1-(β-D-Erythrofuranos­yl)adenosine

The title compound, also known as β-erythroadenosine, C₉H₁₁N₅O₃, (I), a derivative of β-adenosine, (II), that lacks the C5′ exocyclic hydroxy­methyl (–CH₂OH) substituent, crystallizes from hot ethanol with two independent molecules having different conformations, denoted (IA) and (IB). In (IA), the furan­ose conformation is ^OT₁–E₁ (C1′-exo, east), with pseudorotational parameters P and τ_m of 114.4 and 42°, respectively. In contrast, the P and τ_m values are 170.1 and 46°, respectively, in (IB), consistent with a ²E–²T₃ (C2′-endo, south) conformation. The N-glycoside conformation is syn (+sc) in (IA) and anti (−ac) in (IB). The crystal structure, determined to a resolution of 2.0 Å, of a cocrystal of (I) bound to the enzyme 5′-fluoro­deoxy­adenosine synthase from Streptomyces cattleya shows the furan­ose ring in a near-ideal ^OE (east) conformation (P = 90° and τ_m = 42°) and the base in an anti (−ac) conformation.

S1. Comment

In a recent report, the crystal structure of the ribonucleoside derivative 1-(β-D-erythrofuranosyl)cytidine (β-erythrocytidine), (III), was determined and its structural parameters compared with those of β-cytidine, β-erythrouridine and β-uridine (Kline et al., 2007). This prior work is extended in the present investigation to the title compound, (I), which lacks the exocyclic C5' hydroxymethyl group found in β-adenosine, (II).

Solution NMR studies of (I) and (II) have revealed significant differences in the furanose conformation. The ³J_H1,H2, ³J_H2,H3 and ³J_H3,H4S spin-couplings in (I) are 6.7, 4.6 and 1.7 Hz, respectively, whereas the corresponding values in (II) are 6.2, 5.3 and 3.3 Hz, respectively (Kline & Serianni, 1992). Pseudorotational analysis of these NMR couplings shows that (I) greatly prefers a south conformation (~95%) (for definitions, see Fig. 1), with P = 180.1° and τ_m = 40°. For (II), a greater proportion of the north form was found (~23%; P = 19.1° and τ_m = 38°), and the predominant south form (~77%) had P = 153.3° and τ_m = 38°.

The crystal structure of (I) (Fig. 2) contains two different molecular conformations in the unit cell, denoted (IA) and (IB). In (IA), the furanose conformation is ^OT₁-E₁ (C1'-exo, east), with pseudorotational parameters P = 114.4° and τ_m = 42° (Table 1). This conformation is best described as an east form in the pseudorotational itinerary (Fig. 1). For (IB), P = 170.1° and τ_m = 46°, consistent with an ²E-²T₃ (C2'-endo, south) conformation (Fig. 1). The latter geometry, which is observed in the common biologically relevant nucleosides/tides, is structurally similar to that observed in the crystal structure of β-erythrocytidine, (III) (P = 197.8° and τ_m = 44°) (Fig. 1). In comparison, β-adenosine, (II), crystallizes in a ³T₂-³E (C3'-endo, north; P = 7.1° and τ_m = 37°) conformation (Fig. 1). The degree of ring puckering in erythronucleosides (I) and (III), embodied in the τ_m parameter (44±2°), is significantly greater than that observed in (II) (37°), suggesting that removal of the bulky CH₂OH substituent allows greater furanose ring deformation from planarity. This trend also emerged from prior NMR J-coupling analysis (Kline & Serianni, 1992), although the difference is smaller.

The furanose ring conformation influences the conformation about the N-glycoside linkage. The adenine base assumes an anti (-ac) conformation [O4'—C1'—N9—C4 = -114.5 (3)°] in (IB), having the furanose ring in a south (²E) conformation (Table 1). Shifting the furanose conformation towards the east forms, as observed in (IA), causes a radical change in the N-glycoside conformation to the syn (+sc) conformation [O4'—C1'—N9—C4 = 68.4 (3)°]; the quasi-equatorial C1'—N9 bond in the E₁ furanose structure readily accommodates this conformation. It should be noted that a similar N-glycoside conformation is observed in (III) (syn, +sc), where the furanose conformation is E₃, suggesting that syn conformations can be accommodated in a wider range of furanose conformations in erythronucleosides than in ribo- and 2'-deoxyribonucleosides, in which base interactions with the bulky –CH₂OH substituent at C4' limit access to the more sterically demanding syn state. In (II), a north (³E) furanose conformation correlates with an anti (ap) N-glycoside conformation [O4'—C1'—N9—C4 = -171.4°), as expected (Table 1). While the preferred N-glycoside conformation in (I) in solution is currently unknown, these results, and those previously reported (Kline et al., 2007), suggest that an equilibrium mixture of both syn and anti geometries might be expected.

