Effects of the dose of administration, co-antioxidants, food matrix, and digestion-related factors on the in vitro bioaccessibility of rosmarinic acid - A model study.

This study aimed to determine the effect of the administration dose, combinations with co-antioxidants (vitamin C, caffeic acid, chlorogenic acid, catechin, rutin), and different food matrices (cooked and lyophilized hen eggs, chicken breast, soybean seeds, potatoes) on the potential bioaccessibility of rosmarinic acid (RA) in simulated digestion conditions, depending on the digestion stage (gastric and intestinal) and the contribution of physicochemical and biochemical digestion factors. The in vitro bioaccessibility of RA depended on the digestion stage and conditions. The physicochemical factors were mainly responsible for the bioaccessibility of RA applied alone. The higher RA doses improved its bioaccessibility, especially at the intestinal stage of digestion. Furthermore, the addition of vitamin C and protein-rich food matrices resulted in enhanced intestinal bioaccessibility of RA. In the future, the knowledge of factors influencing the bioaccessibility of RA can help enhance its favorable biological effects and therapeutic potential.

Mechanism Behind the Programmed Biosynthesis of Heterotrimeric Fungal Depside Thielavin A.

Thielavin A (1) is a fungal depside composed of one 3-methylorsellinic acid and two 3,5-dimethylorsellinic acid units. It displays diverse biological activities. However, the mechanism underlying the assembly of the heterotrimeric structure of 1 remains to be clarified. In this study, we identified the polyketide synthase (PKS) involved in the biosynthesis of 1. This PKS, designated as ThiA, possesses an unusual domain organization with the C-methyltransferase (MT) domain situated at the C-terminus following the thioesterase (TE) domain. Our findings indicated that the TE domain is solely responsible for two rounds of ester bond formation, along with subsequent chain hydrolysis. We identified a plausible mechanism for TE-catalyzed reactions and obtained insights into how a single PKS can selectively yield a specific heterotrimeric product. In particular, the tandem acyl carrier protein domains of ThiA are critical for programmed methylation by the MT domain. Overall, this study highlighted the occurrence of highly optimized domain-domain communication within ThiA for the selective synthesis of 1, which can advance our understanding of the programming rules of fungal PKSs.

Biosynthetic gene cluster synteny: Orthologous polyketide synthases in Hypogymnia physodes, Hypogymnia tubulosa, and Parmelia sulcata.

Lichens are symbiotic associations consisting of a photobiont (algae or cyanobacteria) and a mycobiont (fungus), which together generate a variety of unique secondary metabolites. To access this biosynthetic potential for biotechnological applications, deeper insights into the biosynthetic pathways and corresponding gene clusters are necessary. Here, we provide a comparative view of the biosynthetic gene clusters of three lichen mycobionts derived from Hypogymnia physodes, Hypogymnia tubulosa, and Parmelia sulcata. In addition, we present a high-quality PacBio metagenome of Parmelia sulcata, from which we extracted the mycobiont bin containing 214 biosynthetic gene clusters. Most biosynthetic gene clusters in these genomes were associated with T1PKSs, followed by NRPSs and terpenes. This study focused on biosynthetic gene clusters related to polyketide synthesis. Based on ketosynthase homology, we identified nine highly syntenic clusters present in all three species. Among the four clusters belonging to nonreducing PKSs, two are putatively linked to lichen substances derived from orsellinic acid (orcinol depsides and depsidones, e.g., lecanoric acid, physodic acid, lobaric acid), one to compounds derived from methylated forms of orsellinic acid (beta orcinol depsides, e.g., atranorin), and one to melanins. Five clusters with orthologs in all three species are linked to reducing PKSs. Our study contributes to sorting and dereplicating the vast PKS diversity found in lichenized fungi. High-quality sequences of biosynthetic gene clusters of these three common species provide a foundation for further exploration into biotechnological applications and the molecular evolution of lichen substances.

Effect of Light Conditions on Polyphenol Production in Transformed Shoot Culture of Salvia bulleyana Diels.

