10.1021/jm060087k
The research investigates the antidiabetic properties of penta-O-galloyl-D-glucopyranose (PGG) and its analogues. The study explores the structure-activity relationship of PGG's R- and α-anomers, which act as insulin mimetics, stimulating glucose transport in adipocytes and reducing blood glucose and insulin levels in diabetic and obese animals. The researchers synthesized and tested various novel compounds, finding that both the glucose core and the galloyl groups are crucial for activity. The galloyl groups linked to positions 1, 2, 3, and 4 of glucose are essential, while the one at position 6 is not. Notably, 6-chloro-6-deoxy-1,2,3,4-tetra-O-galloyl-R-D-glucopyranose (80) exhibited significantly higher glucose transport stimulatory activity than PGG, comparable to insulin. Key chemicals used in the research include PGG, gallic acid, methyl galloate, ellagic acid, and various derivatives of glucose and galloyl groups. The study provides insights into the development of new antidiabetic therapeutics that can address both hyperglycemia and adiposity.
10.1248/cpb.30.4046
This study investigated the glycosides and other polar components of Uncaria rhynchophylla, a plant used in traditional Chinese medicine. The researchers isolated a new glycoalkaloid named rhynchophylline (IV), which was identified as 6'-feruloylvinblastine lactam. They achieved a partial synthesis of rhynchophylline using vinblastine lactam as a starting material. In addition, they isolated five new compounds from the plant: valerine, vinblastine lactam, isofructoside, hyperoside, and trilobite. The study focused on the extraction and characterization of these compounds, using techniques such as UV spectroscopy, H-NMR, and 13C-NMR to elucidate their structures. These findings help understand the chemical composition of Uncaria rhynchophylla, which may have implications for its medicinal applications.