Prior studies (Westhof & Sundaralingam, 1983) have demonstrated the interdependencies between P, τ_m and endocyclic torsion angles in furanose rings. We tested these correlations using data from (IA), (IB) and (III), given that their constituent furanose ring conformations have P values in the range 114–198° with very similar τ_m values. The experimentally observed trends in the C4'—O4'—C1', O4'—C1'—C2', C2'—C3'—C4' and C3'—C4'—O4' bond angles are well predicted using the Westhof–Sundaralingam correlations. For example, the C2'—C3'—C4' and C3'—C4'—O4' bond angles are smallest in (III) and largest in (IA) (Table 1), consistent with the predicted trend. Likewise, the small value of the C4'—O4'—C1' bond angle in (IA) relative to those found in (IB) and (III) (Table 1) fulfills predictions based on the observed differences in ring conformation.

A similar treatment of bond lengths in (I)–(III) is complicated by differences in both furanose and N-glycoside conformations. Moderate differences of 0.018–0.024 Å are observed for bonds C1'—C2', C1'—O4' and C4'—O4', and larger differences of ~0.032 Å are found for bonds C2'—C3' and C3'—C4' (Table 1). The last two bonds are significantly extended in (IA), presumably due to its unique furanose conformation and/or to the syn geometry of its N-glycosidic linkage.

The crystal structure, determined to a resolution of 2.0 Å, of a co-crystal of (I) with the enzyme 5'-fluorodeoxyadenosine synthase, (IV), from Streptomyces cattleya (Cobb et al., 2006), shows that the enzyme binds to (I) in a furanose conformation (^OE, east; P = 90° and τ_m = 42°) similar to that observed in (IA), but in an N-glycoside conformation (anti, -ac) similar to that observed in (IB) (Table 1).

The furanose rings of (IA) and (IB) display different intermolecular hydrogen-bonding motifs (see Table 2). In (IA), atom O2'A serves as a donor to atom N3A of an adjacent (IA) unit. Atom O3'A of (IA) serves as a donor to atom N7B of (IB), while atom O3'A serves as an acceptor to amine atom N6B of (IB); in both cases, the (IB) molecule is that found in the same unit cell. Atom O4'A is not involved in hydrogen bonding, and atom O2'A does not serve as an acceptor in (IA). In (IB), atom O2'B serves as a donor to atom N3B of an adjacent (IB) unit, and atom O2'B serves as an acceptor to amine atom N6A of an adjacent (IA) unit. Atom O3'B serves as a donor to atom N1A of the same adjacent (IA) unit. Atom O4'B is not involved in hydrogen bonding, and atom O3'B does not serve as an acceptor in (IB). No intramolecular hydrogen bonds are found in (IA) or (IB).

Intermolecular base–base (non-Watson–Crick) hydrogen bonding is also present in (I). The amine atom N6A (donor) and atom N7A (acceptor) of (IA) are hydrogen-bonded to atom N1B (acceptor) and amine atom N6B (donor), respectively, of an adjacent (IB) molecule (Fig. 3, Table 2). No base–base hydrogen bonding is observed in the crystal structures of (II) and (III).

The crystal packing of (I) consists of units of the base–base hydrogen-bonded pairs of (IA) and (IB) described above. These base–base hydrogen-bonded pairs extend the structure through contacts from the hydroxyl group to nearby adenosine N atoms of other nearby base–base pairs. The adenosine amine N atoms (N6A and N6B) not only form the base–base pair unit, but also form hydrogen bonds to nearby hydroxyl groups (Fig. 4). The overall packing is a three-dimensional hydrogen-bonded network of pairs of (IA) and (IB) molecules. The layers of adenosine moieties adopt a herringbone arrangement within the lattice.

S2. Experimental

Compound (I) was prepared as described previously (Kline & Serianni, 1992) and crystallized from hot ethanol.

S3. Refinement

There are two crystallographically independent molecules in the asymmetric unit, differing in their rotation about the furanose–adenine bond. H atoms were located in difference Fourier maps and subsequently refined as riding, with C—H = 0.95–1.00 Å, N—H = 0.88 Å and O—H = 0.84 Å [Please check added text] and with U_iso(H) = 1.2U_eq(C,N,O).

