Crystal structure of isopimara-7,15-dien-3-one, C20H30O

Ming-Hong Dong; Jiang-Hai Ye; Chen-Liang Zhao; Lang Zhou; Juan Zou; Jing-Jie Zhang

doi:10.1515/ncrs-2020-0037

Open Access Published by De Gruyter (O) May 6, 2020

Crystal structure of isopimara-7,15-dien-3-one, C₂₀H₃₀O

Ming-Hong Dong , Jiang-Hai Ye , Chen-Liang Zhao , Lang Zhou , Juan Zou and Jing-Jie Zhang

From the journal Zeitschrift für Kristallographie - New Crystal Structures

https://doi.org/10.1515/ncrs-2020-0037

Abstract

C₂₀H₃₀O, triclinic, P1̄ (no. 1), a = 6.6084(9) Å, b = 10.8811(16) Å, c = 12.0845(16) Å, α = 85.719(6)°, β = 79.547(5)°, γ = 89.903(5)°, V = 852.1(2) Å³, Z = 2, R_gt(F) = 0.0744, wR_ref(F²) = 0.1953, T = 173(2) K.

CCDC no.: 1985466

The title molecular structure is shown in the figure. Table 1 contains crystallographic data and Table 2 contains the list of the atoms including atomic coordinates and displacement parameters.

Table 1:

Data collection and handling.

Crystal:	Colourless block
Size:	0.18 × 0.20 × 0.24 mm
Wavelength:	Mo Kα radiation (0.71073 Å)
μ:	0.066 mm⁻¹
Diffractometer, scan mode:	Bruker APEX-II, φ and ω-scans
θ_max, completeness:	28.5, >99%
N(hkl)_measured, N(hkl)_unique, R_int:	27636, 8549, 0.050
Criterion for I_obs, N(hkl)_gt:	I_obs > 2 σ(I_obs), 7322
N(param)_refined:	387
Programs:	Bruker programs [1], SHELX [2], OLEX2 [3], DIAMOND [4]

Table 2:

