C4—C5123.4 (5)C18—C13—C17109.5 (4)
C22—C4—C3124.7 (5)C12—C13—C17115.1 (4)
C5—C4—C3111.8 (4)C14—C13—C17100.9 (4)
C4—C5—C6116.3 (4)C8—C14—C23111.4 (4)
C4—C5—C10109.9 (4)C8—C14—C15114.6 (4)
C6—C5—C10113.3 (4)C23—C14—C15108.7 (4)
C7—C6—C5109.2 (4)C8—C14—C13109.1 (4)
C6—C7—C8111.0 (4)C23—C14—C13111.2 (4)
C7—C8—C14112.9 (4)C15—C14—C13101.5 (4)
C7—C8—C9112.4 (4)C16—C15—C14105.4 (4)
C14—C8—C9112.0 (4)O1—C16—C15108.9 (4)
C10—C9—C1958.5 (3)O1—C16—C17111.9 (5)
C10—C9—C11117.1 (4)C15—C16—C17105.9 (4)
C19—C9—C11116.5 (4)C20—C17—C16114.2 (5)
C10—C9—C8117.9 (4)C20—C17—C13115.1 (4)
C19—C9—C8115.0 (4)C16—C17—C13105.5 (4)
C11—C9—C8118.1 (4)C10—C19—C960.8 (3)
C19—C10—C1117.8 (4)O2—C20—C21121.7 (6)
C19—C10—C960.8 (3)O2—C20—C17123.2 (5)
C1—C10—C9121.0 (4)C21—C20—C17115.1 (5)
C10—C1—C2—C355.4 (7)C19—C9—C11—C12116.4 (5)
C24—N1—C3—C480.0 (6)C8—C9—C11—C1226.9 (6)
C25—N1—C3—C4154.8 (5)C9—C11—C12—C134.6 (7)
C24—N1—C3—C246.4 (7)C11—C12—C13—C1881.1 (5)
C25—N1—C3—C278.8 (6)C11—C12—C13—C1442.7 (5)
C1—C2—C3—N1177.7 (5)C11—C12—C13—C17155.6 (4)
C1—C2—C3—C453.8 (7)C7—C8—C14—C2353.5 (5)
N1—C3—C4—C223.8 (8)C9—C8—C14—C2374.6 (5)
C2—C3—C4—C22125.4 (6)C7—C8—C14—C1570.5 (5)
N1—C3—C4—C5175.4 (4)C9—C8—C14—C15161.4 (4)
C2—C3—C4—C555.4 (6)C7—C8—C14—C13176.6 (4)
C22—C4—C5—C69.3 (7)C9—C8—C14—C1348.5 (5)
C3—C4—C5—C6170.0 (4)C18—C13—C14—C849.6 (5)
C22—C4—C5—C10121.1 (5)C12—C13—C14—C871.9 (5)
C3—C4—C5—C1059.6 (5)C17—C13—C14—C8166.3 (4)
C4—C5—C6—C7179.2 (4)C18—C13—C14—C23172.9 (4)
C10—C5—C6—C750.4 (6)C12—C13—C14—C2351.4 (5)
C5—C6—C7—C869.0 (5)C17—C13—C14—C2370.4 (5)
C6—C7—C8—C14179.4 (4)C18—C13—C14—C1571.7 (5)
C6—C7—C8—C952.7 (5)C12—C13—C14—C15166.8 (4)
C7—C8—C9—C1020.5 (6)C17—C13—C14—C1545.0 (4)
C14—C8—C9—C10148.8 (4)C8—C14—C15—C16157.3 (4)
C7—C8—C9—C1986.5 (5)C23—C14—C15—C1677.3 (5)
C14—C8—C9—C19145.1 (4)C13—C14—C15—C1639.9 (5)
C7—C8—C9—C11129.7 (4)C14—C15—C16—O1102.0 (5)
C14—C8—C9—C111.3 (6)C14—C15—C16—C1718.5 (5)
C2—C1—C10—C1983.2 (6)O1—C16—C17—C20103.9 (5)
C2—C1—C10—C9154.2 (5)C15—C16—C17—C20137.5 (5)
C2—C1—C10—C557.4 (6)O1—C16—C17—C13128.7 (5)
C11—C9—C10—C19105.9 (5)C15—C16—C17—C1310.2 (5)
C8—C9—C10—C19103.6 (4)C18—C13—C17—C2041.8 (6)
C19—C9—C10—C1106.7 (5)C12—C13—C17—C2081.3 (6)
C11—C9—C10—C10.8 (7)C14—C13—C17—C20161.0 (4)
C8—C9—C10—C1149.6 (4)C18—C13—C17—C1685.1 (5)
C19—C9—C10—C5108.2 (5)C12—C13—C17—C16151.9 (4)
C11—C9—C10—C5145.9 (4)C14—C13—C17—C1634.2 (5)
C8—C9—C10—C54.5 (6)C1—C10—C19—C9111.9 (5)
C4—C5—C10—C1980.3 (5)C5—C10—C19—C9111.0 (4)
C6—C5—C10—C1951.7 (6)C11—C9—C19—C10106.9 (4)
C4—C5—C10—C159.9 (5)C8—C9—C19—C10108.7 (4)
C6—C5—C10—C1168.1 (4)C16—C17—C20—O224.3 (8)
C4—C5—C10—C9151.6 (4)C13—C17—C20—O297.9 (6)
C6—C5—C10—C919.6 (6)C16—C17—C20—C21156.8 (5)
C10—C9—C11—C12177.3 (4)C13—C17—C20—C2180.9 (6)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H31···O20.822.172.949 (7)159.4
O3—H32···N1i0.822.052.829 (7)158.9
O1—H1···O3ii0.821.982.790 (6)171
Symmetry codes: (i) x, y+1/2, z+1; (ii) x+1, y, z.