Although the absolute structure parameter [1.2 (11); Flack, 1983] is indicative of the inverted absolute configuration, this is an unreliable measure at the wavelength of radiation used (0.7749 Å), especially for a light-atom structure (a detailed discussion of this problem can be found in Hooft et al., 2008). The correct configuration was therefore determined by the known chirality of the molecule in question. The correct configuration is depicted.

Computing details

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007; data reduction: SAINT (Bruker, 2007; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008) and POV-RAY (Cason, 2003); software used to prepare material for publication: enCIFer (Allen et al., 2004) and publCIF (Westrip, 2010).

Figures

	Fig. 1. Pseudorotational itinerary of furanose rings in nucleosides, showing P values for compounds (I)–(IV).
	Fig. 2. The structures of (IA) (atom labels with suffix A) and (IB) (atom labels with suffix B), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii.
	Fig. 3. Non-Watson–Crick hydrogen bonding (dotted lines) observed between the bases of (IA) and (IB). Er = β-D-erythrofuranosyl ring.
	Fig. 4. Hydrogen-bonding scheme (dashed lines) of (I), viewed down the a axis.

1-(β-D-Erythrofuranosyl)adenosine

Crystal data

C9H11N5O3	F(000) = 992
Mr = 237.23	Dx = 1.572 Mg m^−3
Orthorhombic, P212121	Synchrotron radiation, λ = 0.77490 Å
Hall symbol: P 2ac 2ab	Cell parameters from 3751 reflections
a = 4.793 (3) Å	θ = 2.4–30.5°
b = 11.365 (7) Å	µ = 0.12 mm^−1
c = 36.79 (2) Å	T = 150 K
V = 2004 (2) Å^3	Needle, colourless
Z = 8	0.12 × 0.04 × 0.02 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	2910 independent reflections
Radiation source: synchrotron, beamline 11.3.1, Advanced Light Source	2556 reflections with I > 2σ(I)
Channel-cut Si-<111> crystal monochromator	Rint = 0.112
Detector resolution: 8.33 pixels mm^-1	θmax = 31.1°, θmin = 1.2°
ϕ and ω scans	h = −6→6
Absorption correction: multi-scan [SADABS (Version 2007/4; Sheldrick, 2008)]	k = −15→15
Tmin = 0.986, Tmax = 0.998	l = −48→48
23772 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.047	H-atom parameters constrained
wR(F^2) = 0.126	w = 1/[σ^2(Fo^2) + (0.0556P)^2 + 0.337P] where P = (Fo^2 + 2Fc^2)/3
S = 1.07	(Δ/σ)max < 0.001
2910 reflections	Δρmax = 0.34 e Å^−3
307 parameters	Δρmin = −0.31 e Å^−3
0 restraints	Absolute structure: (Flack, 1983), with how many Friedel pairs?
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 1.2 (11)

Special details

Experimental. Data were collected at the Advanced Light Source at Lawrence Berkeley National Laboratory at beamline 11.3.1. The instrumentation is a standard 3-circle diffractometer mounted to account for the plane-polarized X-rays generated by the synchrotron source. Monochromatic radiation was tuned via the use of a channel-cut Si-<111> crystal monochromator and focused at the sample with a toroidal mirror (spot dimensions: 90 × 280 µm).

