Crystal, mol­ecular structure and Hirshheld surface analysis of 5-hy­droxy-3,6,7,8-tetra­meth­oxy­flavone

Aisa, H.A.; Izotova, L.; Karimov, A.; Botirov, E.; Mamadrahimov, A.; Ibragimov, B.

doi:10.1107/S2056989020013596

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ISSN: 2056-9890

Volume 76| Part 11| November 2020| Pages 1748-1751

https://doi.org/10.1107/S2056989020013596

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Crystal, molecular structure and Hirshheld surface analysis of 5-hydroxy-3,6,7,8-tetramethoxyflavone

Haji Akber Aisa,^a Lidiya Izotova,^b ^* Abdurashid Karimov,^c Erkin Botirov,^c Azimjon Mamadrahimov ^b and Bahtiyar Ibragimov ^b

^aKey Laboratory of Plants Resources and Chemistry of Arid Zone, Xinjiang, Technical Institute of Physics and Chemistry, Chinese Academy of Science, Urumqi 830011, People's Republic of China, ^bInstitute of Bioorganic Chemistry, UzAS, M. Ulugbek Str., 83, 100125,Tashkent, Uzbekistan, and ^cInstitute of the Chemistry of Plant Substances, UzAS, M. Ulugbek Str., 77, 100170, Tashkent, Uzbekistan
^*Correspondence e-mail: li_izotova@mail.ru

Edited by A. Briceno, Venezuelan Institute of Scientific Research, Venezuela (Received 17 September 2020; accepted 12 October 2020; online 13 October 2020)

The title compound (systematic name: 5-hydroxy-3,6,7,8-tetramethoxy-2-phenyl-4H-chromen-4-one), C₁₉H₁₈O₇, is a flavone that was isolated from a butanol extract of the herb Scutellaria nepetoides M. Pop. The flavone molecule is almost planar, with a dihedral angle between the planes of the benzopyran-4-one group and the attached phenyl ring of 6.4 (4)°. The 5-hydroxy group forms a strong intramolecular hydrogen bond with the carbonyl group, resulting in a six-membered hydrogen-bonded ring. The crystal structure has triclinic (P $[\overline{1}]$ ) symmetry. In the crystal, the molecules are linked by C—H⋯O hydrogen bonds into a two dimensional network parallel to the ab plane. The Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (53.9%) and H⋯O/O⋯H (20.9%) interactions.

Keywords: crystal structure; flavones; Hirshfeld surface analysis; hydrogen bonding.

CCDC reference: 2036551

1. Chemical context

Flavonoids are the most numerous class of natural phenolic compounds, which are characterized by structural diversity, high and versatile activity and low toxicity. Plants of the genus Scutellaria L. are widespread in Europe, North America, East Asia and are extensively used in traditional Chinese medicine (Shang et al., 2010 ). Flavonoids isolated from plants of the genus Scutellaria L. exhibit antitumor (Yu et al., 2007 ), hepatoprotective (Jang et al., 2003 ), antioxidant (Sauvage et al., 2010 ), anti-inflammatory (Dai et al., 2013 ), anticonvulsant (Park et al., 2007 ), antimicrobial (Arituluk et al., 2019 ) and antiviral activity (Leonova et al., 2020 ). The creation of drugs based on flavonoids is based on the establishment of the `chemical structure–pharmacological properties' relationship, and the determination of the structure of a new flavonoid may become a key starting point.

2. Structural commentary

The molecular structure of the title compound is presented in Fig. 1. The benzopyran moieties are practically planar, with r.m.s. deviations of 0.01 Å. The molecular conformation is restricted by the relative positions of the benzopyran unit and the phenyl ring, the dihedral angle between them being 6.4 (4)°. Atoms C3, C6, C7 and C8 of the methoxy substituent have an out-of-plane conformation with the methoxy groups at atoms C3 and C6 pointing in the same direction [C16—O2—C3—C2 = 109.3 (2) and C17—O5—C6—C5 = 66. 7(4)°], while the methoxy groups at atoms C7 and C8 point in opposite direction [C18—O6—C7—C6 = −56.3 (3) and C19—O7—C8—C7 = −91.4 (3)°]. The conformation of the molecule is fixed because of the intramolecular O4—H4⋯O3 hydrogen bond [2.599 (2) Å, 147°], which closes a six-membered ring with graph-set notation S(6) (Etter, 1990 ).

