organic compounds
6β-Acetoxy-1α,7β,11β,15β-tetrahydroxy-7α,20-epoxy-ent-kaur-16-ene
aSchool of Pharmacy, Xinxiang Medical University, Xinxiang, Henan 453003, People's Republic of China
*Correspondence e-mail: yannz2009@163.com
The title compound, C22H32O7, a natural ent-kaurane diterpenoid also referred to as Maoyecrystal F, was obtained from the medicinal plant Isodon nervosa. There are four rings with the expected cis and trans junctions. Cyclohexane ring A adopts a chair conformation, rings B and C adopt boat conformations, while the five-membered ring has an The molecules stack along the a axis in the crystal and are linked together by intermolecular O—H⋯O hydrogen bonds.
Related literature
For related literature on the genus Isodon and see: Sun et al. (2001); Zhang et al. (2003); Yan et al. (2008).
Experimental
Crystal data
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Data collection
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Refinement
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Data collection: CrystalClear (Rigaku, 2008); cell CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536810000231/hg2621sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810000231/hg2621Isup2.hkl
The dried and crushed leaves of Isodon nervosa (12 kg, collected from Henan Province, China) were extracted three times with Me2CO/H2O (7:3, v/v) at room temperature over a period of six days. The extract was filtered and the solvent was removed under reduced pressure. The residue was then partitioned between water and AcOEt. After removal of the solvent, the AcOEt residue was separated by repeated silica gel (200–300 mesh) α]D20 -6.1 ° (c 0.52, CH3OH). Crystals suitable for X-ray analysis were obtained by slow evaporation of a solution of the title compound in CH3OH at room temperature.
and recrystallization from CHCl3/CH3OH(8:1), giving 35 mg of the title compound (m.p. 489–491 K. [All H atoms were included in calculated positions and refined as riding atoms, with C—H = 0.98Å (CH3), 0.99Å (CH2), 0.95Å (═CH2), 1.00Å (CH), and O—H = 0.82Å, and with Uiso(H) = 1.2 Ueq(C). In the absence of significant effects, Friedel pairs were merged. The choice of was based on comparison of the with that of related compounds having known stereochemistry.
The title compound, 6β-Acetoxy-1α,7β,11β,15β-tetrahydroxy- 7α,20-epoxy-ent-kaur-16-ene, is a natural ent-kaurane diterpenoid isolated from the medicinal plant Isodon nervosa. It is widely distributed in China, and has long been used as a Chinese folk medicine in the treatment of acute jaundice, hepatitis and acute cholecystitis. We re-examined the leaves of Isodon nervosus collected in Henan province of China and obtained the ent-kaurane diterpenoid, named Maoyecrystal F (Yan et al., 2008). The compound has also been isolated from Isodon japonica and its structure was postulated from spectroscopic methods (Zhang et al., 2003). Its X-ray crystallographic analysis confirms this proposed molecular structure (Fig. 1). In the structure there is a trans junction between ring A (C1—C5/C10) and ring B (C5—C10); cis junctions are present between ring B and ring C (C8/C9/C11—C14), and ring C and ring D (C8/C13—C16). Ring A adopts chair conformation, with an average torsion angles of 53.99 (19) °. Rings B and C adopt boat conformation because of the formation of the oxygen bridge at C-7 and C-20. Ring D shows an evenlope conformation. In addition, the six-membered rings O1/C20/C10/C5—C7 and O1/C7—C10/C20 both adopt boat conformations. The four hydroxy groups at C1, C7, C11 and C15 adopt α, β, β, β-orientations respectively, an acetoxy group at C6 adopt β-orientation. Bond lengths and angles are within expected aranges (Allen et al., 1987), with averages values (Å): Csp3—Csp3 = 1.544 (2), Csp3—Csp2 = 1.516 (2), Csp2—Csp2 (CC) = 1.323 (3), Csp3—O = 1.434 (2).
