Structural, Vibrational, and Electronic Properties of the Glucoalkaloid Strictosidine: A Combined Experimental and Theoretical Study

Table 1

Calculated geometrical parameters for strictosidine compared with the experimental data.

Parameter	B3LYP 6-31G(d)	B3LYP 6-311++G(2d,p)	Molina et al. [27]	Dupont and Dideberg [26]	Lentz and Rossmann [29]
Bond length
N1-C2	1.386	1.384	1.363	1.400
C2-C3	1.507	1.506	—	1.488
C3-N4	1.479	1.477	—	1.477
N4-C5	1.472	1.473	—	1.482
C5-C6	1.543	1.542	—	1.523
C6-C7	1.501	1.501	—	1.490
C7-C2	1.375	1.375	1.442	1.429
C7-C8	1.439	1.439	1.457	1.425
C8-C9	1.406	1.407	—	1.432
C8-C13	1.427	1.426	—	1.406
C9-C10	1.392	1.391	—	1.432
C10-C11	1.411	1.410	—	1.377
C11-C12	1.393	1.392	—	1.346
C12-C13	1.399	1.398		1.409
C13-N1	1.381	1.381	1.406	1.379
C14-C3	1.548	1.548	—	1.541
C14-C15	1.552	1.562	—		1.62
C15-C16	1.515	1.520	—		1.48
C16-C17	1.350	1.350	—		1.60
C18-C19	1.335	1.334	—		1.51
C19-C20	1.512	1.513	—		1.60
C20-C21	1.526	1.526	—		1.50
C21-O	1.401	1.403	—		1.43
C22-C16	1.469	1.471	—		1.60
C23-O	1.437	1.441	—		1.49
C1′-O	1.403	1.401	—		1.42
C1′-C2′	1.528	1.526	—		1.52
C2′-C3′	1.528	1.527	—		1.51
C3′-C4′	1.527	1.528	—		1.55
C4′-C5′	1.537	1.537	—		1.52
C5′-C6′	1.523	1.522			1.52
C5′-O	1.438	1.442	—		1.45
Bond angle
N1-C2-C7	109.570	109.562	108.7	110.5
C2-C7-C8	107.063	107.071	105.7	107.0
C7-C8-C13	106.793	106.792	107.5	107.2
C8-C13-N1	107.347	107.343	—	108.0
C13-N1-C2	109.221	109.221	—	107.3
C2-C3-N4	110.742	110.742	—	106.6
C3-N4-C5	114.580	114.582	—	112.6
N4-C5-C6	114.370	114.370	—	110.1
C5-C6-C7	108.976	108.976	—	109.4
C6-C7-C2	121.873	121.881	128.9	122.1
C7-C2-C3	125.545	125.546	107.9	126.2
C13-C8-C9	118.786	118.771	—	119.7
C8-C9-C10	119.165	119.172	—	115.3
C9-C10-C11	121.057	121.052	—	122.7
C10-C11-C12	121.177	121.181	—	122.2
C11-C12-C13	117.626	117.625	—	117.6
C12-C13-C8	122.186	122.186	—	122.4
C2-C3-C14	111.904	111.903	—	110.8
N4-C3-C14	110.456	110.456	—	116.9
C3-C14-C15	113.558	113.562	—	112.7
C15-C16-C20	112.883	112.883	—	—
C15-C16-C17	112.915	112.914	—	—	107
C16-C17-O	125.412	125.420	—	—	110
C17-O-C21	119.937	119.941	—	—	121
C18-C19-C20	129.038	129.038	—	—	101
C16-C22-O	113.414	113.415	—	—	111
CH3-O-C22	115.912	115.912	—	—	116
C21-O-C1′	115.516	115.516	—	—	114
O-C1′-C2′	108.278	108.278	—	—	106
C1′-C2′-C3′	109.237	109.237	—	—	106
C2′-C3′-C4′	111.945	111.945			110
C3′-C4′-C5′	109.024	109.024	—	—	105
C4′-C5′-O	108.796	108.795	—	—	106
C5′-O-C1′	114.025	114.027	—	—	108

Corresponding to single bonds due to the crystallization process of loganin in loganin penta-acetate monomethyl ether bromide.