Journal of Crystallography

Volume 2014 (2014), Article ID 745074, 6 pages

http://dx.doi.org/10.1155/2014/745074

Research Article

Synthesis, Characterization, and Crystal Structure of Negundoside (2′-p-Hydroxybenzoyl Mussaenosidic Acid)

Suresh Sharma,¹ B. D. Gupta,² Rajni Kant,¹ and Vivek K. Gupta¹

¹Department of Physics & Electronics, University of Jammu, Jammu 180 006, India

²Indian Institute of Integrative Medicine, Jammu, India

Received 25 February 2014; Accepted 17 April 2014; Published 25 May 2014

Academic Editor: Mehmet Akkurt

Copyright © 2014 Suresh Sharma et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract.

The structure of title compound Negundoside (2′-p-hydroxybenzoyl mussaenosidic acid) was established by spectral and X-ray diffraction studies. The compound crystallizes in the monoclinic crystal system with space group P2₁ having unit cell parameters: (5) Å, (4) Å, (5) Å, (4)°, and . The crystal structure was solved by direct method using single crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R value of 0.0520 for 3389 observed reflections.

1. Introduction

Vitex negundo Linn (family: Verbenaceae) is widely used in the indigenous system of medicine in India. The roots and leaves of the plant are used as expectorant, febrifuge, vermifuge tonic, and aromatic [1]. The plant is reported to have anti-inflammatory and antiarthritic properties [2]. A variety of constituents have been reported from this plant. From the leaves Ghosh and Krishna isolated glucononitol, p-hydroxybenzoic acid, 5-hydroxyisophthalic acid, and 3,4-dihydroxy-benzoic acid along with two glucosides and an amorphous alkaloid [3]. In the essential oil of leaves -pinene, camphene, citral, and -caryophyllene have been reported [4].

A large number of flavonoids, namely, casticin, orientin, isoorientin, luteolin, luteolin-7-0-glucoside, corymbosin, gardenins A and B, 3-0-desmethyl-artemetin, 5-0-desmethylnobiletin, 3′,4′,5,5′,6,7,8-heptamethoxyflavone, 3′,5-dihydroxy-4′, 7,8-trimethoxy flavanone, and 3′,5-dihydroxy-4′,6,7-trimethoxy-flavanone, have also been reported from this plant [5–8]. However the major chemical constituents of the plant are the iridoid glycosides. Five iridoid glycosides have been reported from the leaves of V. negundo; these are aucubin, agnuside [9], negundoside, and nishindaside [10]. Negundoside have been found to have significant hepatoprotective activity [11]. A number of pharmacological properties have been attributed to V. negundo including snake venom neutralization [12], hepatoprotective [13], tyrosinase inhibition [14], antiandrogenic [15], antifeeding [16], antifungal [17], analgesic, anti-inflammatory [18], central nervous system activity [19], mosquito repellent [20], nitric oxide scavenging [21], antiradical, antilipoperoxidative [22], antibacterial [23], and larvicidal [24].

2. Experimental

2.1. Synthesis

2.1.1. Extraction of Plant Material

The shade dried and powdered leaves (1 kg) of V. negundo were soaked in ethanol (5 L) and kept overnight. The percolate was filtered and concentrated under reduced pressure at below 50°C. The extraction procedure was repeated three times more using three litres of ethanol each time. The combined ethanolic extract was concentrated at 50°C to get 160 g of dry extract.

2.1.2. Isolation of Negundoside

The ethanolic extract (50 g) was adsorbed over silica gel (100 g) to make it slurry which was packed over a column of silica gel (1 kg) packed in chloroform. Elution was done with chloroform followed by mixture of chloroform and methanol. Elution with 10% methanol in chloroform gave agnuside followed by mixture of agnuside and negundoside and then negundoside. The pure compounds were characterized on the basis of ¹HNMR, ¹³CNMR Mass spectral data.

2.1.3. Crystallization

White block shaped single crystals of the title compound were grown at room temperature by slow evaporation technique.

