Study on Tonghaosu and Its Analogs： Isolation, Structure Identification and Synthesis of Antifeedant B-ring-homo-tonghaosu

The methanolic extract from a Chinese endemic Chrysanthemum plant, Dendranthema indicum var. aromaticum, was found to show high antifeeding activity against Pieris brassicae L., and by bioassay-guided separation, the active component, B-ring-homo-tonghaosu, 2-(2‘,4‘-hexadiynylidene)-1,6-dioxaspiro-[4,5]-dec-3-ene (2) was isolated. Its structure was elucidated by comparing its spectroscopic data with those of 2 reported in the literatures. Furthermore new convenient total synthesis methods of B-ring-homo-tonghaosu were also developed to confirm its structure and make its further application in crop protection available. In addition, extensive comparison of spectroscopic data showed that the structure of compound 21 reported in literature should be revised to 2.     

Persistence of pierisin-1 activities in the adult cabbage white butterfly,Pieris rapae,during storage after killing

Crude extracts from larvae, pupae and adults of cabbage white butterflies, Pieris rapae and Pieris brassicae, and green-veined butterfly, Pieris napi, have an ability to induce apoptosis in the human cancer cell lines. As apoptosis inducing protein, pierisin-1 and -2 have been isolated from pupae of P. rapae and P. brassicae, respectively, and shown to exhibit DNA ADP-ribosylating activity. Although the highest activity was detected in the late phase of larvae and early phase of pupae, certain activity was found in adult butterflies. In order to investigate distribution of substances having pierisin-like activities in butterflies, many species need to be analyzed. However, fresh samples of larvae and pupae are hard to obtain, especially if samples are of scarce species or from overseas. The usage of adult butterflies is practical to examine the distribution of pierisin-like activity in many species. In this study, we examined the cytotoxicity of crude extracts from adults of P. rapae against HeLa cells and DNA ADP-ribosylation ability during storage for 1, 2 and 8 weeks at room temperature after killing adult butterflies after eclosion. Body weights decreased to 18% for 8 weeks through dehydration. Cytotoxicity of samples from butterfly kept for 1, 2 and 8 weeks decreased to 47, 39 and 22%, respectively, of the control value. DNA ADP-ribosylating activity of the samples also decreased to 30, 27 and 23%. Similar reduction was observed on western blot analysis with anti-pierisin-1 antibody. Fortunately, these results suggest that cytotoxic and DNA ADP-ribosylating activity persists to some extent in the body after killing, at least for 8 weeks. Thus, butterfly adult samples kept for two months at room temperature can still be useful for examination of the presence of substance having pierisin-like activity.     

Inhibition Kinetics of Cabbage Butterfly (<Emphasis Type="Italic">Pieris rapae</Emphasis> L.) Larvae Phenoloxidase Activity by 3-Hydroxy-4-Methoxybenzaldehyde Thiosemicarbazone

Phenoloxidase (PO) is a key enzyme in insect development, responsible for catalyzing the hydroxylation of tyrosine into o-diphenols and the oxidation of o-diphenols into o-quinones. In the present study, the kinetic assay in air-saturated solutions and the kinetic behavior of PO from Pieris rapae (Lepidoptera) larvae in the oxidation of l-tyrosine (a monophenol) and l-DOPA (l-3, 4-dihydroxyphenylalanine) (a diphenol) was studied. The inhibitory effects of 3-hydroxy-4-methoxybenzaldehyde thiosemicarbazone (3-H-4-MBT) on the monophenolase and diphenolase activities of PO were also studied. The results show that 3-H-4-MBT can inhibit both the monophenolase and diphenolase activities of PO. The lag period of l-tyrosine oxidation catalyzed by the enzyme was obviously lengthened and the steady-state activities of the enzyme sharply decreased. The inhibitor was found to be noncompetitively reversible with a K _I (K _I = K _IS) of 0.30 μmol/L and an estimated IC₅₀ of 0.14 ± 0.02 μmol/L for monophenolase and 0.26 ± 0.04 μmol/L for diphenolase. In the time course of the oxidation of l-DOPA catalyzed by the enzyme in the presence of different concentrations of 3-H-4-MBT, the rate decreased with increasing time until a straight line was approached. The microscopic rate constants for the reaction of 3-H-4-MBT with the enzyme were determined.     

Highly Acylated 3,4‐Secograyanane Diterpenoids from the Fruits of Pieris formosa

From the fruits of Pieris formosa, four new highly acylated 3,4‐secograyanane diterpenoids, secorhodomollolides E–H ( 1 – 4 , resp.), along with two known ones, secorhodomollolides C and D ( 5 and 6 , resp.), were obtained. Their structures were established mainly by spectroscopic methods, including 1D‐ and 2D‐NMR spectroscopy, and mass spectrometry.     

