Treatment of Vinca minor Leaves with Methyl Jasmonate Extensively Alters the Pattern and Composition of Indole Alkaloids

Abstract

Alkaloids extracted from mature Vinca minor leaves were fractionated by preparative HPLC. By means of HRMS and NMR data, the main alkaloids were identified as vincamine, strictamine, 10-hydroxycathofoline, and vincadifformine. Upon treatment with methyl jasmonate (MeJA), the pattern and composition of the indole alkaloids changed extensively. While 10-hydroxycathofoline and strictamine concentrations remained unaltered, vincamine and vincadifformine levels showed a dramatic reduction. Upon MeJA treatment, four other indole alkaloids were detected in high quantities. Three of these alkaloids have been identified as minovincinine, minovincine, and 9-methoxyvincamine. Whereas minovincinine and minovincine are known to occur in trace amounts in V. minor, 9-methoxyvincamine represents a novel natural product. Based on the high similarities of vincamine and 9-methoxyvincamine and their inverse changes in concentrations, it is postulated that vincamine is a precursor of 9-methoxyvincamine. Similarly, vincadifformine seems to be converted first to minovincinine and finally to minovincine. Because MeJA treatment greatly altered the alkaloidal composition of V. minor, it could be used as a potential elicitor of alkaloids that are not produced under normal conditions.

Asymmetric Total Synthesis of Vincadifformine Enabled by a Thiourea‐Phosphonium Salt Catalyzed Mannich‐Type Reaction

“…Notably, the 1 H and 13 C NMR data of the synthetic vincadifformine were identical to that of natural vincadifformine, which are different from those from Andrade's synthesis. We found that this problem could be solved by adding a trace amount of TFA during collection of the NMR spectroscopic data …”

“…We found that this problem could be solved by adding at race amount of TFAd uring collection of the NMR spectroscopic data. [13] In summary,w eh ave achieveda symmetrict otal syntheses of vincadifformine. The key C19 stereogenic center capitalized on ac hiral-cation-directed asymmetric Mannich reaction, which was catalyzed by our recently developed amino acid derived chiral bifunctional thiourea-phosphonium salt.…”

Identifying Genes Involved in Alkaloid Biosynthesis in Vinca minor through Transcriptomics and Gene Co-Expression Analysis

“…Furthermore, a V. minor counterpart of the C. roseus TPT2 transporter, involved in the secretion of MIAs to the leaf surface, has also been characterized [8] together with a picrinine N-methyltransferase involved in ervincine biosynthesis [11]. At the metabolic level, while the intracellular distribution of MIAs is still a matter of debate in leaves of V. minor [8,12], experimental evidence tends to confirm that MIA metabolism is higher in younger tissues and notably young leaves [13][14][15]. In addition, vincamine has been described as the main alkaloid found in the leaves of V. minor (0.13%) whereas 1,2-dehydroaspidospermidine is the major alkaloid detected in the roots (0.28% [16]).…”

“…In addition, vincamine has been described as the main alkaloid found in the leaves of V. minor (0.13%) whereas 1,2-dehydroaspidospermidine is the major alkaloid detected in the roots (0.28% [16]). Finally, some alkaloids are also specific to V. minor leaves, including vincarubine, picrinine, eburnamine, eburnamonine, minovincinine, minovine, vincadifformine and strictamine [7,8,12,16].…”

“…Interestingly, a mirroring biosynthetic route allows converting vincadifformine into echitovenine through the concerted action of vincadifformine 19-hydroxylase (V19H) [25] and minovincinine acetyltransferase (MAT) [22]. While the presence of tabersonine and derivatives in V. minor has been reported in a few works only [8,61], vincadifformine and vincamine are accumulated at high levels [12]. Importantly, epoxide formation on a vincadifformine-like skeleton has been proposed to be part of the vincamine synthesis process leading to postulate that vincadifformine is a precursor of vincamine [62].…”