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ISSN: 2056-9890

Crystal and mol­ecular structure of aflatrem

aDepartment of Chemistry, Higher Teacher Training College, University of Yaoundé 1, PO Box 47, Yaoundé, Cameroon, bDepartment of Organic Chemistry, University of Yaoundé 1, PO Box 812, Yaoundé, Cameroon, cDepartment of Inorganic Chemistry, University of Yaoundé 1, PO Box 812, Yaoundé, Cameroon, and dDepartment of Chemistry, University of Bielefeld, PO Box 100131, 33501 Bielefeld, Germany
*Correspondence e-mail: lentabruno@yahoo.fr

Edited by A. J. Lough, University of Toronto, Canada (Received 13 September 2015; accepted 9 October 2015; online 17 October 2015)

The crystal structure of the title compound, C32H39NO4, confirms the absolute configuration of the seven chiral centres in the mol­ecule. The molecule has a 1,1-dimethylprop-2-enyl substituent on the indole nucleus and this nucleus shares one edge with the five-membered ring which is, in turn, connected to a sequence of three edge-shared fused rings. The skeleton is completed by the 7,7-trimethyl-6,8-dioxabi­cyclo­[3.2.1]oct-3-en-2-one group connected to the terminal cyclohexene ring. The two cyclohexane rings adopt chair and half-chair conformations, while in the dioxabi­cyclo­[3.2.1]oct-3-en-2-one unit, the six-membered ring has a half-chair conformation. The indole system of the mol­ecule exhibits a tilt of 2.02 (1)° between its two rings. In the crystal, O—H⋯O hydrogen bonds connect mol­ecules into chains along [010]. Weak N—H⋯π inter­actions connect these chains, forming sheets parallel to (10-1).

1. Related literature

For background to indole diterpenoids from endophytes, see: Strobel & Daisy (2003[Strobel, G. & Daisy, B. (2003). Microbiol. Mol. Biol. Rev. 67, 491-502.]); Munday-Finch et al. (1996[Munday-Finch, S. C., Wilkins, A. L. & Miles, C. O. (1996). Phytochemistry, 41, 327-332.]); Gallagher et al. (1980a[Gallagher, R. T., Finer, J., Clardy, J., Leutwiler, A., Weibel, F., Acklin, W. & Arigoni, D. (1980a). Tetrahedron Lett. 21, 235-238.],b[Gallagher, R. T., Clardy, J. & Wilson, B. J. (1980b). Tetrahedron Lett. 21, 239-242.]); Lenta et al. (2007[Ndjakou Lenta, B., Noungoue, D. T., Devkota, K. P., Fokou, P. A., Ngouela, S., Tsamo, E. & Sewald, N. (2007). Acta Cryst. E63, o1282-o1284.]); Phongpaichit et al. (2007[Phongpaichit, S., Nikom, J., Rungjindamai, N., Sakayaroj, J., Hutadilok-Towatana, N., Rukachaisirikul, V. & Kirtikara, K. (2007). FEMS Immunol. Med. Microbiol. 51, 517-525.]). For studies of Aspergillus sp, see: Nicholson et al. (2009[Nicholson, M. J., Koulman, A., Monahan, B. J., Pritchard, B. L., Payne, G. A. & Scott, B. (2009). Appl. Environ. Microbiol. 75, 7469-7481.]); Duran et al. (2006[Duran, R. M., Cary, J. W. & Calvo, A. M. (2006). Appl. Microbiol. Biotechnol. 73, 1158-1168.]). For the pharmacological basis of the behavioural effects of this mol­ecule, see: Tinao-Wooldridge et al. (1995[Tinao-Wooldridge, L. V., Hsiang, B. C. H., Latifi, T. N., Ferrendelli, J. A. & Covey, D. F. (1995). Bioorg. Med. Chem. Lett. 5, 265-270.]). For the isolation of fungal endophytes from the stem of Symphonia globulifera, see: Petrini et al. (1992[Petrini, O., Sueber, I., Titi, L. & Viret, O. (1992). Nat. Toxins, 1, 185-196.]); Amin et al. (2014[Amin, N., Salam, M., Junaid, M., Asman & Baco, M. S. I. (2014). Int J Curr Microbiol Appl Sci. 3, 459-467.]). For geometric details of indole compounds, see: Krishna et al. (1999[Krishna, R., Velmurugan, D., Babu, G. & Perumal, P. T. (1999). Acta Cryst. C55, 75-78.]). For circular dichroism experiments on the title compound, see: Sun et al. (2014[Sun, K., Li, Y., Guo, L., Wang, Y., Liu, P. & Zhu, W. (2014). Mar. Drugs, 12, 3970-3981.]). For information on the Cambridge Structural Database (CSD), see: Groom & Allen (2014[Groom, C. R. & Allen, F. H. (2014). Angew. Chem. Int. Ed. 53, 662-671.]).

[Scheme 1]

2. Experimental

2.1. Crystal data

  • C32H39NO4

  • Mr = 501.64

  • Monoclinic, P 21

  • a = 12.8022 (5) Å

  • b = 6.4019 (2) Å

  • c = 15.9557 (6) Å

  • β = 98.821 (4)°

  • V = 1292.24 (9) Å3

  • Z = 2

  • Cu Kα radiation

  • μ = 0.66 mm−1

  • T = 100 K

  • 0.18 × 0.14 × 0.02 mm

2.2. Data collection

  • Agilent SuperNova Dual Source diffractometer with an Atlas detector

  • Absorption correction: gaussian (CrysAlis PRO; Agilent, 2013[Agilent (2013). CrysAlis PRO Agilent Technologies Ltd, Yarnton, Oxfordshire, England.]) Tmin = 0.899, Tmax = 1.000

  • 19981 measured reflections

  • 4585 independent reflections

  • 4078 reflections with I > 2σ(I)

  • Rint = 0.050

2.3. Refinement

  • R[F2 > 2σ(F2)] = 0.056

  • wR(F2) = 0.150

  • S = 1.06

  • 4585 reflections

  • 341 parameters

  • 1 restraint

  • H-atom parameters constrained

  • Δρmax = 0.35 e Å−3

  • Δρmin = −0.23 e Å−3

  • Absolute structure: Flack x determined using 1671 quotients [(I+)−(I)]/[(I+)+(I)] (Parsons & Flack, 2004[Parsons, S. & Flack, H. (2004). Acta Cryst. A60, s61.])

