Rosmarinic Acid Accumulation Research Articles

Enhanced rosmarinic acid biosynthesis in Solenostemon scutellarioides culture: a precursor-feeding strategy

The aim of this study was to employ precursor-feeding strategy for the improved production of rosmarinic acid (RA) in Solenostemon scutellarioides in vitro. The cultures were fed with precursors, namely l-phenylalanine (Phe), l-tyrosine (Tyr) and cucumber juice (CJ), at different concentrations. Phe (100 mg L− 1) and Tyr (400 mg L− 1) caused ∼1.5- and 2.1-fold increase in RA accumulation within 48 h. CJ (50 mg L− 1) feeding displayed highest RA content (∼1.6-fold) in 72 h. In this study, we focused on the function of individual precursor on key enzymes involved in RA biosynthesis. The phenylalanine ammonia lyase activity was significantly upregulated after Phe (100 mg L− 1) feeding, while tyrosine aminotransferase and hydroxyphenylpyruvate reductase activities were improved with Tyr (400 mg L− 1) treatment. However, rosmarinic acid synthase activity was significantly enhanced by all three precursors. In synergy study, Phe (100 mg L− 1) + Tyr (400 mg L− 1) could enhance (∼3.1-fold) RA biosynthesis within 48 h.

Different secondary metabolic responses to MeJA treatment in shikonin-proficient and shikonin-deficient cell lines from Arnebia euchroma (Royle) Johnst

The administration of methyl jasmonate (MeJA) to A. euchroma suspension-cultured cells elicited distinct responses from a red shikonin-proficient cell line (RCL) and a white shikonin-deficient cell line (WCL). Specifically, MeJA promoted the accumulation of shikonin derivatives, shikonofuran derivatives and rosmarinic acid in the RCL, but no shikonin derivatives accumulated in the WCL. Moreover, MeJA promoted the WCL to produce several unusual shikonofuran derivatives that are thought to be derived from geranylhydroquinone (GHQ), a key intermediate in the biosynthesis of shikonin derivatives. To the best of our knowledge, herein we identified shikonofuran derivatives in A. euchroma for the first time. Further, we found that these secondary metabolic products can be induced by MeJA rapidly (within 1 h) and remained high in the RCL, whereas the WCL responded more slowly to the MeJA treatment. Secondary metabolic products continued to rise gradually after 6 h of treatment and then dramatically increased, to levels 12-fold greater than those of the untreated control, until 72 h after treatment in the WCL. Because shikonin and shikonofuran are generated through a common pathway and are derived from the same GHQ precursor, these different responses likely involve a metabolic flux increase, relocation or redirection from GHQ towards different metabolic end products. Culture experiments also demonstrated that MeJA caused a rapid and massive increase in the expression of 5 important genes involved in shikonin biosynthesis and shikonofuran derivative formation in the WCL. Transcripts of HMGR, GDPS, C4H, 4CL and PGT were rapidly induced within 4 h, peaked within 24 h, and then decreased over time. These findings suggest that MeJA promoted the formation of shikonofuran derivatives, but not shikonin derivatives, via direct stimulation of the transcription of the shikonin biosynthetic genes.

Production of caffeic, chlorogenic and rosmarinic acids in plants and suspension cultures of Glechoma hederacea

Glechoma hederacea L. (Lamiaceae) is a perennial plant, which is distributed widely in Europe, Asia and America. Important anti-oxidant compounds are caffeic acid esters like rosmarinic acid (RA) and chlorogenic acid (CA). Phenylalanine ammonia-lyase (PAL) and rosmarinic acid synthase (RAS, 4-coumaroyl-CoA:hydroxyphenyllactic acid hydroxycinnamoyltransferase) contribute to the formation of RA. Our aim in this study was to follow the accumulation of RA, CA and caffeic acid in a suspension culture of G. hederacea. Growth, medium and secondary metabolism parameters were determined during a culture period of 14 days. The maximal PAL activity was observed on day 5 and the maximal RAS activity on day 8. The RA content was exceedingly high and reached 25.9% of the dry mass on day 7. Caffeic acid and CA contents remained rather low. Furthermore, the presence of RA, CA and caffeic acid and the expression patterns of RAS and hydroxycinnamoyl-CoA:shikimate hydroxycinnamoyltransferase (HST), an important enzyme of monolignol formation, in leaves, flowers, stems and roots of naturally grown G. hederacea were assessed. The expression of RAS and HST genes was detectable in all organs except roots. Flowers accumulated 12.5% RA in their dry mass, leaves, stems and roots about 1%. CA was highest in leaves (2.0%), while it was at 1.6% in flowers, 1.3% in stems and almost undetectable in roots. The caffeic acid content remained at or below 0.4% of the dry weight in all organs.

