New aporphine alkaloids with antitumor activities from the roots of Thalictrum omeiense.

Two new aporphine alkaloids, 6aR-2'-(3-oxobutenyl)-thaliadin (1) and N-methylthalisopynine (2), along with ten known analogs (3-12), were isolated from the roots of Thalictrum omeiense W. T. Wang et S. H. Wang. Their structures were determined by extensive spectroscopic and X-ray crystallographic analyses. Compounds 1-7 and 9-12 were tested for their antiproliferative effects in vitro against two human cancer cell lines (A549 and MCF-7). Among them, compounds 1, 3, and 7 exhibited moderate inhibitory activity against the tested cell lines with IC50 values ranging from 23.73 to 34.97 µM.

Flower morphology as a predictor of pollination mode in a biotic to abiotic pollination continuum.

BACKGROUND AND AIMS: Wind pollination has evolved repeatedly in flowering plants, yet the identification of a wind pollination syndrome as a set of integrated floral traits can be elusive. Thalictrum (Ranunculaceae) comprises temperate perennial herbs that have transitioned repeatedly from insect to wind pollination while also exhibiting mixed pollination, providing an ideal system to test for evolutionary correlation between floral morphology and pollination mode in a biotic to abiotic continuum. Moreover, the lack of floral organ fusion across this genus allows testing for specialization to pollination vectors in the absence of this feature. METHODS: We expanded phylogenetic sampling in the genus from a previous study using six chloroplast loci, which allowed us to test whether species cluster into distinct pollination syndromes based on floral morphology. We then used multivariate analyses on floral traits followed by ancestral state reconstruction of the emerging flower morphotypes and determined whether these traits are evolutionarily correlated under a Bayesian framework with Brownian motion. KEY RESULTS: Floral traits fell into five distinct clusters, which were reduced to three after considering phylogenetic relatedness and were largely consistent with flower morphotypes and associated pollination vectors. Multivariate evolutionary analyses found a positive correlation between the lengths of floral reproductive structures (styles, stigmas, filaments and anthers). Shorter reproductive structures tracked insect-pollinated species and clades in the phylogeny, whereas longer structures tracked wind-pollinated ones, consistent with selective pressures exerted by biotic vs. abiotic pollination vectors, respectively. CONCLUSIONS: Although detectable suites of integrated floral traits across Thalictrum were correlated with wind or insect pollination at the extremes of the morphospace distribution, a presumed intermediate, mixed pollination mode morphospace was also detected. Thus, our data broadly support the existence of detectable flower morphotypes from convergent evolution underlying the evolution of pollination mode in Thalictrum, presumably via different paths from an ancestral mixed pollination state.

[Isoquinoline alkaloids from two species of Thalictrum genus plants].

The chemical constituents from the roots of Thalictrum cultratum and T. baicalense were investigated. By various isolation methods, such as silica gel, aluminium oxide, ODS, and Sephadex LH-20 column chromatographies, and semi-preparative HPLC, 11 simple isoquinoline alkaloids were isolated from the ethanol extract of the roots of these two plants, including a new compound, named dehydrothalflavine(1), and ten known ones(2-11): N-methylcorydaline(2), N-methylthalidaldine(3), thaliflavine(4), oxyhydrastinine(5), noroxyhydrastinine(6), dimethoxyisoquinolone(7), thalactamine(8), dehydronoroxyhydrastinine(9), 6,7-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline(10), and isopicnarrhine(11). Their structures were elucidated on the basis of HR-ESI-MS and 1 D and 2 D NMR techniques. Compound 1 was a new isoquinoline alkaloid. Compound 11 was obtained from Tha-lictrum plant for the first time. All compounds did not show cytotoxic activities against HL-60, U937, HCT116, Caco-2, and HepG2 cancer cell lines.

Cytotoxic isoquinoline alkaloids from the roots of Thalictrum foliolosum.