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
N1A	0.8851 (5)	0.9013 (2)	0.33779 (6)	0.0221 (5)
N3A	0.8258 (5)	0.8716 (2)	0.27279 (6)	0.0202 (5)
N6A	0.6257 (5)	0.8000 (2)	0.38155 (6)	0.0230 (5)
H6A	0.7167	0.8377	0.3987	0.028*
H6B	0.4963	0.7484	0.3873	0.028*
N7A	0.3369 (5)	0.6785 (2)	0.31756 (6)	0.0208 (5)
N9A	0.4502 (5)	0.7275 (2)	0.25991 (5)	0.0188 (5)
C2A	0.9437 (6)	0.9200 (2)	0.30235 (7)	0.0219 (5)
H2A	1.0884	0.9751	0.2977	0.026*
C4A	0.6230 (6)	0.7938 (2)	0.28240 (6)	0.0180 (5)
C5A	0.5474 (6)	0.7623 (2)	0.31757 (7)	0.0198 (5)
C6A	0.6838 (6)	0.8210 (2)	0.34680 (7)	0.0184 (5)
C8A	0.2871 (6)	0.6601 (2)	0.28281 (7)	0.0202 (5)
H8A	0.1518	0.6056	0.2743	0.024*
O2'A	0.1348 (5)	0.89551 (19)	0.20231 (5)	0.0268 (5)
H2'C	0.0649	0.8906	0.2232	0.032*
O3'A	0.3048 (5)	0.8172 (2)	0.13806 (5)	0.0275 (5)
H3'C	0.3621	0.8396	0.1176	0.033*
O4'A	0.6800 (5)	0.67721 (18)	0.20637 (5)	0.0234 (4)
C1'A	0.4303 (6)	0.7265 (2)	0.22045 (6)	0.0181 (5)
H1'A	0.2675	0.6773	0.2128	0.022*
C2'A	0.4083 (6)	0.8491 (2)	0.20282 (7)	0.0200 (5)
H2'A	0.5344	0.9049	0.2159	0.024*
C3'A	0.5261 (6)	0.8258 (3)	0.16392 (7)	0.0226 (6)
H3'A	0.6590	0.8895	0.1568	0.027*
C4'A	0.6814 (7)	0.7076 (3)	0.16793 (7)	0.0270 (6)
H4'A	0.5866	0.6457	0.1536	0.032*
H4'B	0.8755	0.7153	0.1590	0.032*
N1B	−0.1972 (5)	1.1535 (2)	0.08248 (6)	0.0203 (5)
N3B	−0.0859 (5)	1.1228 (2)	0.01876 (6)	0.0186 (5)
N6B	0.0035 (6)	1.0481 (2)	0.12980 (6)	0.0232 (5)
H6C	−0.1046	1.0864	0.1451	0.028*
H6D	0.1215	0.9950	0.1380	0.028*
N7B	0.3554 (5)	0.9253 (2)	0.06939 (6)	0.0203 (5)
N9B	0.2769 (5)	0.97274 (19)	0.01061 (5)	0.0170 (4)
C2B	−0.2219 (6)	1.1742 (2)	0.04678 (7)	0.0195 (5)
H2B	−0.3531	1.2331	0.0402	0.023*
C4B	0.0994 (6)	1.0428 (2)	0.03109 (6)	0.0166 (5)
C5B	0.1502 (6)	1.0126 (2)	0.06722 (6)	0.0180 (5)
C6B	−0.0115 (6)	1.0705 (2)	0.09414 (6)	0.0185 (5)
C8B	0.4222 (6)	0.9048 (2)	0.03529 (7)	0.0202 (5)
H8B	0.5581	0.8483	0.0283	0.024*
O2'B	0.6512 (4)	1.10071 (16)	−0.04909 (5)	0.0209 (4)
H2'D	0.7179	1.1226	−0.0291	0.025*
O3'B	0.3248 (5)	0.99703 (18)	−0.10416 (5)	0.0251 (4)
H3'D	0.4076	1.0240	−0.1225	0.030*
O4'B	0.2011 (5)	0.84730 (17)	−0.03896 (5)	0.0218 (4)
C1'B	0.2836 (5)	0.9642 (2)	−0.02894 (6)	0.0158 (5)
H1'B	0.1487	1.0220	−0.0395	0.019*
C2'B	0.5698 (6)	0.9815 (2)	−0.04667 (6)	0.0172 (5)
H2'B	0.7145	0.9352	−0.0333	0.021*
C3'B	0.5114 (6)	0.9247 (2)	−0.08394 (7)	0.0206 (5)
H3'B	0.6863	0.9064	−0.0976	0.025*
C4'B	0.3565 (7)	0.8137 (3)	−0.07176 (7)	0.0251 (6)
H4'C	0.2274	0.7865	−0.0910	0.030*
H4'D	0.4902	0.7497	−0.0663	0.030*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1A	0.0242 (12)	0.0246 (12)	0.0175 (10)	−0.0026 (10)	0.0007 (9)	−0.0020 (9)