  • Absolute structure parameter: 0.09 (14)

Table 1
Hydrogen-bond geometry (Å, °)

Cg is the centroid of the C17–C22 ring.

D—H⋯A D—H H⋯A DA D—H⋯A
O4—H4⋯O3i 0.82 2.03 2.757 (3) 148
N1—H1⋯Cgii 0.86 2.78 3.527 (1) 146
Symmetry codes: (i) [-x+2, y-{\script{1\over 2}}, -z+2]; (ii) [-x+1, y-{\script{1\over 2}}, -z+1].

Data collection: CrysAlis PRO (Agilent, 2013[Agilent (2013). CrysAlis PRO Agilent Technologies Ltd, Yarnton, Oxfordshire, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 1999[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009[Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339-341.]).

Supporting information


Comment top

The search of compounds from plant endophytes has been the subject of research interest (Strobel & Daisy 2003). They produce a plethora of substances with potential applications in agriculture, medicine, pharmaceutical and for industry (Petrini et al. 1992; Strobel & Daisy, 2003; Phongpaichit et al., 2007). We are interested in the isolation and the structural study of compounds produced by endophytes from Cameroonian medicinal plants with pharmacological properties (Lenta et al., 2007) and one of the compounds that we have isolated from the fungal endophyte of the stem of Symphonia globulifera was aflatrem. Some authors have identified the biosynthetic genes of this molecule in Aspergilius sp (Nicholson et al., 2009; Duran et al., 2006). We report herein the study of its molecular and crystal structure.

Aflatrem crystallizes in the non-centrosymmetric space group P21 and its asymmetric unit consists of a single molecule as shown in Figure 1. As known in the literature, the molecule has a 1,l-dimethyl-2-propenyl substituent on the indole nucleus at position C18 and this nucleus shares one edge with the 5-membered ring (A) belonging to a group of three fused rings like an anthracene system (see Fig.1). The two others rings (6-membered, B and C) also share one edge with the 7, 7-trimethyl-6,8- dioxabicyclo[3.2.1]oct-3-en-2-one group. All the bond distances observed in the compounds are in agreement with the bonds distance of the Cambridge Structural Database (CSD, Groom & Allen, 2014). In the indole ring system, a small tilt of 2.02 (1)° is observed between the 6 and 5-membered rings. This value as well as the values of the bond angles is near the values always obtained in the indole based compounds (Krishna et al., 1999). The ring A (C1/C16/C15/C14/C2) adopts a dihedral angle of 3.12 (1)° with the 5-membered ring of indole system. With the exception of the C1–C2–C14 angle (96.9 (1)°),the values of the bond angles in this ring are in the range between 100 and 112° and they are in good agreement with the ideal conformation for which the angle is 107°. The lower value observed could be favored by the chair conformation of the B ring which shares one edge (C2 and C14) with ring A. This conformation is close to the ideal chair conformation since the bond angles range from 107 to 113° compared to an ideal value of 109°. The ring C assumes a half-chair conformation. The bicyclo[3.2.1]oct-3-en-2-one system is composed by a 6-membered ring named D (C6/C10/C9/C8/C7/O1) sharing one edge (C6 –C7) with a 5-membered ring called E (O1/C7/C6/O2/C25). The carbon atoms of ring D lie in the same plane and the O1 atom is located at 0.80 (1) Å from this plane. This atom is also located at 0.656 (1) Å from the plane which contains the carbon atoms of ring E and the dihedral angle between the two planes is 69.07 (1)°. The methyl and hydroxyl groups linked to the fused ring give the absolute configuration of 1S,3R,6S,7S,11R,12S,13S determined by Cu Kα X-radiation with the Flack parameter being refined to 0.09 (14) and this configuration is in agreement with the previous circular dichroism assignment reported by Sun et al. (2014).

The crystal packing of the aflatrem molecules is illustrated in Figs. 2 and 3. In the crystal, molecules are connected along the b axis via O—H···O hydrogen bonds. In addition, weak N—H···π(indole) interactions connect these chains forming planes parallel to (10-1). This N—H···π(indole) interaction is typical of indole-based molecules as reported by Krishna et al. (1999).

Related literature top

For background to indole diterpenoids from endophytes, see: Strobel & Daisy (2003); Munday-Finch et al. (1996); Gallagher et al. (1980a,b); Lenta et al. (2007); Phongpaichit et al. (2007). For studies of Aspergillus sp, see: Nicholson et al. (2009); Duran et al. (2006). For the pharmacological basis of the behavioural effects of this molecule, see: Tinao-Wooldridge et al. (1995). For the isolation of fungal endophytes from the stem of Symphonia globulifera, see: Petrini et al. (1992); Amin et al. (2014). For geometric details of indole compounds, see: Krishna et al. (1999). For circular dichroism experiments on the title compound, see: Sun et al. (2014). For information on the Cambridge Structural Database (CSD), see: Groom & Allen (2014).

Experimental top

The isolation of fungal endophytes from the stem of Symphonia globulifera was carried out aat the University of Yaoundé 1 (Cameroon) and was based on the method described by Petrini et al. (1992). One of the fungi was identified to Aspergillus sp. according to the method described by Amin et al. (2014) and cultured in solid medium prepared from 1 kg of rice distributed in the glass flask (total capacity of 2.5 L) at a rate of 200 g of rice in 200 ml of distilled water. After one month of incubation at 301K in the same laboratory, the culture medium was extracted with EtOAc and the extract concentrated on a rotary evaporator under vacuum at a temperature of 313K to yield 20.1 g of extract. This extract was subjected to column chromatography (CC) over silica gel (0.023–0.20 mesh, Merck) and eluted with a gradient system of petroleum ether /ethyl acetate to afford aflatrem (7.5 mg). The colourless crystals obtained were sent to the Laboratory of Inorganic and Structural Chemistry at Bielefeld University (Germany) for X-ray diffraction measurements.

