Ajmalicine is an antihypertensive drug used in the treatment of high blood pressure. Catharanthus roseus, and Mitragyna speciosa. Ajmalicine is structurally related to yohimbine, rauwolscine, and other yohimban derivatives. Like corynanthine, it acts as a α1-adrenergic receptor antagonist with preferential actions over α2-adrenergic receptors, underlying its hypotensive rather than hypertensive effects. The effect of scaleup on he production of ajmalicine by a Catharanthus roseus cell suspension culture in a selected induction medium were studied. In preliminary experiments it was observed that the culture turned brown and the production was inhibited upon transfer from a shake flask to a stirred bioreactor with forced aeration. Two factors were recognized as the potential origin of the differences between shake flask and bioreactor cultures: gas composition and mechanical shear forces.
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