N3A	0.0233 (11)	0.0213 (11)	0.0161 (9)	−0.0014 (10)	0.0004 (9)	0.0001 (8)
N6A	0.0284 (13)	0.0264 (12)	0.0141 (10)	−0.0045 (11)	0.0000 (9)	−0.0023 (8)
N7A	0.0241 (11)	0.0224 (11)	0.0161 (10)	−0.0020 (11)	0.0010 (9)	0.0014 (8)
N9A	0.0217 (11)	0.0220 (11)	0.0127 (10)	−0.0020 (10)	−0.0011 (9)	0.0008 (8)
C2A	0.0242 (13)	0.0214 (13)	0.0201 (12)	−0.0022 (12)	−0.0004 (11)	−0.0013 (10)
C4A	0.0206 (12)	0.0203 (13)	0.0132 (10)	0.0007 (11)	−0.0002 (10)	−0.0010 (9)
C5A	0.0214 (12)	0.0218 (13)	0.0161 (11)	0.0009 (12)	0.0004 (10)	0.0004 (9)
C6A	0.0203 (12)	0.0191 (12)	0.0160 (11)	0.0030 (12)	0.0007 (10)	−0.0016 (9)
C8A	0.0228 (12)	0.0202 (13)	0.0178 (11)	−0.0037 (12)	0.0003 (10)	0.0009 (9)
O2'A	0.0274 (11)	0.0335 (11)	0.0194 (9)	0.0076 (10)	0.0024 (8)	0.0024 (8)
O3'A	0.0278 (10)	0.0411 (12)	0.0138 (8)	0.0021 (11)	−0.0034 (8)	0.0047 (8)
O4'A	0.0286 (10)	0.0282 (10)	0.0132 (8)	0.0069 (10)	0.0020 (8)	0.0003 (7)
C1'A	0.0218 (12)	0.0195 (12)	0.0130 (11)	−0.0001 (11)	0.0013 (10)	−0.0006 (9)
C2'A	0.0208 (13)	0.0245 (13)	0.0147 (11)	0.0007 (11)	−0.0018 (10)	0.0014 (10)
C3'A	0.0218 (13)	0.0316 (15)	0.0144 (11)	−0.0022 (12)	0.0002 (10)	0.0022 (10)
C4'A	0.0298 (14)	0.0379 (17)	0.0132 (11)	0.0053 (14)	0.0004 (12)	−0.0010 (11)
N1B	0.0247 (11)	0.0186 (11)	0.0176 (10)	0.0018 (10)	0.0010 (9)	−0.0013 (8)
N3B	0.0213 (11)	0.0198 (11)	0.0146 (9)	0.0010 (10)	−0.0007 (9)	−0.0010 (8)
N6B	0.0302 (13)	0.0246 (12)	0.0147 (10)	0.0061 (11)	0.0021 (9)	0.0006 (9)
N7B	0.0218 (11)	0.0219 (11)	0.0174 (10)	0.0024 (10)	0.0012 (9)	0.0030 (8)
N9B	0.0181 (10)	0.0188 (11)	0.0140 (9)	0.0021 (9)	0.0014 (8)	0.0019 (8)
C2B	0.0207 (12)	0.0188 (12)	0.0190 (11)	0.0021 (11)	0.0016 (10)	−0.0016 (10)
C4B	0.0194 (12)	0.0172 (11)	0.0133 (10)	−0.0025 (10)	0.0013 (9)	−0.0002 (9)
C5B	0.0212 (12)	0.0187 (12)	0.0141 (10)	0.0010 (11)	0.0002 (10)	0.0006 (9)
C6B	0.0209 (13)	0.0186 (12)	0.0159 (11)	−0.0017 (11)	0.0014 (10)	−0.0013 (9)
C8B	0.0224 (12)	0.0220 (13)	0.0164 (11)	0.0028 (12)	0.0000 (10)	0.0034 (10)
O2'B	0.0262 (10)	0.0210 (9)	0.0156 (8)	−0.0043 (9)	−0.0015 (7)	0.0009 (7)
O3'B	0.0278 (10)	0.0344 (11)	0.0132 (8)	0.0000 (10)	−0.0018 (8)	0.0033 (8)
O4'B	0.0272 (10)	0.0200 (9)	0.0183 (8)	−0.0052 (9)	0.0048 (8)	−0.0022 (7)
C1'B	0.0168 (11)	0.0185 (12)	0.0121 (10)	0.0009 (10)	0.0000 (9)	0.0009 (9)
C2'B	0.0181 (11)	0.0194 (12)	0.0139 (10)	0.0013 (10)	0.0003 (9)	0.0016 (9)
C3'B	0.0226 (13)	0.0249 (14)	0.0143 (11)	0.0008 (12)	0.0028 (10)	−0.0006 (10)
C4'B	0.0366 (16)	0.0211 (13)	0.0176 (11)	−0.0024 (13)	0.0069 (12)	−0.0036 (10)