Figure 1
The molecular structure of the title compound with the atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

3. Supramolecular features

In the crystal, the molecules are linked by C—H⋯O hydrogen bonds into a two dimensional network parallel to the ab plane. A perspective view of the crystal packing in the unit cell is depicted in Fig. 2 and numerical details of the hydrogen bonds are presented in Table 1.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4⋯O3	0.82	1.87	2.599 (2)	147
C16—H16A⋯O3	0.96	2.51	3.079 (3)	118
C16—H16B⋯O3ⁱ	0.96	2.39	3.258 (3)	150
C18—H18B⋯O5	0.96	2.28	2.897 (4)	121
C18—H18C⋯O7ⁱⁱ	0.96	2.53	3.278 (4)	135
C17—H17C⋯O4	0.96	2.52	3.010 (4)	111
Symmetry codes: (i) x+1, y, z; (ii) x-1, y, z.

Figure 2
Crystal structure of the title compound in projection on the ac plane. Hydrogen bonds are shown as dashed lines.

4. Hirshfeld surface analysis

In order to visualize the intermolecular interactions in the crystals of the title compound, a Hirshfeld surface analysis was carried out using Crystal Explorer 17.5 (Turner et al., 2017 ). The Hirshfeld surface mapped over d_norm (Fig. 3) shows the expected bright-red spots near atoms O3, O7, H16B, which are involved in the C—H⋯O hydrogen-bonding interactions. Fingerprint plots (Fig. 4) reveal that H⋯H and H⋯O/O⋯H interactions make the greatest contributions to the surface contacts, while H⋯C/C⋯H, O⋯C/C⋯O, C⋯C and O⋯O contacts are less significant.

Figure 3
The Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (53.9%) and H⋯O/O⋯H (20.9%) interactions.

Figure 4
Full two-dimensional fingerprint plots for the title compound, showing all interactions (a), and delineated into (b) H⋯H, (c) H⋯O/O⋯H, (d) H⋯C/C⋯H, (e) O⋯C/C⋯O, (f) C⋯C and (g) O⋯O interactions. The d_i and d_e values are the closest internal and external distances (in Å) from a given point on the Hirshfeld surface.

5. Database survey

A search of the Cambridge Structural Database (CSD Version 5.41, update of November 2019; Groom et al., 2016 ) found 311 hits for the term `flavones'. Among these, nine are tetramethoxyflavones: 3,4′,6,7 (DAVREN; Geng et al., 2011 ), 6,2′3′,4′- (JEMGIN; Wallet et al., 1990a ) and 2′,4′,5,7- (KEPLEW; Wallet et al., 1990b ), 3,4′,6,7- (MENSII; Meng et al., 2006 ), 3′,4′,5,7- (PIQPEK; Shoja, 1997 ), 3,4′5,7- (PUGKEI; Aree et al., 2009 ), 3′,5,5′,6- (TMOFLV10; Ting et al., 1972 ), 3,7,4′,5′- (YASCIF; Etti et al., 2005 ). The compound FATZOR (Vijayalakshmi et al., 1986 ) is also a 3,6,7,8 tetramethylflavone, but with two hydroxy substituents at the 5,4′-positions.