Various strategies have been used to increase the efficiency of secondary metabolite production in Salvia plants. This report is the first to examine the spontaneous development of Salvia bulleyana shoots transformed by Agrobacterium rhizogenes on hairy roots and the influence of light conditions on the phytochemical profile of this shoot culture. The transformed shoots were cultivated on solid MS medium with 0.1 mg/L of IAA (indole-3-acetic acid) and 1 mg/L of m-Top (meta-topolin), and their transgenic characteristic was confirmed by PCR-based detection of the rolB and rolC genes in the target plant genome. This study assessed the phytochemical, morphological, and physiological responses of the shoot culture under stimulation by light-emitting diodes (LEDs) with different wavelengths (white, WL; blue, B; red, RL; and red/blue, ML) and under fluorescent lamps (FL, control). Eleven polyphenols identified as phenolic acids and their derivatives were detected via ultrahigh-performance liquid chromatography with diode-array detection coupled to electrospray ionization tandem mass spectrometry (UPLC-DAD/ESI-MS) in the plant material, and their content was determined using high-performance liquid chromatography (HPLC). Rosmarinic acid was the predominant compound in the analyzed extracts. The mixed red and blue LEDs gave the highest levels of polyphenol and rosmarinic acid accumulation (respectively, 24.3 mg/g of DW and 20.0 mg/g of DW), reaching two times greater concentrations of polyphenols and three times greater rosmarinic acid levels compared to the aerial parts of two-year-old intact plants. Similar to WL, ML also stimulated regeneration ability and biomass accumulation effectively. However, the highest total photosynthetic pigment production (1.13 mg/g of DW for total chlorophyll and 0.231 mg/g of DW for carotenoids) was found in the shoots cultivated under RL followed by BL, while the culture exposed to BL was characterized as having the highest antioxidant enzyme activities.

Rindera graeca (A. DC.) Boiss. & Heldr. (Boraginaceae) In Vitro Cultures Targeting Lithospermic Acid B and Rosmarinic Acid Production.

The in vitro cultures of Rindera graeca, a rare endemic plant, were developed as a sustainable source of phenolic acids. Various shoot and root cultures were established and scaled up in a sprinkle bioreactor. A multiplication rate of 7.2 shoots per explant was achieved. HPLC-PDA-ESI-HRMS analysis revealed the presence of rosmarinic acid (RA) and lithospermic acid B (LAB) as the main secondary metabolites in both the shoot and root cultures. The maximum RA (30.0 ± 3.2 mg/g DW) and LAB (49.3 ± 15.5 mg/g DW) yields were determined in root-regenerated shoots. The strongest free radical scavenging activity (87.4 ± 1.1%), according to 2,2-diphenyl-1-picrylhydrazyl-hydrate assay, was noted for roots cultivated in a DCR medium. The highest reducing power (2.3 µM ± 0.4 TE/g DW), determined by the ferric-reducing antioxidant power assay, was noted for shoots cultivated on an SH medium containing 0.5 mg/L 6-benzylaminopurine. A genetic analysis performed using random amplified polymorphic DNA and start codon targeted markers revealed genetic variation of 62.8% to 96.5% among the investigated shoots and roots. This variability reflects the capacity of cultivated shoots and roots to produce phenolic compounds.

The Influence of Methyl Jasmonate on Expression Patterns of Rosmarinic Acid Biosynthesis Genes, and Phenolic Compounds in Different Species of Salvia subg. Perovskia Kar L.

Salvia yangii B.T. Drew and Salvia abrotanoides Kar are two important fragrant and medicinal plants that belong to the subgenus Perovskia. These plants have therapeutic benefits due to their high rosmarinic acid (RA) content. However, the molecular mechanisms behind RA generation in two species of Salvia plants are still poorly understood. As a first report, the objectives of the present research were to determine the effects of methyl jasmonate (MeJA) on the rosmarinic acid (RA), total flavonoid and phenolic contents (TFC and TPC), and changes in the expression of key genes involved in their biosynthesis (phenylalanine ammonia lyase (PAL), 4-coumarate-CoA ligase (4CL), and rosmarinic acid synthase (RAS)). The results of High-performance liquid chromatography (HPLC) analysis indicated that MeJA significantly increased RA content in S. yungii and S. abrotanoides species (to 82 and 67 mg/g DW, respectively) by 1.66- and 1.54-fold compared with untreated plants. After 24 h, leaves of Salvia yangii and Salvia abrotanoides species treated with 150 M MeJA had the greatest TPC and TFC (80 and 42 mg TAE/g DW, and 28.11 and 15.14 mg QUE/g DW, respectively), which was in line with the patterns of gene expression investigated. Our findings showed that MeJA dosages considerably enhanced the RA, TPC, and TFC contents in both species compared with the control treatment. Since increased numbers of transcripts for PAL, 4CL, and RAS were also detected, the effects of MeJA are probably caused by the activation of genes involved in the phenylpropanoid pathway.