Phytochemical investigation on the 70% EtOH extract of the roots of Thalictrum foliolosum DC. resulted in the isolation of three new isoquinoline alkaloids, 5,6,7,12-tetramethoxy-2-methyl-13-hydroxy-11-(4'-methoxycarbonylphenoxy)benzylisoquinoline (1), 5,6,7,12-tetramethoxy-2-methyl-13-hydroxy-11-(4'-carbonylphenoxy) benzylisoquinoline (2), and 3-methoxy-10-O-acetylprodensiflorin B (3). The new structures were elucidated by using spectroscopic data (NMR, IR, UV, and MS). The isolated alkaloids were tested in vitro for cytotoxic potentials against six human lung cancer cell lines (H460, H23, HTB-58, A549, H441, and H2170). As a result, alkaloids 1 and 2 exhibited significant cytotoxic activities against all the tested tumor cell lines with IC50 values less than 20 µM.

Influence of local density and sex ratio on pollination in an ambophilous flowering plant.

PREMISE: Variation in local density and sex ratio in dioecious plants can affect mating success through the actions of pollen vectors, principally generalist insects or wind. Increased density and male-biased sex ratios should promote pollen transfer and seed production, but their combined effects have not been investigated for ambophilous species, which exhibit both insect and wind pollination. METHODS: We manipulated density (low vs. high) and sex ratio (1:1 vs. 3:1 male-biased) in arrays of dioecious ambophilous Thalictrum pubescens. We quantified visitation rates and foraging times to examine whether pollinators exhibited sex-specific preferences and determined the seed set of arrays. RESULTS: Pollinators visited more plants per foraging bout at high than low density. Visitation rates and foraging times of visitors were greater for male than for female plants but did not depend on the density or sex ratio of arrays. However, whereas solitary bees displayed a strong preference for males, hover flies were indifferent to plant sex phenotype. Solitary bees also visited significantly more plants per foraging bout than hover flies. There was a significant interaction between density and sex ratio on seed set. At low density, seed set was greater for 3:1 than for 1:1 arrays, but at high density the opposite pattern occurred. CONCLUSIONS: The demographic factors we investigated had complex influences on pollinator foraging behavior and patterns of seed set. Several factors may explain our results, including the influence of density and sex ratio on pollen export from arrays, grooming by pollinators, and the contribution of wind pollination.

Three new isoquinoline alkaloids from the whole plants of Thalictrum tenue with cytotoxic activities.

Three new isoquinoline alkaloids, including two aporphines (1 and 2) and one oxoaporphine (3), were isolated from the 90% EtOH extract of the whole plants of Thalictrum tenue Franch. The structures of the isolated compounds were established based on 1D and 2D (1H-1H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry, respectively. The isolated alkaloids were tested in vitro for cytotoxic activity against six esophageal carcinoma cell lines. Consequently, alkaloids 1-3 exhibited some cytotoxic activities against all the tested tumor cell lines with IC50 values less than 20 µM. [Formula: see text].

Antiplasmodial potential of Thalictrum foliolosum (Ranunculaceae) against lethal murine malaria.

BACKGROUND AND OBJECTIVES: The emergence of multi-drug resistant (MDR) strains of Plasmodium falciparum highlights the need to develop novel antimalarial drugs. Present study explores the in vivo antiplasmodial activity of ethanol leaf extract of Thalictrum foliolosum (ELETF) against lethal murine malaria. METHODS: The acute toxicity of the extract was assessed by Limit test of Lorke. The suppressive activity of the extract was evaluated by Peter's 4 day test. In vivo preventive and curative activity of ELETF was assessed by Peter's method and Ryley and Peter's method respectively. Biochemical assays were carried out using standard methods. RESULTS: ELETF (1000 mg/kg) exhibited considerable in vivo schizontocidal activity with 67.11% chemosuppression on Day 5. The ED50 of the extract was 579.56 mg/kg. ELETF also showed significant repository activity with 87.70% chemosuppression at 750 mg/kg, which was greater than pyrimethamine (78.78%). ELETF exhibited dose dependent chemosuppression in the curative test with maximum 70.06% chemosuppression (750 mg/kg). Maximum Mean Survival Time (MST) was 19.2±4.60 and 22.66±4.41 days respectively in the suppressive and curative test, which was extremely statistically significant (p<0.0005) in comparison to untreated control which died by Day 9 post inoculation. Biochemical analysis revealed the safety of ELETF to the hepatic and renal functions of the rodent host. INTERPRETATION & CONCLUSION: The study reports the antiplasmodial potential of Thalictrum foliolosum (ELETF) against Plasmodium berghei infection. The extract can be developed as a phytomedicine against malaria. Alternatively, the active components can be isolated as new lead compounds against the disease.

