| dc.description.abstract | The search for the active principle of ergot was
started soon after the introduction of the drug in
medicine. Tanret (1875) was the first to crystallise
ergotinine in a state of purity, and from the mother
liquors of the crystalline alkaloid he obtained an
active principle but failed to recognise that it was
a separate substance and regarded it as amorphous
ergotinine. Later, Kobert (1884) and Jacobi (1897)
described the active principle as sphacelinic acid and
ch.rysotoxine, Kobert (1884) indeed distinguished a
second active principle - the amorphous alkaloid cornutine
- which he claimed had pharmacological activity
of a different kind and was very toxic. This preparation
was not, however, chemically pure and owed its
activity to a. single alkaloid, a hydrate of ergotinine.
Barger and Carr (1907) first isolated a principle in
the form of a crystalline salt, from the caustic liquor
from which ergotiniñe had been extracted, and named it
ergotoxine.. A little later, _raft (1906) recognised
that the amorphous substance left after crystallising
out the ergotinine was not identical with the latter
but was a second alkaloid. He showed that it could be
formed from ergotinine and could be reconverted into the
latter. He called it hydro-ergotinine. Barger and
Carr (1907) showed by analysis that the two alkaloids,
ergotinine and ergotoxine, did differ by a mol. of
water. Stoll (1920) discovered a third ergot alkaloid,
ergotamine, which crystallised readily and had a
physiological activity indistinguishable from that of
ergotoxine. This alkaloid could be converted into an
inactive isomeride ergotaminine. So four distinct
alkaloids of ergot have been found out, viz., ergotinine,
ergotoxine (which was isolated as hydrate of ergotinine),
ergotamine and ergotaminine. Of the two alkaloids,
ergotamine and ergotaminine, the latter had no physiological
action. These alkaloids were evidently closely
related to ergotinine and ergotoxine. Although the
two less soluble ones, i.e. ergotinine and ergotaminine,
had very slight physiological activity, they could,
however, be changed into the active forms ergotoxine
and ergotamine. The various pharmacological effects
given by the alkaloids, ergotoxine and ergotamine,
were of equal intensity within experimental errors end
it was thought by some investigators that they were
identical. But physical and chemical evidences showed
that the four alkaloids were all quite different and
had separate existence. | en |
