New Insights Into Dietary Toxin Metabolism: Diversity in the Ability of the Natricine Snake Rhabdophis tigrinus to Convert Toad-Derived Bufadienolides.

The Japanese natricine snake Rhabdophis tigrinus sequesters cardiotonic steroids, bufadienolides (BDs), from ingested toads in the nuchal glands as defensive toxins. A previous study showed that R. tigrinus in captivity converts dietary BDs when it sequesters them.

Molecular Basis Underlying Common Cutworm Resistance of the Primitive Soybean Landrace Peking.

The common cutworm (CCW; ) is one of the major insect pests of soybean in Asia and Oceania. Although quantitative trail loci related to CCW resistance have been introduced into leading soybean cultivars, these do not exhibit sufficient resistance against CCW. Thus, understanding the genetic and metabolic resistance mechanisms of CCW as well as integrating other new resistance genes are required.

Variation in Bufadienolide Composition of Parotoid Gland Secretion From Three Taxa of Japanese Toads.

Toads of the genus Bufo synthesize and accumulate bufadienolides (BDs) in their parotoid glands. BDs are cardiotonic steroids that play an important role in defense against the toads' predators. Three bufonid taxa occur in mainland Japan, Bufo japonicus formosus, B.

An easy, inexpensive, and sensitive method for the quantification of chitin in insect peritrophic membrane by image processing.

Chitin, poly (β-(1→4)--acetyl-d-glucosamine), is an important biopolymer for insects that is utilized as a major component of peritrophic membrane. The chitin content in peritrophic membrane is of expedient interest from a pest control perspective, although it is hard to quantify chitin. In this study, we establish a facile method for the quantification of chitin in peritrophic membrane by image processing.

A fragmentation study of isoflavones by IT-TOF-MS using biosynthesized isotopes.

To aid in the identification and quantification of biologically and agriculturally significant natural products, tandem mass spectrometry can provide accurate structural information with high selectivity and sensitivity. In this study, diagnostic fragmentation patterns of isoflavonoids were examined by liquid chromatography-ion trap-time of flight-mass spectrometry (LC-IT-TOF-MS). The fragmentation scheme for [M+H-2CO] ions derived from isoflavones and [M+H-B-ring-CO] ions derived from 5-hydroxyisoflavones, were investigated using different isotopically labeled isoflavones, specifically [1',2',3',4',5',6',2,3,4-C] and [2',3',5',6',2-D] isoflavones.

Inducible De Novo Biosynthesis of Isoflavonoids in Soybean Leaves by Spodoptera litura Derived Elicitors: Tracer Techniques Aided by High Resolution LCMS.

Isoflavonoids are a characteristic family of natural products in legumes known to mediate a range of plant-biotic interactions. For example, in soybean (Glycine max: Fabaceae) multiple isoflavones are induced and accumulate in leaves following attack by Spodoptera litura (Lepidoptera: Noctuidae) larvae. To quantitatively examine patterns of activated de novo biosynthesis, soybean (Var.

Insect-induced daidzein, formononetin and their conjugates in soybean leaves.

In response to attack by bacterial pathogens, soybean (Gylcine max) leaves accumulate isoflavone aglucones, isoflavone glucosides, and glyceollins. In contrast to pathogens, the dynamics of related insect-inducible metabolites in soybean leaves remain poorly understood. In this study, we analyzed the biochemical responses of soybean leaves to Spodoptera litura (Lepidoptera: Noctuidae) herbivory and also S.