6. Synthesis and crystallization

Air-dried whole plants (1.1 kg) of Scutellaria nepetoides M. Pop. were extracted three times (each 3 h) with butanol (5 l) at 353 K. The butanol filtrates were collected and concentrated under reduced pressure to provide 10.2 g of butanol extract. The butanol extract (1 g) was subjected to silica gel (60–100 mesh) column (gradient of butanol:water = 0:1, 2:8, 1:1, 8:2, 1:0) as eluent, and five fractions were collected according to TLC analysis. All fractions were concentrated under reduced pressure. A crystallization procedure with different solvents at high temperature was used to obtain the pure compounds. Fraction 5 (0.23 g) was eluted with butanol (100%) at 353 K and with ethanol (95%) at 343 K. The obtained polycrystals were removed from the butanol solution by filtration. Yellow prismatic single crystals were prepared by slow evaporation of butanol solution at room temperature.

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The C-bound H atoms were positioned geometrically and were included in the refinement in the riding-model approximation, with C—H = 0.96 Å (CH₃), 0.93 Å (aryl H) and O—H = 0.82 Å and with U_iso(H) = 1.2U_eq(C) (aryl H) and 1.5U_eq(C-methyl, O).

Table 2
Experimental details

Crystal data
Chemical formula	C₁₉H₁₈O₇
M_r	358.33
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	293
a, b, c (Å)	5.0789 (4), 8.0801 (6), 20.8682 (19)
α, β, γ (°)	92.481 (7), 91.984 (7), 94.253 (6)
V (Å³)	852.62 (12)
Z	2
Radiation type	Cu Kα
μ (mm⁻¹)	0.90
Crystal size (mm)	0.03 × 0.02 × 0.01

Data collection
Diffractometer	Agilent Xcalibur, Ruby
Absorption correction	Multi-scan (CrysAlis PRO; Agilent, 2014 )
T_min, T_max	0.818, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	6484, 3458, 2408
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.630

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.056, 0.174, 1.03
No. of reflections	3458
No. of parameters	240
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.22, −0.18
Computer programs: CrysAlis PRO (Agilent, 2014), XP (Siemens, 1994 ), SHELXT2018/2 (Sheldrick, 2015a ) and SHELXL2018/3 (Sheldrick, 2015b ).

Supporting information

CCDC reference: 2036551

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989020013596/zn2001sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989020013596/zn2001Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2056989020013596/zn2001Isup3.cml

checkCIF report

Computing details top

Data collection: CrysAlis PRO (Agilent, 2014); cell refinement: CrysAlis PRO (Agilent, 2014); data reduction: CrysAlis PRO (Agilent, 2014); program(s) used to solve structure: SHELXT2018/2 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018/3 (Sheldrick, 2015b); molecular graphics: XP (Siemens, 1994).

5-Hydroxy-3,6,7,8-tetramethoxy-2-phenyl-4H-chromen-4-one top

Crystal data top

C₁₉H₁₈O₇	Z = 2
M_r = 358.33	F(000) = 376
Triclinic, P1	D_x = 1.396 Mg m⁻³
a = 5.0789 (4) Å	Cu Kα radiation, λ = 1.54184 Å
b = 8.0801 (6) Å	Cell parameters from 1498 reflections
c = 20.8682 (19) Å	θ = 5.5–75.0°
α = 92.481 (7)°	µ = 0.90 mm⁻¹
β = 91.984 (7)°	T = 293 K
γ = 94.253 (6)°	Prism, yellow
V = 852.62 (12) Å³	0.03 × 0.02 × 0.01 mm

Data collection top

Agilent Xcalibur, Ruby diffractometer	R_int = 0.023
Radiation source: Enhance (Cu) X-ray Source	θ_max = 76.1°, θ_min = 4.2°
/ω scans	h = −6→4
Absorption correction: multi-scan (CrysAlisPro; Agilent, 2014)	k = −10→9
T_min = 0.818, T_max = 1.000	l = −25→25
6484 measured reflections	3 standard reflections every 100 reflections
3458 independent reflections	intensity decay: 2.6%
2408 reflections with I > 2σ(I)

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.056	H-atom parameters constrained
wR(F²) = 0.174	w = 1/[σ²(F_o²) + (0.0902P)² + 0.0534P] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max < 0.001
3458 reflections	Δρ_max = 0.22 e Å⁻³
240 parameters	Δρ_min = −0.18 e Å⁻³