The compound contains ten chiral centers at C1(S), C5(R), C6(S), C7(S), C8(S), C9(S), C10(S), C11(S),C13(S) and C15(R). Although the
could not be reliably determined from effects, the negative showed this compound to be in the ent-kaurane series as reported in genus Isodon (Sun et al., 2001), rather than in the kaurane series, allowing us to assign the correct configuration. In the intermolecular O—H···O hydrogen bond (table 1) are effective in the stabilization of the structure and are responsible for the formation of a three-dimensional network (Fig. 2).For related literature on the genus Isodon and
see: Sun et al. (2001); Zhang et al. (2003); Yan et al. (2008).Data collection: CrystalClear (Rigaku, 2008); cell
CrystalClear (Rigaku, 2008); data reduction: CrystalClear (Rigaku, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C22H32O7 | F(000) = 440 |
Mr = 408.21 | Dx = 1.396 Mg m−3 |
Monoclinic, P21 | Melting point = 489–491 K |
Hall symbol: P 2yb | Mo Kα radiation, λ = 0.71073 Å |
a = 9.759 (3) Å | Cell parameters from 3508 reflections |
b = 6.6712 (17) Å | θ = 3.3–27.5° |
c = 14.927 (4) Å | µ = 0.10 mm−1 |
β = 90.002 (4)° | T = 93 K |
V = 971.8 (4) Å3 | Prism, colorless |
Z = 2 | 0.50 × 0.33 × 0.23 mm |
Rigaku AFC10 Saturn724+ diffractometer | 2262 reflections with I > 2σ(I) |
Radiation source: rotating anode | Rint = 0.025 |
Graphite monochromator | θmax = 27.5°, θmin = 3.3° |
Detector resolution: 28.5714 pixels mm-1 | h = −9→12 |
ω scans | k = −8→8 |
7880 measured reflections | l = −19→19 |
2412 independent reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.028 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.064 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0336P)2 + 0.163P] where P = (Fo2 + 2Fc2)/3 |
2412 reflections | (Δ/σ)max < 0.001 |
281 parameters | Δρmax = 0.25 e Å−3 |
1 restraint | Δρmin = −0.17 e Å−3 |
C22H32O7 | V = 971.8 (4) Å3 |
Mr = 408.21 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 9.759 (3) Å | µ = 0.10 mm−1 |
b = 6.6712 (17) Å | T = 93 K |
c = 14.927 (4) Å | 0.50 × 0.33 × 0.23 mm |
β = 90.002 (4)° |
Rigaku AFC10 Saturn724+ diffractometer | 2262 reflections with I > 2σ(I) |
7880 measured reflections | Rint = 0.025 |
2412 independent reflections |
R[F2 > 2σ(F2)] = 0.028 | 1 restraint |
wR(F2) = 0.064 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | Δρmax = 0.25 e Å−3 |
2412 reflections | Δρmin = −0.17 e Å−3 |
281 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.71560 (11) | 0.24172 (19) | 0.19745 (8) | 0.0137 (3) | |
O2 | 0.39948 (13) | 0.6243 (2) | 0.07687 (8) | 0.0153 (3) | |
O3 | 0.76328 (11) | 0.54105 (18) | 0.39884 (7) | 0.0130 (3) | |
O4 | 0.91072 (12) | 0.2840 (2) | 0.27898 (9) | 0.0146 (3) | |
O5 | 0.57949 (12) | 0.90169 (19) | 0.06925 (8) | 0.0149 (3) | |
O6 | 0.87086 (12) | 0.86646 (19) | 0.30694 (8) | 0.0143 (3) | |
