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Lignans are a powerful weapon for plants to resist stresses and have diverse bioactive functions to protect human health. Elucidating the mechanisms of stereoselective biosynthesis and response to stresses of lignans is important for the guidance of plant improvement. Here, we identified the complete pathway to stereoselectively synthesize antiviral (−)-lariciresinol glucosides in Isatis indigotica roots, which consists of three-step sequential stereoselective enzymes DIR1/2, PLR, and UGT71B2. DIR1 was further identified as the key gene in respoJanuary 2024nse to stresses and was able to trigger stress defenses by mediating the elevation in lignan content. Mechanistically, the phytohormone-responsive ERF transcription factor LTF1 colocalized with DIR1 in the cell periphery of the vascular regions in mature roots and helped resist biotic and abiotic stresses by directly regulating the expression of DIR1. These systematic results suggest that DIR1 as the first common step of the lignan pathway cooperates with PLR and UGT71B2 to stereoselectively synthesize (−)-lariciresinol derived antiviral lignans in I. indigotica roots and is also a part of the LTF1-mediated regulatory network to resist stresses. In conclusion, the LTF1-DIR1 module is an ideal engineering target to improve plant Defenses while increasing the content of valuable lignans in plants. Proposed working model depicting the roles of LTF1-DIR1 module in lignan stereoselective biosynthesis and stress defense. [Display omitted] [ABSTRACT FROM AUTHOR]

Water-soluble polysaccharides were isolated from the leaves and roots of Isatis indigotica Fort., and their structural features were studied and compared. One neutral polysaccharide fraction (WFIP-N) and three pectin fractions (WFIP-A-A, WFIP-A-B and WFIP-A-C) were obtained from the leaves, and one neutral polysaccharide fraction (WRIP-N) and two pectin fractions (WRIP-A-A and WRIP-A-B) were obtained from the roots. WFIP-A-B (Mw = 34.6 kDa) and WRIP-A-B (Mw = 29.9 kDa) were the major pectic polysaccharides. Monosaccharide composition, FT-IR, enzymatic hydrolysis, NMR and methylation analysis indicated that both WFIP-A-B and WRIP-A-B are composed of rhamnogalacturonan I (RG-I), rhamnogalacturonan II (RG-II) and homogalacturonan (HG) domains with mass ratios of 1.5:1.0:0.4 and 0.3:1.0:1.7, respectively. WFIP-A-B and WRIP-A-B were found to be rich in RG-I and HG domains, respectively, and mainly contained type II arabinogalactan (AG-II) and α-L-1,5-arabinan side chains, but those in WRIP-A-B were more numerous and longer. Our results provide structural features and differences between these polysaccharides which will help to elucidate their functional differences. [ABSTRACT FROM AUTHOR]

Arsenic (As) and cadmium (Cd) belong to the group of major pollutants extremely toxic to plants. Metal hyperaccumulating plants play an important role in phytoextraction of heavy metals. Silicon (Si) plays an important role in the amelioration of heavy metal stress through physio-biochemical mechanisms, which remain poorly understood in hyperaccumulators. The main purpose of this study was to determine the impact of Si on growth and performance of As hyperaccumulator Isatis cappadocica Desv. , exposed to As and Cd. Results showed that Si (especially at 1 mM level) alleviated the harmful impact of As/Cd and significantly increased the root and shoot biomass, root and shoot length and chlorophyll contents of I. cappadocica by enhancing the plant defense mechanisms. Between the two investigated harmful elements, As was accumulated in plant parts significantly more than Cd, however with considerably lower toxic growth effects. The As/Cd concentration, bioaccumulation and translocation factor and total As content both in roots and shoots of Si-supplied plant were significantly reduced as a protective mechanism, especially in Cd exposed plant. In comparison with single As/Cd treatment, Si supply reduced H 2 O 2 content, increased total soluble protein content and enhanced glutathione S-transferase activity in shoots. The results of this study clearly showed that Si minimized As/Cd uptake and root to shoot translocation, and therefore Si cannot enhance the phytoextraction potential of this plant species. Additionally, Si-improved growth and reduced oxidative damages caused by excess of As and Cd suggested that the similar mechanisms of metal(loid) alleviation are adopted in hyperaccumulators as well as non-hyperaccumulating plants. • Si application alleviated As/Cd toxicity in Isatis cappadocica. • As was accumulated significantly more than Cd, however with considerably low toxic growth effects. • Exogenous Si alleviated oxidative stress and enhanced antioxidant enzyme activity. • Si decreased the As/Cd accumulation in Isatis plants. • Si could be a candidate for As/Cd detoxification and phytoremediation potential of I. cappadocica. [ABSTRACT FROM AUTHOR]