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.4105 (3)	0.28804 (17)	0.27044 (7)	0.0575 (4)
O2	0.3672 (3)	0.59876 (19)	0.39973 (8)	0.0659 (4)
O7	0.3450 (3)	0.10219 (19)	0.16067 (8)	0.0685 (4)
O3	0.0122 (3)	0.69625 (19)	0.30889 (9)	0.0714 (5)
O4	−0.2527 (4)	0.6406 (2)	0.20033 (9)	0.0740 (5)
H4	−0.209283	0.687910	0.235051	0.111*
O6	0.0019 (3)	0.1855 (2)	0.06667 (8)	0.0725 (5)
O5	−0.3071 (4)	0.4564 (2)	0.08488 (9)	0.0792 (5)
C9	0.2302 (4)	0.3341 (2)	0.22626 (10)	0.0532 (5)
C2	0.4615 (4)	0.3764 (2)	0.32748 (10)	0.0531 (5)
C1	0.6627 (4)	0.3000 (2)	0.36663 (10)	0.0547 (5)
C3	0.3289 (4)	0.5145 (2)	0.34102 (10)	0.0559 (5)
C10	0.0862 (4)	0.4721 (2)	0.23720 (11)	0.0549 (5)
C8	0.1951 (4)	0.2349 (3)	0.17031 (11)	0.0570 (5)
C4	0.1327 (4)	0.5696 (3)	0.29666 (11)	0.0576 (5)
C5	−0.1022 (4)	0.5106 (3)	0.19027 (12)	0.0598 (5)
C7	0.0153 (4)	0.2777 (3)	0.12324 (11)	0.0591 (5)
C11	0.7909 (5)	0.1680 (3)	0.33913 (12)	0.0621 (5)
H11	0.747162	0.131003	0.297010	0.074*
C6	−0.1322 (4)	0.4180 (3)	0.13258 (12)	0.0620 (5)
C13	1.0487 (5)	0.1457 (3)	0.43582 (13)	0.0693 (6)
H13	1.178385	0.095483	0.458888	0.083*
C12	0.9801 (5)	0.0925 (3)	0.37353 (13)	0.0690 (6)
H12	1.062501	0.004788	0.354580	0.083*
C15	0.7318 (5)	0.3509 (3)	0.42988 (11)	0.0676 (6)
H15	0.648243	0.437172	0.449493	0.081*
C14	0.9221 (5)	0.2750 (3)	0.46366 (13)	0.0735 (7)
H14	0.966483	0.310908	0.505855	0.088*
C16	0.5102 (5)	0.7581 (3)	0.39759 (14)	0.0755 (7)
H16A	0.429300	0.821692	0.365563	0.113*
H16B	0.689782	0.743522	0.387050	0.113*
H16C	0.507312	0.815778	0.438727	0.113*
C18	−0.2471 (6)	0.1157 (4)	0.04230 (15)	0.0884 (9)
H18A	−0.223724	0.046870	0.004568	0.133*
H18B	−0.356737	0.203034	0.031583	0.133*
H18C	−0.329956	0.049683	0.074221	0.133*
C19	0.2318 (8)	−0.0502 (3)	0.1815 (2)	0.1081 (11)
H19A	0.058829	−0.073200	0.161721	0.162*
H19B	0.218626	−0.043294	0.227342	0.162*
H19C	0.341133	−0.137746	0.169734	0.162*
C17	−0.2436 (9)	0.6092 (4)	0.05619 (19)	0.1199 (14)
H17A	−0.331407	0.608230	0.014676	0.180*
H17B	−0.056050	0.624212	0.051646	0.180*
