Chemical Composition and Anticholinesterase Activity of the Essential Oil of Leaves and Flowers from the Ecuadorian Plant Lepechinia paniculata (Kunth) Epling.

This work aimed to study the chemical composition, cholinesterase inhibitory activity, and enantiomeric analysis of the essential oil from the aerial parts (leaves and flowers) of the plant Lepechinia paniculata (Kunth) Epling from Ecuador. The essential oil (EO) was obtained through steam distillation. The chemical composition of the oil was evaluated by gas chromatography, coupled to mass spectrometry (GC-MS) and a flame ionization detector (GC-FID). The analyses led to the identification of 69 compounds in total, of which 40 were found in the leaves and 29 were found in the flowers of the plant. The major components found in the oil were 1,8-Cineole, ß-Pinene, δ-3-Carene, α-Pinene, (E)-Caryophyllene, Guaiol, and ß-Phellandrene. Flower essential oil showed interesting selective inhibitory activity against both enzymes AChE (28.2 ± 1.8 2 µg/mL) and BuChE (28.8 ± 1.5 µg/mL). By contrast, the EO of the leaves showed moderate mean inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), with IC50 values of 38.2 ± 2.9 µg/mL and 47.4 ± 2.3 µg/mL, respectively.

Chitosan stimulates secondary metabolite production and nutrient uptake in medicinal plant Dracocephalum kotschyi.

BACKGROUND: A wide variety of secondary metabolites are synthesized from primary metabolites by plants which have a vast range in pharmaceutical, food additive and industrial applications. In recent years, the use of elicitors has opened a novel approach for the production of secondary metabolite compounds. Dracocephalum kotschyi is a valuable herb due to pharmaceutical compounds like rosmarinic acid, quercetin and apigenin. In the current study, foliar application of chitosan (0, 100, 400 mg L-1 ) as an elicitor was used. RESULTS: After chitosan treatment, the amounts of hydrogen peroxide (H2 O2 ) increased and the plant was able to increase the activities of enzymatic (guaiacol peroxidase, catalase and phenylalanine ammonium lyase) and non-enzymatic (total phenols and flavonoids) defensive metabolites. Also, foliar spray of chitosan promoted nutrient absorption which led to the accumulation of macroelements in the plant. CONCLUSIONS: Chitosan was found to be a very effective elicitor for improving rosmarinic acid and quercetin content (up to 13-fold). Also, the content of apigenin (anticancer flavonoid) showed 16-fold enhancement compared to the control. Therefore, the treatment of D. kotschyi leaves with chitosan caused a very large increase in the induction and production of important pharmaceutical compounds such as rosmarinic acid and quercetin. © 2020 Society of Chemical Industry.

The effect of purine-type cytokinin on the proliferation and production of phenolic compounds in transformed shoots of Dracocephalum forrestii.

Dracocephalum forrestii is a perennial, endemic to China plant with a number of pharmaceutical properties. Transformed shoots of the species spontaneously regenerated from hairy roots induced by Agrobacterium rhizogenes. The transgenic nature of the shoots was confirmed by polymerase chain reaction (PCR). The shoot culture was multiplied on Murashige and Skoog (MS) medium with 0.2 mg/l IAA and 0.2, 0.5, 1.0, 2.0 or 5.0 mg/l purine-type cytokinins (mT, BAR, BPA or BAP). The highest multiplication rate (about thirteen shoot or buds per explant) was obtained on MS medium with 0.2 mg/l mT after four weeks of culture. The phenolic compounds present in the hydromethanolic extracts from the D. forrestii transgenic shoots were characterized using UPLC-PDA-ESI-MS. The shoots were found to biosynthesize three phenolic acids and five flavonoid glycosides. UHPLC analysis of the hydromethanolic extracts found the predominant phenolic acid to be rosmarinic acid, with its highest content observed in shoots cultivated with 5.0 mg/l BPA. In contrast, the greatest production of flavonoid derivatives (especially acacetin derivatives) was observed in the medium supplemented with 2 mg/l BPA.

