Progress in Identification of UDP-Glycosyltransferases for Ginsenoside Biosynthesis.

Ginsenosides, the primary pharmacologically active constituents of the Panax genus, have demonstrated a variety of medicinal properties, including anticardiovascular disease, cytotoxic, antiaging, and antidiabetes effects. However, the low concentration of ginsenosides in plants and the challenges associated with their extraction impede the advancement and application of ginsenosides. Heterologous biosynthesis represents a promising strategy for the targeted production of these natural active compounds. As representative triterpenoids, the biosynthetic pathway of the aglycone skeletons of ginsenosides has been successfully decoded. While the sugar moiety is vital for the structural diversity and pharmacological activity of ginsenosides, the mining of uridine diphosphate-dependent glycosyltransferases (UGTs) involved in ginsenoside biosynthesis has attracted a lot of attention and made great progress in recent years. In this paper, we summarize the identification and functional study of UGTs responsible for ginsenoside synthesis in both plants, such as Panax ginseng and Gynostemma pentaphyllum, and microorganisms including Bacillus subtilis and Saccharomyces cerevisiae. The UGT-related microbial cell factories for large-scale ginsenoside production are also mentioned. Additionally, we delve into strategies for UGT mining, particularly potential rapid screening or identification methods, providing insights and prospects. This review provides insights into the study of other unknown glycosyltransferases as candidate genetic elements for the heterologous biosynthesis of rare ginsenosides.

Raman spectroscopy with graphenated anodized aluminum oxide substrates.

We measured the Raman scattering of graphene deposited nanohole arrays. As the sample was azimuthally rotated, periodicities of 7.5 degrees and 5 degrees were revealed for the 2700 cm(-1) and 1600 cm(-1) Raman lines of graphene, respectively. This is contrary to the scattered laser line azimuthal symmetry of 30 degrees for the hole array alone. When a reference dye (stilbene) was deposited on the graphenated platforms, its Raman peak shifted as a function of incident (tilt) angle; this was contrary to the unshifted 1600 cm(-1) peak of graphene itself. The data suggest strong coupling between the molecular vibrations as portrayed by Raman spectra and surface plasmon polariton waves propagating along the graphene surface.