Increased Antioxidant Activity, Despite Reduced Rosmarinic Acid Accumulation in Methanolic Extracts, of Spearmint (Mentha spicata L.) Plantlets Regenerated In Vitro

One hundred spearmint (Mentha spicata) plantlets were regenerated from apical shoot segments of ten field- grown donor plants. Although the accumulation of rosmarinic acid and total phenolics in vitro was almost half than in vivo, regenerants demonstrated a tenfold-higher hydrogen peroxide compared to the donor plants. This finding may have been associated with the increased activity of hydroxyphenylpyruvate reductase, a key enzyme of the phenolic biosyn- thetic pathway and the increased production of yet unidentified phenolic compounds in vitro. This process of in vitro cul- ture associated with a reduction of rosmarinic acid and total phenolics and with an increase of the antioxidant capacity in- dicated the possible promotion of in vitro-specific biosynthetic pathways.

Hydrogen peroxide is involved in salicylic acid-elicited rosmarinic acid production in Salvia miltiorrhiza cell cultures.

Salicylic acid (SA) is an elicitor to induce the biosynthesis of secondary metabolites in plant cells. Hydrogen peroxide (H2O2) plays an important role as a key signaling molecule in response to various stimuli and is involved in the accumulation of secondary metabolites. However, the relationship between them is unclear and their synergetic functions on accumulation of secondary metabolites are unknown. In this paper, the roles of SA and H2O2 in rosmarinic acid (RA) production in Salvia miltiorrhiza cell cultures were investigated. The results showed that SA significantly enhanced H2O2 production, phenylalanine ammonia-lyase (PAL) activity, and RA accumulation. Exogenous H2O2 could also promote PAL activity and enhance RA production. If H2O2 production was inhibited by NADPH oxidase inhibitor (IMD) or scavenged by quencher (DMTU), RA accumulation would be blocked. These results indicated that H2O2 is secondary messenger for signal transduction, which can be induced by SA, significantly and promotes RA accumulation.

Molecular cloning and characterization of genes involved in rosmarinic acid biosynthesis from Prunella vulgaris.

Prunella vulgaris L., commonly known as "self-heal" or "heal-all," is a perennial herb with a long history of medicinal use. Phenylalanine ammonia-lyase (PAL), cinnamate 4-hydroxylase (C4H), and 4-coumarate:coenzyme-A (CoA) ligase (4CL) are important enzymes in the phenylpropanoid pathway and in the accumulation of rosmarinic acid (RA), which is a major secondary metabolite in P. vulgaris. In this study, we isolated cDNAs encoding PvPAL, PvC4H, and Pv4CL from P. vulgaris using rapid amplification of cDNA ends polymerase chain reaction (PCR). The amino acid sequence alignments of PvPAL, PvC4H, and Pv4CL showed high sequence identity to those of other plants. Quantitative real-time PCR analysis was used to determine the transcript levels of genes involved in RA biosynthesis in the flowers, leaves, stems, and roots of P. vulgaris. The transcript levels of PvPAL, PvC4H, and Pv4CL1 were the highest in flowers, whereas Pv4CL2 was the highest in roots. High-performance liquid chromatography analysis also showed the highest RA content in the flowers (3.71 mg/g dry weight). We suggest that the expression of the PvPAL, PvC4H, and Pv4CL1 genes is correlated with the accumulation of RA. Our results revealed that P. vulgaris flowers are appropriate for medicinal usage, and our findings provide support for increasing RA production in this plant.