Enhanced accumulation of harpagide and 8-O-acetyl-harpagide in Melittis melissophyllum L. agitated shoot cultures analyzed by UPLC-MS/MS.

Harpagide and its derivatives have valuable medicinal properties, such as anti-inflammatory, analgesic and potential antirheumatic effects. There is the demand for searching plant species containing these iridoids or developing biotechnological methods to obtain the compounds. The present study investigated the effects of methyl jasmonate (MeJa, 50 µM), ethephon (Eth, 50 µM) and L-phenylalanine (L-Phe, 2.4 g/L of medium), added to previously selected variant of Murashige and Skoog medium (supplemented with plant growth regulators: 6-benzylaminopurine 1.0 mg/L, α-naphthaleneacetic acid 0.5 mg/L, gibberellic acid 0.25 mg/L) on the accumulation of harpagide and 8-O-acetyl-harpagide in Melittis melissophyllum L. agitated shoot cultures. Plant material was harvested 2 and 8 days after the supplementation. Iridoids were quantitatively analyzed by the UPLC-MS/MS method in extracts from the biomass and the culture medium. It was found that all of the variants caused an increase in the accumulation of harpagide. In the biomass harvested after 2 days, the highest harpagide content of 247.3 mg/100 g DW was found for variant F (L-Phe and Eth), and the highest 8-O-acetyl-harpagide content of 138 mg/100 g DW for variant E (L-Phe and MeJa). After 8 days, in some variants, a portion of the metabolites was released into the culture medium. Considering the total amount of the compounds (in the biomass and medium), the highest accumulation of harpagide, amounting to 619 mg/100 g DW, was found in variant F, and the highest amount of 8-O-acetyl-harpagide, of 255.4 mg/100 g DW, was found in variant H (L-Phe, MeJa, Eth) when harvested on the 8th day. These amounts were, respectively, 24.7 and 4.8 times higher than in the control culture, and were, respectively, 15 and 6.7 times higher than in the leaves of the soil-grown plant. The total amount of the two iridoids was highest for variant F (0.78% DW) and variant H (0.68% DW) when harvested on the 8th day. The results indicate that the agitated shoot cultures of M. melissophyllum can be a rich source of harpagide and 8-O-acetyl-harpagide, having a potential practical application. To the best of our knowledge we present for the first time the results of the quantitative UPLC-MS/MS analysis of harpagide and 8-O-acetyl-harpagide in M. melissophyllum shoot cultures and the enhancement of their accumulation by means of medium supplementation with elicitors and precursor.

Smelling the metal: Volatile organic compound emission under Zn excess in the mint Tetradenia riparia.

This work investigated the effect of Zn excess on growth, metal accumulation and photosynthetic changes in Tetradenia riparia, in relation to possible variations in the composition of the plant volatilome. Experiments were carried out in hydroponics exposing plants to a range of Zn concentrations. Zinc excess negatively affected plant growth in a dose-dependent manner. The metal was accumulated proportionally to its concentration in the medium and preferentially allocated to roots. All the photosynthetic parameters and the concentration of some photosynthetic pigments were negatively affected by Zn, whereas the level of leaf total soluble sugars remained unchanged. Twenty-three different VOCs were identified in the plant volatilome. Each compound was emitted at a different level and intensity of emission was manifold increased by the presence of Zn in the growth medium. The Zn-induced compounds could represent both an adaptive response (f.i. methanol, acetylene, C6-aldehydes, isoprene, terpenes) and a damage by-product (f.i. propanal, acetaldehyde, alkyl fragments) of the metal presence in the culture medium. Given that the Zn-mediated induction of those VOCs, considered protective, occurred even under a Zn-limited photosynthetic capacity, our work supports the hypothesis of an active role of such molecules in an adaptive plant response to trace metal stress.

Fullerene C60 for enhancing phytoremediation of urea plant wastewater by timber plants.