Refinement top

H atoms were placed in calculated positions with C–H = 0.93-0.98Å, N—H = 0.86Å and O—H = 0.82Å. They were included in calculated positions with Uiso(H) = 1.2Ueq(C) or 1.5Ueq(Cmethyl,O).

Structure description top

The search of compounds from plant endophytes has been the subject of research interest (Strobel & Daisy 2003). They produce a plethora of substances with potential applications in agriculture, medicine, pharmaceutical and for industry (Petrini et al. 1992; Strobel & Daisy, 2003; Phongpaichit et al., 2007). We are interested in the isolation and the structural study of compounds produced by endophytes from Cameroonian medicinal plants with pharmacological properties (Lenta et al., 2007) and one of the compounds that we have isolated from the fungal endophyte of the stem of Symphonia globulifera was aflatrem. Some authors have identified the biosynthetic genes of this molecule in Aspergilius sp (Nicholson et al., 2009; Duran et al., 2006). We report herein the study of its molecular and crystal structure.

Aflatrem crystallizes in the non-centrosymmetric space group P21 and its asymmetric unit consists of a single molecule as shown in Figure 1. As known in the literature, the molecule has a 1,l-dimethyl-2-propenyl substituent on the indole nucleus at position C18 and this nucleus shares one edge with the 5-membered ring (A) belonging to a group of three fused rings like an anthracene system (see Fig.1). The two others rings (6-membered, B and C) also share one edge with the 7, 7-trimethyl-6,8- dioxabicyclo[3.2.1]oct-3-en-2-one group. All the bond distances observed in the compounds are in agreement with the bonds distance of the Cambridge Structural Database (CSD, Groom & Allen, 2014). In the indole ring system, a small tilt of 2.02 (1)° is observed between the 6 and 5-membered rings. This value as well as the values of the bond angles is near the values always obtained in the indole based compounds (Krishna et al., 1999). The ring A (C1/C16/C15/C14/C2) adopts a dihedral angle of 3.12 (1)° with the 5-membered ring of indole system. With the exception of the C1–C2–C14 angle (96.9 (1)°),the values of the bond angles in this ring are in the range between 100 and 112° and they are in good agreement with the ideal conformation for which the angle is 107°. The lower value observed could be favored by the chair conformation of the B ring which shares one edge (C2 and C14) with ring A. This conformation is close to the ideal chair conformation since the bond angles range from 107 to 113° compared to an ideal value of 109°. The ring C assumes a half-chair conformation. The bicyclo[3.2.1]oct-3-en-2-one system is composed by a 6-membered ring named D (C6/C10/C9/C8/C7/O1) sharing one edge (C6 –C7) with a 5-membered ring called E (O1/C7/C6/O2/C25). The carbon atoms of ring D lie in the same plane and the O1 atom is located at 0.80 (1) Å from this plane. This atom is also located at 0.656 (1) Å from the plane which contains the carbon atoms of ring E and the dihedral angle between the two planes is 69.07 (1)°. The methyl and hydroxyl groups linked to the fused ring give the absolute configuration of 1S,3R,6S,7S,11R,12S,13S determined by Cu Kα X-radiation with the Flack parameter being refined to 0.09 (14) and this configuration is in agreement with the previous circular dichroism assignment reported by Sun et al. (2014).

The crystal packing of the aflatrem molecules is illustrated in Figs. 2 and 3. In the crystal, molecules are connected along the b axis via O—H···O hydrogen bonds. In addition, weak N—H···π(indole) interactions connect these chains forming planes parallel to (10-1). This N—H···π(indole) interaction is typical of indole-based molecules as reported by Krishna et al. (1999).

For background to indole diterpenoids from endophytes, see: Strobel & Daisy (2003); Munday-Finch et al. (1996); Gallagher et al. (1980a,b); Lenta et al. (2007); Phongpaichit et al. (2007). For studies of Aspergillus sp, see: Nicholson et al. (2009); Duran et al. (2006). For the pharmacological basis of the behavioural effects of this molecule, see: Tinao-Wooldridge et al. (1995). For the isolation of fungal endophytes from the stem of Symphonia globulifera, see: Petrini et al. (1992); Amin et al. (2014). For geometric details of indole compounds, see: Krishna et al. (1999). For circular dichroism experiments on the title compound, see: Sun et al. (2014). For information on the Cambridge Structural Database (CSD), see: Groom & Allen (2014).

