The Structure-Activity Relationship of Pterostilbene Against Candida albicans Biofilms

Abstract

Candida albicans biofilms contribute to invasive infections and dramatic drug resistance, and anti-biofilm agents are urgently needed in the clinic. Pterostilbene (PTE) is a natural plant product with potentials to be developed as an anti-biofilm agent. In this study, we evaluated the structure-activity relationship (SAR) of PTE analogues against C. albicans biofilms. XTT (Sodium 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt) reduction assay was used to evaluate the activity of the analogues against C. albicans biofilms. Knowing that hyphal formation is essential for C. albicans biofilms, anti-hyphal assay was further carried out. By comparing a series of compounds tested in this study, we found that compounds with para-hydroxy (–OH) in partition A exhibited better activity than those with other substituents in the para position, and the double bond in partition B and meta-dimethoxy (–OCH3) in partition C both contributed to the best activity. Consistent results were obtained by anti-hyphal assay. Collectively, para-hydroxy (–OH), double bond and meta-dimethoxy (–OCH3) are all needed for the best activity of PTE against C. albicans biofilms.

Exploring an Innovative Strategy for Suppressing Bacterial Plant Disease: Excavated Novel Isopropanolamine-Tailored Pterostilbene Derivatives as Potential Antibiofilm Agents

“…citri ( Xac )-infected citrus plants to form citrus canker, leading to defoliation and premature fruit drop. Given the above-mentioned investigation, these phytopathogenic bacteria could form emblematic biofilms to block vascular bundles, leading to arduous plant growth and acute symptoms (such as etiolation of leaves, rhizome necrosis, and malformation). − Recently, these bacterial biofilm matrices have exhibited specific resistance to harsh environments, especially antimicrobial agents. − Therefore, launching new agrochemicals bearing innovative action mechanisms could solve this intractable situation and maintain crop production.…”

Plant Preparations and Compounds with Activities against Biofilms Formed by Candida spp.

“…According to the European Committee on Antimicrobial Susceptibility Testing (EUCAST), the antifungal clinical breakpoints are between 0.001 mg/L and 16 mg/L [ 60 ]. Using EUCAST guidelines in this review, the most active compounds that inhibit (>50%) Candida biofilm formation are lichochalcone A (from 0.2 mg/L) [ 61 ], thymol (from 3.12 mg/L) [ 26 ], dioscin (from 3.9 mg/L) [ 31 ], baicalein (from 4 mg/L) [ 62 ], warburganal (4.5 mg/L) [ 52 ], pterostilbene, waltheriones and riccardin D (both from 8 mg/L) [ 63 , 64 , 65 ], polygodial (10.8 mg/L) [ 52 ], cannabidiol and eugenol (both from 12.5 mg/L) [ 58 , 66 ], and ivalin (15.4 mg/L) [ 67 ]. It is interesting that monotherpenes, which represent the highest percentage of substances listed in Table 2 , are not the most active compounds.…”

Genome-wide amplification of proviral sequences reveals new polymorphic HERV-K(HML-2) proviruses in humans and chimpanzees that are absent from genome assemblies

“…Solo LTR formation is predominantly a phenomenon of younger proviruses, whose LTR sequences have not diverged, and so it is hypothesised that the meiotic recombination process that generates solo LTRs requires a high degree of sequence similarity [ 61 ]. However, by contrast, an ancient HERV-H provirus that integrated prior to the diversification of gibbons, generated a solo LTR after the divergence of the human and chimpanzee lineages, many millions of years after its integration and fixation [ 77 ]. Similarly, here we describe an ancient HERV-K(HML-2) provirus (1p31.1a) that integrated and became fixed prior to the diversification of the gorillini tribe, which is variable for solo LTR versus provirus in humans.…”