A penem is a type of unsaturated β-lactam.
An example is faropenem.
Penems are similar in structure to carbapenems. However, where penems have a sulfur, carbapenems have another carbon.
There are no known naturally occurring penems; all of them are synthetically made.
Penem molecules do not occur naturally, and production of penems is an entirely synthetic process.
Although structurally distinct, the penems are often confused with the carbapenem class of drugs.
Five main penem subgroups — thiopenems, oxypenems, aminopenems, alkylpenems, and arylpenems — have been produced and are distinguished by the side chain (at position 2) of the unsaturated five-membered ring. One structurally distinct penem is BRL 42715. This molecule has no substitution at the above position, but has a bulky group attached to the β-lactam ring, and it displays effective inhibition of class C β-lactamases, but no antimicrobial activity.
One possible consequence of these structural differences of penems from other β-lactams may be reduced immunogenicity and immunogenic cross-reactivity
By the rivers of Babylon, there we sat down
ye-eah we wept, when we remembered Zion.
By the rivers of Babylon, there we sat down
ye-eah we wept, when we remembered Zion.
When the wicked
Carried us away in captivity
Required from us a song
Now how shall we sing the lord's song in a strange land
When the wicked
Carried us away in captivity
Requiering of us a song
Now how shall we sing the lord's song in a strange land
Let the words of our mouth and the meditations of our heart
be acceptable in thy sight here tonight
Let the words of our mouth and the meditation of our hearts
be acceptable in thy sight here tonight
By the rivers of Babylon, there we sat down
ye-eah we wept, when we remembered Zion.
By the rivers of Babylon, there we sat down
ye-eah we wept, when we remembered Zion.
By the rivers of Babylon (dark tears of Babylon)
there we sat down (You got to sing a song)
ye-eah we wept, (Sing a song of love)
when we remember Zion. (Yeah yeah yeah yeah yeah)
By the rivers of Babylon (Rough bits of Babylon)
there we sat down (You hear the people cry)
ye-eah we wept, (They need that ???)