Computing details top

Data collection: CrysAlis PRO (Agilent, 2013); cell refinement: CrysAlis PRO (Agilent, 2013); data reduction: CrysAlis PRO (Agilent, 2013); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of aflatrem with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. Crystal packing of aflatrem showing O—H···O hydrogen-bonded (dashed lines) zigzag chains along the b axis in the (010) plane . Weak N—H···π interactions are also shown as dashed lines. Symmetry codes: (i) - x+ 2, y - 1/2, -z + 2; (ii) -x + 1, y - 1/2, -z + 1; (iii) -x + 1, y + 1/2, -z + 1; (iv) -x + 2, y + 1/2, -z + 2.
[Figure 3] Fig. 3. Crystal packing of aflatrem showing O—H···O hydrogen-bonded (dashed lines) zigzag chains along the b axis in the (001) plane. Weak N—H···π interactions are also shown as dashed lines. Symmetry codes: (i) -x + 2, y - 1/2, -z +2; (ii) -x + 1, y - 1/2, -z + 1; (iii) -x + 1, y + 1/2, -z + 1 and (iv) -x + 2, y + 1/2, -z + 2.
(3R,5bS,7aS,13bS,13cR,15aS)-9-(1,1-Dimethyl-2-propenyl)-2,3,5b,6,7,7a,8,13,13b,13c,14,15-dodecahydro-5b-hydroxy-2,2,13b,13c-tetramethyl-4H-3,15a-epoxy-1-benzoxepino[6',7':6,7]indeno[1,2-b]indol-4-one top
Crystal data top
C32H39NO4F(000) = 540
Mr = 501.64Dx = 1.289 Mg m3
Monoclinic, P21Cu Kα radiation, λ = 1.5418 Å
a = 12.8022 (5) ÅCell parameters from 6775 reflections
b = 6.4019 (2) Åθ = 4.8–66.4°
c = 15.9557 (6) ŵ = 0.66 mm1
β = 98.821 (4)°T = 100 K
V = 1292.24 (9) Å3Plate, colourless
Z = 20.18 × 0.14 × 0.02 mm
Data collection top
Agilent SuperNova Dual Source
diffractometer with an Atlas detector
4585 independent reflections
Radiation source: SuperNova (Cu) X-ray Source4078 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.050
Detector resolution: 5.3114 pixels mm-1θmax = 66.9°, θmin = 2.8°
ω scansh = 1515
Absorption correction: gaussian
(CrysAlis PRO; Agilent, 2013)
k = 77
Tmin = 0.899, Tmax = 1.000l = 1818
19981 measured reflections
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.056 w = 1/[σ2(Fo2) + (0.0948P)2 + 0.4383P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.150(Δ/σ)max < 0.001
S = 1.06Δρmax = 0.35 e Å3
4585 reflectionsΔρmin = 0.23 e Å3
341 parametersAbsolute structure: Flack x determined using 1671 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons & Flack, 2004)
1 restraintAbsolute structure parameter: 0.09 (14)
Primary atom site location: structure-invariant direct methods
Crystal data top
C32H39NO4V = 1292.24 (9) Å3
Mr = 501.64Z = 2
Monoclinic, P21Cu Kα radiation
a = 12.8022 (5) ŵ = 0.66 mm1
b = 6.4019 (2) ÅT = 100 K
c = 15.9557 (6) Å0.18 × 0.14 × 0.02 mm
β = 98.821 (4)°
Data collection top
Agilent SuperNova Dual Source
diffractometer with an Atlas detector
4585 independent reflections
Absorption correction: gaussian
(CrysAlis PRO; Agilent, 2013)
4078 reflections with I > 2σ(I)
Tmin = 0.899, Tmax = 1.000Rint = 0.050
19981 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.056H-atom parameters constrained
wR(F2) = 0.150Δρmax = 0.35 e Å3
S = 1.06Δρmin = 0.23 e Å3
4585 reflectionsAbsolute structure: Flack x determined using 1671 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons & Flack, 2004)
341 parametersAbsolute structure parameter: 0.09 (14)
1 restraint
Special details top

Experimental. Numerical absorption correction based on gaussian integration over a multifaceted crystal model

