Bacteria, individually, are incredibly tiny, (about 1 picogram - one trillionth of a gram) (or 600 billion daltons in molecule talk).
Tiny, even when compared to a typical human red blood cell (which are about 30 times heavier).
Just as penicillin molecules are tiny compared to average large biological molecules like human blood hemoglobin
(it would take about 200 penicillin molecules to weigh as much as one hemoglobin molecule.)
(And human titin molecules can weigh almost 4 million daltons !)
But perhaps the most useful index is to compare the size of the tiny penicillin (300 daltons) or sulfa molecule (250 daltons) to the tiny bacteria organism it is trying to kill.
At least a billion times smaller.
That makes them highly diffusible, in theory.
Because the danger is always that once inside a living body, they will be more attracted to other molecules than to their designated target molecule. A very common situation that remains one of the great uncertainties of drug discovery.
Still they are pretty diffusible, all in all - approaching the real tiny and hence very highly diffusible molecules like water (18 daltons).
And to chemists, trying in the interwar years to determine the molecular structure of big biological molecules like hemoglobin, the tiny sized penicillin seemed as easy to synthesize as the similarly sized synthetic sulfa drugs.
(Or their most recent biological synthesis success - man-made Vitamin C, weighing in at about 200 daltons.)
But quinine also weighs about the same as penicillin and the best chemists throughout history had failed to synthesize it commercially.
Size, it turned out was not the best indicator of the complexity of making penicillin molecules synthetically....
Showing posts with label synthetic chemistry. Show all posts
Showing posts with label synthetic chemistry. Show all posts
Saturday, June 20, 2015
Tuesday, August 27, 2013
The irony of 1945's twin triumphs ...
1945 was , on any account, an extraordinary year, not the least for its twin scientific triumphs.
At the time, it was almost universally held that the Man-made Bomb was the way of an atomic future so bright we'd have to wear shades .
By contrast, 1945's new Microbe-made medicine (natural penicillin) was viewed as but a temporary anomaly, a dusty throw back to the outdated caldron practises of medieval midwives.
But more than a half century later we are no longer so sure of all of this.
Atomic energy has not at all fulfilled its early promise.
Meanwhile, microbiology and biotechnology (descendants of 1945's natural-produced penicillin) have far outshot their 1945 rival, synthetic chemistry.
So today, with 20/20 hindsight, while 1945 can still feel like the apogee of the Modern age,it is also revealed as its very nadir.
Because 1945 is now seen as the birthday of our present post-Modern age.
In which case, Henry Dawson's twin follies of advocating on behalf of small individuals and on behalf of small microbes can be seen as promoting a distinguishing hallmark of postmodernity.
For few of us, under the age of eighty, devote much energy these days to replacing our current rainbow of many small cultures with a return to yesterday's dreary unitary monoculture of constipated WASP-dom.....
At the time, it was almost universally held that the Man-made Bomb was the way of an atomic future so bright we'd have to wear shades .
By contrast, 1945's new Microbe-made medicine (natural penicillin) was viewed as but a temporary anomaly, a dusty throw back to the outdated caldron practises of medieval midwives.
But more than a half century later we are no longer so sure of all of this.
Atomic energy has not at all fulfilled its early promise.
Meanwhile, microbiology and biotechnology (descendants of 1945's natural-produced penicillin) have far outshot their 1945 rival, synthetic chemistry.
So today, with 20/20 hindsight, while 1945 can still feel like the apogee of the Modern age,it is also revealed as its very nadir.
Because 1945 is now seen as the birthday of our present post-Modern age.
In which case, Henry Dawson's twin follies of advocating on behalf of small individuals and on behalf of small microbes can be seen as promoting a distinguishing hallmark of postmodernity.
For few of us, under the age of eighty, devote much energy these days to replacing our current rainbow of many small cultures with a return to yesterday's dreary unitary monoculture of constipated WASP-dom.....
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