H17C	−0.300412	0.698631	0.082812	0.180*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0628 (8)	0.0517 (7)	0.0575 (8)	0.0094 (6)	−0.0003 (7)	−0.0097 (6)
O2	0.0782 (10)	0.0584 (8)	0.0601 (9)	0.0080 (7)	0.0036 (8)	−0.0145 (7)
O7	0.0779 (10)	0.0586 (9)	0.0692 (10)	0.0145 (7)	0.0065 (8)	−0.0124 (7)
O3	0.0744 (10)	0.0578 (9)	0.0823 (11)	0.0181 (7)	0.0011 (8)	−0.0153 (8)
O4	0.0755 (10)	0.0626 (9)	0.0847 (12)	0.0200 (8)	−0.0046 (9)	−0.0056 (8)
O6	0.0745 (10)	0.0820 (11)	0.0589 (9)	0.0029 (8)	0.0009 (8)	−0.0155 (8)
O5	0.0868 (11)	0.0719 (10)	0.0773 (12)	0.0038 (9)	−0.0178 (9)	0.0043 (9)
C9	0.0550 (10)	0.0496 (10)	0.0547 (11)	0.0038 (8)	0.0037 (9)	−0.0023 (8)
C2	0.0550 (10)	0.0492 (10)	0.0541 (11)	0.0013 (8)	0.0058 (9)	−0.0070 (8)
C1	0.0545 (10)	0.0497 (10)	0.0591 (12)	0.0011 (8)	0.0036 (9)	−0.0022 (9)
C3	0.0616 (11)	0.0486 (10)	0.0565 (12)	0.0016 (9)	0.0064 (9)	−0.0079 (8)
C10	0.0585 (11)	0.0474 (10)	0.0583 (12)	0.0025 (8)	0.0050 (9)	−0.0016 (9)
C8	0.0612 (11)	0.0510 (10)	0.0585 (12)	0.0047 (9)	0.0063 (9)	−0.0053 (9)
C4	0.0595 (11)	0.0472 (10)	0.0657 (13)	0.0040 (9)	0.0096 (10)	−0.0058 (9)
C5	0.0591 (11)	0.0503 (11)	0.0702 (14)	0.0062 (9)	0.0036 (10)	−0.0006 (10)
C7	0.0628 (12)	0.0570 (11)	0.0560 (12)	−0.0022 (9)	0.0039 (10)	−0.0046 (9)
C11	0.0675 (12)	0.0539 (11)	0.0639 (13)	0.0065 (10)	−0.0025 (10)	−0.0081 (9)
C6	0.0617 (12)	0.0585 (12)	0.0651 (13)	0.0012 (10)	−0.0036 (10)	0.0039 (10)
C13	0.0669 (13)	0.0645 (13)	0.0766 (16)	0.0085 (11)	−0.0065 (12)	0.0067 (11)
C12	0.0695 (13)	0.0565 (12)	0.0816 (16)	0.0148 (10)	−0.0023 (12)	−0.0039 (11)
C15	0.0737 (14)	0.0685 (13)	0.0608 (13)	0.0133 (11)	0.0015 (11)	−0.0085 (11)
C14	0.0782 (15)	0.0806 (16)	0.0610 (14)	0.0112 (13)	−0.0066 (12)	−0.0056 (12)
C16	0.0753 (15)	0.0613 (13)	0.0871 (17)	0.0041 (11)	−0.0025 (13)	−0.0212 (12)
C18	0.0800 (16)	0.0908 (19)	0.090 (2)	−0.0031 (14)	−0.0024 (14)	−0.0297 (15)
C19	0.129 (3)	0.0560 (15)	0.142 (3)	0.0176 (16)	0.020 (2)	0.0052 (17)
C17	0.164 (4)	0.085 (2)	0.107 (3)	−0.005 (2)	−0.047 (3)	0.0312 (19)