Phytoremediation has been applied as a promising and cost-effective technique for removing nutrient pollutants from wastewater. In this study, the effect of fullerene C60 was assessed on enhancing the phytoremediation efficiency of teak plants over a period of 1 month. Teak plants were supplied with fullerene C60 (0, 25, or 50 mg L-1) and fed daily with two types of urea plant wastewater (with and without adding optimum ratio of phosphorus and potassium). The required volume of wastewater by the teak plants, nitrogen removal percentage, plant growth parameters (plant height, number of leaves, leaf surface area, and dry biomass), and nutrient content was recorded throughout the study. The results showed that addition of 25 mg L-1 fullerene C60 to urea plant wastewater could increase water uptake and nitrogen recovery of the teak plants. Plant growth and nutrient contents of teak plants were also increased in the presence of 25 mg L-1 fullerene C60. However, addition of 50 mg L-1 fullerene C60 to the wastewater decreased the values for water uptake and nitrogen recovery. The findings indicated that addition of proper amount of fullerene C60 to the teak-based remediation system can increase the efficiency of the plants for nitrogen removal.

Effect of different ethanolic concentrations on antioxidant properties and cytoprotective activities of Platostoma palustre Blume.

The objective of this study was to evaluate the antioxidant activities of Mesona procumbens ethanolic extracts (MPEEs) which displayed variable antioxidant levels with different ethanolic concentrations. Compared to MPEEs with 20, 40 and 80% ethanol, the 60% MPEE exhibited a higher total phenol content (TPC), total flavonoid content (TFC), 1,1-diphenyl-2-picryl hydrazyl (DPPH)- and 2,2-azino-bis-(3-ethyl benzothiazoline-6-sulphonic acid (ABTS)-scavenging activities, reducing power, protection of Raw 264.7 mouse macrophages against H2O2-induced damage, and inhibition of reactive oxygen species (ROS) induced by 2,2-azobis(2-amidino propane) dihidrochloride (AAPH). IC50 values of DPPH and ABTS radicals by MPEEs were highly and significantly associated with TPCs and TFCs. The most significant protective effect against oxidative DNA damage was also found to be the 60% MPEE at a concentration of 3.6 mg/mL. In addition, the cell viability test showed that none of the MPEEs had any cell toxicity up to a concentration of 250 µg/mL. The 60% MPEE exhibited higher in vitro and ex vivo antioxidant activities, possessed a protective capability for the biological membrane system, and can be used as a functional ingredient representing a potential source of natural antioxidants to prevent and treat oxidative stress-related disorders.

Molecular cloning and expression profiling of a chalcone synthase gene from Lamiophlomis rotata.

Lamiophlomis rotata is a renowned Chinese medicinal plant. Chalcone synthase (CHS) is important in flavonoid and isoflavonoid biosynthesis, catalysing the formation of naringenin chalcone in plants. A full-length cDNA encoding the CHS gene was cloned from L. rotata based on the highly conserved CHS gene sequences of Labiatae plants. A blast search showed its homology (named LrCHS) with other CHS genes of Labiate plants. The full-length genomic DNA of LrCHS was 2026 bp with one intron of 651 bp, two exons of 178 bp and 998 bp, flanked by a 73 bp 5'-UTR and a 126 bp 3'-UTR. The cDNA sequence of the LrCHS gene had an 1176 bp open reading frame encoding a 391 amino acid protein of 42,798 Da. The CHS protein predicted from L. rotata showed 79-86% identity with CHS of other plant species. We conducted a phylogenetic analysis of nine families containing 48 plants and L. rotata based on the full amino acid sequences of CHS proteins. Consequently, LrCHS was located in the Labiatae branch. Additionally, we examined LrCHS gene expression patterns in different tissues by quantitative real-time PCR with specific primers. The expression analysis showed preferential expression of LrCHS in flowers and leaves during the flowering stage. Total flavonoid content and CHS gene expression exhibited similar patterns during L. rotata organ development. In agreement with its function as an elicitor-responsive gene, LrCHS expression was coordinated by methyl jasmonate and UV light, and induced between 6 and 18 h. These results provide a molecular basis for additional functional studies of LrCHS in L. rotata.