Rosmarinic acid alleviates acetaminophen-induced hepatotoxicity by targeting Nrf2 and NEK7-NLRP3 signaling pathway.

Rosmarinic acid (RA) is a natural polyphenol with various biological activities, such as anti-oxidative, anti-fibrotic, and hepatoprotective properties. The objective of this study was to investigate the protective effect of RA against acetaminophen (APAP)-induced hepatotoxicity (AILI) and explore the underlying mechanisms. Kunming mice were treated with RA (20, 40, or 80 mg/kg, i.g) for 7d, followed by an intraperitoneal injection of APAP (500 mg/kg). The liver injury was evaluated by serum biochemical and liver histopathological examinations. Human HepG2 cells were pre-treated with RA (20, 40, or 80 µmol/L) and then incubated with APAP (25 mmol/L) for 24 h. The MTT assay, wound healing assay, transwell migration assay, flow cytometry, and western blotting were employed to further evaluate RA's protective effects on AILI and explore the mechanisms. The results indicated that RA pre-treatment lowered the serum ALT and AST levels, ameliorated the histological damage to the liver, and reduced ROS generation and the production of IL-1ß and IL-18 in the liver tissues in APAP-treated mice. Moreover, pre-treatment with RA could promote the cell viability and migration ability and inhibit apoptosis in APAP-treated HepG2 cells. Mechanistically, RA could significantly suppress the APAP-induced activation of the NEK7-NLRP3 signaling pathway. Notably, depletion of Nrf2 by short hairpin RNA (shRNA) partly eliminated the protective effects of RA on AILI and the suppression of NEK7-NLRP3 signaling by RA. In summary, these results indicate that RA has a protective role against AILI through Nrf2-mediated inhibition of ROS production and suppression of the NEK7-NLRP3 pathway.

Rosmarinic Acid, as an NHE1 Activator, Decreases Skin Surface pH and Improves the Skin Barrier Function.

Stratum corneum (SC) pH regulates skin barrier functions and elevated SC pH is an important factor in various inflammatory skin diseases. Acidic topical formulas have emerged as treatments for impaired skin barriers. Sodium proton exchanger 1 (NHE1) is an important factor in SC acidification. We investigated whether topical applications containing an NHE1 activator could improve skin barrier functions. We screened plant extracts to identify NHE1 activators in vitro and found Melissa officinalis leaf extract. Rosmarinic acid, a component of Melissa officinalis leaf extract, significantly increased NHE1 mRNA expression levels and NHE1 production. Immunofluorescence staining of NHE1 in 3D-cultured skin revealed greater upregulation of NHE1 expression by NHE1 activator cream, compared to vehicle cream. Epidermal lipid analysis revealed that the ceramide level was significantly higher upon application of the NHE1 activator cream on 3D-cultured skin, compared to application of a vehicle cream. In a clinical study of 50-60-year-old adult females (n = 21), application of the NHE1 activator-containing cream significantly improved skin barrier functions by reducing skin surface pH and transepidermal water loss and increasing skin hydration, compared to patients who applied vehicle cream and those receiving no treatment. Thus, creams containing NHE1 activators, such as rosmarinic acid, could help maintain or recover skin barrier functions.

Hydroxycinnamoyltransferase and CYP98 in phenolic metabolism in the rosmarinic acid-producing hornwort Anthoceros agrestis.