O7 | 0.78961 (13) | 0.2859 (2) | 0.49762 (9) | 0.0232 (3) | |
C1 | 0.41761 (16) | 0.6066 (3) | 0.17186 (11) | 0.0124 (3) | |
H1 | 0.4059 | 0.7432 | 0.1983 | 0.015* | |
C2 | 0.30078 (17) | 0.4772 (3) | 0.20568 (11) | 0.0157 (4) | |
H2A | 0.3104 | 0.3398 | 0.1814 | 0.019* | |
H2B | 0.2125 | 0.5326 | 0.1843 | 0.019* | |
C3 | 0.30058 (17) | 0.4693 (3) | 0.30758 (11) | 0.0162 (4) | |
H3A | 0.2223 | 0.3867 | 0.3280 | 0.019* | |
H3B | 0.2878 | 0.6065 | 0.3314 | 0.019* | |
C4 | 0.43380 (16) | 0.3814 (3) | 0.34543 (11) | 0.0132 (3) | |
C5 | 0.55753 (16) | 0.4991 (3) | 0.30404 (11) | 0.0116 (3) | |
H5 | 0.5535 | 0.6368 | 0.3304 | 0.014* | |
C6 | 0.69539 (16) | 0.4098 (3) | 0.33418 (10) | 0.0119 (3) | |
H6 | 0.6780 | 0.2771 | 0.3632 | 0.014* | |
C7 | 0.78918 (16) | 0.3783 (3) | 0.25387 (11) | 0.0121 (3) | |
C8 | 0.82107 (16) | 0.5716 (3) | 0.20203 (11) | 0.0116 (3) | |
C9 | 0.68182 (16) | 0.6785 (3) | 0.17895 (11) | 0.0111 (3) | |
H9 | 0.6720 | 0.7965 | 0.2198 | 0.013* | |
C10 | 0.56065 (16) | 0.5289 (3) | 0.19985 (11) | 0.0111 (3) | |
C11 | 0.68778 (17) | 0.7582 (3) | 0.08150 (11) | 0.0132 (3) | |
H11 | 0.6716 | 0.6433 | 0.0398 | 0.016* | |
C12 | 0.82467 (17) | 0.8558 (3) | 0.05703 (11) | 0.0166 (4) | |
H12A | 0.8296 | 0.9898 | 0.0854 | 0.020* | |
H12B | 0.8285 | 0.8750 | −0.0087 | 0.020* | |
C13 | 0.95062 (17) | 0.7303 (3) | 0.08700 (11) | 0.0160 (4) | |
H13 | 1.0228 | 0.7243 | 0.0395 | 0.019* | |
C14 | 0.90325 (17) | 0.5203 (3) | 0.11600 (11) | 0.0143 (3) | |
H14A | 0.9820 | 0.4315 | 0.1292 | 0.017* | |
H14B | 0.8444 | 0.4569 | 0.0700 | 0.017* | |
C15 | 0.92640 (16) | 0.7137 (3) | 0.24989 (11) | 0.0132 (3) | |
H15 | 0.9913 | 0.6298 | 0.2857 | 0.016* | |
C16 | 1.00555 (17) | 0.8127 (3) | 0.17408 (11) | 0.0152 (4) | |
C17 | 1.10478 (18) | 0.9460 (3) | 0.18423 (13) | 0.0210 (4) | |
H17A | 1.1495 | 1.0001 | 0.1332 | 0.025* | |
H17B | 1.1313 | 0.9875 | 0.2426 | 0.025* | |
C18 | 0.43741 (17) | 0.4168 (3) | 0.44718 (11) | 0.0165 (4) | |
H18A | 0.3619 | 0.3437 | 0.4756 | 0.020* | |
H18B | 0.4278 | 0.5604 | 0.4595 | 0.020* | |
H18C | 0.5248 | 0.3689 | 0.4713 | 0.020* | |
C19 | 0.43608 (18) | 0.1517 (3) | 0.32907 (12) | 0.0169 (4) | |
H19A | 0.3618 | 0.0884 | 0.3630 | 0.020* | |
H19B | 0.5243 | 0.0970 | 0.3488 | 0.020* | |
H19C | 0.4236 | 0.1247 | 0.2651 | 0.020* | |
C20 | 0.59817 (16) | 0.3306 (3) | 0.15381 (11) | 0.0124 (3) | |
H20A | 0.5194 | 0.2372 | 0.1568 | 0.015* | |
H20B | 0.6194 | 0.3554 | 0.0899 | 0.015* | |
C21 | 0.81536 (17) | 0.4540 (3) | 0.47425 (11) | 0.0158 (4) | |
C22 | 0.90964 (19) | 0.5955 (3) | 0.52190 (12) | 0.0221 (4) | |
H22A | 0.9963 | 0.6051 | 0.4890 | 0.027* | |
H22B | 0.9273 | 0.5457 | 0.5826 | 0.027* | |
H22C | 0.8670 | 0.7283 | 0.5253 | 0.027* | |
H5O | 0.597 (2) | 0.957 (4) | 0.0218 (15) | 0.022 (6)* | |
H6O | 0.834 (2) | 0.812 (4) | 0.3491 (15) | 0.025 (6)* | |