Geometric parameters (Å, º)

N1A—C2A	1.351 (3)	N1B—C2B	1.340 (3)
N1A—C6A	1.369 (4)	N1B—C6B	1.366 (4)
N3A—C2A	1.343 (3)	N3B—C4B	1.350 (3)
N3A—C4A	1.361 (4)	N3B—C2B	1.352 (3)
N6A—C6A	1.330 (3)	N6B—C6B	1.338 (3)
N6A—H6A	0.8800	N6B—H6C	0.8800
N6A—H6B	0.8800	N6B—H6D	0.8800
N7A—C8A	1.317 (3)	N7B—C8B	1.315 (3)
N7A—C5A	1.388 (4)	N7B—C5B	1.400 (4)
N9A—C8A	1.381 (3)	N9B—C8B	1.381 (3)
N9A—C4A	1.392 (3)	N9B—C4B	1.388 (3)
N9A—C1'A	1.455 (3)	N9B—C1'B	1.459 (3)
C2A—H2A	0.9500	C2B—H2B	0.9500
C4A—C5A	1.390 (3)	C4B—C5B	1.394 (3)
C5A—C6A	1.424 (4)	C5B—C6B	1.420 (4)
C8A—H8A	0.9500	C8B—H8B	0.9500
O2'A—C2'A	1.413 (3)	O2'B—C2'B	1.413 (3)
O2'A—H2'C	0.8400	O2'B—H2'D	0.8400
O3'A—C3'A	1.428 (3)	O3'B—C3'B	1.425 (3)
O3'A—H3'C	0.8400	O3'B—H3'D	0.8400
O4'A—C1'A	1.420 (3)	O4'B—C1'B	1.435 (3)
O4'A—C4'A	1.456 (3)	O4'B—C4'B	1.469 (3)
C1'A—C2'A	1.540 (4)	C1'B—C2'B	1.531 (4)
C1'A—H1'A	1.0000	C1'B—H1'B	1.0000
C2'A—C3'A	1.561 (4)	C2'B—C3'B	1.542 (3)
C2'A—H2'A	1.0000	C2'B—H2'B	1.0000
C3'A—C4'A	1.542 (4)	C3'B—C4'B	1.530 (4)
C3'A—H3'A	1.0000	C3'B—H3'B	1.0000
C4'A—H4'A	0.9900	C4'B—H4'C	0.9900
C4'A—H4'B	0.9900	C4'B—H4'D	0.9900
C2A—N1A—C6A	119.0 (2)	C2B—N1B—C6B	119.1 (2)
C2A—N3A—C4A	110.9 (2)	C4B—N3B—C2B	110.6 (2)
C6A—N6A—H6A	120.0	C6B—N6B—H6C	120.0
C6A—N6A—H6B	120.0	C6B—N6B—H6D	120.0
H6A—N6A—H6B	120.0	H6C—N6B—H6D	120.0
C8A—N7A—C5A	103.9 (2)	C8B—N7B—C5B	104.0 (2)
C8A—N9A—C4A	105.9 (2)	C8B—N9B—C4B	105.9 (2)
C8A—N9A—C1'A	124.6 (2)	C8B—N9B—C1'B	127.4 (2)
C4A—N9A—C1'A	129.5 (2)	C4B—N9B—C1'B	126.4 (2)
N3A—C2A—N1A	129.0 (3)	N1B—C2B—N3B	129.0 (3)
N3A—C2A—H2A	115.5	N1B—C2B—H2B	115.5
N1A—C2A—H2A	115.5	N3B—C2B—H2B	115.5
N3A—C4A—C5A	126.5 (2)	N3B—C4B—N9B	127.4 (2)
N3A—C4A—N9A	128.5 (2)	N3B—C4B—C5B	127.0 (2)
C5A—C4A—N9A	105.0 (2)	N9B—C4B—C5B	105.6 (2)
N7A—C5A—C4A	111.5 (2)	C4B—C5B—N7B	110.6 (2)
N7A—C5A—C6A	131.0 (2)	C4B—C5B—C6B	117.1 (2)
C4A—C5A—C6A	117.5 (3)	N7B—C5B—C6B	132.3 (2)
N6A—C6A—N1A	120.0 (2)	N6B—C6B—N1B	118.3 (2)
N6A—C6A—C5A	123.1 (3)	N6B—C6B—C5B	124.5 (3)
N1A—C6A—C5A	116.9 (2)	N1B—C6B—C5B	117.2 (2)