Bioproduction and Optimization of Rosmarinic Acid Production in Solenostemon Scutellarioides through Media Manipulation and Conservation of High Yielding Clone via Encapsulation

The present study describes the role of different exogenous phytohormones, polyamines and sucrose on growth and rosmarinic acid (RA) production in whole plant culture of Solenostemon scutellarioides. It was further aimed to conserve elite clones via synthetic seed technology. S. scutellarioides was treated either singly or in combination with different phytohormones. Cultures incubated with NAA (0.5 mg L(-1)) yielded the highest RA accumulation (g(-1FW)), but negatively affected the growth. So, overall RA content was insignificant. Cultures incubated with IBA, BAP and GA3 at low concentration significantly improved growth and RA bioaccumulation. In the combinatorial study, IBA+BAP+GA3 (0.5 mg L(-1) each) was found optimum for plant biomass and RA production (65.2% improvement of total RA). Amongst polyamines, putrescine (1 mg L(-1)) exhibited 20.4% improvement of total RA content. The intracellular RA accumulation (g(-1FW)) was significantly higher between 5 and 7% of sucrose concentrations. However, the total increase in RA content was inhibited due to deterioration of the culture with increasing sucrose concentration. Based on the effect of different treatments on growth and RA accumulation, a high yielding and stable plant line was selected for conservation via alginate encapsulation. Uniform shaped alginate coated synthetic seeds conserved up to 6 months exhibited high regeneration potential and RA content.

Optimisation of potassium chloride nutrition for proper growth, physiological development and bioactive component production in Prunella vulgaris L.

Prunella vulgaris L. is an important medicinal plant with a variety of pharmacological activities, but limited information is available about its response to potassium chloride (KCl) supplementation. P. vulgaris seedlings were cultured in media with four different KCl levels (0, 1.00, 6.00 and 40.00 mM). Characteristics relating to the growth, foliar potassium, water and chlorophyll content, photosynthesis, transpiration, nitrogen metabolism, bioactive constituent concentrations and yield were determined after three months. The appropriate KCl concentration was 6.00 mM to result in the highest values for dry weight, shoot height, spica and root weight, spica length and number in P. vulgaris. The optimum KCl concentration resulted in a maximum net photosynthetic rate (Pn) that could be associated with the highest chlorophyll content and fully open stomata conductance. A supply of surplus KCl resulted in a higher concentration of foliar potassium and negatively correlated with the biomass. Plants that were treated with the appropriate KCl level showed a greater capacity for nitrate assimilation. The Pn was significantly and positively correlated with nitrate reductase (NR) and glutamine synthetase (GS) activities and was positively correlated with leaf-soluble protein and free amino acid (FAA) contents. Both KCl starvation (0 mM) and high KCl (40.00 mM) led to water loss through a high transpiration rate and low water absorption, respectively, and resulted in increased concentrations of ursolic acid (UA), oleanolic acid (OA) and flavonoids, with the exception of rosmarinic acid (RA). Moreover, the optimum concentration of KCl significantly increased the yields of RA, UA, OA and flavonoids. Our findings suggested that significantly higher plant biomass; chlorophyll content; Pn; stronger nitrogen anabolism; lower RA, UA, OA and flavonoid accumulation; and greater RA, UA, OA and flavonoid yields in P. vulgaris could be expected in the presence of the appropriate KCl concentration (6.00 mM).

In vitro callus induction and rosmarinic acid accumulation of Salvia officinalis

In vitro callus induction and rosmarinic acid accumulation of Salvia officinalis

Metabolomics analysis and biosynthesis of rosmarinic acid in Agastache rugosa Kuntze treated with methyl jasmonate.

This study investigated the effect of methyl jasmonate (MeJA) on metabolic profiles and rosmarinic acid (RA) biosynthesis in cell cultures of Agastache rugosa Kuntze. Transcript levels of phenylpropanoid biosynthetic genes, i.e., ArPAL, Ar4CL, and ArC4H, maximally increased 4.5-fold, 3.4-fold, and 3.5-fold, respectively, compared with the untreated controls, and the culture contained relatively high amounts of RA after exposure of cells to 50 µM MeJA. RA levels were 2.1-, 4.7-, and 3.9-fold higher after exposure to 10, 50, and 100 µM MeJA, respectively, than those in untreated controls. In addition, the transcript levels of genes attained maximum levels at different time points after the initial exposure. The transcript levels of ArC4H and Ar4CL were transiently induced by MeJA, and reached a maximum of up to 8-fold at 3 hr and 6 hr, respectively. The relationships between primary metabolites and phenolic acids in cell cultures of A. rugosa treated with MeJA were analyzed by gas chromatography coupled with time-of-flight mass spectrometry. In total, 45 metabolites, including 41 primary metabolites and 4 phenolic acids, were identified from A. rugosa. Metabolite profiles were subjected to partial least square-discriminate analysis to evaluate the effects of MeJA. The results indicate that both phenolic acids and precursors for the phenylpropanoid biosynthetic pathway, such as aromatic amino acids and shikimate, were induced as a response to MeJA treatment. Therefore, MeJA appears to have an important impact on RA accumulation, and the increased RA accumulation in the treated cells might be due to activation of the phenylpropanoid genes ArPAL, ArC4H, and Ar4CL.