Experimental details

Crystal data
Chemical formulaC25H39NO2·H2O
Mr403.59
Crystal system, space groupMonoclinic, P21
Temperature (K)293
a, b, c (Å)6.1333 (8), 24.365 (3), 8.0681 (6)
β (°) 108.496 (8)
V3)1143.4 (2)
Z2
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.38 × 0.29 × 0.25
Data collection
DiffractometerRigaku AFC-6S
diffractometer
Absorption correctionψ scan
(North, Phillips & Mathews, 1968)
Tmin, Tmax0.972, 0.981
No. of measured, independent and
observed [I > 2σ(I)] reflections
5848, 5257, 2901
Rint0.038
(sin θ/λ)max1)0.651
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.059, 0.255, 1.07
No. of reflections5257
No. of parameters270
No. of restraints1
H-atom treatmentH atoms not refined
Δρmax, Δρmin (e Å3)0.22, 0.24
Absolute structureFlack (1983)
Absolute structure parameter1 (3)

Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988), MSC/AFC Diffractometer Control Software, TEXSAN (Molecular Structure Corporation, 1994), SAPI91 (Fan, 1991), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976).

Selected geometric parameters (Å, º) top
O1—C161.430 (6)C4—C221.317 (7)
O2—C201.200 (7)C9—C101.525 (7)
N1—C241.452 (8)C9—C191.526 (7)
N1—C251.473 (8)C10—C191.490 (7)
N1—C31.482 (7)
C24—N1—C25110.0 (5)C10—C9—C1958.5 (3)
C24—N1—C3114.7 (5)C19—C10—C960.8 (3)
C25—N1—C3110.6 (5)C10—C19—C960.8 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H31···O20.822.172.949 (7)159.4
O3—H32···N1i0.822.052.829 (7)158.9
O1—H1···O3ii0.821.982.790 (6)170.6
Symmetry codes: (i) x, y+1/2, z+1; (ii) x+1, y, z.
 

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