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

Atom	x	y	z	U_iso*/U_eq
O1	−0.1182(5)	−0.1221(3)	0.3766(3)	0.0474(8)
C1	0.0664(5)	0.1781(3)	0.3772(3)	0.0284(7)
H1A	0.040557	0.248408	0.425155	0.034*
H1AB	−0.011683	0.192069	0.314841	0.034*
C2	−0.0114(6)	0.0595(4)	0.4474(3)	0.0327(8)
H2A	0.062911	0.046458	0.511351	0.039*
H2AB	−0.159771	0.066759	0.478526	0.039*
C3	0.0213(5)	−0.0484(3)	0.3765(3)	0.0299(7)
C4	0.2342(5)	−0.0658(3)	0.3075(3)	0.0257(6)
C5	0.3359(5)	0.0608(3)	0.2556(3)	0.0226(6)
H5	0.273041	0.082527	0.187532	0.027*
C6	0.5670(5)	0.0504(3)	0.2106(3)	0.0302(7)
H6A	0.638447	0.024796	0.273660	0.036*
H6AB	0.590071	−0.013489	0.155544	0.036*
C7	0.6551(6)	0.1715(4)	0.1545(3)	0.0311(7)
H7	0.786400	0.171366	0.106912	0.037*
C8	0.5604(5)	0.2789(3)	0.1675(3)	0.0260(6)
C9	0.3559(5)	0.2905(3)	0.2461(3)	0.0238(6)
H9	0.249213	0.297787	0.196961	0.029*
C10	0.2974(5)	0.1737(3)	0.3276(3)	0.0211(6)
C11	0.3455(6)	0.4091(3)	0.3069(3)	0.0349(8)
H11A	0.201818	0.421305	0.344750	0.042*
H11B	0.431672	0.400031	0.365943	0.042*
C12	0.4179(6)	0.5229(3)	0.2283(4)	0.0348(8)
H12A	0.411805	0.595555	0.273369	0.042*
H12B	0.322878	0.537101	0.174127	0.042*
C13	0.6373(6)	0.5111(3)	0.1625(3)	0.0293(7)
C1_1	0.9380(5)	0.6550(4)	0.6204(3)	0.0306(7)
H1A_1	0.964878	0.732791	0.571913	0.037*
H1AB_1	1.015895	0.658554	0.682819	0.037*
C14	0.6424(6)	0.3953(4)	0.0968(3)	0.0333(8)
H14A	0.560841	0.410859	0.036226	0.040*
H14B	0.786328	0.381290	0.060342	0.040*
C15	0.7944(8)	0.5010(4)	0.2418(4)	0.0460(10)
H15A	0.933900	0.503389	0.197005	0.069*
H15B	0.772347	0.423131	0.288766	0.069*
H15C	0.777250	0.570042	0.290146	0.069*
C16	0.6820(7)	0.6215(4)	0.0784(3)	0.0365(8)
H16	0.603041	0.625889	0.019955	0.044*
C17	0.8120(9)	0.7110(5)	0.0742(5)	0.0652(17)
H17A	0.896394	0.712830	0.129952	0.078*
H17B	0.823287	0.775048	0.015464	0.078*
C18	0.3537(6)	−0.1400(3)	0.3880(3)	0.0331(8)
H18A	0.284887	−0.219717	0.412138	0.050*
H18B	0.357766	−0.093892	0.454279	0.050*
H18C	0.494473	−0.153355	0.348864	0.050*
C19	0.2178(7)	−0.1469(4)	0.2111(4)	0.0409(9)
H19A	0.136213	−0.104717	0.159996	0.061*
H19B	0.150865	−0.225445	0.242179	0.061*
H19C	0.355922	−0.162402	0.169394	0.061*
C20	0.4231(6)	0.1691(3)	0.4232(3)	0.0290(7)
H20A	0.565372	0.194901	0.392344	0.043*
H20B	0.421355	0.084724	0.458054	0.043*
H20C	0.362528	0.224635	0.480146	0.043*
O1_1	1.1184(5)	0.3537(3)	0.6248(3)	0.0535(9)
C2_1	1.0136(6)	0.5470(4)	0.5513(3)	0.0354(8)
H2A_1	0.938153	0.543994	0.487818	0.042*
H2AB_1	1.161857	0.558334	0.519419	0.042*
C3_1	0.9804(5)	0.4280(4)	0.6240(3)	0.0322(8)
C4_1	0.7659(5)	0.4016(3)	0.6943(3)	0.0280(7)
C5_1	0.6653(5)	0.5210(3)	0.7434(3)	0.0227(6)
H5_1	0.727282	0.532541	0.811560	0.027*
C6_1	0.4340(5)	0.5047(3)	0.7878(3)	0.0294(7)
H6A_1	0.363190	0.489163	0.724554	0.035*
H6AB_1	0.409628	0.432439	0.843501	0.035*
C7_1	0.3468(5)	0.6177(3)	0.8422(3)	0.0299(7)
H7_1	0.215437	0.610964	0.889785	0.036*
C8_1	0.4431(5)	0.7268(3)	0.8277(3)	0.0246(6)
C9_1	0.6490(5)	0.7483(3)	0.7495(3)	0.0236(6)
H9_1	0.755049	0.747987	0.798961	0.028*
C10_1	0.7075(5)	0.6436(3)	0.6694(3)	0.0213(6)
C11_1	0.6591(7)	0.8769(4)	0.6874(3)	0.0369(9)
H11A_1	0.802139	0.894125	0.647912	0.044*
H11B_1	0.570435	0.877492	0.629565	0.044*
C12_1	0.5914(6)	0.9791(3)	0.7649(3)	0.0349(8)
H12A_1	0.597429	1.058644	0.718945	0.042*
H12B_1	0.688779	0.984388	0.817762	0.042*
C13_1	0.3723(6)	0.9586(3)	0.8332(3)	0.0295(7)
C14_1	0.3665(6)	0.8319(3)	0.8985(3)	0.0310(7)
H14A_1	0.450695	0.836375	0.957993	0.037*
H14B_1	0.222969	0.813258	0.936376	0.037*
C15_1	0.2132(8)	0.9647(5)	0.7561(5)	0.0497(11)
H15A_1	0.227864	1.043370	0.710196	0.075*
H15B_1	0.074707	0.957956	0.802015	0.075*
H15C_1	0.234756	0.896672	0.706668	0.075*
C16_1	0.3382(7)	1.0562(4)	0.9175(4)	0.0376(8)
H16_1	0.427308	1.052999	0.971088	0.045*
C17_1	0.2027(10)	1.1442(6)	0.9263(6)	0.0677(17)
H17A_1	0.108881	1.152606	0.875370	0.081*
H17B_1	0.198101	1.199728	0.983754	0.081*
C18_1	0.6464(6)	0.3385(4)	0.6149(4)	0.0339(8)
H18A_1	0.636614	0.395536	0.549392	0.051*
H18B_1	0.507820	0.315755	0.655444	0.051*
H18C_1	0.719133	0.264262	0.589372	0.051*
C19_1	0.7843(8)	0.3071(4)	0.7929(4)	0.0436(10)
H19A_1	0.844457	0.231192	0.763186	0.065*
H19B_1	0.647463	0.288897	0.837988	0.065*
H19C_1	0.872867	0.340997	0.840276	0.065*
C20_1	0.5809(6)	0.6543(3)	0.5739(3)	0.0297(7)
H20A_1	0.640646	0.719205	0.516787	0.045*
H20B_1	0.438537	0.674946	0.604999	0.045*
H20C_1	0.583098	0.575606	0.539283	0.045*

