Isolation antidote

Atropiae (41), isolated from the deadly nightshade Airopa belladonna L.) is the racemic form, as isolated, of (—)-hyoscyamine [which is not isolated, of course, from the same plant but is typically found ia solanaceous plants such as henbane (HyosQiamus mgerl. )]. Atropiae is used to dilate the pupil of the eye ia ocular inflammations and is available both as a parasympatholytic agent for relaxation of the intestinal tract and to suppress secretions of the saUvary, gastric, and respiratory tracts. In conjunction with other agents it is used as part of an antidote mixture for organophosphorus poisons (see Chemicals in war). 

Therapeutic modalities to treat extravasation events consist of specific antidotes to halt or decrease the severity of local tissue necrosis. It should be noted that only one-third of extravasation events will lead to local tissue necrosis, and most studies of antidotes are in animal models or isolated case reports. Antidotes either disperse or bind the chemotherapy agent and accelerate the removal of the agent from the tissues. Specific antidotes and their uses are presented in Table 96-16. 

Hirudin, a polypeptide originally isolated from the salivary glands of the medicinal leech Hirudo medicalis, is now produced by recombinant technology. It is a potent and specific inhibitor of thrombin with which it forms an almost irreversible complex. It is cleared predominantly by the kidneys and has a of 40 minutes after i.v. administration. No antidote is available for a bleeding patient. It has been used successfully in patients with heparin-induced thrombocytopenia (HIT), thromboprophylaxis in elective hip arthroplasty, xmstable angina and myocardial infarction. 

The seeds of Aframomum hanburyi K. Schum. (Zingiberaceae) are used as an antidote and ingredient in certain medicinal preparations in Cameroon [93]. From an acetone extract of the seeds of this plant, two sweet dihydroflavonols, 3-acetoxy-5,7-dihydroxy-4 -methoxyflavanone (68) and 2/ ,3/ -(+)-3-acetoxy-5,7,4 -trihydroxyflavanone (69), were isolated [93]. 3-Acetoxy-5,7-dihydroxy-4 -methoxyflavanone (68) was previously isolated from a different species, Aframomum pruinosum Gagnepain [112]. However, the sweetness intensities of these compounds were not indicated [93,112]. The previously known 2R,2>R)-dihydroquercetin 3-0-acetate (71) which was rated as 80 times sweeter than sucrose, was isolated from Tessaria dodoneifolia (Hook. Am.)... 

Adequate supportive care should be assured in the phencyclidine-intoxicated patient. There is no antidote for phencyclidine overdose. The patient should be isolated from all sensory stimuli as much as possible and protected from self-inflicted injury. Benzodiazepines should be administered liberally and titrated until the phencyclidine-intoxicated patient calms. Adequate hydration should be assured to maintain the urine output at l-2cckg h. Although urine acidification theoretically enhances phencyclidine elimination, it is not recommended because of the high frequency of rhabdomyolysis and myoglobinuric renal failure seen with significant intoxication. Seizures should be treated with... 

The cholinolytic properties of reactivator-cholinolytics were characterized in in vitro tests on the model of contracture suppression in rat s isolated intestine, induced by ACh. Antidotic-and-therapeutic effects of the compounds were studied in the model of rats intoxication with dichlorvos. Therefore, it was for the first time that the synthesis of ChR-cholinolytics, as new antidotes of OPC, was realized in the rank of thiohydroxime esters. 

Wolthuis, O., Vanwerch, R., and van der Wiel, H., The efficacy of some bis-pyridinium oximes as antidotes to soman in isolated smooth muscles of several species including man, 70, 355-369, 1981. 

Cabenegrius. Orally active antidotes against snake venoms isolated from the root of a South American plant called "Cabeca de Negra and structurally related to pterocarpin. q.v. Isoln. L. L. Darko el al, Eur. pat. Appl. 89,229 eidem, U.S, pat. 4,429,161 0983, 1984 both to... 

This review describes the bioassay, isolation and identification of these active compounds, and compares their activity with that of various other related, and unrelated, chemicals of either plant or synthetic origin. The possible ecochemical role and mode of action of flavone and non-flavone antidotes and attractants is briefly discussed. 

Plant materials were collected in and around Sapporo during the summer months. For the screening test, 10 g (fresh weight) of the aerial parts (mainly leaves/stems) were immersed in 150 ml of MeOH for 3-4 days at room temperature. The resulting extract was then reduced to dryness and the residue was partitioned between EtOAc and water. In order to isolate and characterize the antidotes, Polygonum lapathifolium L. subsp. nodosum, P. sachalinense Fr. Schm. and P. thunbergii were collected in large quantities and extracted with MeOH. 

Shceme 1. Isolation procedures for Polygonum lapathifolium antidotes. 

Three further benzimidazole antidotes have also been identified, two in P. lapathifolium subsp. nodosum, and one in P. thunbergii. Isolation and purification procedures for the two active compounds in P. lapathifolium are shown in Scheme 1 [13]. 

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