Effects of Cadmium Stress on Seedlings Growth and Active Ingredients in Salvia miltiorrhiza

Effects of cadmium stress on seedlings growth and active ingredients in Salvia miltiorrhiza were investigated. Results showed that cadmium stress inhibited seedlings growth and increased Cd2+accumulation in both soil and seedlings. Moreover,both soluble protein content and membrane lipid peroxidation degree increased,while photosynthetic pigments content decreased under stress conditions. Compared with the control, in stressed S. miltiorrhiza leaves,the accumulation of six phenolic acid compounds showed different variant characteristics. Both caffeic acid and rosmarinic acid accumulation decreased significantly( p0. 05),while the content of protocatechuic acid increased( p0. 05),and the levels of tanshinol,protocatechuic aldehyde and salvianolic acid B decreased( p 0. 05). However, the accumulations of the phenolic acids components and four tanshinone ingredients all decreased in stressed roots, and the variances of rosmarinic acid, dihydrotanshinone, tanshinone Ⅰ and cryptotanshinone were significant( p 0. 05). Moreover,in the leaves of the stressed plant,the activities of PAL and TAT decreased significantly,but C4H and 4CL content increased significantly. These results showed that cadmium stress could reduce the production and quality of S. miltiorrhiza.

Elicitor-induced rosmarinic acid accumulation and secondary metabolism enzyme activities in Solenostemon scutellarioides

This study aimed to improve rosmarinic acid (RA) production in the whole plant culture of Solenostemon scutellarioides through elicitation. Amongst selected elicitors methyl jasmonate (MJ), salicylic acid (SA), and yeast extract (YE) caused significant elevation in RA accumulation. Elicitation with MJ (50 μM) and SA (50 μM) caused almost 1.7 and 1.4-fold increase in RA accumulation, respectively, within day 1. While YE (100 μg ml−1) elicitation showed highest RA content (~1.5-fold) in day 3. Preceding the elicitor-induced RA accumulation, there was a notable alteration in the specific activities of RA biosynthetic enzymes viz. phenylalanine ammonia lyase, tyrosine aminotransferase, hydroxyl-phenylpyruvate reductase and rosmarinic acid synthase up on MJ (50 μM), SA (50 μM) and YE (100 mg ml−1) elicitation. Based on differential responses of aforementioned enzymes, RA synthesis was further scaled up through combination of elicitors in pre-optimized doses. In synergy study, at a time exposure with MJ + SA + YE and MJ + SA followed by YE after 24 h has been found to produce significant elevation of RA (2.0 and 1.9-fold, respectively) within 24 h while later maintained a steady state increased level (~1.7 ± 0.2-fold) over control up to day 7.

RNAi suppression and overexpression studies of hydroxyphenylpyruvate reductase (HPPR) and rosmarinic acid synthase (RAS) genes related to rosmarinic acid biosynthesis in hairy root cultures of Coleus blumei

Hydroxyphenylpyruvate reductase (HPPR) and rosmarinic acid synthase (RAS) have been described as enzymes involved in rosmarinic acid (RA) biosynthesis. In this study, elucidating the role of HPPR and RAS in the formation of RA was pursued. For this purpose, hairy root lines of Coleus blumei carrying HPPR or RAS RNAi suppression and overexpression constructs were established using Agrobacterium rhizogenes-mediated transformation. Transgenic lines were evaluated for RA accumulation. Hairy root lines showing undetectable HPPR or RAS mRNA levels displayed strongly reduced RA contents with reduction of up to 92 % compared to control hairy root lines. An increase of RA levels up to 176 % was shown in overexpression hairy root lines with equally increased HPPR transcript levels while RAS overexpression resulted in co-suppression effects with reduced RA levels. These observations support the participation of HPPR and RAS in RA biosynthesis.

