Swietenolide monohydrate

Seok-Keik Tan; Hasnah Osman; Keng-Chong Wong; Hoong-Kun Fun; Suchada Chantrapromma

doi:10.1107/S1600536808017431

. 2008 Jun 13;64(Pt 7):o1267–o1268. doi: 10.1107/S1600536808017431

Swietenolide monohydrate

Seok-Keik Tan ^a, Hasnah Osman ^a,^‡, Keng-Chong Wong ^a, Hoong-Kun Fun ^b,^*, Suchada Chantrapromma ^c,^§

PMCID: PMC2961806 PMID: 21202901

Abstract

The title compound, a natural b,d-seco-limonoid, C₂₇H₃₄O₈·H₂O, and known as Swietenolide monohydrate, has been isolated from S. macrophylla King. In the molecular structure, the four fused six-membered rings adopt twist-boat (ring A), approximate chair (ring B), envelope (ring C) and half-chair (ring D) conformations. The attached furan ring is essentially planar. O—H⋯O hydrogen bonds and weak C—H⋯O interactions connect the molecules into a two-dimensional network parallel to the (100) plane. C—H⋯π interactions are also observed.

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For ring conformations, see: Cremer & Pople (1975 ▶). For related structures, see, for example: Fowles et al. (2007 ▶); Solomon et al. (2003 ▶). For the bioactivities of Swietenolide, see, for example: Chan et al. (1976 ▶); Jean et al. (2000 ▶); Kipassa et al. (2008 ▶); Munoz et al. (2000 ▶); Soediro et al. (1990 ▶).

Experimental

Crystal data

C₂₇H₃₄O₈·H₂O
M _r = 504.56
Monoclinic,
a = 11.5897 (1) Å
b = 8.8972 (1) Å
c = 11.7397 (1) Å
β = 90.571 (1)°
V = 1210.49 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100.0 (1) K
0.51 × 0.26 × 0.15 mm

Data collection

Bruker SMART APEX2 CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.949, T _max = 0.985
29214 measured reflections
3748 independent reflections
3473 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.036
wR(F ²) = 0.102
S = 1.06
3748 reflections
336 parameters
3 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.60 e Å⁻³
Δρ_min = −0.30 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 ▶); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808017431/is2302sup1.cif

e-64-o1267-sup1.cif^{(28.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808017431/is2302Isup2.hkl

e-64-o1267-Isup2.hkl^{(183.7KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2A⋯O1Wⁱ	0.82	2.02	2.835 (2)	171
O5—H5A⋯O1Wⁱⁱ	0.82	2.05	2.760 (2)	144
O1W—H1W1⋯O1ⁱⁱⁱ	0.84 (2)	1.98 (3)	2.809 (2)	169 (3)
O1W—H2W1⋯O6	0.842 (19)	1.994 (19)	2.821 (2)	167 (3)
C1—H1A⋯O1^iv	0.98	2.38	3.325 (2)	160
C3—H3A⋯O2	0.98	2.57	3.032 (2)	109
C3—H3A⋯O7	0.98	2.40	2.861 (2)	108
C7—H7A⋯O2	0.97	2.34	2.690 (2)	100
C7—H7B⋯O4^v	0.97	2.38	3.282 (2)	155
C21—H21B⋯O1	0.96	2.59	3.459 (2)	150
C21—H21C⋯O5	0.96	2.46	3.077 (3)	122
C27—H27B⋯O3	0.96	2.57	2.911 (2)	101
C23—H23A⋯Cg1^vi	0.98	3.04	3.884 (2)	146
C25—H25A⋯Cg1^vii	0.96	3.15	3.981 (3)	146

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) . Cg1 is the centroid of the C17–C20/O8 furan ring.

