Studies On The Chemical Constituents And Biological Activities Of The Bulbs Of Hybridized Lycoris

The genus Lycoris consists of about20species in the word,15species of whichare native to China. Lycoris plants widely distributed in the tropics and warmtemperature regions and have been used as folk medicines for the treatment ofulcerative carbuncle, edema and sore throat in China.The referred Hybridized Lycoris was collected from Huaihua county in the southof Hunan province, China, which was naturally hybridized from Lycoris. radiata andLycoris. aurea. Chemical and biological studies on this plant have never been reportedbefore. In our search for new, potentially biologically active compounds from plants,the chemical constituents of the bulbs of the Hybridized Lycoris were investigated.Accordingly,32coumpouds were isolated and31of them were identified by theirphysical and chemical constants and spectral data, including thirty alkaloids togetherwith one phenolic glycoside. They are:2-methoxy-6-O-ethyloduline （HL-1）,O-demethyllycoramine N-Oxide （HL-2）, N-chloromethyl ungiminorine （HL-3）,1-ethoxy allyl group-3-methoxy-4-O-β-D-glucopyranosyl-benzene （HL-4）, radiatine（HL-5）,2-hydroxy-6-O-methyloduline （HL-6）, O-Ethyllycorenine （HL-7）,O-Methyllycorenine （HL-8）,8-O-Demethylhomolycorine （HL-9）,9-O-Demethyl-2-hydroxy-homolycorine （HL-10）, Hippeastrine （HL-11）, lycoramine N-Oxide （HL-12）,O-demethyllycoramine （HL-13）, Lycoramine （HL-14）, galanthamine N-Oxide（HL-15）, Sanguinine （HL-16）, Galanthamine （HL-17）, epi-zephyranthine （HL-18）,dihydrolycorine （HL-19）, Lycorine （HL-20）, Hippamine （HL-21）,4-O-methyllycorine （HL-22）, Pseudolycorine （HL-23）, Pluviine （HL-24）,pancratinine C （HL-25）,（-）-3-O-methyl-pancracine （HL-26）, pancracine （HL-27）,Lycoricidinol （HL-28）,2’-deoxythymidine （HL-29）, Homolycorine hydrochloride（HL-30） and8-O-demethylhomolycorine N-Oxide （HL-31）. Compounds HL-1-3werethree new alkaloids and HL-4was a new phenolic glycoside. Other compounds HL-5-31were isolated from this plant for the first time.The crude extract and selected alkaloids were tested for their neuroprotectivepotential against CoCl₂, H₂O₂or Aβ_25-35-induced cell injuries in SH-SY5Y cellsrespectively. The crude extract exhibited very weak neuroprotective effects againstCoCl₂and Aβ_25-35-induced SH-SY5Y cell injury, while a modest anti-oxidativeactivity against H₂O₂-induced SH-SY5Y cell injury. HL-1-3exhibited significantneuroprotective effects against CoCl₂or H₂O₂-induced SH-SY5Y cell injury, whileHL-3displayed apparent neuroprotective of Aβ_25-35-induced SH-SY5Y cell injury.The known alkaloids also exhibited similar anti-hypoxia or antioxidant bioactivities ofdifferent degrees. These findings highlight the fact that the over100reportedAmaryllidaceae alkaloids may have a big potential to neuroprotective activity andanti-Alzheimer’s disease.The crude extract and parts of the alkaloids were evaluated for theirantiproliferative activities against MKN45cell line. The crude extract exhibitedsignificant cytotoxicities to MKN45. Except HL-20and HL-26exhibited moderatecytotoxic activity （their IC50were （12.20.2） μM and （48.10.1） μM）, all the IC50of the other compounds were larger than100μM.