MAIN CONCLUSION: Anthoceros agrestis hydroxycinnamoyltransferase accepts shikimic and 3-hydroxyanthranilic acids while hydroxycinnamoylester/amide 3-hydroxylase (CYP98A147) preferred p-coumaroyl-(3-hydroxy)anthranilic acid compared to the shikimic acid derivative. Alternative pathways towards rosmarinic acid have to be considered. Rosmarinic acid (RA) is a well-known ester of caffeic acid and 3,4-dihydroxyphenyllactic acid. In the search for enzymes involved in RA biosynthesis in the hornwort Anthoceros agrestis, the hydroxycinnamoyltransferase sequence with the highest similarity to rosmarinic acid synthase from Lamiaceae has been amplified and heterologously expressed in Escherichia coli. In parallel, the single cytochrome P450 sequence belonging to the CYP98 group in Anthoceros agrestis was isolated and expressed in Saccharomyces cerevisiae which did not result in protein formation. Codon optimization and co-expression with NADPH:cytochrome P450 reductase (CPR) from Coleus blumei resulted in the formation of active enzymes. Both, the hydroxycinnamoyltransferase and CYP98 were characterized with respect to their temperature and pH optimum as well as their substrate acceptance. The hydroxycinnamoyltransferase (AaHCT6) readily accepted p-coumaroyl- and caffeoyl-CoA with a slightly higher affinity towards p-coumaroyl-CoA. The best acceptor substrate was shikimic acid (Km 25 µM with p-coumaroyl-CoA) followed by 3-hydroxyanthranilic acid (Km 153 µM with p-coumaroyl-CoA). Another accepted substrate was 2,3-dihydroxybenzoic acid. Anthranilic acid and 4-hydroxyphenyllactic acid (as precursor for RA) were not used as substrates. p-Coumaroylesters and -amides are substrates hydroxylated by CYP98 hydroxylases. The only CYP98 sequence from Anthoceros agrestis is CYP98A147. The best substrates for the NADPH-dependent hydroxylation were p-coumaroylanthranilic and p-coumaroyl-3-hydroxyanthranilic acids while p-coumaroylshikimic and p-coumaroyl-4-hydroxyphenyllactic acids were poor substrates. The biosynthetic pathway towards rosmarinic acid thus still remains open and other enzyme classes as well as an earlier introduction of the 3-hydroxyl group to afford the caffeic acid substitution pattern must be taken into consideration.

Rosmarinic Acid and Sodium Citrate Have a Synergistic Bacteriostatic Effect against Vibrio Species by Inhibiting Iron Uptake.

BACKGROUND: New strategies are needed to combat multidrug-resistant bacteria. The restriction of iron uptake by bacteria is a promising way to inhibit their growth. We aimed to suppress the growth of Vibrio bacterial species by inhibiting their ferric ion-binding protein (FbpA) using food components. METHODS: Twenty spices were selected for the screening of FbpA inhibitors. The candidate was applied to antibacterial tests, and the mechanism was further studied. RESULTS: An active compound, rosmarinic acid (RA), was screened out. RA binds competitively and more tightly than Fe3+ to VmFbpA, the FbpA from V. metschnikovii, with apparent KD values of 8 µM vs. 17 µM. Moreover, RA can inhibit the growth of V. metschnikovii to one-third of the control at 1000 µM. Interestingly, sodium citrate (SC) enhances the growth inhibition effect of RA, although SC only does not inhibit the growth. The combination of RA/SC completely inhibits the growth of not only V. metschnikovii at 100/100 µM but also the vibriosis-causative pathogens V. vulnificus and V. parahaemolyticus, at 100/100 and 1000/100 µM, respectively. However, RA/SC does not affect the growth of Escherichia coli. CONCLUSIONS: RA/SC is a potential bacteriostatic agent against Vibrio species while causing little damage to indigenous gastrointestinal bacteria.

The Beneficial Effect of Rosmarinic Acid on Benzophenone-3-Induced Alterations in Human Skin Fibroblasts.

Benzophenone-3 (BP-3) is one of the most widely used chemical sunscreens. The results of many in vitro and in vivo tests confirm its high percutaneous penetration and systemic absorption, which question the safety of its wide use. The aim of our research was to assess the effect of this compound on components of the skin extracellular matrix, and to investigate whether rosmarinic acid (RA) could reduce BP-3-induced changes in human skin fibroblasts. BP-3 used at concentrations of 0.1-100 µM caused a number of unfavorable changes in the level of type I collagen, decorin, sulfated glycosaminoglycans, hyaluronic acid, elastin, and expression or activity of matrix metalloproteinases (MMP-1, MMP-2), elastase and hyaluronidase. Moreover, the intracellular retention of collagen was accompanied by changes in the expression of proteins modifying and controlling the synthesis and secretion of this protein. Most importantly, RA at a concentration of 100 µM significantly reduced or completely abolished the adverse effects of BP-3. Based on these findings, it can be concluded that this polyphenol may provide effective protection against BP-3-induced disturbances in skin cells, which may have important clinical implications.