H2O | 0.444 (2) | 0.730 (4) | 0.0632 (15) | 0.029 (6)* | |
H4O | 0.892 (2) | 0.166 (4) | 0.2884 (16) | 0.031 (7)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0143 (5) | 0.0100 (6) | 0.0166 (6) | 0.0011 (5) | −0.0030 (4) | −0.0022 (5) |
O2 | 0.0183 (6) | 0.0157 (7) | 0.0119 (6) | −0.0004 (5) | −0.0039 (5) | −0.0004 (5) |
O3 | 0.0139 (5) | 0.0136 (6) | 0.0116 (5) | −0.0020 (5) | −0.0024 (4) | −0.0010 (5) |
O4 | 0.0116 (5) | 0.0100 (7) | 0.0223 (6) | 0.0012 (5) | −0.0015 (5) | 0.0024 (5) |
O5 | 0.0174 (6) | 0.0129 (6) | 0.0143 (6) | 0.0027 (5) | −0.0016 (5) | 0.0034 (5) |
O6 | 0.0178 (6) | 0.0108 (6) | 0.0145 (6) | −0.0008 (5) | 0.0011 (5) | −0.0015 (5) |
O7 | 0.0194 (6) | 0.0275 (8) | 0.0227 (7) | −0.0025 (6) | −0.0052 (5) | 0.0115 (6) |
C1 | 0.0137 (8) | 0.0126 (8) | 0.0109 (7) | 0.0022 (7) | −0.0028 (6) | −0.0008 (6) |
C2 | 0.0127 (7) | 0.0170 (9) | 0.0174 (8) | −0.0002 (7) | −0.0035 (6) | −0.0001 (7) |
C3 | 0.0116 (7) | 0.0191 (9) | 0.0179 (8) | 0.0000 (7) | 0.0011 (6) | 0.0005 (7) |
C4 | 0.0118 (7) | 0.0144 (9) | 0.0135 (7) | −0.0011 (7) | −0.0003 (6) | −0.0003 (7) |
C5 | 0.0118 (7) | 0.0112 (8) | 0.0117 (7) | 0.0005 (7) | −0.0011 (6) | −0.0012 (6) |
C6 | 0.0116 (7) | 0.0111 (8) | 0.0130 (7) | −0.0015 (7) | −0.0026 (6) | 0.0002 (7) |
C7 | 0.0122 (7) | 0.0090 (8) | 0.0150 (7) | 0.0012 (7) | −0.0027 (6) | −0.0013 (7) |
C8 | 0.0116 (7) | 0.0100 (8) | 0.0132 (7) | 0.0013 (6) | 0.0007 (6) | −0.0001 (7) |
C9 | 0.0122 (7) | 0.0095 (8) | 0.0115 (7) | 0.0013 (6) | −0.0013 (6) | −0.0003 (6) |
C10 | 0.0114 (7) | 0.0102 (8) | 0.0116 (7) | 0.0003 (7) | −0.0011 (6) | 0.0001 (6) |
C11 | 0.0160 (7) | 0.0117 (8) | 0.0119 (7) | 0.0033 (7) | 0.0000 (6) | −0.0002 (6) |
C12 | 0.0179 (8) | 0.0157 (9) | 0.0161 (8) | −0.0009 (8) | 0.0016 (6) | 0.0014 (7) |
C13 | 0.0157 (8) | 0.0155 (9) | 0.0169 (8) | 0.0006 (7) | 0.0042 (6) | 0.0010 (7) |
C14 | 0.0149 (7) | 0.0128 (9) | 0.0154 (8) | 0.0023 (7) | 0.0031 (6) | −0.0019 (7) |
C15 | 0.0127 (7) | 0.0112 (9) | 0.0158 (8) | 0.0018 (7) | −0.0011 (6) | 0.0000 (7) |
C16 | 0.0133 (7) | 0.0123 (9) | 0.0199 (8) | 0.0038 (7) | 0.0017 (6) | 0.0007 (7) |
C17 | 0.0184 (8) | 0.0189 (10) | 0.0257 (9) | −0.0017 (8) | 0.0036 (7) | 0.0006 (8) |
C18 | 0.0158 (8) | 0.0189 (10) | 0.0147 (8) | −0.0005 (7) | 0.0017 (6) | 0.0006 (7) |
C19 | 0.0167 (8) | 0.0156 (9) | 0.0186 (8) | −0.0040 (7) | −0.0005 (7) | 0.0028 (7) |
C20 | 0.0134 (7) | 0.0103 (8) | 0.0136 (7) | 0.0010 (7) | −0.0014 (6) | −0.0017 (7) |
C21 | 0.0115 (7) | 0.0236 (10) | 0.0124 (7) | 0.0018 (7) | −0.0002 (6) | 0.0026 (7) |
C22 | 0.0190 (9) | 0.0298 (11) | 0.0175 (8) | 0.0000 (8) | −0.0049 (7) | −0.0014 (8) |
O1—C7 | 1.434 (2) | C8—C9 | 1.573 (2) |
O1—C20 | 1.4453 (19) | C9—C11 | 1.550 (2) |
O2—C1 | 1.4337 (19) | C9—C10 | 1.578 (2) |
O2—H2O | 0.85 (3) | C9—H9 | 1.0000 |
