Isolation and structural identification of insecticidal compounds from Tripterygium wilfordii.

Five compounds were identified from Tripterygium wilfordii, including two novel compounds and three previously known compounds. Two newly discovered compounds are celangulin CY (1α,2α,3ß,4ß,6ß,8α,13-hepacetoxy-9ß-benzoyloxy-ß-dihydroagarofuran) and celangulin CQ (1α-nicotinoyloxy-2α,3ß,6ß-triacetoxy-9ß-furancarbonyloxy-13-isobutanoyloxy-4ß-hydroxy-ß-dihydroagarofuran). Their structures were determined using nuclear magnetic resonance (NMR), mass spectrometry (MS), and high-pressure liquid chromatography (HPLC). The isolated compounds were tested for insecticidal activity against the third instar larvae of Spodoptera frugiperda. Both celangulin CY and celangulin CQ exhibited significantly higher oral toxicity in the larvae than that exhibited by the three known compounds.

Two new compounds from the roots of Pueraria peduncularis and their molluscicidal effects on Pomacea canaliculata.

Two oleanane-type triterpenoid saponins named pedunsaponin D (1) and pedunsaponin E (2) were isolated from the roots of Pueraria peduncularis. The structures of the new compounds were elucidated based on chemical and physicochemical evidence as follows: pedunsaponin D, 3-O-ß-glucopyranosyl-(1-3)-ß-glucuronopyranosyl-3ß,15α,23α-trihydroxy-11,13(18)-oleanadien-16-one (1); pedunsaponin E, 3-O-ß-glucopyranosyl-(1-2)-ß-glucopy ranosyl(1-2)[ß-glucopyranosyl(1-3)-ß-glucuronopyranosyl]-3ß-hydroxy-16-oxoolean-12-en-30-oic acid (2). The two compounds showed moderate molluscicidal activity.[Formula: see text].

Phenotypic and Genetic Characterization of Botrytis cinerea Population from Kiwifruit in Sichuan Province, China.

Botrytis cinerea (anamorph of Botryotinia fuckeliana) causes gray mold on numerous plants, including kiwifruit. The primary aim of this study was to investigate the phenotypic and genetic characteristics of the Botrytis cinerea population from kiwifruit in Sichuan Province, China. In all, 176 isolates were collected from kiwifruit orchards from eight geographic regions in Sichuan. All isolates were identified as B. cinerea sensu stricto based on the combined datasets, including morphological criteria, determination of the Bc-hch allele, and phylogenetic analysis of the genes RPB2, G3PDH, and HSP60. Three colony types (i.e., sclerotial, mycelial, and conidial) were observed on potato dextrose agar after 2 weeks, with sclerotial isolates, the predominant category, accounting for 40.91%. No obvious differences in microscopic characteristics were observed among the three types. Three genotypes of transposable elements were identified in the B. cinerea population: boty, flipper, and transposa types. The most prevalent genotype from different geographic populations of B. cinerea was transposa; in contrast, the flipper genotype accounted for only 3.98% of the total population, whereas the vacuma genotype was absent. According to MAT locus amplification, 87 and 89 isolates are MAT1-1 and MAT1-2 type, respectively, and the two mating types were found to be balanced overall in the population. Forty-eight representative isolates were all able to cause gray mold to some extent, and disease severities were significantly different between the cultivars Hongyang and Hort16A (P < 0.01). Disease severity was significantly greater on young leaves than on mature leaves (P < 0.01). No significant relationship was found between pathogenicity and geographical region, colony type, or transposon distribution. The results obtained in the present study suggest a relatively uniform species diversity of Botrytis but rich phenotypic and genetic differentiation within the B. cinerea population on kiwifruit in China. Utilizing resistant cultivars and rain-shelter cultivation instead of fungicides may be an effective approach to delaying pathogen variability.