Discovery And Structural Modification Of Antitumor Constituents From Veratrum Dahuricum

Veratrum dahuricum (Liliaceae) is one of the 14 species of the genus Veratrum in China. The rhizomes of some Veratrum species incuding Veratrum dahuricum, named as Lilu in Chinese traditional medicine, are used for some diseases such as aphasia arising apoplexy, epilepsy, wind type dysentery, jaundice, chronic malaria and acariasis. The crude extracts and compounds isolated from Veratrum plant havd benn reported possessing various pharmacological activities, including hypotensive, antithrombotic and antitumor function.1. Chemical investigation of Veratrum dahuricumBy modern chromatographic methods, 60 compounds were isolated from the ethanol extract of rhizomes of Veratrum dahuricum. Their structures were elucidated on the basis of spectral data including 1H-NMR, 13C-NMR, DEPT, 1H-1HCOSY, NOESY, HMQC, HMBC, ESI-MS, IR, as follows: XL-1: 14α-hydroxy-?11-cyclopamine XL-2: Veratrobasine XL-3: Cyclopamine XL-4: Jervine XL-5: Veratramine XL-6: Veratrsine XL-7: Pseudojervine XL-8: Verazine XL-9: Veramitaline XL-10: Etioline XL-11: Etioline-3-O-glucoside XL-12: 3-acetyl-15-angyloylgermine XL-13: 3, 7-diacetyl-15-angeloylgermine XL-14: 3-veratroylgermine XL-15: 3-veratroyl-15angyloylgermine XL-16: 3-veratroyl-15-methylbutyrylgermine XL-17: 3-acetyl-15-methylbutyroylgermine XL-18: Germerine XL-19: 15-angyloylgermine XL-20: 3, 7-diangyloylgermine XL-21: 3, 15-diangyloyl-7-acetylgermine XL-22: 3-angeloylgermine XL-23: 3-angeloylzygadenine XL-24: 3-veratroylzygadenine XL-25: Zygadenine XL-26: Germine XL-27: Resveratrol XL-28: Oxyresveratrol XL-29: (E)-piceid XL-30: (Z)-piceid XL-31: Oxyresveratrol-3-O-glucoside XL-32: Resveratrol-4'-O-glucoside XL-33: Oxyresveratrol-4'-O-glucoside XL-34: 4'-methylresveratrol-3-O-glucoside XL-35: 2'-hydroxy-5-methylresveratrol-3, 4'- diglucosides XL-36: Mulberroside A XL-37: Eupatilin XL-38: 3', 4', 7-trimethylluteolin XL-39: 4'-methylisorhamnetin XL-40: Luteolin XL-41: Kaempferol XL-42: Quercetin XL-43: Apigenin XL-44: Pectolinaringenin XL-45: Acacetin XL-46: Quercetin-7-O-rhamnoside XL-47: 4', 5, 7-trihydroxy-6-methoxyl-7-O- glucoside XL-48: 4'-hydroxyl-3', 5-dimethoxylflavone-7-O -glucoside XL-49: Luteolin-7-O-glucoside XL-50: Acacetin-7-O-glucoside XL-51: Apigenin-7-O-glucoside XL-52: Quercetin-3-O-glucoside XL-53: Quercetin-3-O-rhamnoside XL-54: Sucrose XL-55:β-sitosterol XL-56:β-daucosterol XL-57: Benzoic acid XL-58: Cerylalcohol XL-59: 3, 4-dihydroxylbenzoic acid XL-60: Koumine 2. Pharmacology research on Veratrum dahuricumThe acute toxic trials showed that the total alkaloids extract was the most toxic of all the samples, including petroleum ether, CHCl3, EtOAC, n-BuOH fraction, ethanol extract and total alkaloids. The better cytotoxic and antitumor activities were found on the jerveratrum alkaloids compared to the ceveratrum alkaloids.3. Determination of Six Steroidal Alkaloids of Veratrum dahuricumA high performance liquid chromatography coupled with evaporative light scattering detection (HPLC-ELSD) and electrospray ionization multistage mass spectrometry (HPLC-ESI-MSn), respectively, has been performed for the simultaneous determination of six steroidal alkaloids, including pseudojervine, veratrosine, jervine, veratramine, 3-veratroylzygadenine, 3-angeloylzygadenine, in Veratrum dahuricum of different season. The plants were soaked in methanol and extracted ultrasonically. The intra-day and inter-day precisions of the method were evaluated and were less than 1.4%. The content of steroidal alkaloids in the plant varied significantly from spring to autumn, confirming the necessity to control the quality of Veratrum dahuricum during its preparation and application. And we know from this assay that the appropriate time for collecting the Veratrum dahuricum was from June 25 to July 10 for higher content of jervine.4. The modification of three active compoundsWe have gained above 107 derivatives of veratramine, jervine and cyclopamine by chemical and biotransformational methods. Among them, 24 compounds further optimized exhibited significent activities, thereinto, 3 compounds were tested in vivo assay, with promising antitumor activity. Especially, cyclopamine from Veratrum plant we studied, a special inhibitor to the Hedgehog signal pathway, had significant antitumor avtivity.