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.77480 (17)0.1640 (3)1.04104 (13)0.0330 (5)
O20.64687 (16)0.3772 (3)0.97693 (13)0.0307 (5)
O30.88440 (18)0.5994 (4)1.15707 (14)0.0414 (6)
O40.91050 (17)0.2056 (3)0.85758 (13)0.0316 (5)
H40.96980.22030.84490.047*
N10.61755 (19)0.3716 (4)0.58123 (15)0.0267 (5)
H10.57820.28850.60500.032*
C10.7110 (2)0.4610 (4)0.61906 (19)0.0260 (6)
C20.7906 (2)0.4099 (4)0.69719 (18)0.0252 (6)
C30.7579 (2)0.4000 (5)0.78767 (18)0.0264 (6)
C40.6942 (2)0.1981 (4)0.80235 (19)0.0279 (6)
H4A0.61950.22880.78700.033*
H4B0.71170.09120.76370.033*
C50.7119 (2)0.1065 (5)0.89279 (19)0.0301 (6)
H5A0.64820.03380.90210.036*
H5B0.76840.00440.89680.036*
C60.7394 (2)0.2648 (5)0.96202 (19)0.0293 (7)
C70.7658 (3)0.3273 (5)1.10039 (19)0.0327 (7)
H70.77140.27291.15830.039*
C80.8486 (2)0.4967 (5)1.0940 (2)0.0338 (7)
C90.8771 (2)0.5268 (5)1.0107 (2)0.0328 (7)
H90.92970.62181.00280.039*
C100.8270 (2)0.4165 (5)0.94420 (19)0.0287 (6)
C110.8592 (2)0.4071 (5)0.85721 (18)0.0270 (6)
C120.9380 (2)0.5804 (5)0.8432 (2)0.0316 (7)
H12A0.90800.71440.85510.038*
H12B1.00220.56140.88340.038*
C130.9661 (2)0.5851 (5)0.75408 (19)0.0326 (7)
H13A1.01170.70320.74770.039*
H13B1.00290.45800.74300.039*
C140.8634 (2)0.6041 (5)0.69266 (19)0.0277 (6)
H140.82560.72160.71350.033*
C150.8636 (2)0.6488 (5)0.59791 (19)0.0313 (7)
H15A0.87590.79550.58760.038*
H15B0.91570.56490.57510.038*
C160.7522 (2)0.5841 (4)0.56234 (19)0.0276 (6)
C170.6812 (2)0.5766 (4)0.48313 (18)0.0262 (6)
C180.6770 (2)0.6725 (4)0.40181 (18)0.0267 (6)
C190.5951 (2)0.6126 (5)0.33970 (19)0.0310 (7)
H190.59180.66870.28560.037*
C200.5165 (2)0.4704 (5)0.35503 (19)0.0308 (7)
H200.46440.43180.31050.037*
C210.5147 (2)0.3863 (5)0.43453 (19)0.0279 (6)
H210.46050.29860.44550.033*
C220.5987 (2)0.4402 (4)0.49762 (18)0.0262 (6)
C230.8453 (3)0.2072 (5)0.6718 (2)0.0308 (7)
H23A0.79370.09830.65980.046*
H23B0.89870.16480.71760.046*
H23C0.87740.23380.62230.046*
C240.6862 (2)0.5888 (4)0.80049 (19)0.0281 (6)
H24A0.72700.71500.80350.042*
H24B0.65760.57120.85230.042*
H24C0.62940.59710.75370.042*
C250.6530 (2)0.4108 (6)1.06813 (19)0.0336 (7)
C260.6353 (3)0.6379 (5)1.0847 (2)0.0384 (8)
H26A0.68170.72111.05650.058*
H26B0.64970.66391.14470.058*
H26C0.56330.67381.06370.058*
C270.5722 (3)0.2731 (6)1.1015 (2)0.0376 (8)
H27A0.50280.30751.07310.056*
H27B0.57570.29541.16140.056*
H27C0.58720.12921.09120.056*
C280.7593 (2)0.8372 (4)0.38782 (18)0.0295 (7)
C290.7411 (3)0.9297 (5)0.2981 (2)0.0381 (8)
H29A0.74830.82170.25760.057*
H29B0.79241.03720.29400.057*
H29C0.67140.98810.28660.057*
C300.7512 (3)1.0194 (5)0.4492 (2)0.0351 (7)
H30A0.68701.09540.43130.053*
H30B0.81061.11090.44940.053*
H30C0.75080.96570.50540.053*
C310.8695 (3)0.7438 (5)0.4004 (2)0.0340 (7)
H310.92550.83280.41950.041*
C320.8925 (3)0.5482 (6)0.3866 (2)0.0426 (8)
H32A0.83880.45400.36750.051*
H32B0.96250.50390.39600.051*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0397 (12)0.0260 (10)0.0297 (11)0.0012 (9)0.0062 (9)0.0028 (9)
O20.0311 (10)0.0307 (11)0.0269 (10)0.0007 (9)0.0065 (8)0.0031 (9)
O30.0390 (12)0.0489 (14)0.0317 (12)0.0085 (11)0.0090 (10)0.0092 (11)
O40.0329 (11)0.0272 (11)0.0327 (11)0.0059 (9)0.0019 (9)0.0019 (9)
N10.0308 (12)0.0218 (12)0.0254 (12)0.0015 (10)0.0027 (10)0.0024 (10)
C10.0273 (14)0.0188 (13)0.0298 (15)0.0013 (11)0.0018 (12)0.0022 (11)
C20.0296 (14)0.0163 (12)0.0270 (14)0.0012 (12)0.0037 (11)0.0015 (11)
C30.0304 (14)0.0177 (13)0.0276 (15)0.0005 (12)0.0062 (12)0.0004 (11)
C40.0310 (15)0.0198 (14)0.0303 (14)0.0030 (12)0.0031 (12)0.0014 (11)
C50.0368 (16)0.0186 (13)0.0330 (16)0.0041 (12)0.0006 (13)0.0036 (12)
C60.0351 (16)0.0229 (15)0.0268 (15)0.0005 (12)0.0055 (12)0.0014 (11)
C70.0348 (16)0.0349 (16)0.0250 (15)0.0017 (13)0.0065 (12)0.0008 (13)
C80.0299 (15)0.0364 (17)0.0325 (16)0.0013 (13)0.0034 (13)0.0014 (13)
C90.0330 (15)0.0330 (16)0.0296 (15)0.0062 (13)0.0044 (12)0.0008 (13)
C100.0307 (14)0.0212 (14)0.0314 (15)0.0026 (12)0.0038 (12)0.0015 (12)
C110.0281 (14)0.0216 (13)0.0286 (15)0.0006 (12)0.0044 (12)0.0014 (12)
C120.0316 (15)0.0278 (15)0.0325 (16)0.0030 (13)0.0047 (12)0.0014 (13)
C130.0306 (15)0.0311 (15)0.0330 (16)0.0027 (13)0.0055 (13)0.0035 (13)
C140.0285 (14)0.0231 (14)0.0290 (15)0.0015 (12)0.0037 (12)0.0008 (12)