O3—C21 | 1.365 (2) | C10—C20 | 1.535 (2) |
O3—C6 | 1.4620 (19) | C11—C12 | 1.530 (2) |
O4—C7 | 1.394 (2) | C11—H11 | 1.0000 |
O4—H4O | 0.82 (3) | C12—C13 | 1.553 (2) |
O5—C11 | 1.438 (2) | C12—H12A | 0.9900 |
O5—H5O | 0.82 (2) | C12—H12B | 0.9900 |
O6—C15 | 1.434 (2) | C13—C16 | 1.510 (2) |
O6—H6O | 0.81 (2) | C13—C14 | 1.537 (3) |
O7—C21 | 1.201 (2) | C13—H13 | 1.0000 |
C1—C2 | 1.517 (2) | C14—H14A | 0.9900 |
C1—C10 | 1.546 (2) | C14—H14B | 0.9900 |
C1—H1 | 1.0000 | C15—C16 | 1.521 (2) |
C2—C3 | 1.522 (2) | C15—H15 | 1.0000 |
C2—H2A | 0.9900 | C16—C17 | 1.323 (3) |
C2—H2B | 0.9900 | C17—H17A | 0.9500 |
C3—C4 | 1.534 (2) | C17—H17B | 0.9500 |
C3—H3A | 0.9900 | C18—H18A | 0.9800 |
C3—H3B | 0.9900 | C18—H18B | 0.9800 |
C4—C18 | 1.538 (2) | C18—H18C | 0.9800 |
C4—C19 | 1.552 (3) | C19—H19A | 0.9800 |
C4—C5 | 1.567 (2) | C19—H19B | 0.9800 |
C5—C6 | 1.539 (2) | C19—H19C | 0.9800 |
C5—C10 | 1.568 (2) | C20—H20A | 0.9900 |
C5—H5 | 1.0000 | C20—H20B | 0.9900 |
C6—C7 | 1.523 (2) | C21—C22 | 1.498 (3) |
C6—H6 | 1.0000 | C22—H22A | 0.9800 |
C7—C8 | 1.535 (2) | C22—H22B | 0.9800 |
C8—C14 | 1.552 (2) | C22—H22C | 0.9800 |
C8—C15 | 1.570 (2) | ||
C7—O1—C20 | 113.65 (13) | C5—C10—C9 | 106.89 (12) |
C1—O2—H2O | 104.1 (16) | O5—C11—C12 | 109.13 (14) |
C21—O3—C6 | 117.28 (14) | O5—C11—C9 | 108.68 (13) |
C7—O4—H4O | 106.7 (17) | C12—C11—C9 | 113.75 (13) |
C11—O5—H5O | 104.9 (16) | O5—C11—H11 | 108.4 |
C15—O6—H6O | 108.2 (17) | C12—C11—H11 | 108.4 |
O2—C1—C2 | 106.46 (13) | C9—C11—H11 | 108.4 |
O2—C1—C10 | 113.96 (13) | C11—C12—C13 | 113.12 (14) |
C2—C1—C10 | 113.43 (14) | C11—C12—H12A | 109.0 |
O2—C1—H1 | 107.6 | C13—C12—H12A | 109.0 |
C2—C1—H1 | 107.6 | C11—C12—H12B | 109.0 |
C10—C1—H1 | 107.6 | C13—C12—H12B | 109.0 |
C1—C2—C3 | 110.70 (14) | H12A—C12—H12B | 107.8 |
C1—C2—H2A | 109.5 | C16—C13—C14 | 101.32 (14) |
C3—C2—H2A | 109.5 | C16—C13—C12 | 109.43 (15) |
C1—C2—H2B | 109.5 | C14—C13—C12 | 109.54 (14) |
C3—C2—H2B | 109.5 | C16—C13—H13 | 112.0 |
H2A—C2—H2B | 108.1 | C14—C13—H13 | 112.0 |
C2—C3—C4 | 112.34 (14) | C12—C13—H13 | 112.0 |
C2—C3—H3A | 109.1 | C13—C14—C8 | 100.80 (13) |
C4—C3—H3A | 109.1 | C13—C14—H14A | 111.6 |
C2—C3—H3B | 109.1 | C8—C14—H14A | 111.6 |
C4—C3—H3B | 109.1 | C13—C14—H14B | 111.6 |
H3A—C3—H3B | 107.9 | C8—C14—H14B | 111.6 |
C3—C4—C18 | 108.92 (14) | H14A—C14—H14B | 109.4 |
C3—C4—C19 | 109.37 (15) | O6—C15—C16 | 108.98 (15) |
C18—C4—C19 | 107.88 (15) | O6—C15—C8 | 116.86 (13) |
C3—C4—C5 | 108.42 (14) | C16—C15—C8 | 104.85 (13) |
C18—C4—C5 | 107.14 (13) | O6—C15—H15 | 108.6 |
C19—C4—C5 | 114.95 (14) | C16—C15—H15 | 108.6 |
C6—C5—C4 | 111.35 (14) | C8—C15—H15 | 108.6 |
C6—C5—C10 | 108.79 (13) | C17—C16—C13 | 127.09 (17) |
C4—C5—C10 | 117.99 (13) | C17—C16—C15 | 125.33 (16) |
C6—C5—H5 | 106.0 | C13—C16—C15 | 107.58 (14) |
C4—C5—H5 | 106.0 | C16—C17—H17A | 120.0 |