Synthesis and Bio-activities of Pyrazolyl or Pyridinyl Substituted Tonghaosu Analogs

11 pyrazolyl or pyridinyl substituted tonghaosu analogs were synthesized. Structures of all the new compounds were confirmed by ^1H NMR, IR, MS, HREIMS or elemental analysis. Their antifeedant activity against larvae of large white butterfly （Pieris brassicae L.）, larvicidal activity toward mosquito （Culex quinquefasciatus Say） and growth control activity toward larvae of Spodoptera litura Fab were examined. Some of them exhibited antifeeding activities comparable to or stronger than tonghaosu Z-1. Based on the activity data, the preliminary structure-activity relationship was also discussed, which might be instructive for finding out lead compounds with better bioactivities in the future.     

Grayanane Diterpenoids from Pieris formosa

Pierisformosa(Wall)D.Don(Ericaceae)isawell-knownpoisonousplantwhichgrowsmainlyinthehillyandvalleyregionsofSouthandSouthwestChina.ItwasreportedthatthepoultrywouldgointoacomaiftheyateitSleavesorstemsaccidentally.Thesymptoms,includingdyspnea,motionimbalanceandspreadingofthefourlimbs,aPpearedinndceuponadndnistrationofitschloroformextractS.Infolkpractice,thejuiceofthefreshleavescanbeusedasaninsecticideandasalotionforthetreatmentoftineaandscabiesinclinics'.Inthecourseofsearchingforanaturalbioact…     

Synthesis and Biological Activity of Tonghaosu Analogs Containing Phenoxy-phenyl Moiety

A new series of phenoxy-phenyl moieties containing tonghaosu analogs with varied B-ring 9 were synthesized and characterized by spectral studies. Their insect antifeedant activity against Pieris brassicae and insecticidal activity against Culex quinquefasciatus were investigated. Compound 9e exhibited excellent antifeeding activity.     

Metabolic fate of dietary volatile compounds in Pieris brassicae

In this work, the evolution of the qualitative and quantitative profile of the volatile fraction of Pieris brassicae after feeding on Brassica oleracea var. acephala (kale) was monitored through time. HS-SPME/GC-MS was applied to both the host plant and the living insect and its excrements. A total of seventy seven compounds (lipoxygenase pathway by-products, nitrogen compounds, norisoprenoids, sulphur compounds, terpenes, among others) were identified. Thirty eight compounds were identified in insect after 2 h of starvation and forty eight compounds in excrements. Qualitative and quantitative changes were detected along time. Dimethyldisulfide, dimethyltrisulfide, limonene and eugenol were major compounds for all analysed times in both matrices, being limonene an important compound in insect after starvation. The accumulation by P. brassicae of some compounds, such as limonene, was verified, suggesting a mechanism by which the insect can take benefit from bioactive constituents from the diet. Along with accumulation, complete excretion of some compounds, including nitrogen bearing compounds, by-products of glucosinolates was detected. These results reflect one of the strategies used to overcome plant barriers, namely detoxification of toxic compounds. The findings contribute to the knowledge of the metabolization of the volatile compounds in insects and contribute to the body of knowledge of this ecologic system.     

苏云金杆菌H3-7对蔬菜害虫的防效及对其天敌的影响

苏云金杆菌BtH3- 7菌株对蔬菜主要害虫菜青虫、小菜蛾有较好的防效 ,大田应用稀释 10 0 0倍 ,72h防效 >76 % ,好于辛硫磷效果 ;同时BtH3- 7制剂对菜青虫、小菜蛾的天敌蝶蛹金小蜂和小菜蛾绒茧蜂的影响很小 ,在菜青虫、小菜蛾的寄生率分别达 5 4%和 86 % ,与不用药的对照区几乎没有区别 ,大大高于化学农药辛硫磷防治区的 4 %和 4 6 % .     

新型茼蒿素类似物的合成和抗虫构效关系研究

Twenty-one tonghaosu analogs were synthesized via hydroamination or selective reduction of the endocyclic double bond of the corresponding dienol spiroketals. Structures of all the new compounds were confirmed by ^1H NMR, IR, MS, HREIMS or elemental analysis. Their antifeedant activity against large white butterfly （Pieris brassicae L） and larvicidal activity toward mosquito （Culex quinquefasciatus Say） were examined. Some of them exhibited antifeeding activities comparable to or stronger than tonghaosu Z-1. Based on the activity data, the preliminary structure-activity relationship was also discussed, which might be instructive for finding out lead compounds with better bioactivities in the future.