Depside and Depsidone Synthesis in Lichenized Fungi Comes into Focus through a Genome-Wide Comparison of the Olivetoric Acid and Physodic Acid Chemotypes of Pseudevernia furfuracea.

Primary biosynthetic enzymes involved in the synthesis of lichen polyphenolic compounds depsides and depsidones are non-reducing polyketide synthases (NR-PKSs), and cytochrome P450s. However, for most depsides and depsidones the corresponding PKSs are unknown. Additionally, in non-lichenized fungi specific fatty acid synthases (FASs) provide starters to the PKSs. Yet, the presence of such FASs in lichenized fungi remains to be investigated. Here we implement comparative genomics and metatranscriptomics to identify the most likely PKS and FASs for olivetoric acid and physodic acid biosynthesis, the primary depside and depsidone defining the two chemotypes of the lichen Pseudevernia furfuracea. We propose that the gene cluster PF33-1_006185, found in both chemotypes, is the most likely candidate for the olivetoric acid and physodic acid biosynthesis. This is the first study to identify the gene cluster and the FAS likely responsible for olivetoric acid and physodic acid biosynthesis in a lichenized fungus. Our findings suggest that gene regulation and other epigenetic factors determine whether the mycobiont produces the depside or the depsidone, providing the first direct indication that chemotype diversity in lichens can arise through regulatory and not only through genetic diversity. Combining these results and existing literature, we propose a detailed scheme for depside/depsidone synthesis.

Rosmarinic acid inhibits DNA glycation and modulates the expression of Akt1 and Akt3 partially in the hippocampus of diabetic rats.

Non-enzymatic glycation of DNA and the associated effects are among pathogenic factors in diabetes mellitus. Natural polyphenols have anti-diabetic activity. Herein, the protective role of one of the phytochemicals, rosmarinic acid (RA), was evaluated in glycation (with fructose) of human DNA and expression of Akt genes in the hippocampus of diabetic rats. In-vitro studies using fluorescence, agarose gel electrophoresis, fluorescence microscopy, and thermal denaturation analyses revealed that glycation causes DNA damage and that RA inhibits it. In-vivo studies were performed by induction of diabetes in rats using streptozotocin. The diabetic rats were given RA daily through gavage feeding. The expression of Akt genes (inhibitors of apoptosis) in the hippocampus was evaluated using RT-qPCR. In diabetic rats, Akt1 and Akt3 were significantly down-regulated compared to the control group. Treating the diabetic rats with RA returned the expression of Akt1 and Akt3 relatively to the normal condition. Past studies have shown that diabetes induces apoptosis in the hippocampal neurons. Given that glycation changes the genes expression and causes cell death, apoptosis of the hippocampal neurons can be due to the glycation of DNA. The results also suggest that RA has reliable potency against the gross modification of DNA under hyperglycemic conditions.

HPTLC and ATR/FTIR Characterization of Antioxidants in Different Rosemary Extracts.

The effect of spontaneous fermentation by lactic acid bacteria on the extraction yield of bioactive compounds and antioxidant activity from rosemary leaf extracts was investigated using high-performance thin-layer chromatography (HPTLC). Brining and spontaneous fermentation with lactic acid bacteria more than doubled extraction of polyphenolics and antioxidants from the rosemary leaves. The results show that lactic acid fermentation enhances antioxidant activity in extracts by increasing the total phenolic content but does not increase extraction of phytosterols. Increased extraction of phenolic oxidants during fermentation assisted extraction, results from the in situ generated natural eutectic solvent from the plant sample. ATR-FTIR spectra from the bioactive bands suggests that this increased antioxidant activity is associated with increased extraction of rosmarinic acid, depolymerised lignin, abietane diterpenoids and 15-hydroxy-7-oxodehydroabietic acid.

Effect of Elicitation with (+)-Usnic Acid on Accumulation of Phenolic Acids and Flavonoids in Agitated Microshoots of Eryngium alpinum L.

