One gram of onion added to the food of rats inhibits significantly (p < 0.05) bone resorption as assessed by the urinary excretion of tritium released from bone of 9-week-old rats prelabeled with tritiated tetracycline from weeks 1 to 6. To isolate and identify the bone resorption inhibiting compound from onion, onion powder was extracted and the extract fractionated by column chromatography and medium-pressure liquid chromatography. A single active peak was finally obtained by semipreparative high-performance liquid chromatography. The biological activity of the various fractions was tested in vitro on the activity of osteoclasts to form resorption pits on a mineralized substrate. Medium, containing the various fractions or the pure compound, was added to osteoclasts of new-born rats settled on ivory slices. After 24 h of incubation, the tartrate-resistant acid phosphatase positive multinucleated cells, that is, osteoclasts, were counted. Subsequently, the number of resorption pits was determined. Activity was calculated as the ratio of resorption pits/osteoclasts and was compared to a negative control, that is, medium containing 10% fetal bovine serum only and to calcitonin (10(-12) M) as a positive control. Finally, a single peak inhibited osteoclast activity significantly (p < 0.05). The structure of this compound was elucidated with high-performance liquid chromatography-electrospray ionization-mass spectrometry, time-of-flight electrospray ionization mass spectrometry, and nuclear magnetic resonance spectroscopy. The single peak was identified as gamma-L-glutamyl-trans-S-1-propenyl-L-cysteine sulfoxide (GPCS). It has a molecular mass of 306 Da and inhibits dose-dependently the resorption activity of osteoclasts, the minimal effective dose being approximately 2 mM. As no other peak displayed inhibitory activity, it likely is responsible for the effect of onion on bone resorption.

We present a new pulse sequence that yields two simultaneously detected types of long-range correlation spectra. The one spectrum is to show all n J(C,H) connectivities and the other is to show exclusively 2 J(C,H) connectivities. The method is demonstrated by using strychnine as a test sample. A comparison with HMBC shows that the 2 J(C,H)/ n J(C,H) experiment supplies a n J(C,H) spectrum that is of equal standard with regard to sensitivity and spectral information. The additional 2 J(C,H) spectrum allows the disentanglement of 2 J(C,H) and n J(C,H) signals (n > 2) in HMBC type spectra, which greatly simplifies signal assignment and structure elucidation in general.

Benzothiazole derivatives R 0270Pseudosaccharin Amine Derivatives: Synthesis and Elastase Inhibitory Activity.-Two structural features are combined incorporating the pseudosaccharin amine skeleton as an antiinflammatory moiety and the carbonyl functionality as a center for the hydroxyl attack by the elastase. Only compounds (IV) and (VI) with a valine or isoleucine unit show Human Leukocyte Elastase inhibitory activity. Both compounds show a reversible inhibition. -(RODE, H. B.; SPRANG, T.; BESCH, A.; LOOSE, J.; OTTO*, H.-H.; Pharmazie 60 (2005) 10, 723-731;

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