2.1.4. Characterisation of Negundoside

Negundoside was obtained as crystalline compound from methanol, m.p. 163–64°C M⁺: 496, ¹HNMR (200 MHz, CD₃OD) δ 5.48 (J, 3, H-1) 7.09 (s, H-3) 2.95 (m-H-5) 2.19 (m, H-9) 1.25 (s, H-10), 6.80 (dd, 2, 7, H-3′′, H-5′′), 7. 83 (d, 2, 7, H-2′′, 6′′) 4.99 (d, 7, H-1′) 4.69 (d, J, 7, H-2′′) ¹³C NMR, 122.99 (C-1), 133.67, (C-2′′, 6′′) 116.92 (C-3′′, 5′′), 164.11 (C-4′′) 168.08 (CO) (95.83 (C-1), 151.98 (C-3), 116.92 (C-4), 30.96 (C-5) 31.98 (C-6) 42.04 (C-7), 80.64 (C-8), 53.19 (C-9) 25.15 (C-10), 170.71 (C-11) 98.64 (C-1′), 76.85 (C-2′) 75.70 (C-3′), and 72.55 (C-4′) 79.30 (C-5′) 63.54 (C-6′).

For crystallographic studies the compound was recrytallized from water to get needles.

2.1.5. X-Ray Intensity Data Collection

X-ray intensity data of 13067 reflections (of which 5060 unique) were collected at 293(2) K on a CCD area-detector diffractometer (X’calibur system —Oxford diffraction make, UK) equipped with graphite monochromated MoKα radiation ( Å). The crystal used for data collection was of dimensions 0.30 mm × 0.20 mm × 0.20 mm. The cell dimensions were determined by least-squares fit of angular settings of 6074 reflections in the range from 3.3499° to 28.9448°. The intensities were measured by scan mode for range from 3.41°to 26.00° with hkl values (, , ). 3389 reflections were treated as observed (). Data were corrected for Lorentz, absorption, and polarisation factors.

2.1.6. Structure Solution and Refinement

The crystal structure was solved by direct methods using SHELXS-97 software [25]. The values of and show the quality of data satisfactory. A total of 256 phase sets were refined with the correct phase set having an absolute figure of merit, , and combined figure of merit CFOM = 0.068. Multisolution tangent refinement was carried out using 845 -values with . Two water molecules were also observed. An -map drawn with the correct set of phases revealed all the nonhydrogen atoms of the molecule. The -factor based on the 845 -values was .

Full-matrix least-squares refinement was carried out using SHELXL-97 software. During an anisotropic refinement of all the nonhydrogen atoms, one of the water molecules, O2W, was found disordered to another position with refinable occupancy. The refined occupancy converged to 0.56(1) : 0.44(1). All the hydrogen atoms (except water hydrogen atoms) were geometrically fixed and allowed to ride on the corresponding nonhydrogen atoms with C-H = 0.93 Å–0.98 Å, and of the attached C-atom for methyl H atoms and for other H atoms. Water hydrogen atoms could not be located due to disorder. The final refinement cycles converged to and wR (F²) = 0.1111. Final cycles of refinement resulted in a residual electron density in the range  eÅ⁻³. Chemical structure of the molecule is shown in Scheme 1.

Scheme 1: Chemical structure of the compound 2′-p-hydroxybenzoyl mussaenosidic acid.

3. Results and Discussion

The molecular structure of 2′-p-hydroxybenzoyl mussaenosidic acid is depicted in Figure 1 and crystallographic data are given in Table 1. The molecule consists of four rings in which two are condensed rings. The bond angles around the carbon atom C7 (i.e., O3–C7–C8 = 111.5 (3)°, O3–C7–O4 = 123.3 (3)°, and O4–C7–C8 = 125.2 (3)°) and carbon atom C23 (i.e., C21–C23–O9 = 119.4 (3)°, C21–C23–O10 = 115.7 (3)°, and O9–C23–O10 = 124.8 (3)°) are close to 120° which shows that these two carbon atoms are in sp ² hybridized state. The bond length C7=O4 is 1.199 (3) Å which is very close to average C=O bond length in esters, that is, 1.196 Å. The six C–C bond lengths in phenyl ring-A lie in the range from 1.359 (4) Å to 1.389 (4) Å as expected for a fully delocalized benzyl system. The other important bond lengths and bond angles of the molecule are listed in Table 2. These bond lengths and angles are comparable with the expected values.