The present work was aimed at studying the potential of elicitation on the accumulation of phenolic compounds in in vitro shoot cultures of Eryngium alpinum L., a protected plant from the Apiaceae family. The study examined the influence of (+)-usnic acid on the biomass growth as well as on the biosynthesis of the desired flavonoids and phenolic acids in the cultured microshoots. The phenolic compound content was determined by HPLC-DAD. The flavonoid of the highest concentration was isoquercetin, and the phenolic acids of the highest amount were rosmarinic acid, caffeic acid and 3,4-dihydroxyphenylacetic acid, both in the non-elicited and elicited biomass. Isoquercetin accumulation was efficiently increased by a longer elicitation with a lower concentration of lichenic compound (107.17 ± 4.67 mg/100 g DW) or a shorter elicitation with a higher concentration of acid (127.54 ± 11.34 and 108.37 ± 12.1 mg/100 g DW). Rosmarinic acid production generally remained high in all elicited and non-elicited microshoots. The highest content of this acid was recorded at 24 h of elicitation with 3.125 µM usnic acid (512.69 ± 4.89 mg/100 g DW). The process of elicitation with (+)-usnic acid, a well-known lichenic compound with allelopathic nature, may therefore be an effective technique of enhancing phenolic compound accumulation in alpine eryngo microshoot biomass.

Effect of graphene / metal nanocomposites on the key genes involved in rosmarinic acid biosynthesis pathway and its accumulation in Melissa officinalis.

BACKGROUND: Recently, numerous investigations have been done to study graphene and silver nanoparticle in the fields of agriculture and medicine. In the present study, the green synthesis of nanoparticles with two concentrations (0, 40, 60 mM) and their effect on the molecular and biochemical biosynthesis pathway of rosmarinic acid in a new method, low cost, and safe for the environment has been investigated. The transcript levels of key genes in the rosmarinic acid biosynthesis pathway (Tyrosine aminotransferase, rosmarinic acid synthase, and phenylalanine-ammonia lyase) were studied using real-time quantitative polymerase chain reaction. Then, the rosmarinic acid content was evaluated using HPLC. RESULTS: The results showed that a concentration-dependent manner was observed in treated plants. At the biochemical level, the use of nanocomposites at concentration of 40 mM showed higher soluble carbohydrate (37%), flavonoids (21%), total phenol (35%) as well as total protein (47%) compared to the control plants. HPLC results showed that rosmarinic acid content in the treated plants with a low concentration of nanocomposite (40 mM) was more affected than plants treated with a high concentration of nanocomposite (60 mM) (26%) and also compared to other treatments. At the molecular level, the result showed that Tyrosine aminotransferase and rosmarinic acid synthase gene expression was positively correlated with both silver nanoparticle concentrations and nanocomposite treatments, but phenylalanine-ammonia lyase gene expression was positively correlated only with nanocomposite at 40 mM concentration. CONCLUDE: It can conclude that the nanocomposite at low concentration is more likely to induce molecular and biochemical parameters. And also, in the rosmarinic acid biosynthesis pathway, the Tyrosine aminotransferase -derived pathway is more efficient than the phenylalanine-ammonia lyase -derived pathway by causing a nano-elicitor. Therefore, it was concluded that studied elicitor at low concentration, can create plants with higher production capacity.

The Contents of Polyphenols in Perilla frutescens (L.) Britton var. frutescens (Egoma) Leaves are Determined by Vegetative Stage, Spatial Leaf Position, and Timing of Harvesting during the Day.

The leaf of Perilla frutescens (L.) Britton var. frutescens (egoma) is a rich source of polyphenolic compounds, including rosmarinic acid. However, there is still a lack of detailed information concerning the content of phenolic compounds in these leaves. Since some flavonoids were found as a conjugated form, leaves were used untreated or hydrolyzed using ß-glucuronidase for analysis. Enzymatic hydrolysis method successfully identified some polyphenols, which have not been reported before. Scutellarin, a flavone glucuronide with a molecular mass similar to that of luteolin 7-O-glucuronide, was present in egoma leaves. Scutellarin was the second most abundant polyphenolic compound, after rosmarinic acid. Egoma leaves at the top of the plant contained a higher amount of rosmarinic acid and scutellarin compared to that in the leaves below. The difference in plant growth stage also influenced the rosmarinic acid and scutellarin contents, while the time of harvesting during the day did rosmarinic acid contents only. This is the first time that scutellarin, a traditional Chinese medicine, widely used for the treatment of cerebrovascular disease, was quantitatively determined in egoma leaves. The present study may help adding value to egoma leaves, developing dietary supplements, functional foods, and cosmetics.