[A new antiviral isoquinoline alkaloid from Thalictrum glandulosissimum].

A new isoquinoline alkaloid(1) has been isolated from the whole plant of Thalictrum glandulosissimum by using various chromatographic techniques, including silica gel, sephadex, MCI-gel resin, and RP-HPLC, and its structure was determined as 1-(6-hydroxy-7-methylisoquinolin-1-yl) ethantone by physicochemical properties and spectroscopic data. This compound was evaluated for anti-tobacco mosaic virus(TMV) activity. The results showed that it had prominent anti-TMV activity with inhibition rates of 28.4%. This rate was closed to that of positive control.

Comparison of Anticancer Activity and HPLC-DAD Determination of Selected Isoquinoline Alkaloids from Thalictrum foetidum, Berberis sp. and Chelidonium majus Extracts.

Background: Plants are an important origin of natural substances that the raw material for various pharmaceutical and therapeutic applications due to the presence of phytochemicals, such as alkaloids. Alkaloids, which are found in different plant species, possess numerous biological activities. Some alkaloids have strong cytotoxic effects on various cancer cells. The search for new drugs to treat various cancers is one of the most important challenges of modern scientific research. Objective: This study aimed to investigate of cytotoxic activity of extracts that were obtained from Chelidonium Majus; Berberis sp.; Thalictrum foetidum containing various alkaloids on selected cancer cell lines. The aim was also the quantification of selected alkaloids in the investigated extracts by HPLC. Methods: The analysis of alkaloids contents were performed while using HPLC in reversed phase (RP) mode using Polar RP column and mobile phase containing acetonitrile, water, and ionic liquid. The cytotoxic effect of the tested plant extracts and respective alkaloids' standards were examined while using human pharyngeal squamous carcinoma cells (FaDu), human tongue squamous carcinoma cells (SCC-25), human breast adenocarcinoma cell line (MCF-7), and human triple-negative breast adenocarcinoma cell line (MDA-MB-231). Conclusion: All of the investigated plant extracts possess cytotoxic activity against cancer cell lines: FaDu, SCC-25, MCF-7, and MDA-MB-231. The highest cytotoxic activity against FaDu and MDA-MB-231 cells was observed for Chelidonium majus root extract, while the highest cytotoxic activity against SCC-25 and MCF-7 cells was estimated for the Thalictrum foetidum root extract. There obtained significant differences in the cytotoxic activity of extracts that were obtained from the roots and herbs of Chelidonium majus and Thalictrum foetidum. Based on these results, investigated plant extracts can be recommended for further investigations of anticancer activity.

Partial redundancy and functional specialization of E-class SEPALLATA genes in an early-diverging eudicot.

Plant MADS-box genes have duplicated extensively, allegedly contributing to the immense diversity of floral form in angiosperms. In Arabidopsis thaliana (a core eudicot model plant), four SEPALLATA (SEP) genes comprise the E-class from the extended ABCE model of flower development. They are redundantly involved in the development of the four types of floral organs (sepals, petals, stamens and carpels) and in floral meristem determinacy. E-class genes have been examined in other core eudicots and monocots, but have been less investigated in non-core eudicots. Our goal was to functionally characterize the E-class genes in the early-diverging eudicot Thalictrum thalictroides (Ranunculaceae), whose flowers are apetalous. We identified four SEP orthologs, which when placed in a phylogenetic context, resulted from a major gene duplication event before the origin of angiosperms and a subsequent duplication at the origin of the Ranunculales. We used Virus-Induced Gene Silencing (VIGS) to down-regulate the three expressed paralogs individually and in combination to investigate their function and to determine the degree of conservation versus divergence of this important plant transcription factor. All loci were partially redundant in sepal and stamen identity and in promoting petaloidy of sepals, yet the SEP3 ortholog had a more pronounced role in carpel identity and development. The two other paralogs appear to have subfunctionalized in their cadastral roles to keep the boundaries between either sepal and stamen zones or stamen and carpel zones. Double knockdowns had enhanced phenotypes and the triple knockdown had an even more severe phenotype that included partial to complete homeotic conversion of stamens and carpels to sepaloid organs and green sepals, highlighting a role of E-class genes in petaloidy of sepals in this species. While no floral meristem determinacy defects were observed, this could be due to residual amounts of gene expression in the VIGS experiments being sufficient to perform this function or to the masking role of a redundant gene.

