Indole alkaloid

About: Indole alkaloid is a research topic. Over the lifetime, 868 publications have been published within this topic receiving 15401 citations. The topic is also known as: indole alkaloids.

Localization of monoterpenoid indole alkaloid (MIA) biosynthesis by in situ hybridization (ISH)

Abstract: Monoterpenoid indole alkaloids (MIA) are among the largest and most complex group of nitrogen containing secondary metabolites that are characteristic of the Apocynaceae plant family including the most notable Catharanthus roseus. These compounds have demonstrated activity as successful drugs for treating various cancers, neurological disorders and cardiovascular conditions. Due to the low yields of these compounds and high pharmacological value, their biosynthesis is a major topic of study. Previous work highlighting the leaf epidermis and leaf surface as a highly active area in MIA biosynthesis and MIA accumulation has made the epidermis a major focus of this thesis. This thesis provides an in-depth analysis of the valuable technique of RNA in situ hybridization (ISH) and demonstrates the application of the technique to analyze the location of the biosynthetic steps involved in the production of MIAs. The work presented in this thesis demonstrates that most of the MIAs of Eurasian Vinca minor, African Tabernaemontana e/egans and five Amsonia species, including North American Amsonia hubrichitii and Mediterranean A. orienta/is, accumulate in leaf wax exudates, while the rest of the leaf is almost devoid of alkaloids. Biochemical studies on Vinca minor displayed high tryptophan decarboxylase (TOe) enzyme activity and protein expression in the leaf epidermis compared to whole leaves. ISH studies aimed at localizing TOe and strictosidine synthase suggest the upper and lower epidermis of V. minor and T. e/egans as probable significant production sites for MIAs that will accumulate on the leaf surface, however the results don't eliminate the possibility of the involvement of other cell types. The monoterpenoid precursor to all MIAs, secologanin, is produced through the MEP pathway occurring in two cell types, the IPAP cells (Gl0H) and epidermal cells (LAMT and SLS). The work presented in this thesis, localizes a novel enzymatic step, UDPG-7-deoxyloganetic acid glucosyltransferase (UGT8) to the IPAP cells of Catharanthus longifolius. These results enable the suggestion that all steps from Gl0H up to and including UGT8 occur in the IPAP cells of the leaf, making the IPAP cells the main site for the majority of secologanin biosynthesis. It also makes the IPAP cells a likely cell type to begin searching for the gene of the uncharacterized steps between Gl0H and UGT8. It also narrows the compound to be transported from the IPAP cells to either 7-deoxyloganic acid or loganic acid, which aids in the identification of the transportation mechanism.

Moschamine-Related Indole Alkaloids.

Abstract: Moschamine-related alkaloids originate mainly from feruloylserotonin by cyclization or dimerization. This review provides a comprehensive overview on the achievements in the field of moschamine-related alkaloids. In the isolation part, a detailed structural characterization of moschamine-related alkaloids is followed by their spectral data. Besides the well-known antioxidative activities, other screened biological properties are also outlined. Since their isolation, different protocols have been developed to synthesize these alkaloids. The synthetic part is organized according to the different synthetic methodologies for the formation of key structural elements.

Total Synthesis of Fused Polycyclic Alkaloids Based on Oxidative Phenolic Couplings and Aza-Michael Reactions

Abstract: Alkaloids with fused polycyclic frameworks are attractive targets for synthetic organic chemists because of their structural complexity and biological activities, and a variety of synthetic strategies have been developed. Herein, we describe our strategy of utilizing oxidative phenolic coupling reaction and regioselective intramolecular aza-Michael reaction to generate fused polycyclic structural frameworks, and its application to total syntheses of (+)-gracilamine and various hasubanan alkaloids.

Benzo-macrolactam indole alkaloid and application thereof in preparation of anti-complement medicines

Abstract: The invention belongs to the field of preparation of traditional Chinese medicines and relates to a benzo-macrolactam indole alkaloid, indigo naturalis alkaloid C, and an application thereof in preparation of anti-complement medicines. In the invention, the benzo-macrolactam indole alkaloid, indigo naturalis alkaloid C, is separated from powder of indigo naturalis, wherein the compound has a novel and unique structure and is formed by complexing two 3-carbonyl indole groups on benzo-macrolactam. A modern pharmacological experiment proves that the compound has strong inhibition effects on both a classic pathway and a bypass pathway of a complement system, wherein the CH50 value and the AP50 value of the compound are respectively 0.018 +/- 0.004 mg/ml and 0.042 +/- 0.014 mg/ml. The compound can be used for preparing a complement inhibitor.