Tava Aldo, Mella Mariella, Avato Pinarosa, Biazzi Elisa, Pecetti Luciano, Bialy Zbigniew, Jurzysta Marian
CRA-FLC Centro di Ricerca per le Produzioni Foraggere e Lattiero Casearie, Viale Piacenza 29, 26900 Lodi, Italy.
J Agric Food Chem. 2009 Apr 8;57(7):2826-35. doi: 10.1021/jf8036984.
The reinvestigation of saponin composition from Medicago arabica from Italy allowed the detection of nineteen (1-19) saponins. All of them were purified by reverse-phase chromatography and their structures elucidated by spectroscopic and spectrometric (1D and 2D NMR; ESI-MS/MS) and chemical methods. Fourteen were known saponins, previously found in other plants including other Medicago species. They have been identified as glycosides of oleanolic acid, 2beta,3beta-dihydroxyolean-12-en-28-oic acid, hederagenin, bayogenin and soyasapogenol B. Five saponins, identified as 3-O-[-alpha-L-arabinopyranosyl(1-->2)-beta-D-glucuronopyranosyl]-30-O-beta-D-glucopyranosyl 2beta,3beta,30-trihydroxyolean-12-en-28-oic acid (1), 3-O-[alpha-L-arabinopyranosyl(1-->2)-beta-D-glucuronopyranosyl]-30-O-[beta-D-glucopyranosyl] 3beta,30-dihydroxyolean-12-en-28-oic acid (2), 3-O-[beta-D-glucuronopyranosyl]-30-O-[alpha-L-arabinopyranosyl(1-->2)-beta-d-glucopyranosyl] 2beta,3beta,30-trihydroxyolean-12-en-28-oic acid (3), 3-O-[beta-D-glucuronopyranosyl]-30-O-[alpha-L-arabinopyranosyl(1-->2)-beta-D-glucopyranosyl] 3beta,30-dihydroxyolean-12-en-28-oic acid (4) and 3-O-[beta-D-glucuronopyranosyl]-30-O-[beta-D-glucopyranosyl] 2beta,3beta,30-trihydroxyolean-12-en-28-oic acid (5), are reported here as new natural compounds. These new saponins, possessing a hydroxy group at the 30-methyl position of the triterpenic skeleton, have never been previously found in the genus Medicago.
对来自意大利的阿拉伯苜蓿皂苷成分进行的重新研究，检测出了19种（1 - 19）皂苷。所有这些皂苷均通过反相色谱法进行纯化，并通过光谱和波谱法（1D和2D NMR；ESI-MS/MS）以及化学方法阐明其结构。其中14种是已知皂苷，此前在包括其他苜蓿属物种在内的其他植物中发现过。它们已被鉴定为齐墩果酸、2β,3β - 二羟基齐墩果 - 12 - 烯 - 28 - 酸、常春藤皂苷元、贝萼皂苷元和大豆皂苷元B的糖苷。5种皂苷，分别鉴定为3 - O - [-α - L - 阿拉伯吡喃糖基(1→2)-β - D - 葡萄糖醛酸吡喃糖基]-30 - O - β - D - 葡萄糖吡喃糖基2β,3β,30 - 三羟基齐墩果 - 12 - 烯 - 28 - 酸（1）、3 - O - [α - L - 阿拉伯吡喃糖基(1→2)-β - D - 葡萄糖醛酸吡喃糖基]-30 - O - [β - D - 葡萄糖吡喃糖基]3β,30 - 二羟基齐墩果 - 12 - 烯 - 28 - 酸（2）、3 - O - [β - D - 葡萄糖醛酸吡喃糖基]-30 - O - [α - L - 阿拉伯吡喃糖基(1→2)-β - D - 葡萄糖吡喃糖基]2β,3β,30 - 三羟基齐墩果 - 12 - 烯 - 28 - 酸（3）、3 - O - [β - D - 葡萄糖醛酸吡喃糖基]-30 - O - [α - L - 阿拉伯吡喃糖基(1→2)-β - D - 葡萄糖吡喃糖基]3β,30 - 二羟基齐墩果 - 12 - 烯 - 28 - 酸（4）和3 - O - [β - D - 葡萄糖醛酸吡喃糖基]-30 - O - [β - D - 葡萄糖吡喃糖基]2β,3β,30 - 三羟基齐墩果 - 12 - 烯 - 28 - 酸（5），在此作为新的天然化合物进行报道。这些新皂苷在三萜骨架的30 - 甲基位置上具有一个羟基，此前从未在苜蓿属中发现过。