Table 1: Crystal and experimental data.

Crystal description
White block

Empirical formula
C₂₃H₂₈O₁₂·2H₂O

Formula weight
528.5

Radiation, wavelength
MoK, 0.71073 

Unit cell volume
1304.71(10) 

Number of molecules per unit cell,
2

Temperature
293(2) K

Absorption coefficient
0.113 mm⁻¹

556

Scan mode
scan

range for entire data collection
3.41° < < 26.00°

Reflections collected/unique
13068/5060

Reflections observed
3389

0.0440

0.0747

Structure determination
Direct methods

Refinement
Full-matrix least-squares on

Number of parameters refined
344

Weight
1/ ++ where

Goodness-of-fit
0.949

Table 2: Bond lengths () and bond angles (°) for nonhydrogen atoms (e.s.d.’s are given in parentheses).

Bond lengths

O1–C3
1.412(3)
O1–C4
1.431(4)

C5–O6
1.424(4)
C5–C1
1.499(4)

C5–C4
1.517(4)
O3–C7
1.357(4)

O3–C2
1.441(3)
O5–C1
1.424(4)

O2–C3
1.392(3)
O2–C14
1.417(3)

C3–C2
1.511(4)
C4–C6
1.513(4)

C2–C1
1.517(4)
O8–C22
1.365(4)

O8–C14
1.438(4)
O11–C16
1.438(4)

C7–O4
1.199(3)
C7–C8
1.481(4)

C8–C9
1.387(4)
C8–C13
1.389(4)

C15–C14
1.496(4)
C15–C16
1.528(4)

C15–C20
1.555(4)
C6–O7
1.416(4)

C13–C12
1.359(4)
C11–O12
1.366(4)

C11–C12
1.384(5)
C11–C10
1.386(4)

C21–C22
1.319(4)
C21–C23
1.465(4)

C21–C20
1.487(5)
C23–O9
1.262(4)

C23–O10
1.270(4)
C9–C10
1.380(4)

C20–C19
1.562(4)
C16–C17
1.496(5)

C16–C18
1.524(5)
C18–C19
1.515(5)

Bond angles

C3–O1–C4
113.4(2)
O6–C5–C1
112.1(2)

O6–C5–C4
109.1(3)
C1–C5–C4
110.5(2)

C7–O3–C2
118.0(2)
C3–O2–C14
113.7(2)

O2–C3–O1
106.9(2)
O2–C3–C2
109.6(2)

O1–C3–C2
109.1(2)
O1–C4–C6
105.6(3)

O1–C4–C5
109.7(2)
C6–C4–C5
113.4(2)

O3–C2–C3
107.0(2)
O3–C2–C1
109.5(2)

C3–C2–C1
108.9(2)
C22–O8–C14
114.6(2)

O5–C1–C5
109.3(2)
O5–C1–C2
112.1(3)

C5–C1–C2
109.9(2)
O4–C7–O3
123.3(3)

O4–C7–C8
125.2(3)
O3–C7–C8
111.5(3)

C9–C8–C13
118.5(3)
C9–C8–C7
118.4(3)

C13–C8–C7
123.1(3)
C14–C15–C16
116.5(3)

C14–C15–C20
114.2(3)
C16–C15–C20
106.0(2)

O7–C6–C4
109.9(3)
C12–C13–C8
121.3(3)

O12–C11–C12
121.0(3)
O12–C11–C10
118.8(3)

C12–C11–C10
120.2(3)
C22–C21–C23
117.8(3)

C22–C21–C20
122.9(3)
C23–C21–C20
119.3(3)