C10—C5—H5 | 106.0 | C16—C17—H17B | 120.0 |
O3—C6—C7 | 109.26 (12) | H17A—C17—H17B | 120.0 |
O3—C6—C5 | 110.92 (14) | C4—C18—H18A | 109.5 |
C7—C6—C5 | 110.41 (13) | C4—C18—H18B | 109.5 |
O3—C6—H6 | 108.7 | H18A—C18—H18B | 109.5 |
C7—C6—H6 | 108.7 | C4—C18—H18C | 109.5 |
C5—C6—H6 | 108.7 | H18A—C18—H18C | 109.5 |
O4—C7—O1 | 107.27 (13) | H18B—C18—H18C | 109.5 |
O4—C7—C6 | 111.22 (13) | C4—C19—H19A | 109.5 |
O1—C7—C6 | 104.41 (12) | C4—C19—H19B | 109.5 |
O4—C7—C8 | 110.02 (13) | H19A—C19—H19B | 109.5 |
O1—C7—C8 | 109.84 (13) | C4—C19—H19C | 109.5 |
C6—C7—C8 | 113.76 (14) | H19A—C19—H19C | 109.5 |
C7—C8—C14 | 109.67 (14) | H19B—C19—H19C | 109.5 |
C7—C8—C15 | 114.24 (13) | O1—C20—C10 | 109.92 (12) |
C14—C8—C15 | 99.86 (13) | O1—C20—H20A | 109.7 |
C7—C8—C9 | 108.42 (13) | C10—C20—H20A | 109.7 |
C14—C8—C9 | 111.41 (13) | O1—C20—H20B | 109.7 |
C15—C8—C9 | 113.04 (14) | C10—C20—H20B | 109.7 |
C11—C9—C8 | 109.19 (12) | H20A—C20—H20B | 108.2 |
C11—C9—C10 | 115.50 (13) | O7—C21—O3 | 123.98 (17) |
C8—C9—C10 | 108.50 (13) | O7—C21—C22 | 125.39 (16) |
C11—C9—H9 | 107.8 | O3—C21—C22 | 110.63 (16) |
C8—C9—H9 | 107.8 | C21—C22—H22A | 109.5 |
C10—C9—H9 | 107.8 | C21—C22—H22B | 109.5 |
C20—C10—C1 | 112.54 (13) | H22A—C22—H22B | 109.5 |
C20—C10—C5 | 109.85 (14) | C21—C22—H22C | 109.5 |
C1—C10—C5 | 107.03 (12) | H22A—C22—H22C | 109.5 |
C20—C10—C9 | 106.13 (13) | H22B—C22—H22C | 109.5 |
C1—C10—C9 | 114.25 (14) | ||
O2—C1—C2—C3 | −173.23 (14) | C2—C1—C10—C9 | −170.68 (14) |
C10—C1—C2—C3 | 60.63 (19) | C6—C5—C10—C20 | 54.20 (17) |
C1—C2—C3—C4 | −60.1 (2) | C4—C5—C10—C20 | −73.84 (17) |
C2—C3—C4—C18 | 168.91 (15) | C6—C5—C10—C1 | 176.66 (14) |
C2—C3—C4—C19 | −73.40 (19) | C4—C5—C10—C1 | 48.62 (19) |
C2—C3—C4—C5 | 52.65 (19) | C6—C5—C10—C9 | −60.52 (17) |
C3—C4—C5—C6 | −176.20 (14) | C4—C5—C10—C9 | 171.44 (14) |
C18—C4—C5—C6 | 66.39 (18) | C11—C9—C10—C20 | 73.03 (17) |
C19—C4—C5—C6 | −53.47 (19) | C8—C9—C10—C20 | −49.90 (16) |
C3—C4—C5—C10 | −49.38 (19) | C11—C9—C10—C1 | −51.57 (18) |
C18—C4—C5—C10 | −166.79 (15) | C8—C9—C10—C1 | −174.50 (13) |
C19—C4—C5—C10 | 73.35 (19) | C11—C9—C10—C5 | −169.77 (14) |
C21—O3—C6—C7 | −104.90 (15) | C8—C9—C10—C5 | 67.31 (16) |
C21—O3—C6—C5 | 133.16 (14) | C8—C9—C11—O5 | −163.90 (13) |
C4—C5—C6—O3 | −107.33 (15) | C10—C9—C11—O5 | 73.54 (17) |
C10—C5—C6—O3 | 120.97 (14) | C8—C9—C11—C12 | −42.11 (19) |
C4—C5—C6—C7 | 131.41 (15) | C10—C9—C11—C12 | −164.67 (15) |
C10—C5—C6—C7 | −0.29 (19) | O5—C11—C12—C13 | 167.63 (13) |
C20—O1—C7—O4 | −170.16 (13) | C9—C11—C12—C13 | 46.1 (2) |
C20—O1—C7—C6 | 71.74 (15) | C11—C12—C13—C16 | −98.54 (17) |
C20—O1—C7—C8 | −50.61 (16) | C11—C12—C13—C14 | 11.7 (2) |
O3—C6—C7—O4 | 62.10 (17) | C16—C13—C14—C8 | 47.88 (15) |
C5—C6—C7—O4 | −175.65 (14) | C12—C13—C14—C8 | −67.65 (16) |
O3—C6—C7—O1 | 177.48 (13) | C7—C8—C14—C13 | −168.02 (13) |