Source of material

The leaves and stems of Isodon amethystoides collected from Libo country, Guizhou province, were extracted by methanol three times at room temperature. The combined filtrate was concentrated and extracted with petroleum ether. The crude (1.0 kg) product was purified by TLC (silica gel), then devided into A-D fractions by silca gel column with petroleum ether/ethyl acetate (volume ratio 100:1). The colourless block crystals of the title compound were isolated from fraction A and recrystallized with ethyl acetate. The title compound (56 mg; systematic name: 1,1,4a,7-tetramethyl-7-vinyl-3,4,4a,4b,5,6,7,8,10,10a-decahydrophenanthren-2(1H)-one) were obtained after five days.

Experimental details

The carbon-bound hydrogen atoms were placed in their geometrically idealized positions and constrained to ride on their parent atoms with d(C—H) = 0.95–1.00 Å, U_iso(H) = 1.5 times U_eq(C) and 1.2 times U_eq(O).

Comment

In recent years, many groups have studied the chemical composition and pharmacological activity of the Isodon plants, and have shown that they are rich in diterpenoids and have good biological activity including antibacterial, antitumor and immunosuppressive effects [5], [6]. Thus it is necessary to investigate further examples of diterpenoids. The crystal structure of the title compound has not been previously reported.

The title molecular structure contains two alkenyl, one keto, and four methyl groups, respectively. The bond lengths and angles which were derived from the title structure are within normal ranges. The olefinic bonds were identified by the distance d(C₇–C₈) = 1.331(5) Å and d(C₁₆–C₁₇) = 1.292(6) Å, and the keto bonds were confirmed by the distances d(C₃–O₁) = 1.222(5) Å, respectively.

Acknowledgements

The authors gratefully acknowledge support from the National Natural Science Foundation of China [No.81760772] , the Graduate Research Fund of Guizhou [No.YJSCXJH(2019)082], the Domestic First-rate Fund of China [No.GNYL(2017)008] and the Science and Technology Fund of Guizhou [No.LH(2016)7114].

References

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Received: 2020-01-18

Accepted: 2020-02-21

Published Online: 2020-05-06

Published in Print: 2020-08-26

This work is licensed under the Creative Commons Attribution 4.0 International License.