N7A—C8A—N9A	113.7 (2)	N7B—C8B—N9B	113.9 (2)
N7A—C8A—H8A	123.2	N7B—C8B—H8B	123.0
N9A—C8A—H8A	123.2	N9B—C8B—H8B	123.0
C2'A—O2'A—H2'C	109.5	C2'B—O2'B—H2'D	109.5
C3'A—O3'A—H3'C	109.5	C3'B—O3'B—H3'D	109.5
C1'A—O4'A—C4'A	105.3 (2)	C1'B—O4'B—C4'B	108.2 (2)
O4'A—C1'A—N9A	108.2 (2)	O4'B—C1'B—N9B	108.15 (19)
O4'A—C1'A—C2'A	105.1 (2)	O4'B—C1'B—C2'B	104.9 (2)
N9A—C1'A—C2'A	114.7 (2)	N9B—C1'B—C2'B	115.8 (2)
O4'A—C1'A—H1'A	109.6	O4'B—C1'B—H1'B	109.3
N9A—C1'A—H1'A	109.6	N9B—C1'B—H1'B	109.3
C2'A—C1'A—H1'A	109.6	C2'B—C1'B—H1'B	109.3
O2'A—C2'A—C1'A	114.0 (2)	O2'B—C2'B—C1'B	113.4 (2)
O2'A—C2'A—C3'A	112.7 (2)	O2'B—C2'B—C3'B	113.3 (2)
C1'A—C2'A—C3'A	102.0 (2)	C1'B—C2'B—C3'B	99.3 (2)
O2'A—C2'A—H2'A	109.3	O2'B—C2'B—H2'B	110.1
C1'A—C2'A—H2'A	109.3	C1'B—C2'B—H2'B	110.1
C3'A—C2'A—H2'A	109.3	C3'B—C2'B—H2'B	110.1
O3'A—C3'A—C4'A	111.3 (2)	O3'B—C3'B—C4'B	108.9 (2)
O3'A—C3'A—C2'A	110.7 (2)	O3'B—C3'B—C2'B	109.7 (2)
C4'A—C3'A—C2'A	103.6 (2)	C4'B—C3'B—C2'B	99.95 (19)
O3'A—C3'A—H3'A	110.4	O3'B—C3'B—H3'B	112.5
C4'A—C3'A—H3'A	110.4	C4'B—C3'B—H3'B	112.5
C2'A—C3'A—H3'A	110.4	C2'B—C3'B—H3'B	112.5
O4'A—C4'A—C3'A	107.3 (2)	O4'B—C4'B—C3'B	105.8 (2)
O4'A—C4'A—H4'A	110.3	O4'B—C4'B—H4'C	110.6
C3'A—C4'A—H4'A	110.3	C3'B—C4'B—H4'C	110.6
O4'A—C4'A—H4'B	110.3	O4'B—C4'B—H4'D	110.6
C3'A—C4'A—H4'B	110.3	C3'B—C4'B—H4'D	110.6
H4'A—C4'A—H4'B	108.5	H4'C—C4'B—H4'D	108.7
C4A—N3A—C2A—N1A	−0.4 (4)	C6B—N1B—C2B—N3B	0.4 (4)
C6A—N1A—C2A—N3A	1.6 (4)	C4B—N3B—C2B—N1B	−1.5 (4)
C2A—N3A—C4A—C5A	−2.2 (4)	C2B—N3B—C4B—N9B	−179.9 (3)
C2A—N3A—C4A—N9A	178.8 (3)	C2B—N3B—C4B—C5B	0.7 (4)
C8A—N9A—C4A—N3A	178.3 (3)	C8B—N9B—C4B—N3B	−179.2 (3)
C1'A—N9A—C4A—N3A	−2.8 (5)	C1'B—N9B—C4B—N3B	−5.4 (4)
C8A—N9A—C4A—C5A	−0.9 (3)	C8B—N9B—C4B—C5B	0.2 (3)
C1'A—N9A—C4A—C5A	178.0 (3)	C1'B—N9B—C4B—C5B	174.0 (2)
C8A—N7A—C5A—C4A	0.0 (3)	N3B—C4B—C5B—N7B	179.4 (3)
C8A—N7A—C5A—C6A	177.5 (3)	N9B—C4B—C5B—N7B	0.0 (3)
N3A—C4A—C5A—N7A	−178.6 (3)	N3B—C4B—C5B—C6B	0.9 (4)
N9A—C4A—C5A—N7A	0.6 (3)	N9B—C4B—C5B—C6B	−178.6 (2)
N3A—C4A—C5A—C6A	3.5 (4)	C8B—N7B—C5B—C4B	−0.2 (3)
N9A—C4A—C5A—C6A	−177.3 (2)	C8B—N7B—C5B—C6B	178.1 (3)