C5—C6—C7—O1 | −60.27 (17) | C15—C8—C14—C13 | −47.72 (15) |
O3—C6—C7—C8 | −62.79 (17) | C9—C8—C14—C13 | 71.94 (16) |
C5—C6—C7—C8 | 59.46 (18) | C7—C8—C15—O6 | −92.48 (18) |
O4—C7—C8—C14 | 60.79 (17) | C14—C8—C15—O6 | 150.59 (14) |
O1—C7—C8—C14 | −57.07 (17) | C9—C8—C15—O6 | 32.1 (2) |
C6—C7—C8—C14 | −173.68 (13) | C7—C8—C15—C16 | 146.76 (14) |
O4—C7—C8—C15 | −50.34 (18) | C14—C8—C15—C16 | 29.83 (16) |
O1—C7—C8—C15 | −168.19 (13) | C9—C8—C15—C16 | −88.63 (15) |
C6—C7—C8—C15 | 75.20 (17) | C14—C13—C16—C17 | 150.63 (18) |
O4—C7—C8—C9 | −177.37 (13) | C12—C13—C16—C17 | −93.8 (2) |
O1—C7—C8—C9 | 64.77 (16) | C14—C13—C16—C15 | −29.05 (16) |
C6—C7—C8—C9 | −51.83 (17) | C12—C13—C16—C15 | 86.56 (17) |
C7—C8—C9—C11 | −137.89 (14) | O6—C15—C16—C17 | 53.7 (2) |
C14—C8—C9—C11 | −17.12 (19) | C8—C15—C16—C17 | 179.54 (17) |
C15—C8—C9—C11 | 94.40 (16) | O6—C15—C16—C13 | −126.61 (14) |
C7—C8—C9—C10 | −11.23 (17) | C8—C15—C16—C13 | −0.78 (18) |
C14—C8—C9—C10 | 109.54 (15) | C7—O1—C20—C10 | −15.94 (18) |
C15—C8—C9—C10 | −138.94 (14) | C1—C10—C20—O1 | −166.48 (13) |
O2—C1—C10—C20 | −53.85 (19) | C5—C10—C20—O1 | −47.35 (17) |
C2—C1—C10—C20 | 68.20 (17) | C9—C10—C20—O1 | 67.87 (16) |
O2—C1—C10—C5 | −174.62 (14) | C6—O3—C21—O7 | −12.8 (2) |
C2—C1—C10—C5 | −52.56 (18) | C6—O3—C21—C22 | 166.23 (14) |
O2—C1—C10—C9 | 67.26 (18) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2O···O5 | 0.85 (3) | 1.75 (3) | 2.5539 (19) | 156 (2) |
O4—H4O···O6i | 0.82 (3) | 2.03 (3) | 2.843 (2) | 172 (2) |
O5—H5O···O2ii | 0.82 (2) | 1.85 (2) | 2.6467 (18) | 165 (2) |
O6—H6O···O3 | 0.81 (2) | 2.07 (3) | 2.7743 (18) | 145 (2) |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, y+1/2, −z. |
Experimental details
Crystal data | |
Chemical formula | C22H32O7 |
Mr | 408.21 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 93 |
a, b, c (Å) | 9.759 (3), 6.6712 (17), 14.927 (4) |
β (°) | 90.002 (4) |
V (Å3) | 971.8 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.50 × 0.33 × 0.23 |
Data collection | |
Diffractometer | Rigaku AFC10 Saturn724+ |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7880, 2412, 2262 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.649 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.028, 0.064, 1.00 |
No. of reflections | 2412 |
No. of parameters | 281 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.25, −0.17 |
Computer programs: CrystalClear (Rigaku, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2O···O5 | 0.85 (3) | 1.75 (3) | 2.5539 (19) | 156 (2) |
O4—H4O···O6i | 0.82 (3) | 2.03 (3) | 2.843 (2) | 172 (2) |
O5—H5O···O2ii | 0.82 (2) | 1.85 (2) | 2.6467 (18) | 165 (2) |
O6—H6O···O3 | 0.81 (2) | 2.07 (3) | 2.7743 (18) | 145 (2) |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, y+1/2, −z. |
Acknowledgements
