酰基葡萄糖是由茄科产生的一组专门的代谢产物。茄属植物,野生型番茄植株,在其毛状表皮结构中产生酰基葡萄糖,称为毛状体。这些化合物已被发现是除草剂,微生物生长抑制剂,或化感化合物。然而,由于分离困难,有一些关于纯形式的酰基葡萄糖的分离和生物活性研究的报道。这里,我们报道了一种新的酰基葡萄糖,pennellisideD,从S.pennellii分离和鉴定。通过1DNMR和2DNMR确定其结构,与FD-MS分析。为了阐明天然化合物中2-甲基丁酰基的酰基部分的绝对构型,从β-D-葡萄糖五乙酸酯开始合成两种可能的异构体。通过比较天然和合成的异构体化合物的光谱数据,确认了邻苯二甲苷D的结构为3,4-O-二异丁酰基-2-O-((S)-2-甲基丁酰基)-D-葡萄糖。PennellisideD及其组成脂肪酸部分,(S)-2-甲基丁酸,没有显示根生长抑制活性。此外,在这项研究中,化学合成途径适合于苯甲皂苷A和B,得到1,6-O-二苄基苯甲皂苷A和B。
Acyl glucoses are a group of specialized metabolites produced by Solanaceae. Solanum pennellii, a wild-type tomato plant, produces acyl glucoses in its hair-like epidermal structures known as trichomes. These compounds have been found to be herbicides, microbial growth inhibitors, or allelopathic compounds. However, there are a few reports regarding isolation and investigation of biological activities of acyl glucoses in its pure form due to the difficulty of isolation. Here, we report a new acyl glucose, pennelliiside D, isolated and identified from S. pennellii. Its structure was determined by 1D NMR and 2D NMR, together with FD-MS analysis. To clarify the absolute configuration of the acyl moiety of 2-methylbutyryl in the natural compound, two possible isomers were synthesized starting from β-D-glucose pentaacetate. By comparing the spectroscopic data of natural and synthesized compounds of isomers, the structure of pennelliiside D was confirmed to be 3,4-O-diisobutyryl-2-O-((S)-2-methylbutyryl)-D-glucose. Pennelliiside D and its constituent fatty acid moiety, (S)-2-methylbutanoic acid, did not show root growth-inhibitory activity. Additionally, in this study, chemical synthesis pathways toward pennelliisides A and B were adapted to give 1,6-O-dibenzylpennelliisides A and B.