Identification of candidate genes related to calanolide biosynthesis by transcriptome sequencing of Calophyllum brasiliense (Calophyllaceae)

Abstract

BackgroundCalophyllum brasiliense is highlighted as an important resource of calanolides, which are dipyranocoumarins that inhibit the reverse transcriptase of human immunodeficiency virus type 1 (HIV-1 RT). Despite having great medicinal importance, enzymes involved in calanolide, biosynthesis and the pathway itself, are still largely unknown. Additionally, no genomic resources exist for this plant species.ResultsIn this work, we first analyzed the transcriptome of C. brasiliense leaves, stem, and roots using a RNA-seq strategy, which provided a dataset for functional gene mining. According to the structures of the calanolides, putative biosynthetic pathways were proposed. Finally, candidate unigenes in the transcriptome dataset, potentially involved in umbelliferone and calanolide (angular pyranocoumarin) biosynthetic pathways, were screened using mainly homology-based BLAST and phylogenetic analyses.ConclusionsThe unigene dataset that was generated in this study provides an important resource for further molecular studies of C. brasiliense, especially for functional analysis of candidate genes involved in the biosynthetic pathways of linear and angular pyranocoumarins.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-016-0862-9) contains supplementary material, which is available to authorized users.

Calophyllum brasiliense Extracts Induced Apoptosis in Human Breast Adenocarcinoma Cells

“…In the present study, the presence of coumarins in both STE and LFE extracts was reported. Mammea-type coumarins, [42,44,46 49,51,52,58,60,61,65]; calanolide coumarins [45,68,71] sulamarin [43] and soulattrolide [67,68] were identified in the leaves. From the barks, stem barks or heartwood, coumarins as calophyllolide [57] an…”

“…The structures of some compounds that are already identified in the species as shown in Figs 5 and In the present study, the presence of coumarins was reported. type coumarins, [42,44,[46][47][48][49]51,52,58,60,61,65]; calanolide-type coumarins [45,68,71] sulamarin [43] and soulattrolide [67,68] were identified in the leaves. From the barks, stem barks or heartwood, coumarins as calophyllolide [57] and brasimarins [56] were isolated, as well as mammea coumarins [57,69].…”

Naturally Occurring Calanolides: Occurrence, Biosynthesis, and Pharmacological Properties Including Therapeutic Potential

“…The biosynthesis of dipetalolactone, a pyranocoumarin, and subsequent conversion to the 3-propyl-intermediate for calanolides may proceed through two routes, one through conversion of umbelliferone to osthenol (Scheme 1), and the other via formation of 5,7-dihdroxycoumarin (Scheme 2). Reactions are generally mediated by p450 monooxygenase and other non-p450 enzymes [28]. 3-Propyl-intermediate is converted to the precursor compound for calanolides A-C (1, 4 and 6), utilizing the Wagner-Meerwein rearrangement reaction, and the precursor compound is believed to be converted to calanolides with the help of p450 monooxygenase enzyme (Scheme 3).…”

“…3-Propyl-intermediate is converted to the precursor compound for calanolides A-C (1, 4 and 6), utilizing the Wagner-Meerwein rearrangement reaction, and the precursor compound is believed to be converted to calanolides with the help of p450 monooxygenase enzyme (Scheme 3). Published studies on the biosynthesis of calanolides are rather limited and only two publications are available on this topic to date [28,29]. Therefore, detailed knowledge of specific enzymes involved in the biosynthesis of calanolides is still in its infancy.…”

“…As genes dictate biosynthesis of secondary metabolites, a study was conducted to identify candidate genes that regulate to the biosynthesis of calanolides in C. brasiliense [28]. The unigene dataset constructed in this study could offer an insight for further molecular studies of C. brasiliense, particularly for characterizing candidate genes responsible for the biosynthesis of angular and linear pyranocoumarins.…”