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ANTI TUMOR DRUGS
Antitumour (Latin : Tumor swelling, neoplasm) drugs are used in the treatment of cancer. The cancer or carcinogenic growth is an abnormal mass of new tissue growing in or on part of the body. Several types of carcinogenic growths have been reported. The cancer is regarded to be an incurable disease in secondary stages. The radioactive substances, metal compounds and several chemotherapeutic drugs have been suggested to control the carcinogenic growths.
The promising natural antitumour drugs or their isolates are obtained from the following:
Vinca : (Catharanthus roseus) Podophyllum : (Podophyllum hexandrum)
Colchicum : (Colchicum Iuteum) Benafsha : (Viola odorata)
Anacardium : (Semecarpus anacardium)
VlNCA
Synonyms : Catharanthus, Vinca rosea, Periwinkle
Biological Source: It is the dried whole plant of Catharanthus roseus 'G. Don., (syn vinca-roseai (Family : Apocynaceae).
Geographical Distribution:
It is probably indigenous to Madagascar. It is cultivated in South Africa, West indies, lndia, U.S.A., Europe and Australia as an ornamental plant, as well as, for its medicinal properties.
Organoleptic Characters (Fig) :
The leaves are green, roots are pale grey, flowers are violet, pink-white or carmine-red in colour. The odour is characteristic and taste is bitter. Vinca is an erect, pubescent herb, with branched tap-root. Leaves are simple, petiolate, ovate, or oblong, unicostate, reticulate, entire, brittle with acute apex and glossy appearance. Flowers are bractate,pedicellate, complete, hermaphrodite, normally 2 to 3 in cymose axillary clusters. Fruits are follicles with several black seeds.
Chemical Constituents :
Vinca contains wide varieties of chemicals including the glycosides and alkaloids. The indole~indoline alkaloids are very important constituents. About 60 alkaloids have been isolated so far from different parts of vinca. The important alkaloids with anticancer property are vincristine and vinblastine. Vincristine is obtained in about 0.0002 % yield from the crude drug. The other alkaloids present in the drug are ajmalicine, serpentine, lochnerine and tetrahydroalstonine. The total alkaloidal content of the drug is about 1 %, of which only a fraction contains therapeutically active alkaloids.
Both vinblastine and vincristine have the same structures with the difference that in vinblastine there is N-methyl group while, in vincristine it is N-formyl group and both Possess different activities. The other alkaloids are vindoline, vindolinine and catharanthine.
Uses:
Vincristine is used in treatment of leukaemia. Vinblastine is used for the treatment of generalised Hodgkin's disease and chorionepithelioma. Vinca also exhibits hypotensive and antidiabetic activity.
Antitumour (Latin : Tumor swelling, neoplasm) drugs are used in the treatment of cancer. The cancer or carcinogenic growth is an abnormal mass of new tissue growing in or on part of the body. Several types of carcinogenic growths have been reported. The cancer is regarded to be an incurable disease in secondary stages. The radioactive substances, metal compounds and several chemotherapeutic drugs have been suggested to control the carcinogenic growths.
The promising natural antitumour drugs or their isolates are obtained from the following:
Vinca : (Catharanthus roseus) Podophyllum : (Podophyllum hexandrum)
Colchicum : (Colchicum Iuteum) Benafsha : (Viola odorata)
Anacardium : (Semecarpus anacardium)
VlNCA
Synonyms : Catharanthus, Vinca rosea, Periwinkle
Biological Source: It is the dried whole plant of Catharanthus roseus 'G. Don., (syn vinca-roseai (Family : Apocynaceae).
Geographical Distribution:
It is probably indigenous to Madagascar. It is cultivated in South Africa, West indies, lndia, U.S.A., Europe and Australia as an ornamental plant, as well as, for its medicinal properties.
Organoleptic Characters (Fig) :
The leaves are green, roots are pale grey, flowers are violet, pink-white or carmine-red in colour. The odour is characteristic and taste is bitter. Vinca is an erect, pubescent herb, with branched tap-root. Leaves are simple, petiolate, ovate, or oblong, unicostate, reticulate, entire, brittle with acute apex and glossy appearance. Flowers are bractate,pedicellate, complete, hermaphrodite, normally 2 to 3 in cymose axillary clusters. Fruits are follicles with several black seeds.
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| VINCA ROSEA |
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| VINCA FLOWER |
Chemical Constituents :
Vinca contains wide varieties of chemicals including the glycosides and alkaloids. The indole~indoline alkaloids are very important constituents. About 60 alkaloids have been isolated so far from different parts of vinca. The important alkaloids with anticancer property are vincristine and vinblastine. Vincristine is obtained in about 0.0002 % yield from the crude drug. The other alkaloids present in the drug are ajmalicine, serpentine, lochnerine and tetrahydroalstonine. The total alkaloidal content of the drug is about 1 %, of which only a fraction contains therapeutically active alkaloids.
Both vinblastine and vincristine have the same structures with the difference that in vinblastine there is N-methyl group while, in vincristine it is N-formyl group and both Possess different activities. The other alkaloids are vindoline, vindolinine and catharanthine.
Uses:
Vincristine is used in treatment of leukaemia. Vinblastine is used for the treatment of generalised Hodgkin's disease and chorionepithelioma. Vinca also exhibits hypotensive and antidiabetic activity.
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