This work was supported by the Henan Province Science and Technology Foundation of China (No. 611042600)
References
Rigaku (2008). CrystalClear. Rigaku Corporation, The Woodlands, Texas, USA. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sun, H. D., Xu, Y. L. & Jiang, B. (2001). Diterpenoids from Isodon Species, pp. 4–17. Beijing: Science Press. Google Scholar
Yan, F. L., Guo, L. Q., Bai, S. P. & Sun, H. D. (2008). J. Chin. Chem. Soc. 55, 933–936. CAS Google Scholar
Zhang, J. X., Han, Q. B., Zhao, A. H. & Sun, H. D. (2003). Fitoterapia, 74, 435–438. Web of Science CrossRef PubMed CAS Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
The title compound, 6β-Acetoxy-1α,7β,11β,15β-tetrahydroxy- 7α,20-epoxy-ent-kaur-16-ene, is a natural ent-kaurane diterpenoid isolated from the medicinal plant Isodon nervosa. It is widely distributed in China, and has long been used as a Chinese folk medicine in the treatment of acute jaundice, hepatitis and acute cholecystitis. We re-examined the leaves of Isodon nervosus collected in Henan province of China and obtained the ent-kaurane diterpenoid, named Maoyecrystal F (Yan et al., 2008). The compound has also been isolated from Isodon japonica and its structure was postulated from spectroscopic methods (Zhang et al., 2003). Its X-ray crystallographic analysis confirms this proposed molecular structure (Fig. 1). In the structure there is a trans junction between ring A (C1—C5/C10) and ring B (C5—C10); cis junctions are present between ring B and ring C (C8/C9/C11—C14), and ring C and ring D (C8/C13—C16). Ring A adopts chair conformation, with an average torsion angles of 53.99 (19) °. Rings B and C adopt boat conformation because of the formation of the oxygen bridge at C-7 and C-20. Ring D shows an evenlope conformation. In addition, the six-membered rings O1/C20/C10/C5—C7 and O1/C7—C10/C20 both adopt boat conformations. The four hydroxy groups at C1, C7, C11 and C15 adopt α, β, β, β-orientations respectively, an acetoxy group at C6 adopt β-orientation. Bond lengths and angles are within expected aranges (Allen et al., 1987), with averages values (Å): Csp3—Csp3 = 1.544 (2), Csp3—Csp2 = 1.516 (2), Csp2—Csp2 (CC) = 1.323 (3), Csp3—O = 1.434 (2).
The compound contains ten chiral centers at C1(S), C5(R), C6(S), C7(S), C8(S), C9(S), C10(S), C11(S),C13(S) and C15(R). Although the absolute configuration could not be reliably determined from anomalous dispersion effects, the negative optical rotation showed this compound to be in the ent-kaurane series as reported in genus Isodon (Sun et al., 2001), rather than in the kaurane series, allowing us to assign the correct configuration. In the crystal structure, intermolecular O—H···O hydrogen bond (table 1) are effective in the stabilization of the structure and are responsible for the formation of a three-dimensional network (Fig. 2).