Isatis indigotica Fort., belongs to the Brassicaceae family and its leaf is an important Chinese traditional folklore medicine. After many years of research, phytochemical investigations on it have led to the identification of 197 alkaloids, which could serve as valuable chemotaxonomic markers for the identification of I. indigotica. We summarize the chemotaxonomic value of alkaloids , and the results showed that I. indigotica is a typical species in the Brassicaceae family. It has some chemotaxonomic relationships with genera of Brassica L., Arabidopsis (DC.) Heynh., Thellungiella O. E. Schulz, Raphanus L., Lepidium L., together with families of Acanthaceae, Apocynaceae, Nitrariaceae, Orchidaceae and Orchidoideae. • 197 alkaloids (1 – 197) were summarized from the Isatis indigotica. • The structural characteristics of various alkaloids were described. • The chemotaxonomic significance of the compounds isolated was presumed in this paper by network analyses. [ABSTRACT FROM AUTHOR]

• Strong light promoted the energy metabolism of Isatis indigotica Fortune. • Light intensity affected the expression of 89 miRNAs and 16,485 mRNAs. • 12 miRNA-mRNA pairs play important roles in mitochondrial biological processes. • Light intensity affects 4 mitochondria-associated miRNA-mRNA pairs. Light is the main source of energy for plant growth. Studies have shown that I. indigotica is a light-demanding plant and its yield and various active components are positively correlated with light intensity, but no studies of light intensity affecting energy metabolism in I. indigotica have been reported. Mitochondria are the main site of energy metabolism, and miRNAs are important factors in regulating gene expression, this experiment attempts to study the effects of different light intensities on energy metabolism from the perspective of mitochondria and miRNAs. The results show that the biomass、mitochondrial structural integrity and energy metabolism in I. indigotica were found to be positively correlated with light intensity. Small RNA and transcriptome sequencing identified 241 miRNAs and 36,372 mRNAs, and degradomic technology identified 72 miRNAs targeting 106 mRNAs, among which 12 pairs of miRNA-mRNAs were annotated on mitochondria. Combined with RT-qPCR validation, it was concluded that miR167a-5p positively regulates LETM1 and affects mitochondrial structure, miR400-5p and mIR169m-p3_1ss15CT negatively regulate GRXS15 and CMC4 , respectively, affecting SDH and CCO activities, and miR395a- APS4 may affect the utilization of ATP and sulfate assimilation. In summary, the results of this study complement and enrich knowledge of light effects on mitochondria from the perspective of miRNA, while providing guidance for the cultivation of I. indigotica. [ABSTRACT FROM AUTHOR]

The AGL6 (AGMOUSE LIKE 6) gene is a member of the SEP subfamily and functions as an E-class floral homeotic gene in the development of floral organs. In this study, we cloned IiAGL6 , the orthologous gene of AGL6 in Isatis indigotica. The constitutive expression of IiAGL6 in Arabidopsis thaliana resulted in a late-flowering phenotype and the development of curly leaves during the vegetative growth period. Abnormal changes in floral organ development were observed during the reproductive stage. In woad plants, suppression of IiAGL6 using TRV-VIGS (tobacco rattle virus-mediated virus-induced gene silencing) decreased the number of stamens and led to the formation of aberrant anthers. Similar changes in stamen development were also observed in miRNA-AGL6 transgenic Arabidopsis plants. Yeast two-hybrid and BiFC tests showed that IiAGL6 can interact with other MADS-box proteins in woad; thus, playing a key role in defining the identities of floral organs, particularly during stamen formation. These findings might provide novel insights and help investigate the biological roles of MADS transcription factors in I. indigotica. • IiAGL6 was the orthologous gene of AGL6 in Isatis indigotica. • IiAGL6 transgenic Arabidopsis plants were late-flowering and produce curly leaves. • IiAGL6 overexpression resulted in abnormal changes in floral organs. • Suppression of IiAGL6 using TRV-VIGS led to aberrant stamens. • IiAGL6 play a crucial role in defining the identities of stamens. [ABSTRACT FROM AUTHOR]

Indigo naturalis (IN) is a dried powder derived from plants such as Baphicacanthus cusia (Neeks) Bremek., Polygonum tinctorium Ait. and Isatis indigotica Fork. It has a historical application as a dye in ancient India, Egypt, Africa and China. Over time, it has been introduced to China and Japan for treatment of various ailments including hemoptysis, epistaxis, chest discomfort, and aphtha. Clinical and pre-clinical studies have widely demonstrated its promising effects on autoimmune diseases like psoriasis and Ulcerative colitis (UC). Despite the documented efficacy of IN in UC patients, concerns have been raised on the development of adverse effects with long term consumption, prompting a closer examination of its safety and tolerability in these contexts. This review aims to comprehensively assess the efficacy of IN in both clinical and pre-clinical settings, with a detailed exploration of the mechanisms of action involved. Additionally, it summarizes the observed potential toxicity of IN in animal and human settings was summarized. This review will deepen our understanding on the beneficial and detrimental effects of IN in UC, providing valuable insights for its future application in patients with this condition. [ABSTRACT FROM AUTHOR]