Geometric parameters (Å, º) top

O1—C9	1.360 (3)	C5—C6	1.387 (3)
O1—C2	1.368 (2)	C7—C6	1.414 (3)
O2—C3	1.376 (2)	C11—C12	1.374 (3)
O2—C16	1.434 (3)	C11—H11	0.9300
O7—C8	1.373 (3)	C13—C12	1.376 (4)
O7—C19	1.413 (3)	C13—C14	1.384 (4)
O3—C4	1.252 (3)	C13—H13	0.9300
O4—C5	1.357 (3)	C12—H12	0.9300
O4—H4	0.8200	C15—C14	1.373 (4)
O6—C7	1.365 (3)	C15—H15	0.9300
O6—C18	1.415 (3)	C14—H14	0.9300
O5—C6	1.372 (3)	C16—H16A	0.9600
O5—C17	1.416 (4)	C16—H16B	0.9600
C9—C8	1.386 (3)	C16—H16C	0.9600
C9—C10	1.393 (3)	C18—H18A	0.9600
C2—C3	1.370 (3)	C18—H18B	0.9600
C2—C1	1.474 (3)	C18—H18C	0.9600
C1—C15	1.391 (3)	C19—H19A	0.9600
C1—C11	1.403 (3)	C19—H19B	0.9600
C3—C4	1.444 (3)	C19—H19C	0.9600
C10—C5	1.406 (3)	C17—H17A	0.9600
C10—C4	1.443 (3)	C17—H17B	0.9600
C8—C7	1.390 (3)	C17—H17C	0.9600

C9—O1—C2	121.52 (16)	C5—C6—C7	119.4 (2)
C3—O2—C16	114.26 (18)	C12—C13—C14	119.1 (2)
C8—O7—C19	114.8 (2)	C12—C13—H13	120.4
C5—O4—H4	109.5	C14—C13—H13	120.4
C7—O6—C18	119.0 (2)	C11—C12—C13	120.5 (2)
C6—O5—C17	115.0 (2)	C11—C12—H12	119.7
O1—C9—C8	116.32 (18)	C13—C12—H12	119.7
O1—C9—C10	121.69 (19)	C14—C15—C1	120.7 (2)
C8—C9—C10	122.0 (2)	C14—C15—H15	119.7
O1—C2—C3	119.82 (19)	C1—C15—H15	119.7
O1—C2—C1	110.68 (17)	C15—C14—C13	120.9 (2)
C3—C2—C1	129.50 (19)	C15—C14—H14	119.5
C15—C1—C11	117.9 (2)	C13—C14—H14	119.5
C15—C1—C2	123.54 (19)	O2—C16—H16A	109.5
C11—C1—C2	118.60 (19)	O2—C16—H16B	109.5
C2—C3—O2	120.3 (2)	H16A—C16—H16B	109.5
C2—C3—C4	121.67 (19)	O2—C16—H16C	109.5
O2—C3—C4	117.84 (18)	H16A—C16—H16C	109.5
C9—C10—C5	118.9 (2)	H16B—C16—H16C	109.5
C9—C10—C4	119.0 (2)	O6—C18—H18A	109.5
C5—C10—C4	122.2 (2)	O6—C18—H18B	109.5
O7—C8—C9	120.3 (2)	H18A—C18—H18B	109.5
O7—C8—C7	121.05 (19)	O6—C18—H18C	109.5
C9—C8—C7	118.6 (2)	H18A—C18—H18C	109.5
O3—C4—C10	121.9 (2)	H18B—C18—H18C	109.5
O3—C4—C3	121.7 (2)	O7—C19—H19A	109.5
C10—C4—C3	116.34 (18)	O7—C19—H19B	109.5
O4—C5—C6	119.3 (2)	H19A—C19—H19B	109.5
O4—C5—C10	120.4 (2)	O7—C19—H19C	109.5
C6—C5—C10	120.2 (2)	H19A—C19—H19C	109.5
O6—C7—C8	117.0 (2)	H19B—C19—H19C	109.5
O6—C7—C6	122.1 (2)	O5—C17—H17A	109.5
C8—C7—C6	120.8 (2)	O5—C17—H17B	109.5
C12—C11—C1	120.9 (2)	H17A—C17—H17B	109.5
C12—C11—H11	119.5	O5—C17—H17C	109.5
C1—C11—H11	119.5	H17A—C17—H17C	109.5
O5—C6—C5	121.6 (2)	H17B—C17—H17C	109.5
O5—C6—C7	119.0 (2)

