Instituto de Productos Naturales y Agrobiología (IPNA), CSIC, La Laguna, Tenerife, Spain.
Phytochemistry. 2010 May;71(7):810-5. doi: 10.1016/j.phytochem.2010.02.004. Epub 2010 Feb 26.
The absolute configuration (AC) of 6beta-hydroxy-3alpha-senecioyloxytropane (1), 3alpha-hydroxy-6beta-tigloyloxytropane (2), 3alpha-hydroxy-6beta-senecioyloxytropane (3), and 3alpha-hydroxy-6beta-angeloyloxytropane (4) was assigned as (1R,3R,5S,6R) using density functional theory (DFT) calculations at the B3LYP/DGDZVP level of theory in combination with experimental vibrational circular dichroism (VCD) measurements and comparison with the spectra of similar tropanes. The AC of 1 followed from a sample isolated from Schizanthus grahamii, while those of the mixture of 2 and 3, isolated from the same source, were determined by comparing the VCD measurement to a weighted calculation of the individual VCD spectra according to a 69:31 ratio of 2:3 determined by (1)H NMR signal integration. In turn, Schizanthus pinnatus provided a 7:3 mixture of 1:4 whose AC was determined using the experimental VCD absorptions in the 1150-950 cm(-1) spectral region which were compared with those observed for 1-3 and with those described for other 3alpha,6beta-tropanediol derivatives.
6β-羟基-3α-千里光酰氧基托烷（1）、3α-羟基-6β-金合欢酰氧基托烷（2）、3α-羟基-6β-千里光酰氧基托烷（3）和 3α-羟基-6β-当归酰氧基托烷（4）的绝对构型（AC）被分配为（1R，3R，5S，6R），使用密度泛函理论（DFT）计算在 B3LYP/DGDZVP 理论水平，结合实验振动圆二色性（VCD）测量，并与类似托烷的光谱进行比较。1 的 AC 来自于从 Schizanthus grahamii 中分离出的样品，而混合物 2 和 3 的 AC 则是通过将 VCD 测量值与根据（1）H NMR 信号积分确定的 2:3 比例的单个 VCD 光谱的加权计算进行比较来确定的。反过来，Schizanthus pinnatus 提供了 1:4 的 7:3 混合物，其 AC 使用 1150-950 cm(-1)光谱区域的实验 VCD 吸收来确定，这些吸收与观察到的 1-3 进行了比较，并与其他 3α,6β-托烷二醇衍生物的描述进行了比较。