O9–C23–O10
124.8(3)
O9–C23–C21
119.4(3)

O10–C23–C21
115.7(3)
C10–C9–C8
120.9(3)

C9–C10–C11
119.3(3)
C21–C22–O8
125.6(3)

C21–C20–C15
111.7(3)
C21–C20–C19
114.4(3)

C15–C20–C19
103.7(3)
O2–C14–O8
108.2(2)

O2–C14–C15
108.1(2)
O8–C14–C15
114.1(2)

O11–C16–C17
106.0(3)
O11–C16–C18
112.0(3)

C17–C16–C18
112.1(3)
O11–C16–C15
110.5(2)

C17–C16–C15
114.9(3)
C18–C16–C15
101.5(3)

C13–C12–C11
119.9(3)
C19–C18–C16
103.8(3)

C18–C19–C20
106.1(3)

Figure 1: ORTEP view of the molecule with displacement ellipsoids drawn at 40% probability level. H atoms are shown as small spheres of arbitrary radii.

The phenyl ring-A is almost planar with maximum deviation from planarity observed for the atom C11 by −0.0099 (36) Å. The oxygen atom O12 deviated from the least square plane of ring-A by 0.0554 (29) Å. In the title molecule, ring-B is in chair conformation with best mirror plane passing through O1 and C1 (asymmetric parameter ) and the best twofold rotation axis bisecting the bonds O1–C3 and C1–C5 (asymmetric parameter ). Torsion angles for nonhydrogen atoms are listed in Table 3.

Table 3: Torsion angles (°) for nonhydrogen atoms (e.s.d.’s are given in parentheses).

C14–O2–C3–O1
−78.3(3)
C14–O2–C3–C2
163.5(2)

C4–O1–C3–O2
178.7(2)
C4–O1–C3–C2
−62.8(3)

C3–O1–C4–C6
−177.4(2)
C3–O1–C4–C5
60.0(3)

O6–C5–C4–O1
−178.4(2)
C1–C5–C4–O1
−54.7(3)

O6–C5–C4–C6
63.8(3)
C1–C5–C4–C6
−172.5(3)

C7–O3–C2–C3
135.0(3)
C7–O3–C2–C1
−107.1(3)

O2–C3–C2–O3
−65.6(3)
O1–C3–C2–O3
177.7(2)

O2–C3–C2–C1
176.2(2)
O1–C3–C2–C1
59.4(3)

O6–C5–C1–O5
−60.2(3)
C4–C5–C1–O5
177.9(3)

O6–C5–C1–C2
176.4(2)
C4–C5–C1–C2
54.4(3)

O3–C2–C1–O5
65.1(3)
C3–C2–C1–O5
−178.2(2)

O3–C2–C1–C5
−173.1(2)
C3–C2–C1–C5
−56.4(3)

C2–O3–C7–O4
4.3(4)
C2–O3–C7–C8
−175.2(2)

O4–C7–C8–C9
12.8(5)
O3–C7–C8–C9
−167.7(3)

O4–C7–C8–C13
−168.1(3)
O3–C7–C8–C13
11.4(4)

O1–C4–C6–O7
−61.4(3)
C5–C4–C6–O7
58.7(4)

C9–C8–C13–C12
−0.1(5)
C7–C8–C13–C12
−179.2(3)

C22–C21–C23–O9
0.4(5)
C20–C21–C23–O9
178.2(3)

C22–C21–C23–O10
−177.8(3)
C20–C21–C23–O10
−0.1(4)

C13–C8–C9–C10
−0.6(5)
C7–C8–C9–C10
178.5(3)

C8–C9–C10–C11
0.0(5)
O12–C11–C10–C9
−177.9(3)

C12–C11–C10–C9
1.4(5)
C23–C21–C22–O8
176.2(3)

C20–C21–C22–O8
−1.5(5)
C14–O8–C22–C21
−21.2(4)

C22–C21–C20–C15
−0.4(4)
C23–C21–C20–C15
−178.0(3)

