Ngo-1962, izazi zezitshalo zoMnyango Wezolimo wase-US zathola i-yew yasePacific evela eGifford National Forest Park eWashington, e-USA. Ngemuva kokukhishwa nokuhlolwa komsebenzi wezithako ezisebenzayo, isithako esisebenzayo se-anticancer paclitaxel sitholwe.
Njengoba isihlahla esivamile singanikeza amagxolo angu-2kg kuphela, inani le-paclitaxel emagxolweni e-Taxus chinensis liphansi kakhulu, futhi okungenani ama-12 kg amagxolo omile ayedingeka ukuze kutholwe cishe u-0.5 g we-paclitaxel ngaleso sikhathi. Ingxenye yayo enkulu yezinto eziphilayo icishe ibe ngu-0.004%, okuyingxenye yemvelo "ye-niche" eyiqiniso.
Nakuba incane, i-paclitaxel ingenye yezidakamizwa ezingcono kakhulu zokulwa-nezimila ezitholiwe kuze kube manje, futhi yaziwa njengesigaba "se-blockbuster" semithi-ye-spectrum ebanzi kanye{2}}enamandla eqeda isimila emhlabeni. Isetshenziselwa umdlavuza wesibeletho, umdlavuza webele, umdlavuza wesibeletho, umdlavuza wekhanda nentamo. njll ukwelashwa.
Esinye isibonelo esiyimpumelelo socwaningo lwesimanje lwezidakamizwa zasolwandle simayelana nenhlanganisela yemvelo "ye-niche" - i-ascidiantin ET-743, eyatholwa ku-Caribbean sea squirt (cishe ngo-0.0001% ngobuningi) futhi isithuthukiswe yaba izidakamizwa ze-Antineoplastic ezisetshenziselwa ukwelapha ama-sarcomas ezicubu ezithambile eziphikisayo.
Eqinisweni, emlonyeni wososayensi, izinhlanganisela zemvelo "ze-niche" nazo zinegama elithi - landelela izithako ezisebenzayo. Ocwaningweni lomuthi wendabuko waseShayina noma imikhiqizo yemvelo, ngokuvamile kubhekwa ukuthi izingxenye zazo ezinengxenye enkulu engaphansi kwe-1/10,000 (<0.01%) in the organism are trace components.
Lawa manani alandelayo ezithako ezisebenzayo, njengengxenye ebalulekile yomthombo wemithi emisha, enze umnikelo obalulekile ocwaningweni nasekuthuthukisweni kwemithi emisha. Okubaluleke kakhulu, ukutholakala kwabo akukhuthazi nje kuphela ucwaningo nokuthuthukiswa kwemithi emisha, kodwa futhi kukhuthaza ukuthuthuka okusheshayo kwemikhakha ehlobene efana nekhemikhali yokuhlaziya, i-chromatography, i-spectroscopy, i-organic chemistry, i-pharmacology kanye ne-synthetic biology. Njengenye yezindlela ezibalulekile zokudala imithi emisha, ucwaningo lokulandela umkhondo wezinto ezisebenzayo bekulokhu kuyisizinda socwaningo ekhaya naphesheya.