Acknowledgments

The authors thank Universiti Sains Malaysia for the University Golden Goose (grant No. 1001/PFIZIK/811012) and the Malaysian Government for the E-Science Fund (grant No. 305/PKIMIA/613411).

supplementary crystallographic information

Comment

Swietenia macrophylla King (Meliaceae) or locally known as Big-leaf mahogany is an evergreen tree that reaches 45 to 60 meter in height. The decoction of the seeds of Swietenia macrophylla King was used traditionally to induce abortion, to heal wounds and to treat various skin ailments (Munoz et al., 2000). In Malaysia, the seeds were ingested by local folks to provide cure for high blood pressure (Chan et al., 1976). The bark extract of Swietenia macrophylla King was also found to be active in antimalaria activity (Soediro et al., 1990). In a continual research on this plant, the leaf extracts of S. macrophylla were examined. The title compound, (I), (systematic name: 7,11-Methano-2H-cycloocta[f][2]benzopyran-8-acetic acid, 4-(3-furanyl)-1,4,4a,5,6,6a,7,8,9,10,11,12-dodecahydro-α,10-dihydroxy- 4a,7,9,9-tetramethyl-2,13-dioxo-methyl ester monohydrate) has been isolated from the n-hexane extract. It has been shown to possess biological activities such as antimalaria (Jean et al., 2000) and antifeedant (Kipassa et al., 2008).

The title molecule (Fig. 1) has four fused six-membered rings (A/B/C/D). The conformations adopted by rings A, B, C and D are twist boat, approximate chair, envelope and half-chair, respectively, with the puckering parameter (Cremer & Pople, 1975) Q = 0.774 (2) Å, θ = 85.0 (1)° and φ = 72.70 (15)° for ring A; Q = 0.642 (2) Å, θ = 161.9 (2)° and φ = 200.9 (6)° for ring B; Q = 0.460 (2) Å, θ = 127.4 (2)° and φ = 354.3 (3)° for ring C, with atom C11 displaced from the C8/C9/C10/C12/C13 plane by 0.329 (2) Å; and Q = 0.587 (2) Å, θ = 111.3 (2)° and φ = 93.72 (19)° for ring D, with the C12 and C16 pucker atoms deviating from the C13—C15/O3 plane by 0.343 (2) Å and -0.384 (2) Å, respectively. The furan ring (C17—C20/O8) is planar and is attached equatorially to lactone ring D, the torsion angle C12–C16–C17–C20 being 101.9 (2)°. The orientation of the acetic acid, 2-hydroxy-methyl ester group (C23—C25/O5—O7) at C3 can be indicated by the torsion angles of C2–C3–C23–O5 = -46.9 (2)° and C2–C3–C23–C24 = 73.2 (2)° and the methyoxyl group is slightly deviated with respect to the carbonyl group with the torsion angle C25–O7–C24–O6 of 6.5 (3)°. The bond lengths and angles in (I) are within normal ranges (Allen et al., 1987) and comparable to the related structures (Fowles et al., 2007; Solomon et al., 2003).

In the crystal packing (Fig. 2), O—H···O hydrogen bonds and weak C—H···O interactions connect the molecules into two-dimensional network parallel to the (1 0 0) plane. O—H···O hydrogen bonds between the water and swietenolide molecules together with weak C—H···O intra- and intermolecular interactions (Table 1) play an important role in the stabilization of the crystal structure. C—H···π interactions involving furan ring (C17—C20/O8, centroid Cg1) are also observed in the crystal (Table 1).

Experimental

Air-dried powdered leaves of S. macrophylla were extracted with n-hexane, CH₂Cl₂ and MeOH (5 L each) for five days respectively at room temperature. The solvents were evaporated under reduced pressure to afford n-hexane extract (12.8 g), CH₂Cl₂ extract (18.2 g) and MeOH extract (107.8 g). The n-hexane extract was subjected to column chromatography using silica gel with petroleum ether-ethyl acetate gradient to afford seven fractions (M1—M7). Fraction M7 (1.05 g) was further separated by preparative TLC with eluent system n-hexane–ethyl acetate (5:1 v/v) to afford three sub-fractions (M7a—M7c). Fraction M7b was recrystallized from CHCl₃ to yield white single crystals of the title compound (m.p. 494–495 K).