C22–C21–C20–C19
−117.9(4)
C23–C21–C20–C19
64.5(4)

C14–C15–C20–C21
23.7(4)
C16–C15–C20–C21
−105.8(3)

C14–C15–C20–C19
147.4(3)
C16–C15–C20–C19
17.9(3)

C3–O2–C14–O8
−72.8(3)
C3–O2–C14–C15
163.3(2)

C22–O8–C14–O2
−75.7(3)
C22–O8–C14–C15
44.6(4)

C16–C15–C14–O2
−161.8(3)
C20–C15–C14–O2
74.0(3)

C16–C15–C14–O8
77.9(3)
C20–C15–C14–O8
−46.3(4)

C14–C15–C16–O11
74.9(4)
C20–C15–C16–O11
−156.9(3)

C14–C15–C16–C17
−44.9(4)
C20–C15–C16–C17
83.3(4)

C14–C15–C16–C18
−166.1(3)
C20–C15–C16–C18
−37.9(3)

C8–C13–C12–C11
1.4(5)
O12–C11–C12–C13
177.2(3)

C10–C11–C12–C13
−2.1(5)
O11–C16–C18–C19
161.4(3)

C17–C16–C18–C19
−79.5(4)
C15–C16–C18–C19
43.5(4)

C16–C18–C19–C20
−33.0(4)
C21–C20–C19–C18
131.2(4)

C15–C20–C19–C18
9.2(4)

Six membered ring-C adopts a sofa conformation with best mirror plane passing through C14 and C21 (asymmetric parameter ). The carboxylic group attached to ring-C is found to be coplanar with the least square plane of ring-C as reflected from the small values of torsion angles C22–C21–C23–O9 = 0.4 (5)° and C20–C21–C23–O10 = −0.1 (4)°, respectively (Table 3). The five membered ring-D adopts half chair conformation with best twofold axis passing through atom C20 and bisecting the bond C16–C18 (asymmetry parameter ).

A packing view of the molecules in the unit cell viewed down the -axis is shown in Figure 2. A stereo view of unit cell is shown in Figure 3 which shows how the molecules are stacked over each other parallel to [010] direction. An examination of nonbonded contacts reveals five O–H⋯O intermolecular hydrogen bonds which are responsible for the stability of molecules within the unit cell. A summary of intra- and intermolecular hydrogen bonds is given in Table 4.

Table 4: Geometry of intra- and intermolecular hydrogen bonds.

D–H⋯A
D–H ()
D⋯A ()
H⋯A ()
D–H⋯A (°)

O11–H11⋯O2W
0.82
2.72
1.94
158.6(3)

O7–H7⋯O9i
0.82
2.65
1.84
170.1(2)

O5–H5A⋯O10ii
0.82
1.89
1.90
155.8(2)

O6–H6⋯O7iii
0.82
2.87
2.10
156.4(2)

O10–H10A⋯O5iv
0.82
2.66
1.90
157.6(2)

O12–H12⋯O6v
0.82
2.77
2.02
152.4(2)

.

−.

−.

−.

.

Figure 2: Packing of the molecules down b-axis.

Figure 3: Stereo plot of the unit cell viewed down the b-axis with c horizontal and a vertical.

Supplementary Data

CCDC no. 955069 contain the supplementary crystallographic data for the compound 2′-p-hydroxybenzoyl mussaenosidic acid. The data can be obtained free of charge via http://www.ccdc.cam.ac.uk/data_request/cif by e-mailing data request@ccdc.cam.ac.uk, or by contacting The Cambridge Crystallography Data Centre, 12 Union Road, Cambridge, CB2 IEZ, UK. Fax: +44(0) 1223-336033.

Conflict of Interests

The authors declare that there is no conflict of interests regarding the publication of this paper.

Acknowledgment

One of the authors (Rajni Kant) acknowledges the Department of Science & Technology for single crystal X-ray diffractometer as a National Facility sanctioned by the Ministry of Science and Technology, Government of India, under Research Project no. SR/S2/CMP-47/2003.

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