Liang L, Zhu N J, Jiang L J
Institute of Biophysics, Academia Sinica, Beijing, PRC.
Sci China B. 1990 Jun;33(6):649-55.
In attempting to study the phototherapeutic action and the photosensitized oxygenation mechanism, we have determined the crystal structure of the main oxidized product of hypocrellin A (HA). It was crystallized in monoclinic system with space group P2(1). The cell data are: a = 10.030(3), b = 8.877(3), c = 15.764(5)A, beta = 104.50(2) degrees, Z = 2. The crystal structure has been determined by direct method and refined to a final R of 0.055 based on the 1408 observed reflections with I greater than 2.5 sigma (I). The photooxidized product is composed of a heptacyclic aliphatic hydrocarbon connecting with two alpha-naphthoquinone derivatives as its skeletal molecule. No peroxidic linkage has been found. On the basis of the crystal structure determined, we have deduced part of the process of formation of the oxide, i. e. firstly, the peroxide was formed by photocycloaddition of oxygen molecule to Hypocrellin A, then thermodissociation took place to form a stable oxide.
在试图研究光疗作用和光敏氧化机制的过程中，我们测定了竹红菌素A（HA）主要氧化产物的晶体结构。它以单斜晶系结晶，空间群为P2(1)。晶胞数据如下：a = 10.030(3)，b = 8.877(3)，c = 15.764(5)埃，β = 104.50(2)度，Z = 2。晶体结构通过直接法测定，并基于1408个I大于2.5σ(I)的观察反射将最终R值精修至0.055。光氧化产物由一个与两个α-萘醌衍生物相连的七环脂肪烃作为其骨架分子组成。未发现过氧键。基于所测定的晶体结构，我们推断出了氧化物形成过程的一部分，即首先，氧分子与竹红菌素A发生光环加成反应形成过氧化物，然后发生热解离形成稳定的氧化物。