C2A—N1A—C6A—N6A	179.0 (3)	C2B—N1B—C6B—N6B	−177.7 (3)
C2A—N1A—C6A—C5A	−0.2 (4)	C2B—N1B—C6B—C5B	1.4 (4)
N7A—C5A—C6A—N6A	1.3 (5)	C4B—C5B—C6B—N6B	177.1 (3)
C4A—C5A—C6A—N6A	178.8 (3)	N7B—C5B—C6B—N6B	−1.0 (5)
N7A—C5A—C6A—N1A	−179.4 (3)	C4B—C5B—C6B—N1B	−2.0 (4)
C4A—C5A—C6A—N1A	−2.0 (4)	N7B—C5B—C6B—N1B	179.9 (3)
C5A—N7A—C8A—N9A	−0.6 (3)	C5B—N7B—C8B—N9B	0.3 (3)
C4A—N9A—C8A—N7A	1.0 (3)	C4B—N9B—C8B—N7B	−0.3 (3)
C1'A—N9A—C8A—N7A	−178.0 (2)	C1'B—N9B—C8B—N7B	−174.1 (2)
C4'A—O4'A—C1'A—N9A	−164.9 (2)	C4'B—O4'B—C1'B—N9B	−146.3 (2)
C4'A—O4'A—C1'A—C2'A	−41.9 (3)	C4'B—O4'B—C1'B—C2'B	−22.1 (3)
C8A—N9A—C1'A—O4'A	−112.9 (3)	C8B—N9B—C1'B—O4'B	58.0 (3)
C4A—N9A—C1'A—O4'A	68.4 (3)	C4B—N9B—C1'B—O4'B	−114.5 (3)
C8A—N9A—C1'A—C2'A	130.2 (3)	C8B—N9B—C1'B—C2'B	−59.3 (3)
C4A—N9A—C1'A—C2'A	−48.5 (4)	C4B—N9B—C1'B—C2'B	128.2 (3)
O4'A—C1'A—C2'A—O2'A	158.2 (2)	O4'B—C1'B—C2'B—O2'B	162.60 (19)
N9A—C1'A—C2'A—O2'A	−83.2 (3)	N9B—C1'B—C2'B—O2'B	−78.3 (3)
O4'A—C1'A—C2'A—C3'A	36.3 (3)	O4'B—C1'B—C2'B—C3'B	42.0 (2)
N9A—C1'A—C2'A—C3'A	155.0 (2)	N9B—C1'B—C2'B—C3'B	161.2 (2)
O2'A—C2'A—C3'A—O3'A	−20.3 (3)	O2'B—C2'B—C3'B—O3'B	−50.8 (3)
C1'A—C2'A—C3'A—O3'A	102.4 (3)	C1'B—C2'B—C3'B—O3'B	69.8 (2)
O2'A—C2'A—C3'A—C4'A	−139.7 (2)	O2'B—C2'B—C3'B—C4'B	−165.1 (2)
C1'A—C2'A—C3'A—C4'A	−17.0 (3)	C1'B—C2'B—C3'B—C4'B	−44.5 (2)
C1'A—O4'A—C4'A—C3'A	30.3 (3)	C1'B—O4'B—C4'B—C3'B	−7.3 (3)
O3'A—C3'A—C4'A—O4'A	−125.7 (2)	O3'B—C3'B—C4'B—O4'B	−81.9 (3)
C2'A—C3'A—C4'A—O4'A	−6.7 (3)	C2'B—C3'B—C4'B—O4'B	33.0 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N6A—H6A···O2′B^i	0.88	2.14	2.988 (3)	162
N6A—H6B···N1B^ii	0.88	2.11	2.957 (4)	161
O2′A—H2′C···N3A^iii	0.84	2.17	2.999 (3)	171
O2′B—H2′D···N3B^iv	0.84	2.00	2.807 (3)	162
O3′A—H3′C···N7B	0.84	2.02	2.820 (3)	158
N6B—H6C···N7A^v	0.88	2.05	2.934 (3)	177
N6B—H6D···O3′A	0.88	2.20	3.011 (4)	152
O3′B—H3′D···N1A^vi	0.84	1.96	2.798 (3)	175

Symmetry codes: (i) −x+3/2, −y+2, z+1/2; (ii) −x, y−1/2, −z+1/2; (iii) x−1, y, z; (iv) x+1, y, z; (v) −x, y+1/2, −z+1/2; (vi) −x+3/2, −y+2, z−1/2.