C150.0386 (17)0.0234 (14)0.0283 (15)0.0022 (12)0.0056 (13)0.0026 (12)
C160.0322 (14)0.0193 (13)0.0292 (15)0.0002 (12)0.0021 (12)0.0022 (12)
C170.0307 (14)0.0206 (13)0.0260 (14)0.0018 (12)0.0001 (12)0.0008 (11)
C180.0329 (15)0.0207 (13)0.0247 (14)0.0001 (12)0.0007 (11)0.0007 (11)
C190.0353 (15)0.0265 (15)0.0287 (15)0.0036 (13)0.0034 (13)0.0026 (12)
C200.0329 (15)0.0247 (14)0.0300 (15)0.0019 (12)0.0099 (13)0.0009 (12)
C210.0293 (14)0.0200 (13)0.0318 (15)0.0002 (12)0.0032 (12)0.0019 (12)
C220.0327 (15)0.0190 (14)0.0254 (14)0.0028 (11)0.0006 (12)0.0004 (11)
C230.0365 (16)0.0212 (15)0.0326 (15)0.0024 (12)0.0016 (13)0.0028 (12)
C240.0362 (16)0.0183 (13)0.0280 (14)0.0027 (12)0.0013 (12)0.0020 (11)
C250.0339 (16)0.0382 (17)0.0255 (15)0.0009 (14)0.0059 (12)0.0034 (13)
C260.0408 (17)0.0387 (18)0.0317 (16)0.0011 (14)0.0074 (13)0.0077 (14)
C270.0336 (17)0.0419 (19)0.0354 (17)0.0041 (14)0.0010 (14)0.0025 (14)
C280.0384 (16)0.0222 (15)0.0262 (15)0.0027 (12)0.0007 (12)0.0031 (12)
C290.0478 (19)0.0319 (17)0.0310 (16)0.0070 (14)0.0054 (14)0.0056 (13)
C300.0453 (18)0.0211 (15)0.0359 (17)0.0015 (13)0.0034 (14)0.0009 (13)
C310.0332 (16)0.0319 (16)0.0349 (16)0.0061 (13)0.0013 (13)0.0006 (13)
C320.0397 (18)0.0356 (18)0.052 (2)0.0042 (15)0.0068 (16)0.0025 (15)
Geometric parameters (Å, º) top
O1—C71.427 (4)C15—C161.509 (4)
O1—C61.427 (4)C15—H15A0.9700
O2—C61.437 (4)C15—H15B0.9700
O2—C251.461 (4)C16—C171.440 (4)
O3—C81.231 (4)C17—C221.417 (4)
O4—C111.447 (4)C17—C181.429 (4)
O4—H40.8200C18—C191.382 (4)
N1—C11.379 (4)C18—C281.532 (4)
N1—C221.390 (4)C19—C201.406 (5)
N1—H10.8600C19—H190.9300
C1—C161.366 (4)C20—C211.381 (4)
C1—C21.520 (4)C20—H200.9300
C2—C231.557 (4)C21—C221.399 (4)
C2—C141.562 (4)C21—H210.9300
C2—C31.565 (4)C23—H23A0.9600
C3—C241.550 (4)C23—H23B0.9600
C3—C41.565 (4)C23—H23C0.9600
C3—C111.573 (4)C24—H24A0.9600
C4—C51.542 (4)C24—H24B0.9600
C4—H4A0.9700C24—H24C0.9600
C4—H4B0.9700C25—C261.501 (5)
C5—C61.500 (4)C25—C271.517 (5)
C5—H5A0.9700C26—H26A0.9600
C5—H5B0.9700C26—H26B0.9600
C6—C101.543 (4)C26—H26C0.9600
C7—C81.531 (5)C27—H27A0.9600
C7—C251.552 (4)C27—H27B0.9600
C7—H70.9800C27—H27C0.9600
C8—C91.443 (5)C28—C311.516 (4)
C9—C101.351 (4)C28—C291.533 (4)
C9—H90.9300C28—C301.537 (4)
C10—C111.508 (4)C29—H29A0.9600
C11—C121.538 (4)C29—H29B0.9600
C12—C131.521 (4)C29—H29C0.9600
C12—H12A0.9700C30—H30A0.9600
C12—H12B0.9700C30—H30B0.9600
C13—C141.520 (4)C30—H30C0.9600
C13—H13A0.9700C31—C321.313 (5)
C13—H13B0.9700C31—H310.9300
C14—C151.539 (4)C32—H32A0.9300
C14—H140.9800C32—H32B0.9300
C7—O1—C6102.0 (2)C14—C15—H15A111.8
C6—O2—C25108.6 (2)C16—C15—H15B111.8
C11—O4—H4109.5C14—C15—H15B111.8
C1—N1—C22107.5 (2)H15A—C15—H15B109.5
C1—N1—H1126.3C1—C16—C17107.9 (3)
C22—N1—H1126.3C1—C16—C15110.4 (3)
C16—C1—N1110.3 (2)C17—C16—C15140.5 (3)
C16—C1—C2112.9 (2)C22—C17—C18119.1 (3)
N1—C1—C2134.2 (3)C22—C17—C16105.3 (2)
C1—C2—C23103.7 (2)C18—C17—C16135.6 (3)
C1—C2—C1496.9 (2)C19—C18—C17116.8 (3)
C23—C2—C14110.8 (2)C19—C18—C28123.4 (3)
C1—C2—C3121.6 (2)C17—C18—C28119.8 (2)
C23—C2—C3113.7 (2)C18—C19—C20122.6 (3)
C14—C2—C3108.7 (2)C18—C19—H19118.7
C24—C3—C2109.7 (2)C20—C19—H19118.7
C24—C3—C4106.9 (2)C21—C20—C19121.7 (3)
C2—C3—C4113.0 (2)C21—C20—H20119.2
C24—C3—C11109.0 (2)C19—C20—H20119.2
C2—C3—C11109.9 (2)C20—C21—C22116.5 (3)
C4—C3—C11108.1 (2)C20—C21—H21121.8
C5—C4—C3116.7 (2)C22—C21—H21121.8
C5—C4—H4A108.1N1—C22—C21127.9 (3)
C3—C4—H4A108.1N1—C22—C17109.1 (2)
C5—C4—H4B108.1C21—C22—C17123.0 (3)
C3—C4—H4B108.1C2—C23—H23A109.5
H4A—C4—H4B107.3C2—C23—H23B109.5
C6—C5—C4114.6 (2)H23A—C23—H23B109.5
C6—C5—H5A108.6C2—C23—H23C109.5
C4—C5—H5A108.6H23A—C23—H23C109.5
C6—C5—H5B108.6H23B—C23—H23C109.5
C4—C5—H5B108.6C3—C24—H24A109.5
H5A—C5—H5B107.6C3—C24—H24B109.5
O1—C6—O2103.8 (2)H24A—C24—H24B109.5
O1—C6—C5110.6 (2)C3—C24—H24C109.5
O2—C6—C5110.7 (2)H24A—C24—H24C109.5
O1—C6—C10107.8 (2)H24B—C24—H24C109.5
O2—C6—C10110.9 (2)O2—C25—C26109.4 (3)
C5—C6—C10112.6 (3)O2—C25—C27109.2 (3)
O1—C7—C8110.3 (3)C26—C25—C27111.8 (3)
O1—C7—C25101.4 (2)O2—C25—C7100.7 (2)
C8—C7—C25110.6 (3)C26—C25—C7115.7 (3)
O1—C7—H7111.4C27—C25—C7109.5 (3)
C8—C7—H7111.4C25—C26—H26A109.5
C25—C7—H7111.4C25—C26—H26B109.5
O3—C8—C9124.6 (3)H26A—C26—H26B109.5
O3—C8—C7119.9 (3)C25—C26—H26C109.5
C9—C8—C7115.5 (3)H26A—C26—H26C109.5
