An Iridoid Glucoside and the Related Aglycones from Cornus florida

Abstract

A new iridoid glucoside, cornusoside A (1), and four new natural product iridoid aglycones, cornolactones A–D (2–5), together with 10 known compounds were isolated from the leaves of Cornus florida. The structures of compounds 1–5 were established by interpretation of their spectroscopic data. Cornolactone B (3) is the first natural cis-fused tricyclic dilactone iridoid containing both a five- and a six-membered lactone ring. A biosynthesis pathway is proposed for cornolactones C (4) and D (5), the C-6 epimers of compounds 1–3.

Discovering variation of secondary metabolite diversity and its relationship with disease resistance inCornus floridaL.

“…This analysis, combined with the GWA results, revealed SNP–metabolite connections for a putative group of terpenoid glucosides (Figure 6a). We noted GGM connections of three metabolites consisting of an annotated iridoid glucoside/Eleganoside C (M435T576; Bailleul, Leveau, & Durand, 1981; Ali, Uzair, Krebs, Jahangir, & Habermehl, 2000; Xu, Wang, Zhang, & Yang, 2008), an aglycone/Cornolactone C (M227T630; He et al., 2014), and a possible intermediate (M451T432). Moreover, several SNPs were repeatedly found to be significantly associated with chemical features of these three metabolites (Figure 6a).…”

“…Biomarker M435T576 and its related metabolites belong to a class of terpenoid derivatives that have known antimicrobial and antifungal properties (Bartsch et al., 2010; Chang, Xuan, Xu, & Zhang, 2001; Meng, Lu, Li, Yang, & Tan, 1999; Whitehead, Tiramani, & Bowers, 2016) and are likely sensitive to disease‐mediated signaling processes (Caplan, Padmanabhan, & Dinesh‐Kumar, 2008). For instance, M227T630 was identified as Cornolactone C, an iridoid isolated previously from C. florida (He et al., 2014), which belongs to a compound class known to accumulate in response to infection and has documented antimicrobial properties (Marak, Biere, & Van Damme, 2002). …”

“…We noted GGM connections of three metabolites consisting of an annotated iridoid glucoside/Eleganoside C (M435T576; Bailleul, Leveau, & Durand, 1981;Ali, Uzair, Krebs, Jahangir, & Habermehl, 2000;Xu, Wang, Zhang, & Yang, 2008), an aglycone/Cornolactone C (M227T630; He et al, 2014), and a possible intermediate be significantly associated with chemical features of these three metabolites (Figure 6a). SNP loci with multiple significant associations (labeled yellow; Figure 6) within this associated group were as follows: B506_11, B1401_69 (aligned to gene encoding for oligo- Sawaki et al, 2009;Fan, Lou, Yang, & Zheng, 2016).…”

“…Other SNP loci like B440 may encode regulatory proteins (Fan et al, 2016;Sawaki et al, 2009), which similarly respond to stress by regu- (Caplan, Padmanabhan, & Dinesh-Kumar, 2008). For instance, M227T630 was identified as Cornolactone C, an iridoid isolated previously from C. florida (He et al, 2014), which belongs to a compound class known to accumulate in response to infection and has documented antimicrobial properties (Marak, Biere, & Van Damme, 2002).…”

“…We use a multidisciplinary approach to characterize and evaluate how properties of genetic diversity and chemodiversity contribute to susceptibility or resistance to disease in Cornus florida (L.), the flowering dogwood tree. In addition, we have applied exploratory analyses to winnow an untargeted list of metabolites down to a select group of potential antimicrobial compounds-closely resembling compounds previously observed in dogwoods (He, Peng, Hamann, & West, 2014;Stermitz & Krull, 1998;Yue et al, 2006). The species itself occurs naturally throughout much of eastern North America and is ecologically important partly because of calcium it delivers to food chains in deciduous forests (Baird, 1980;Blair, 1982;Borer, Sapp, & Hutchinson, 2013;Holzmueller, Jose, Jenkins, Camp, & Long, 2006;Linzey & Brecht, 2003;Lovenshimer & Frick-Ruppert, 2013).…”