Spectroscopic and molecular docking studies for the binding and interaction aspects of curcumin-cysteine conjugate and rosmarinic acid with human telomeric G-quadruplex DNA.

The binding and interaction aspects of potential anticancer ligands like: curcumin-cysteine (CC) and rosmarinic acid (RA) with human telomeric G-quadruplex DNA, a novel anticancer target, have been probed by spectroscopic and molecular docking approach. The circular dichroism study unravels the conformational switching from mixed hybrid to parallel structure for the short sequence of human telomeric G-quadruplex structure in the presence of both the ligands. Further a good correlation for binding affinity has been established from the emission and absorption binding spectrum analysis. Further our spectroscopic and molecular docking studies have suggested that the CC having better binding capability than RA to human telomeric G-quadruplex. The presence of L-cysteine moiety in CC ligand is responsible factor for its binding via both minor as well as major groove of human telomeric G-quadruplex DNA where-as RA binds only via minor groove of telomeric G-DNA.

Insights into salvianolic acid B biosynthesis from chromosome-scale assembly of the Salvia bowleyana genome.

Salvia bowleyana is a traditional Chinese medicinal plant that is a source of nutritional supplements rich in salvianolic acid B and a potential experimental system for the exploration of salvianolic acid B biosynthesis in the Labiatae. Here, we report a high-quality chromosome-scale genome assembly of S. bowleyana covering 462.44 Mb, with a scaffold N50 value of 57.96 Mb and 44,044 annotated protein-coding genes. Evolutionary analysis revealed an estimated divergence time between S. bowleyana and its close relative S. miltiorrhiza of ~3.94 million years. We also observed evidence of a whole-genome duplication in the S. bowleyana genome. Transcriptome analysis showed that SbPAL1 (PHENYLALANINE AMMONIA-LYASE1) is highly expressed in roots relative to stem and leaves, paralleling the location of salvianolic acid B accumulation. The laccase gene family in S. bowleyana outnumbered their counterparts in both S. miltiorrhiza and Arabidopsis thaliana, suggesting that the gene family has undergone expansion in S. bowleyana. Several laccase genes were also highly expressed in roots, where their encoded proteins may catalyze the oxidative reaction from rosmarinic acid to salvianolic acid B. These findings provide an invaluable genomic resource for understanding salvianolic acid B biosynthesis and its regulation, and will be useful for exploring the evolution of the Labiatae.

Transcriptome analysis to identify key genes involved in terpenoid and rosmarinic acid biosynthesis in lemon balm (Melissa officinalis).

Melissa officinalis (lemon balm) is a well-known pharmaceutical plant in traditional medicine around the world because of the high-value secondary metabolites. Nowadays, advances in computational biology and bioinformatics have opened new avenues to plant-based natural product drug discovery. Despite the pharmacological importance, there is low information about the genes encoding the important biosynthetic pathways related to the secondary metabolite in M. officinalis. In this study, the main genes related to the rosmarinic acid (RA) and terpenoid biosynthesis pathways were detected using transcriptome analysis. Furthermore, we isolated and characterized a novel M. officinalis Hydroxyphenylpyruvate reductase (HPPR) gene involved in RA biosynthesis pathway. An effective pipeline was used to generate 37,055 unigenes by evaluating 42,837,601 Illumina paired-end reads. Functional annotation of the unigenes revealed that 27,363 (73.84%) and 35,822 (96.67%) unigenes had significant similarity to identified proteins in the SwissProt and NR databases, respectively. Also, 10,062 (36.83%) out of 37,055 unigenes were assigned to 399 KEGG pathways. Since terpenes and RA are two prominent metabolites in this plant, the attention of this study has been on the pathways related to them. A total of 149 unigenes were found that are related to the terpenoids biosynthesis, including 75 unigenes involved in the methyl-erythritol phosphate and mevalonate pathway, terpenoid backbone biosynthesis genes, and 74 unigenes related to the terpene synthase. We also identified 144 and 30 unigenes that were associated with the biosynthesis of phenylpropanoid and the rosmarinic acid pathway. Consequently, this investigation can be a comprehensive and accurate transcriptome basis for further investigation in the metabolic engineering and detection of new genes and pathways in M. officinalis.