C2—O1—C9—C8	−179.93 (18)	C2—C3—C4—C10	−0.5 (3)
C2—O1—C9—C10	−0.8 (3)	O2—C3—C4—C10	−176.28 (18)
C9—O1—C2—C3	0.1 (3)	C9—C10—C5—O4	177.6 (2)
C9—O1—C2—C1	179.66 (17)	C4—C10—C5—O4	−1.6 (3)
O1—C2—C1—C15	−172.2 (2)	C9—C10—C5—C6	−3.7 (3)
C3—C2—C1—C15	7.3 (4)	C4—C10—C5—C6	177.1 (2)
O1—C2—C1—C11	7.3 (3)	C18—O6—C7—C8	128.1 (3)
C3—C2—C1—C11	−173.2 (2)	C18—O6—C7—C6	−56.3 (3)
O1—C2—C3—O2	176.21 (17)	O7—C8—C7—O6	−2.2 (3)
C1—C2—C3—O2	−3.2 (3)	C9—C8—C7—O6	174.70 (19)
O1—C2—C3—C4	0.6 (3)	O7—C8—C7—C6	−177.85 (19)
C1—C2—C3—C4	−178.9 (2)	C9—C8—C7—C6	−1.0 (3)
C16—O2—C3—C2	109.3 (2)	C15—C1—C11—C12	−0.5 (3)
C16—O2—C3—C4	−74.9 (2)	C2—C1—C11—C12	180.0 (2)
O1—C9—C10—C5	−178.38 (18)	C17—O5—C6—C5	66.7 (4)
C8—C9—C10—C5	0.7 (3)	C17—O5—C6—C7	−115.1 (3)
O1—C9—C10—C4	0.8 (3)	O4—C5—C6—O5	1.2 (4)
C8—C9—C10—C4	179.88 (19)	C10—C5—C6—O5	−177.50 (19)
C19—O7—C8—C9	91.8 (3)	O4—C5—C6—C7	−177.0 (2)
C19—O7—C8—C7	−91.4 (3)	C10—C5—C6—C7	4.4 (3)
O1—C9—C8—O7	−2.4 (3)	O6—C7—C6—O5	4.3 (3)
C10—C9—C8—O7	178.53 (19)	C8—C7—C6—O5	179.8 (2)
O1—C9—C8—C7	−179.25 (18)	O6—C7—C6—C5	−177.5 (2)
C10—C9—C8—C7	1.7 (3)	C8—C7—C6—C5	−2.0 (3)
C9—C10—C4—O3	179.0 (2)	C1—C11—C12—C13	−0.3 (4)
C5—C10—C4—O3	−1.8 (3)	C14—C13—C12—C11	0.8 (4)
C9—C10—C4—C3	−0.2 (3)	C11—C1—C15—C14	0.8 (4)
C5—C10—C4—C3	179.03 (19)	C2—C1—C15—C14	−179.7 (2)
C2—C3—C4—O3	−179.7 (2)	C1—C15—C14—C13	−0.3 (4)
O2—C3—C4—O3	4.6 (3)	C12—C13—C14—C15	−0.5 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4···O3	0.82	1.87	2.599 (2)	147
C16—H16A···O3	0.96	2.51	3.079 (3)	118
C16—H16B···O3ⁱ	0.96	2.39	3.258 (3)	150
C18—H18B···O5	0.96	2.28	2.897 (4)	121
C18—H18C···O7ⁱⁱ	0.96	2.53	3.278 (4)	135
C17—H17C···O4	0.96	2.52	3.010 (4)	111

Symmetry codes: (i) x+1, y, z; (ii) x−1, y, z.

Acknowledgements

We are especially grateful to Jamshid Ashurov DSc for help in discussing the results.

Funding information

Funding for this research was provided by: Chinese Academy of Sciences Center of Drag Discovery and Development Center of Central Asia (grant No. CAM 201907).

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