Surface Mine Lakes: An Important Water Resource For Iowa

A survey, in 1981, revealed that Iowa had 1,215 active surface mines. Of the active and abandoned surface mines, 625 had water withdrawal permits from the Iowa Natural Resources Council. The majority of these permits were for dewatering and/or processing water but several were for other beneficial uses. Several of the surface mines are also used for recreation. This usage, for water supply and recreation, indicates the value of surface mine lakes as a water resource for the people of Iowa

Structures and biological activities of cycloheptamycins A and B

The heptadepsipeptide cycloheptamycin A was isolated from the terrestrial Streptomyces sp. Tü 6314. Its constitution was elucidated on the basis of NMR spectroscopic experiments and mass spectrometric analysis. Its stereostructure was investigated by peptide hydrolysis and derivatization and firmly established by X-ray structure analysis. In addition to the parent compound, a new cycloheptamycin analog, cycloheptamycin B, was discovered and structurally assigned using comparative MS/MS experiments and NMR. The biological profile of both compounds was investigated, revealing a selective inhibitory potential of cycloheptamycins against Propionibacterium acnes