C10—C9—C8119.8 (3)H26B—C26—H26C109.5
C10—C9—H9120.1C25—C27—H27A109.5
C8—C9—H9120.1C25—C27—H27B109.5
C9—C10—C11125.4 (3)H27A—C27—H27B109.5
C9—C10—C6117.1 (3)C25—C27—H27C109.5
C11—C10—C6116.9 (3)H27A—C27—H27C109.5
O4—C11—C10102.7 (2)H27B—C27—H27C109.5
O4—C11—C12109.6 (2)C31—C28—C18110.9 (2)
C10—C11—C12112.5 (2)C31—C28—C29106.3 (3)
O4—C11—C3107.6 (2)C18—C28—C29113.1 (3)
C10—C11—C3109.8 (2)C31—C28—C30111.6 (3)
C12—C11—C3114.0 (2)C18—C28—C30108.3 (2)
C13—C12—C11113.9 (2)C29—C28—C30106.7 (3)
C13—C12—H12A108.8C28—C29—H29A109.5
C11—C12—H12A108.8C28—C29—H29B109.5
C13—C12—H12B108.8H29A—C29—H29B109.5
C11—C12—H12B108.8C28—C29—H29C109.5
H12A—C12—H12B107.7H29A—C29—H29C109.5
C14—C13—C12107.4 (2)H29B—C29—H29C109.5
C14—C13—H13A110.2C28—C30—H30A109.5
C12—C13—H13A110.2C28—C30—H30B109.5
C14—C13—H13B110.2H30A—C30—H30B109.5
C12—C13—H13B110.2C28—C30—H30C109.5
H13A—C13—H13B108.5H30A—C30—H30C109.5
C13—C14—C15121.1 (3)H30B—C30—H30C109.5
C13—C14—C2111.7 (2)C32—C31—C28125.6 (3)
C15—C14—C2106.5 (2)C32—C31—H31117.2
C13—C14—H14105.4C28—C31—H31117.2
C15—C14—H14105.4C31—C32—H32A120.0
C2—C14—H14105.4C31—C32—H32B120.0
C16—C15—C14100.1 (2)H32A—C32—H32B120.0
C16—C15—H15A111.8
C22—N1—C1—C160.0 (3)C4—C3—C11—C12171.7 (2)
C22—N1—C1—C2159.8 (3)O4—C11—C12—C1370.5 (3)
C16—C1—C2—C2388.8 (3)C10—C11—C12—C13175.9 (2)
N1—C1—C2—C2370.7 (4)C3—C11—C12—C1350.1 (3)
C16—C1—C2—C1424.7 (3)C11—C12—C13—C1455.7 (3)
N1—C1—C2—C14175.9 (3)C12—C13—C14—C15170.0 (3)
C16—C1—C2—C3141.7 (3)C12—C13—C14—C263.3 (3)
N1—C1—C2—C358.8 (4)C1—C2—C14—C13169.4 (2)
C1—C2—C3—C2444.3 (3)C23—C2—C14—C1361.8 (3)
C23—C2—C3—C24169.4 (2)C3—C2—C14—C1363.8 (3)
C14—C2—C3—C2466.6 (3)C1—C2—C14—C1535.2 (3)
C1—C2—C3—C474.9 (3)C23—C2—C14—C1572.4 (3)
C23—C2—C3—C450.1 (3)C3—C2—C14—C15162.0 (2)
C14—C2—C3—C4174.1 (2)C13—C14—C15—C16162.6 (3)
C1—C2—C3—C11164.2 (2)C2—C14—C15—C1633.6 (3)
C23—C2—C3—C1170.7 (3)N1—C1—C16—C170.6 (3)
C14—C2—C3—C1153.2 (3)C2—C1—C16—C17165.0 (2)
C24—C3—C4—C593.2 (3)N1—C1—C16—C15169.2 (2)
C2—C3—C4—C5145.9 (3)C2—C1—C16—C154.8 (3)
C11—C3—C4—C524.0 (3)C14—C15—C16—C118.0 (3)
C3—C4—C5—C630.1 (4)C14—C15—C16—C17177.3 (4)
C7—O1—C6—O244.4 (3)C1—C16—C17—C220.9 (3)
C7—O1—C6—C5163.2 (3)C15—C16—C17—C22164.0 (4)
C7—O1—C6—C1073.3 (3)C1—C16—C17—C18177.8 (3)
C25—O2—C6—O122.5 (3)C15—C16—C17—C1817.3 (6)
C25—O2—C6—C5141.2 (2)C22—C17—C18—C194.7 (4)
C25—O2—C6—C1093.0 (3)C16—C17—C18—C19176.7 (3)
C4—C5—C6—O1168.4 (2)C22—C17—C18—C28173.7 (3)
C4—C5—C6—O277.1 (3)C16—C17—C18—C284.8 (5)
C4—C5—C6—C1047.7 (3)C17—C18—C19—C202.3 (4)
C6—O1—C7—C869.4 (3)C28—C18—C19—C20176.1 (3)
C6—O1—C7—C2547.9 (3)C18—C19—C20—C212.1 (5)
O1—C7—C8—O3149.9 (3)C19—C20—C21—C223.8 (4)
C25—C7—C8—O398.7 (3)C1—N1—C22—C21178.2 (3)
O1—C7—C8—C931.6 (4)C1—N1—C22—C170.6 (3)
C25—C7—C8—C979.8 (3)C20—C21—C22—N1177.4 (3)
O3—C8—C9—C10174.8 (3)C20—C21—C22—C171.2 (4)
C7—C8—C9—C103.5 (4)C18—C17—C22—N1178.0 (3)
C8—C9—C10—C11170.2 (3)C16—C17—C22—N10.9 (3)
C8—C9—C10—C61.0 (4)C18—C17—C22—C213.1 (4)
O1—C6—C10—C940.5 (4)C16—C17—C22—C21178.0 (3)
O2—C6—C10—C972.5 (3)C6—O2—C25—C26128.7 (3)
C5—C6—C10—C9162.8 (3)C6—O2—C25—C27108.7 (3)
O1—C6—C10—C11131.5 (3)C6—O2—C25—C76.5 (3)
O2—C6—C10—C11115.5 (3)O1—C7—C25—O233.0 (3)
C5—C6—C10—C119.2 (4)C8—C7—C25—O284.1 (3)
C9—C10—C11—O4102.7 (3)O1—C7—C25—C26150.7 (3)
C6—C10—C11—O468.5 (3)C8—C7—C25—C2633.7 (4)
C9—C10—C11—C1215.1 (4)O1—C7—C25—C2781.9 (3)
C6—C10—C11—C12173.7 (2)C8—C7—C25—C27161.0 (3)
C9—C10—C11—C3143.1 (3)C19—C18—C28—C31118.9 (3)
C6—C10—C11—C345.7 (3)C17—C18—C28—C3162.7 (3)
C24—C3—C11—O4165.8 (2)C19—C18—C28—C290.4 (4)
C2—C3—C11—O473.9 (3)C17—C18—C28—C29178.0 (3)
C4—C3—C11—O449.9 (3)C19—C18—C28—C30118.4 (3)
C24—C3—C11—C1054.8 (3)C17—C18—C28—C3060.0 (3)
C2—C3—C11—C10175.1 (2)C18—C28—C31—C3229.3 (4)
C4—C3—C11—C1061.1 (3)C29—C28—C31—C3294.0 (4)
C24—C3—C11—C1272.4 (3)C30—C28—C31—C32150.1 (3)
C2—C3—C11—C1247.9 (3)
Hydrogen-bond geometry (Å, º) top
Cg is the centroid of the C17–C22 ring.
D—H···AD—HH···AD···AD—H···A
O4—H4···O3i0.822.032.757 (3)148
N1—H1···Cgii0.862.783.527 (1)146
Symmetry codes: (i) x+2, y1/2, z+2; (ii) x+1, y1/2, z+1.
Hydrogen-bond geometry (Å, º) top
Cg is the centroid of the C17–C22 ring.
D—H···AD—HH···AD···AD—H···A
O4—H4···O3i0.822.032.757 (3)148.2
N1—H1···Cgii0.862.7813.527 (1)145.96
Symmetry codes: (i) x+2, y1/2, z+2; (ii) x+1, y1/2, z+1.
 

