ABSTRACT
Among various polycyclic aromatic hydrocarbons, C6 -C5 -C6 -C7 -C6 fused pentacyclic aromatic hydrocarbons have the unique potential to adopt quinonoid, zwitterion, singlet, or triplet biradical electronic configurations. Two such hybrid structures between pentacene and azulene were synthesized and their ground state electronic configurations were deduced from the reactivity patterns they exhibit respectively. Compound 6, where the radicaloid carbons are linked through a para-phenylene, forms a head-to-head dimer like a singlet biradical. In contrast, isomer 7, where the para-linkage was switched to meta, reacts readily with oxygen which resembles the reactivity of a triplet state. The oxidized intermediate(s) then undergoes rearrangement to furnish the C6 -C5 -C6 -C6 -C6 ring contraction product 13. Cation 14, the protonated form of 7, was synthesized, which implies 7 also reacts like a zwitterion. It was revealed the oxidative rearrangement takes place even with mesityl dibenzotropylium cation despite its perceived aromaticity. DFT calculations confirm the most stable forms of 6 and 7 are singlet and triplet diradical, which is consistent with the observed reactivity of respective molecules.
ABSTRACT
OBJECTIVE: To test the effect of asarinin, the extract of Herba Asari, on the acute heart transplantation rejection and the expression of adhesion molecule. METHOD: Asarinin was extracted from herba asari. 64 SD rats undergone heart transplantation were divided into four groups: group A (control group), group B (Cyclosporine A treated), group C (Asarinin treated), and group D (1/2 CsA and 1/2 Asarinin). Some rats were used to examine survival time (n = 8) and the others were used to observe the pathological injury and the expression level of interrellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-I (VCAM-1) by using immunohistochemistry. RESULT: Asarinin could prolong the survival time of allografts, which was similar to CsA group (P > 0.05). Asarinin could relieve the damage of cardiomyocytes of the transplanted. Asarinin could also decrease the level of ICAM-1 and VCAM-1 in the allografts. CONCLUSION: Asarinin may play important roles in suppressing the immune rejection, prolong the allografts survival time and protect the donor organ, which was similar to CsA. The expression level of ICAM-1 and VCAM-1 is increased in suppressing the course of acute rejection and asarinin can inhibit their expression level. Asarinin can decrease the dosage of CsA.