Flavonoids of Ammothamnus lehmannii. Structure of lehmannin and of ammothamnidin

The new flavanon lehmannin (I) has been isolated from the roots ofAmmothamnus lehmannii Bunge. On the basis of chemical transformations and with the aid of physicochemical characteristics it has been established that compound (I) has the structure of 2′,4′,7-trihydroxy-8-(2″-isopropenyl-5″-methylhex-4″-enyl)flavanone. The alkaline cleavage of lehmannin gave ammothamnidin (V). The structure proposed previously for the chalcone ammothamnidin has been corrected. It has been shown that it has the structure of 2,2′-4,4′-tetrahydroxy-3′-(2″-isopropenyl-5″-methylhex-4″- enyl)chalcone. A comparative study of the¹³C NMR spectra of a number of flavanones has revealed an empirical law permitting the prediction of the presence or absence of substituents (OH and OCH₃) at C-2′ from the value of the chemical shift of the signal of the C-2 carbon atom.     

Structure of a new chalcone ammothamnidin fromAmmothamnus lehmanni

A new chalcone ammothamnidin with the composition C₂₅H₂₈O₄, mp 112–114°C [] _D ²⁰ + 4.5° (methanol) has been isolated from the epigeal part and roots ofAmmothamnus lehmanni Bge. On the basis of chemical transformations and IR, UV,¹H and¹³C NMR, and mass spectra it has been shown that ammothamnidin has the structure of 2,2,4-trihydroxy-3-(2-isopropenyl-5-methylhex-4-enyl)chalcone.A. Navoi Samarkand State University. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 445–450, July–August, 1983.     

Flavonoids ofHaplophyllum perforatum. Structure and hypoazotemic activity of haploside C

A new acylated glycoside of limocitrin has been isolated from the epigeal part ofHaplophyllum perforatum (M.B.) Kar. et Kir. — haploside C — which has the structure of 3,4,5,7-tetrahydroxy-3,8-dimethoxyflavone 7-O-[O--L-rhamnopyranosyl-(1 2)-(6-O-acetyl--D-glucopyranoside)]. It has been established that haploside C possesses a pronounced hypoazotemic action.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 66–70, January–February, 1987.     

蒲公英黄酮抗氧化活性的构效关系分析

蒲公英作为传统的中药材,具有抗氧化、抗肿瘤、抗菌、抗炎等多种药用价值。黄酮是蒲公英发挥抗氧化作用的重要活性成分。蒲公英黄酮抗氧化性能的实验研究备受关注,然而从分子水平对蒲公英黄酮结构与抗氧化活性之间的内在关系缺乏系统的研究。本文借助于密度泛函理论,针对蒲公英中5种重要的黄酮化合物(槲皮素、芦丁、木犀草素、芹菜素、香叶木素),通过优化结构参数、捕获DPPH自由基的热力学能量分析,NBO电荷分布、半醌自由基的自旋密度分析等方面深入探讨了蒲公英黄酮化合物抗氧化活性的构效关系及内在规律。结果表明：5种蒲公英黄酮化合物抗氧化活性为芦丁>槲皮素>木犀草素>>香叶木素>芹菜素,酚羟基的位置是影响蒲公英黄酮抗氧化活性差异的主要因素。蒲公英黄酮不同位点抗氧化活性的高低与其酚羟基上H原子的电荷分布、黄酮自由基的稳定性成正比关系,自由基单电子的离域程度和分子内氢键的稳定化作用共同决定了B环4’-OH是蒲公英黄酮的关键活性位点。     

见血封喉根中类黄酮的结构鉴定

从海南产见血封喉[Antiaris toxicaria (Pers.) Lesch.]根的乙醇提取物中分离得到8个黄酮类化合物, 分别鉴定为antiarones K, B, F～I (1～6), (±)-sigmoidin A (7)和2-[2,3-二氢-4-羟基-2-(2-羟基-2-丙基)-5-甲氧基-1H-茚基]-1-(2,4,6-三羟基苯基)乙酮(8). 其中antiarone K (1)为新的异戊烯基二氢黄酮. 运用现代波谱技术, 包括二维核磁共振谱和高分辨质谱, 对上述化合物的结构进行了确证. 以上化合物经滤纸片法进行抗菌活性测试, 结果表明化合物1和3均具有抗金黄色葡萄球菌活性, 化合物3还具有抗耐甲氧西林金黄色葡萄球菌(MRSA)活性; 经MTT法进行细胞毒活性测试, 结果表明化合物1和6～8对慢性髓原白血病细胞(K562)、人胃癌细胞(SGC-7901)和人肝癌细胞(SMMC-7721)的增殖显示了生长抑制活性.     

An investigation of the alkaloids of Ammothamnus lehmanni the structure of lehmannine

Summary 1. The qualitative and quantitative composition of the combined alkaloids from the leaves, stems, seeds, and roots ofAmmothamnus lehmanni Bge. according to its vegetation periods have been studied.2. It has been found that the young plant contains predominantly the N-oxide forms of the matrine alkaloids, and as the plant develops these are reduced to the free bases.3. A new base lehmannine, C₁₅H₂₂ON₂ has been isolated for which 12,13-dehydromatrine is proposed as the most probable structure.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 377–380, May–June, 1975.     

Chemical study of the epigeal parts of the plantsAmmothamnus lehmannii andCicer mogoltavicum

Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 321-323, March-April, 1995. Original article submitted November 9, 1994.