Acknowledgements

The authors wish to acknowledge the Alexander von Humboldt Foundation for providing a fellowship to B. N. Lenta at Bielefeld University

References

First citationAgilent (2013). CrysAlis PRO Agilent Technologies Ltd, Yarnton, Oxfordshire, England.  Google Scholar
First citationAmin, N., Salam, M., Junaid, M., Asman & Baco, M. S. I. (2014). Int J Curr Microbiol Appl Sci. 3, 459–467.  Google Scholar
First citationBrandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationDolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationDuran, R. M., Cary, J. W. & Calvo, A. M. (2006). Appl. Microbiol. Biotechnol. 73, 1158–1168.  Web of Science CrossRef PubMed Google Scholar
First citationGallagher, R. T., Clardy, J. & Wilson, B. J. (1980b). Tetrahedron Lett. 21, 239–242.  CrossRef CAS Web of Science Google Scholar
First citationGallagher, R. T., Finer, J., Clardy, J., Leutwiler, A., Weibel, F., Acklin, W. & Arigoni, D. (1980a). Tetrahedron Lett. 21, 235–238.  CSD CrossRef CAS Web of Science Google Scholar
First citationGroom, C. R. & Allen, F. H. (2014). Angew. Chem. Int. Ed. 53, 662–671.  Web of Science CSD CrossRef CAS Google Scholar
First citationKrishna, R., Velmurugan, D., Babu, G. & Perumal, P. T. (1999). Acta Cryst. C55, 75–78.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationNdjakou Lenta, B., Noungoue, D. T., Devkota, K. P., Fokou, P. A., Ngouela, S., Tsamo, E. & Sewald, N. (2007). Acta Cryst. E63, o1282–o1284.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationMunday-Finch, S. C., Wilkins, A. L. & Miles, C. O. (1996). Phytochemistry, 41, 327–332.  CAS Google Scholar
First citationNicholson, M. J., Koulman, A., Monahan, B. J., Pritchard, B. L., Payne, G. A. & Scott, B. (2009). Appl. Environ. Microbiol. 75, 7469–7481.  Web of Science CrossRef PubMed CAS Google Scholar
First citationParsons, S. & Flack, H. (2004). Acta Cryst. A60, s61.  CrossRef IUCr Journals Google Scholar
First citationPetrini, O., Sueber, I., Titi, L. & Viret, O. (1992). Nat. Toxins, 1, 185–196.  CrossRef PubMed CAS Google Scholar
First citationPhongpaichit, S., Nikom, J., Rungjindamai, N., Sakayaroj, J., Hutadilok-Towatana, N., Rukachaisirikul, V. & Kirtikara, K. (2007). FEMS Immunol. Med. Microbiol. 51, 517–525.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationStrobel, G. & Daisy, B. (2003). Microbiol. Mol. Biol. Rev. 67, 491–502.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSun, K., Li, Y., Guo, L., Wang, Y., Liu, P. & Zhu, W. (2014). Mar. Drugs, 12, 3970–3981.  Web of Science CrossRef CAS PubMed Google Scholar
First citationTinao-Wooldridge, L. V., Hsiang, B. C. H., Latifi, T. N., Ferrendelli, J. A. & Covey, D. F. (1995). Bioorg. Med. Chem. Lett. 5, 265–270.  CAS Google Scholar

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