Isatis indigotica Fort. (I. indigotica) has a long history of use in the treatment of respiratory tract infections. Here, we investigated the anti-influenza effects exerted by I. indigotica on human alveolar epithelial cells via altering virulent protein production and disrupting autophagy. I. indigotica water extract was analysed by HPLC with epigoitrin specified as the fingerprint. Cellular viability was detected via XTT assay. Hemagglutination assay, plaque assay, and quantitative reverse transcription PCR were used to evaluate the inhibitory effects on H1N1 viral infection. The initial step of the viral infection was detected by attachment and penetration assays. Western blot was applied to measure the matrix-1 (M1), matrix-2 (M2), nucleoprotein, light chain 3 beta, and Beclin-1 protein levels. The extraction rate of the I. indigotica was 12.48%. The results of the hemagglutination assay, plaque assay, and quantitative reverse transcription PCR demonstrated that I. indigotica can effectively impede viral propagation. In addition, I. indigotica inhibited the production of the M1, M2, and nucleoprotein proteins, most notably in the M2 and M1 proteins, thereby hindering viral attachment, internalisation, and penetration. After treatment with I. indigotica , light chain 3 beta II levels decreased significantly, while we noted no marked change in the production of Beclin-1. This study demonstrates that I. indigotica water extract can rescue host cells from H1N1 influenza infection by inhibiting viral attachment, penetration, and propagation. This is achieved by significantly reducing virulent protein production and disrupting the process of autophagy. Collectively, our findings indicate that I. indigotica may provide an effective alternative treatment for patients infected with the H1N1 influenza virus. • I. indigotica effectively inhibited viral propagation through the production of the M1, M2 and NP proteins. • I. indigotica induced LC3B II levels decreased significantly, while we noted no marked change in the production of Beclin-1. • I. indigotica significantly reduced virulent protein production and disrupting the process of autophagy. [ABSTRACT FROM AUTHOR]

• Analyzed the synthase genes and compounds related to the lignan in diploid Isatis indigotica Fortune, tetraploid I.indigotica , and Isatis tinctoria Linnaeus through metabolomic and transcriptomic. • The analysis of transcription factors showed that the AP2-EREBP family (Iin24319), MYB family (Iin24843), and WRKY family (Iin08158) displayed expression patterns similar to Iin14549. • Serve as a reference for improving the quality of I. indigotica and developing germplasms with high lignan content. Lay a foundation for the functional characterization of UGTs in lignan biosynthesis pathway. Isatis indigotica Fortune is a plant species containing lignan compounds of significant economic value. Its root plays a crucial role in treating viruses and exhibits antitumor, anti-inflammatory, antibacterial, and other biological activities. Now, I. indigotica has been included in Isatis tinctoria Linnaeus. In this study, the roots of diploid I. indigotica , tetraploid I. indigotica , and Isatis tinctoria Linnaeus were analyzed using metabolome and transcriptome analysis. The metabolomic analysis detected 48 lignan metabolites, including Lirioresinol A, Vladinol A, Syringaresinol, Arctigenin, Acanthoside B, and Sesamin as characteristic compounds, without significant variations among the remaining metabolites. The transcriptomic analysis identified 41 differentially expressed phenylpropanoid synthase genes, which were further analyzed for variations in lignan transcriptome profiles across different samples. RT-qPCR analysis also revealed differential genes expression related to lignan biosynthesis pathway among the three sample groups. The analysis of transcription factors showed that the AP2-EREBP family (Iin24319), MYB family (Iin24843), and WRKY family (Iin08158) displayed expression patterns similar to Iin14549. Phylogenetic analyses also indicate that Iin14549 may play a role in lignan synthesis. These transcription factor families exhibited high expression in tetraploid I. indigotica , moderate expression in diploid I. indigotica , and low expression in I. tinctoria. The findings of this study can serve as a reference for improving the quality of I. indigotica and developing germplasms with high lignan content. Additionally, these results lay a foundation for the functional characterization of UGTs in lignan biosynthesis pathway. [ABSTRACT FROM AUTHOR]

