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A 13C nmr analysis method is described for the identification of carbohydrate residues in galactosides and glucosides. This method reveals the capability of 13C nmr to distinguish the difference in structural configuration of these carbohydrate residues. Not only can the anomeric configuration be assigned, the furanyl and pyranyl nature of the ring is concomitantly determined. This method is consistent for all reported 13C nmr spectra of nonaromatic galactosides and glucosides.

Tremetone, the major toxic component in white snakeroot (Eupatorium rugosum Houtt) extracts, was isolated following an in vitro bioactivity assay. Microsomal activation was required to produce a product toxic to murine melanoma (B16F1) cells as well as five other mammalian cell cultures. The metabolic activation product(s) of tremetone is suspected to be responsible for the toxic activity of the plant. Tremetone is also smoothly converted to dehydrotremetone in the plant and cell free homogenates, and readily decomposes to dehydrotremetone in extracts. Dehydrotremetone is not toxic even after microsomal activation. The efficient conversion of tremetone to dehydrotremetone may explain why white snakeroot plant material and extracts have varied activities, and why a previous claim that tremetone was responsible for the toxic activity of white snakeroot was withdrawn. Rayless goldenrod extracts show the same toxic activity as white snakeroot and the toxic activity of rayless goldenrod is most likely due to tremetone.

A brief account of the Michael reaction is provided, illustrating its versatility as a topic in undergraduate chemistry courses. Included is a short biography of the reaction's namesake, examples of its use in organic synthesis, and its unique role in the defense mechanism of the bacterium Micromonospora echinospora. A computational rationale for the selectivity of 1,4 versus 1,2 addition of nucleophiles to α,β-unsaturated carbonyls is discussed and links to animations suitable for an introductory organic chemistry course are provided.

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