Crystal structure of norcoclaurine-6-O-methyltransferase, a key rate-limiting step in the synthesis of benzylisoquinoline alkaloids.

Growing pharmaceutical interest in benzylisoquinoline alkaloids (BIA) coupled with their chemical complexity make metabolic engineering of microbes to create alternative platforms of production an increasingly attractive proposition. However, precise knowledge of rate-limiting enzymes and negative feedback inhibition by end-products of BIA metabolism is of paramount importance for this emerging field of synthetic biology. In this work we report the structural characterization of (S)-norcoclaurine-6-O-methyltransferase (6OMT), a key rate-limiting step enzyme involved in the synthesis of reticuline, the final intermediate to be shared between the different end-products of BIA metabolism, such as morphine, papaverine, berberine and sanguinarine. Four different crystal structures of the enzyme from Thalictrum flavum (Tf 6OMT) were solved: the apoenzyme, the complex with S-adenosyl-l-homocysteine (SAH), the complexe with SAH and the substrate and the complex with SAH and a feedback inhibitor, sanguinarine. The Tf 6OMT structural study provides a molecular understanding of its substrate specificity, active site structure and reaction mechanism. This study also clarifies the inhibition of Tf 6OMT by previously suggested feedback inhibitors. It reveals its high and time-dependent sensitivity toward sanguinarine.

The complete plastome of Thalictrum elegans Wall. ex Royle and its phylogenetic analysis.

Thalictrum elegans Wall. ex Royle, a species within the family Ranunculaceae, is mainly distributed along forest margins and grassy slopes at altitudes 2700-4000 m on the Qinghai-Tibetan Plateau. Despite its wide distribution in alpine ecosystems, its genetic diversity remains poorly understood. In this study, we assembled and characterized the complete chloroplast genome of T. elegans, addressing a significant gap in our understanding of its genetic composition. The chloroplast genome is 155,864 base pairs long and contains 131 genes, including 86 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. Phylogenetic analysis of 15 representative Thalictrum species revealed that the genus can be classified into three clades. T. elegans along with another nine other species formed the largest monophyletic clade and is most closely related to T. petaloideum and T. foliosum. These findings enhance our understanding of the genetic diversity of T. elegans and contribute to its conservation and utilization.

Bioactives from medicinal herb against bedaquiline resistant tuberculosis: removing the dark clouds from the horizon.

Tuberculosis is a contagious bacterial ailment that primarily affects the lungs and is brought on by the bacterium Mycobacterium tuberculosis (MTB). An antimycobacterial medication called bedaquiline (BQ) is specified to treat multidrug-resistant tuberculosis (MDR-TB). Despite its contemporary use in clinical practice, the mutations (D32 A/G/N/V/P) constrain the potential of BQ by causing transitions in the structural conformation of the atpE subunit-c after binding. In this study, we have taken the benzylisoquinoline alkaloids from thalictrum foliolosum due to its antimicrobial activity reported in prior literature. We used an efficient and optimized structure-based strategy to examine the wild type (WT) and mutated protein upon molecule binding. Our results emphasize the drastic decline in BQ binding affinity of mutant and WT atpE subunit-c complexes compared to thalirugidine (top hit) from thalictrum foliolosum. The decrease in BQ binding free energy is due to electrostatic energy because nearly every atom in a macromolecule harbors a partial charge, and molecules taking part in molecular recognition will interact electrostatically. Similarly, the high potential mean force of thalirugidine than BQ in WT and mutant complexes demonstrated the remarkable ability to eradicate mycobacteria efficiently. Furthermore, the Alamar blue cell viability and ATP determination assay were performed to validate the computational outcomes in search of novel antimycobacterial. Upon closer examination of the ATP determination assay, it became apparent that both BQ and thalirugidine showed similar reductions in ATP levels at their respective MICs, presenting a potential common mechanism of action.