Efficient micropropagation of highly economic, medicinal and ornamental plant Lallemantia iberica (Bieb.) Fisch. and C. A. Mey.

Lallemantia iberica (Bieb.) Fisch. and C. A. Mey is high valued annual ornamental and medicinal plant from Lamiaceae family that prefers dry sunny hillsides, roadsides, slopes, and fallow fields over an altitude of 500-2150 m. It bears beautiful white flowers and bloom from April to June each year. This study reports L. iberica micropropagation using cotyledon node explants isolated from 15-day-old in vitro regenerated plantlets. The cotyledon node explants were cultured on MS medium containing 0.50, 1.00 plus 2.00 mg/L BAP, 0.00, 0.01, and 0.02 mg/L NAA. Maximum shoot regeneration was noted on MS medium containing 0.50 mg/L BAP. Well-developed micropropagated shoots were rooted on MS medium containing 1.00 mg/L IBA. The rooted plants were easily hardened in the growth chamber and acclimatised in greenhouse.

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.

[Effects of waste batteries leaching solution stress on resistance physiological indices of volatile constituents from Schizonepeta tenuifolia].

OBJECTIVE: The effect of waste batteries leaching on the seedling growth and volatile constituents in leaves of Schizonepeta tenuifolia was assayed. METHOD: The different concentrations of waste batteries leaching on the seedling growth were discussed. Volatile compounds were analyzed by solid-phase micro-extraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). RESULT: The results indicated that S. tenuifolia showed resistance to heavy metal polluting, but the high rate of waste batteries leaching had the inhibiting effect to seedlings growth. The waste batteries leaching cause the major volatile constituents in leaves of S. tenuifolia was changed greatly under waste batteries leaching solution stress. CONCLUSION: Heavy metal leached by waste batteries had great effect on growth of S. tenuifolia, reducing its value for food and medical purposes.

[Effects of lead, copper and cadmium stresses on growth and inherent quality of Prunalla vulgaris].

OBJECTIVE: Prunalla vulgaris was used as the experimental material to study the effects of lead (Pb), copper (Cu) and cadmium (Cd) on the related physiological and growth indexes of the plant. METHOD: By referencing the GAP and the soil environmental quality standard, the growth and inherent quality of the plant were observed under different concentrations of the heavy metals stresses. The data were statistically processed. RESULT: The results showed that the plant grew normally when the heavy metal concentrations in soil were close to up limits of the soil environmental quality standard II. The content of heavy metal in spica met the requirement of the standard, and under the circumstances the content of ursolic acid was increased in a certain range. The critical values of Pb, Cu, Cd in the P. vulgaris grown soil were set at 450, 100, 1.0 mg x kg(-1), respectively. CONCLUSION: The harmful influence of the heavy metal stress at a lower concentration is lighter than at a higher concentration, and it could increase the content of ursolic acid. The stress of Pb, Cu and Cd is more obvious than that of Zn.

The genus Scutellaria an ethnopharmacological and phytochemical review.

Scutellaria (HUANG QIN) (Lamiaceae), which includes about 350 species commonly known as skullcaps, is widespread in Europe, the United States and East Asia. Some species are taken to clear away the heat-evil and expel superficial evils in traditional Chinese medicine (TCM). The present paper reviews the ethnopharmacology, the biological activities and the correlated chemical compounds of Scutellaria species. More than 295 compounds have been isolated, among them flavonoids and diterpenes. Studies show that Scutellaria and its active principles possess wide pharmacological actions, such as antitumor, anti-angiogenesis, hepatoprotective, antioxidant, anticonvulsant, antibacterial and antiviral activities. Currently, effective monomeric compounds or active parts have been screened for pharmacological activity from Scutellaria in vivo and in vitro. Increasing data supports application and exploitation for new drug development.

Comparative effects of different triazole compounds on growth, photosynthetic pigments and carbohydrate metabolism of Solenostemon rotundifolius.