The Effect of Lactobacillus plantarum ATCC 8014 and Lactobacillus acidophilus NCFM Fermentation on Antioxidant Properties of Selected in Vitro Sprout Culture of Orthosiphon aristatus (Java Tea) as a Model Study.

High rosmarinic acid (RA) productivity has been achieved by applying jasmonic acid and yeast extract elicitors to the in vitro sprout culture of Orthosiphon aritatus (IOSC). The highest RA accumulation from three solvents was detected in IOSC after treatment with yeast extract (5 g/L). HPLC analysis clearly confirmed a drastic increase in RA subjected to yeast extract elicitation. Therefore, this yeast extract elicited IOSC was chosen for a lactic acid bacteria (LAB) fermentation study as a model system. This selected IOSC was subjected to different types of LAB fermentations (Lactobacillus plantarum ATCC 8014 and Lactobacillus acidophilus NCFM) for different periods of time 24, 48 and 72 h. The LAB fermentations consisted of solid state fermentations (SSF) and liquid state fermentations (LSF) in a Digital Control Unit (DCU) fermenter system. The aim was to determine the effect of fermentation on the antioxidant properties of the plant extract. Results indicated that all types of LAB fermentation decreased the level of RA and total phenolics, however, a slight increase in total flavonoids and flavonols was observed in SSF samples. HPLC results confirmed that the longer the fermentation, the greater the reduction in RA content. The highest reduction was obtained in the sample of LSF inoculated with L. plantarum for a period of 72 h. The temperature of fermentation (37 °C) was predicted as contributing to the declining level in RA content. The loss in RA was concomitant with a loss of total antioxidant activity (1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, Trolox Equivalent Antioxidant Capacity (TEAC), and Superoxide Dismutase (SOD)-like activity). These results indicate that RA is the major contributor to the antioxidant activity of this plant.

Accumulation and variation of rosmarinic acid content in Orthosiphon stamineus Benth. based on phenological stages

Orthosiphon Stamineus Benth. (Lamiaceae) is a medicinal herb trusted for many centuries for treating ailments of the kidney, bladder stone, urinary tract infection, liver and bladder problems, diabetes, rheumatism and gout. It is also used to reduce cholesterol and blood pressure. Rosmarinic acid is one of the most important and specific active compound in O. stamineus. The biological effects of rosmarinic acid have been proved. In the research, plant material was harvested at different phenological stages (before budding, full flowering, and after flowering) of the life cycle of the species. The content of rosmarinic acid in samples was measured using HPLC method. Results showed that the accumulation of rosmarinic acid in leaf was higher than that in other organs. The content of rosmarinic acid was increased gradually from before budding stage to flowering stage and reached the maximum content at time of after flowering stage. The content of rosmarinic acid of the 2nd variety was higher than that of the 1st variety at the same time (p < 0.05).

An integrated analysis of the rosmarinic acid-biosynthetic genes to uncover the regulation of rosmarinic acid pathway in Salvia miltiorrhiza

Medicinal Salvia miltiorrhiza is renowned for its curative effects on cardiovascular diseases. Its biologically active ingredients include rosmarinic acid (RA) and its derivative, salvianolic acid B (SAB). We used available bioinformatics tools to improve our knowledge about the biosynthesis of these phenolic compounds. Our comprehensive description of cis-acting regulatory elements in the RA pathway provides insights into the potential transcriptional regulation of that pathway. For example, a light-responsive element was the most abundant and widespread motif, suggesting that light is a universal regulatory factor of RA synthesis in S. miltiorrhiza. Therefore, we examined gene transcripts and the accumulation of hydrophilic pharmacological compounds in light-treated plants. Canonical correlation analysis was also used to construct a gene-to-metabolite network. We obtained a high correlation coefficient (0.986), which generally indicated a clear and close relationship between RA-biosynthetic genes and desirable metabolites. We also screened PAL1, C4H, and HPPR, genes directly linked to the accumulation of RA and SAB. Our results can serve as the basis for better understanding RA synthesis in S. miltiorrhiza, and they will increase the practical potential for metabolic engineering of this important medicinal species.

