Small molecules of biological origin continue to yield the most promising leads for drug design, but systematic approaches for exploring nature's cache of structural diversity are lacking. Here, we demonstrate the use of 2D NMR spectroscopy to screen a library of biorationally selected insect metabolite samples for partial structures indicating the presence of new chemical entities. This NMRspectroscopic survey enabled detection of novel compounds in complex metabolite mixtures without prior fractionation or isolation. Our screen led to discovery and subsequent isolation of two families of tricyclic pyrones in Delphastus catalinae, a tiny ladybird beetle that is employed commercially as a biological pest control agent. The D. catalinae pyrones are based on 23-carbon polyketide chains forming 1,11-dioxo-2,6,10-trioxaanthracene and 4,8-dioxo-1,9,13-trioxaanthracene derivatives, representing ring systems not previously found in nature. This study highlights the utility of 2D NMR-spectroscopic screening for exploring nature's structure space and suggests that insect metabolomes remain vastly underexplored.

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This 76-page book is the latest in a series of pocket MRI atlases from the Raven Press. It is presented by two widely respected authors in the field. It covers the normal anatomy of the neck, para-nasal sinuses, pharynx and skull base including a section on the temporal bone.

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This well-known text book of the anatomy of the domestic animals for students of veterinary medicine is now in its third edition, but Professor S. Sisson, of Ohio University, its original author, has been succeeded by Professor D. Grossman.The book sets forth the descriptive macroscopic anatomy of each bodily system of the horse, ox, sheep, pig and dog in turn. A brief but adequate account of the systematic anatomy of the chicken is added to the present edition. The text is restricted to the descriptive features that can be elucidated by the ordinary method of dissection. The book contains about 950 pages of text, 770 illustrations-the blood vessels are coloured-and a sufficiently detailed index.