The effects of two triazole compounds, triadimefon and hexaconazole, on the growth and carbohydrate metabolism were studied in Solenostemon rotundifolius Poir., Morton plants under pot culture. Plants were treated with triadimefon at 15mg l(-1) and hexaconazole at 10mg l(-1) separately by soil drenching on 80, 110 and 140 days after planting (DAP). The plants were harvested randomly and growth parameters were studied on 90, 120 and 150 DAP for determining the effect of both the triazole on growth and chlorophyll pigments. These triazole compounds increased the chlorophyll pigments. However, both the treatments decreased the fresh and dry weights of shoot and leaf area. Both these triazole resulted in a marginal increase in starch content and decreased the sugar contents. The carbohydrate metabolizing enzymes alpha- and beta-amylase activities were reduced and invertase activity increased in S. rotundifolius under triadimefon and hexaconazole treatments.

Drought-induced changes in the redox state of alpha-tocopherol, ascorbate, and the diterpene carnosic acid in chloroplasts of Labiatae species differing in carnosic acid contents.

To assess antioxidative protection by carnosic acid (CA) in combination with that of other low-molecular weight (M(r)) antioxidants (alpha-tocopherol [alpha-T] and ascorbate [Asc]) in chloroplasts, we measured endogenous concentrations of these antioxidants, their redox states, and other indicators of oxidative stress in chloroplasts of three Labiatae species, differing in their CA contents, exposed to drought stress in the field. Damage to the photosynthetic apparatus was observed neither in CA-containing species (rosemary [Rosmarinus officinalis]) and sage [Salvia officinalis]) nor in CA-free species (lemon balm [Melissa officinalis]) at relative leaf water contents between 86% and 58%, as indicated by constant maximum efficiency of photosystem II photochemistry ratios and malondialdehyde levels in chloroplasts. The three species showed significant increases in alpha-T, a shift of the redox state of alpha-T toward its reduced state, and increased Asc levels in chloroplasts under stress. Lemon balm showed the highest increases in alpha-T and Asc in chloroplasts under stress, which might compensate for the lack of CA. Besides, whereas in rosemary and sage, the redox state of CA was shifted toward its oxidized state and the redox state of Asc was kept constant, lemon balm displayed a shift of the redox state of Asc toward its oxidized state under stress. In vitro experiments showed that both CA and Asc protect alpha-T and photosynthetic membranes against oxidative damage. These results are consistent with the contention that CA, in combination with other low-M(r) antioxidants, helps to prevent oxidative damage in chloroplasts of water-stressed plants, and they show functional interdependence among different low-M(r) antioxidants in chloroplasts.

Isoprenoid biosynthesis. Metabolite profiling of peppermint oil gland secretory cells and application to herbicide target analysis.

Two independent pathways operate in plants for the synthesis of isopentenyl diphosphate and dimethylallyl diphosphate, the central intermediates in the biosynthesis of all isoprenoids. The mevalonate pathway is present in the cytosol, whereas the recently discovered mevalonate-independent pathway is localized to plastids. We have used isolated peppermint (Mentha piperita) oil gland secretory cells as an experimental model system to study the effects of the herbicides fosmidomycin, phosphonothrixin, methyl viologen, benzyl viologen, clomazone, 2-(dimethylamino)ethyl diphosphate, alendronate, and pamidronate on the pools of metabolites related to monoterpene biosynthesis via the mevalonate-independent pathway. A newly developed isolation protocol for polar metabolites together with an improved separation and detection method based on liquid chromatography-mass spectrometry have allowed assessment of the enzyme targets for a number of these herbicides.

In vitro adventitious shoot formation from leaf cultures of Clerodendrum inerme (L) Gaertn.

In vitro adventitious shoots (about 28) of Clerodendrum inerme were regenerated from leaf segments on MS medium containing BA (4 mg/L). These shoots developed directly from the leaf explants without callusing after 5 weeks. Leaf explant when cultured in MS medium containing BA (2 mg/L) and NAA (0.5 mg/L) developed compact callus that became nodular and regenerated shoots (about 50) after 5 weeks. The in vitro developed shoots were rooted in MS medium supplemented with IAA (2 mg/L). The hardened plantlets were successfully established in the field with 90% survival.