Molecular characterization of prophenoloxidase-1 (PPO1) and the inhibitory effect of kojic acid on phenoloxidase (PO) activity and on the development of Zeugodacus tau (Walker) (Diptera: Tephritidae).

Phenoloxidase (PO) plays a key role in melanin biosynthesis during insect development. Here, we isolated the 2310-bp full-length cDNA of PPO1 from Zeugodacus tau, a destructive horticultural pest. qRT-polymerase chain reaction showed that the ZtPPO1 transcripts were highly expressed during larval-prepupal transition and in the haemolymph. When the larvae were fed a 1.66% kojic acid (KA)-containing diet, the levels of the ZtPPO1 transcripts significantly increased by 2.79- and 3.39-fold in the whole larvae and cuticles, respectively, while the corresponding PO activity was significantly reduced; in addition, the larval and pupal durations were significantly prolonged; pupal weights were lowered; and abnormal phenotypes were observed. An in vitro inhibition experiment indicated that KA was an effective competitive inhibitor of PO in Z. tau. Additionally, the functional analysis showed that 20E could significantly up-regulate the expression of ZtPPO1, induce lower pupal weight, and advance pupation. Knockdown of the ZtPPO1 gene by RNAi significantly decreased mRNA levels after 24 h and led to low pupation rates and incomplete pupae with abnormal phenotypes during the larval-pupal interim period. These results proved that PO is important for the normal growth of Z. tau and that KA can disrupt the development of this pest insect.

[Synthesis of dihydroindoline compounds and their anticholinesterase activity].

A series of dihydroindoline compounds were synthesized. The N-alkylation and O-acylation were controlled selectively by the presence or absence of phase transfer catalyst. The structure of compounds synthesized were ascertained by elemental analyses, 1HNMR, MS, and IR. The anticholinesterase activity was determined by modified Hestrin method and their pCI50 were calculated by Hill's pharmacodynamic formula. The structure-activity relationship was briefly discussed. (1) 5-carbamoyl group is the important factor for the anticholinesterase activity. If cyclic phosphoryl or sulfonyl group is used instead of the carbamoyl group, the inhibiting activity drops sharply. (2) Compounds in which C-3 of the indoline nucleus is quaternary are more potent than those in which C-3 is tertiary or secondary. So the methyl group at C-3 plays an important role in combining the inhibitor with the active center of cholinesterase by the hydrophobic bond. (3) When the indolines are changed into 2-indolinones the inhibiting activity drop steeply.

[Synthesis of indolinyl-N,N-dimethylcarbamates as reversible anticholinesterase agents].

A series of new indolinyl derivatives (I1-5, II1-3 and III1-8) with different substituents at 1-, 3- or 5-position were synthesized in order to study the relationship of structure and anticholinesterase activities of CUI XING NING and its derivatives. The method of phase transfer catalysis was successfully applied in the C3-alkylation of intermediate A as well as in the N-alkylation and the carbamylation. Three by-products were obtained during the C3-alkylation and their structures and all of the structures of the 24 new compounds (including the intermediate) were identified by spectral and elementary analysis. Preliminary pharmacologic tests showed that most of the compounds have potent anticholinesterase activities. All of the substituents of 1-, 3- or 5-position of the compounds may affect their activities (see Table 4).

[Synthesis of isoflavones as cardiovascular drug].

On the basis of the chemical structure of daidzein, a series of isoflavones have been synthesized. The intermediates, 7-methoxy-4'-hydroxy-isoflavone(V) and 7-hydroxy-4'-methoxyisoflavone(IX) were prepared by condensation of corresponding desoxybenzoin with dimethylformamide dimethylacetal. 7-Methoxy-2-methyl-4'-hydroxyisoflavone (VII) was also prepared from desoxybenzoin IV by reacting with acetic anhydride and anhydrous sodium acetate and followed by hydrolysis. Compounds I1-5 were obtained by Mannich reaction and compounds II1,2 III1,2 were obtained by etherification of corresponding isoflavones. All compounds were tested for resistance to hypoxia in mice and I1-3, I5, II1 and III2 were shown to have significant effect. Compound I1 and I5 were also found to increase coronary blood flow.