Rosmarinic acid content in basil plants grown in vitro and in hydroponics

Abstract The accumulation of selected caffeic acid derivatives (CADs), in particular rosmarinic acid (RA), was investigated in different tissues (leaves, roots and plantlet shoots) of sweet basil (Ocimum basilicum L.) plants grown either in vitro or in hydroponic culture (floating system) under greenhouse conditions. Two cultivars with green leaves (Genovese and Superbo) and one with purple leaves (Dark Opal) were tested. The content of CADs in HCl-methanol extracts was determined by HPLC. LC-MS and LC-MS-MS were used to confirm the identification of the metabolites of interest. Apart from rosmarinic acid (RA) and a methylated form of this substance, no other CADs were detected at significant level in any of the analyzed samples. The content of RA ranged approximately from 4 to 63 mg/g DW, depending on the growing system. The highest RA content was found during the in vitro multiplication, in the acclimatized plants and in the roots of hydroponically-grown seedlings at full bloom. In vitro, 6-benzyladenine reduced the accumulation of RA in purple-leaf Dark Opal cultivar, but an opposite effect of this growth regulator was observed in the green-leaf genotypes. Our findings suggest the possibility to scale-up RA production by means of in vitro or hydroponic culture of sweet basil.

The effects of jasmonic acid and methyl jasmonate on rosmarinic acid production in Mentha × piperita cell suspension cultures

The effects of two elicitors: jasmonic acid and methyl jasmonate on cell growth as well as on rosmarinic acid accumulation in cell suspension cultures of Mentha × piperita were investigated. The highest rosmarinic acid accumulation 117.95 mg g−1 DW (12% DW) was measured 24 h after addition of 100 μM methyl jasmonate. A similar concentration 110.12 mg g−1 DW was detected 48 h after application of 200 μM jasmonic acid. Those values were nearly 1.5 times higher compared to the control sample, without elicitation. There was no substantial influence of elicitors on rosmarinic acid secretion into the culture media. Extracellular concentrations of rosmarinic acid were similar to the values from the control variants. It was documented that suspension cultures of M. piperita treated with elicitors showed a decrease in biomass accumulation when compared to the control.

Screening of Dracocephalum kotschyi accession for surface flavonoids and rosmarinic acid

Dracocephalum kotschyi Boiss, of the Labiatae family, is an endemic and native herbaceous plant of Iran, where it is known as Badrandjboie-Dennaie and Zarrin-Giah[1]. It has been traditionally used as a folk medicine and an additive to improve the taste and scent of tea and yogurt. D. kotschyi is an important source of essential oils [2] and flavonoids such as xanthomicrol[3], calycopterin and cirsimaritin with anticancer properties. In this study we collected plant samples in 13 natural habitats to locate valuable accessions for domestication and breeding. Methanolic (80%) extract of leaves was used to quantify xanthomicrol, cirsimaritin, calycopterin, apigenin and rosmarinic acid, which were also identified and quantified by ESI-MS and HPLC-DAD methods. Plants collected from the central regions of Iran showed the highest levels of methylated flavonoids whereas the plants from the north of the country contained the most rosmarinic acid. Taken as a whole, our results show that flavonoid contents in D. kotschyi depend on environmental conditions; a semi-arid climate and high exposure of the plants to UV radiation leads to an accumulation of methoxy derivatives, while wet and cold conditions increase rosmarinic acid accumulation.

Cloning and characterisation of rosmarinic acid synthase from Melissa officinalis L.

Lemon balm ( Melissa officinalis L.; Lamiaceae) is a well-known medicinal plant mainly due to two groups of compounds, the essential oil and the phenylpropanoid derivatives. The prominent phenolic compound is rosmarinic acid (RA), an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid. RA shows a number of interesting biological activities. Rosmarinic acid synthase (RAS; 4-coumaroyl-CoA:hydroxyphenyllactic acid hydroxycinnamoyltransferase) catalyses the ester formation. Cell cultures of M. officinalis have been established in order to characterise the formation of RA in an important diploid medicinal plant. RAS activity as well as the expression of the RAS gene are closely correlated with the accumulation of RA in suspension cultures of M. officinalis. The RAS cDNA and gene ( MoRAS) were isolated. The RAS gene was shown to be intron-free. MoRAS belongs to the BAHD superfamily of acyltransferases. Southern-blot analysis suggests the presence of only one RAS gene copy in the M. officinalis genome. The enzyme was characterised with respect to enzyme properties, substrate preferences and kinetic data in crude plant extracts and as heterologously synthesised protein from Escherichia coli.