Pharmacological Assessment of Aqueous Ethanolic Extract of Thalictrum Foetidum Against Haloperidol-Induced Parkinson's Like Symptoms in Animal Model: A Dose-Dependent Study With Mechanistic Approach.

Introduction: Parkinson's disease (PD) is characterized by dopamine deficiency in the corpus striatum due to the degeneration of dopaminergic neurons in the substantia nigra. Symptoms include bradykinesia, resting tremors, unstable posture, muscular rigidity, and a shuffled gait. Thalictrum foetidum is traditionally used for neurodegenerative disorders. Objectives: This study aimed to explore the therapeutic potential of aqueous ethanolic extract of Thalictrum foetidum (AETF) against Parkinson-like symptoms and to investigate its underlying mechanism. Methodology: Thirty-six albino mice were randomly divided into 6 groups (n = 6): normal control, disease control, standard treatment (levodopa/carbidopa, 100/25 mg/kg), and 3 treatment groups (AETF at 200, 400, and 600 mg/kg). One hour before treatment, haloperidol (1 mg/kg, i. p.) was administered to induce Parkinson's disease in all groups except the normal control group. Results: Behavioral analysis showed significant improvement (P < .001) in motor function, muscular coordination, and reduced muscular rigidity and tremors. AETF also reduced oxidative stress. Histological examination of the brain showed reduced Lewy bodies, neurofibrillary tangles, and plaque formation. Conclusion: AETF alleviated PD symptoms by reducing neurodegeneration, modulating oxidative stress, and inhibiting the expression of nuclear factor-κB (NF-κB) and associated inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6).

The first complete chloroplast genome of Thalictrum fargesii: insights into phylogeny and species identification.

Introduction: Thalictrum fargesii is a medicinal plant belonging to the genus Thalictrum of the Ranunculaceae family and has been used in herbal medicine in the Himalayan regions of China and India. This species is taxonomically challenging because of its morphological similarities to other species within the genus. Thus, herbal drugs from this species are frequently adulterated, substituted, or mixed with other species, thereby endangering consumer safety. Methods: The present study aimed to sequence and assemble the entire chloroplast (cp) genome of T. fargesii using the Illumina HiSeq 2500 platform to better understand the genomic architecture, gene composition, and phylogenetic relationships within the Thalictrum. Results and discussion: The cp genome was 155,929 bp long and contained large single-copy (85,395 bp) and small single-copy (17,576 bp) regions that were segregated by a pair of inverted repeat regions (26,479 bp) to form a quadripartite structure. The cp genome contains 133 genes, including 88 protein-coding genes (PCGs), 37 tRNA genes, and 8 rRNA genes. Additionally, this genome contains 64 codons that encode 20 amino acids, the most preferred of which are alanine and leucine. We identified 68 SSRs, 27 long repeats, and 242 high-confidence C-to-U RNA-editing sites in the cp genome. Moreover, we discovered seven divergent hotspot regions in the cp genome of T. fargesii, among which ndhD-psaC and rpl16-rps3 may be useful for developing molecular markers for identifying ethnodrug species and their contaminants. A comparative study with eight other species in the genus revealed that pafI and rps19 had highly variable sites in the cp genome of T. fargesii. Additionally, two special features, (i) the shortest length of the ycf1 gene at the IRA-SSC boundary and (ii) the distance between the rps19 fragment and trnH at the IRA-LSC junction, distinguish the cp genome of T. fargesii from those of other species within the genus. Furthermore, phylogenetic analysis revealed that T. fargesii was closely related to T. tenue and T. petaloidium. Conclusion: Considering all these lines of evidence, our findings offer crucial molecular and evolutionary information that could play a significant role in further species identification, evolution, and phylogenetic studies on T. fargesii.

