Oblon, Fisher, Spivak, McClelland & Maier
.beta.-Lactam antibiotics
 A novel antibiotic designated as KA-6643 and having the formula, ##STR1## wherein R is hydrogen or --SO.sub.3 H. 
Kowa Co., Ltd.
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C07D C12N C12P C12R
inventional inventional inventional additional
Shigeru Masahito Akira Isamu Hisakatsu Sohei Toshimi Akio Toshihito Masao
Kimura Nakayama Murakami Watanabe Ito Tanabe Mizoguchi Iwasaki Mori Okuchi