Corrigendum: Organization, phylogenetic marker exploitation, and gene evolution in the plastome of Thalictrum (Ranunculaceae).

[This corrects the article DOI: 10.3389/fpls.2022.897843.].

Dimeric benzylisoquinoline alkaloids from Thalictrum delavayi and their biological activities.

A phytochemical investigation of the whole plants of T. delavayi led to the isolation of five new dimeric benzylisoquinoline alkaloids, thalidelavines A-E (1-5), together with six known congeners (6-11). The structures and absolute configurations of new compounds were established based on analyses of spectroscopic data, ECD calculations, and single crystal X-ray crystallography. Thalidelavines A-E (1-5) were structurally complex bisbenzylisoquinoline alkaloids with various configurations. These isolated alkaloids were evaluated for their cytotoxic and immunosuppressive effects. Among them, both 9 and 10 displayed significant cytotoxicities against T98G cell lines with an IC50 value of 2.1 µM, compared with the positive CPT-11 (IC50 = 3.0 µM). In addition, 5-7 showed remarkable immunosuppressive effects. These findings not only enrich the structural diversity of bisbenzylisoquinoline alkaloids, but also provide potential candidates for the further development of the antitumor and immunosuppressive agents.

Characterization of the complete chloroplast genome of Thalictrum foliolosum DC. 1817, a folk medicine plant in China.

Thalictrum foliolosum DC. 1817, a widely distributed species in the genus of Thalictrum, is used as a traditional herbal medicine in China. For the first time, the complete chloroplast (cp) genome of T. foliolosum was assembled and characterized for the first time in this study. The cp genome of T. foliolosum was 155,764 bp in length, including a large-single copy region of 85,086 bp, a small-single copy region of 17,636 bp, and a pair of inverted repeats region of 53,042 bp. The overall GC content was 38.50%. A total of 127 genes were predicted, including 82 protein-coding genes, 37 tRNA genes, and 8 ribosomal RNA genes. Phylogenetic analysis indicated that T. foliolosum is closely related to T. petaloideum.

Characterization of the complete plastome of Thalictrum aquilegiifolium var. sibiricum (Ranunculaceae), an annual herb.

Thalictrum aquilegiifolium var. sibiricum, is an annual herb that grows on slopes or in mountain gullies in areas of damp forest. In this study, we report for the first time the complete plastome sequence of T. aquilegiifolium var. sibiricum. The plastome sequence is 156,244 bp in length and comprises a large single-copy region (85,447 bp), a small single-copy region (17,599 bp), and a pair of inverted repeat regions (26,480 bp). The genome encodes 112 unique genes, including 78 protein-coding genes, 30 tRNAs, and four rRNAs, and has total GC content of 38.4%. Phylogenomic analysis based on the plastome sequences of 20 species in the family Ranunculaceae indicated that T. aquilegiifolium var. sibiricum is clustered with Thalictrum minus.

Complete chloroplast genome sequence of Thalictrum viscosum W.T.Wang & S.H.Wang, 1979 (Ranunculaceae).

Thalictrum viscosum W.T.Wang & S.H.Wang, 1979 is a flowering plant species in family Ranunculaceae that is endemic to Yunnan province of China. To facilitate genetic study of T. viscosum, we de novo assembled and annotated the complete chloroplast (cp) genome of T. viscosum for the first time. The total length of the cp genome of T. viscosum was 155,984 bp, with a GC content of 38.4%. The T. viscosum cp genome had a typical quadripartite structure with a large single-copy region of 85,339 bp, a small single-copy region of 17,656 bp, and a pair of inverted repeat regions of 26,495 bp. The cp genome consisted of 133 genes, including 87 protein-coding genes, 38 transfer RNA genes, and eight ribosomal RNA genes. We performed phylogenetic analysis of T. viscosum with the maximum-likelihood phylogenetic tree and indicated that T. viscosum was closely related to T. cirrhosum and T. foeniculaceum.