The JAK-STAT pathway plays a crucial role in the signaling cascade associated with various cytokines that have been implicated in the pathogenesis of inflammatory diseases and myeloproliferative neoplasms (MPN). Among the isoforms of JAKs, the JAK2 subtype is primarily responsible for the function of hematopoietic system cells, making it a significant target in the treatment of MPN. However, the precise regulatory role of JAK2 in inflammatory diseases requires further investigation and confirmation. The current study employed a selective JAK2 inhibitor, ZT55, derived from Isatis indigotica roots, to examine its regulatory effects on inflammatory and immune responses in delayed-type hypersensitivity (DTH) and arthritis in mice. To evaluate the efficacy of ZT55 treatment, DNFB-induced DTH and collagen-induced arthritis (CIA) mouse models were utilized. T cells were cultured and subsequently analyzed for proliferation and activation using flow cytometry and EdU assay. Additionally, the maturation and function of dendritic cells were assessed through flow cytometry and ELISA. Our findings indicate that ZT55 significantly reduced DNFB-induced DTH and attenuated inflammation, cartilage degradation, and bone destruction in CIA mice. Moreover, ZT55 was found to inhibit the proliferation and activation of T cells and the maturation of dendritic cells by regulating the JAK2-STAT3 signaling pathway. These results suggest that selectively targeting the JAK2 isoform could have anti-inflammatory and immunosuppressive effects by regulating the adaptive and innate immune responses via the JAK2-STAT3 signaling pathway. Therefore, ZT55 has the potential to be a promising pharmaceutical candidate for the treatment of inflammatory and autoimmune diseases. [ABSTRACT FROM AUTHOR]

Drought is a major abiotic stress factor affecting plant growth and production, while utilizing beneficial endophytic fungi is one of the most promising strategies for enhancing plant growth and drought tolerance. In the present study, a pot experiment was conducted to investigate the beneficial effects of dark septate endophytes (DSE) (Acrocalymma aquatica and Alternaria alstroemeriae) combine with organic residues from sterilized or non-sterilized fermented corn straw by Trichoderma afroharzianum on the growth and drought resistance of Isatis indigotica. Drought stress (30% field water capacity) reduced the shoot biomass, root biomass, and epigoitrin content of I. indigotica by 34.30%, 80.85%, and 16.51%, respectively. The DSE inoculation alone increased shoot biomass and epigoitrin content under well-watered condition (70% field water capacity) by 13.75%− 65.98% and 52.33%− 67.59%, respectively, and shoot biomass under drought stress by 37.27%− 84.91%. The organic residues application alone increased root biomass under well-watered condition and drought stress by 71.88%− 107.06% and 463.61%− 678.69%, respectively. The mixed application of DSE and organic residues increased root biomass and epigoitrin content under well-watered condition by 66.79%− 144.66% and 89.02%− 136.63%, respectively, and under drought stress by 410.66%− 580.49% and 28.26%− 88.37%, respectively. Structural equation modeling demonstrated that DSE inoculation, organic residue application, and the mixed application improved the growth of I. indigotica under drought stress through different direct and indirect pathways. Variation partitioning showed that DSE was the primary factor improving the epigoitrin content , and organic residue was the primary factor influencing plant biomass and morphological parameters. The mixed application of DSE and organic residue had further synergistic effects on soil enzyme activities, soil organic matter, root biomass, and epigoitrin content, especially the mixed application of A. aquatica and sterilized organic residue. These results contribute to a further understanding of the ecological function of DSE in dryland soils and reveal the synergistic application value of DSE and organic residue for medicinal plant cultivation. [Display omitted] • Symbionts and organic amendment are beneficial to crop growth and drought resistance. • Dark septate endophytes was the primary factor improving the epigoitrin content. • Fermented organic residue improved soil organic matter and root development. • DSE improved the utilization of organic residues that affected DSE-plant symbiosis. • Acrocalymma aquatica and sterilized residue can be used for dryland crop cultivation. [ABSTRACT FROM AUTHOR]

Isatis spp. are well-known for their industrial significance due to natural sources of indigotin and indirubin, important indole alkaloids, used in the dye and pharmaceutical industries. In this study, silver nanoparticles (AgNP) and salicylic acid-chitosan nanoparticles (SA-CNP) were synthesized and applied to enhance the production of indigotin and indirubin in shoot and root cultures of Isatis tinctoria and Isatis ermenekensis. Different doses of AgNP and SA-CNP were administered to three-week-old shoot and root cultures, and the effects were assessed at 12, 24, and 48 h. The harvested samples were analyzed to quantify indigotin and indirubin levels. Furthermore, the expression levels of It-TSA and CYP79B2 genes, known to be involved in indole alkaloid biosynthesis, were determined. In I. tinctoria roots, the highest levels of indigotin and indirubin were observed after applying 150 mg L−1 of SA-CNP for 48 h while in I. ermenekensis shoots, indigotin and indirubin reached the maximum levels with the application of 8 mg L−1 AgNP for 48 h. NP application had no remarkable effects on the accumulation of indigotin and indirubin in I. tinctoria shoots and I. ermenekensis roots compared to controls. Additionally, shoot cultures demonstrated superior indirubin production, which significantly increased with AgNP applications. The gene expression analysis also exhibited significant correlations with the changes in indigotin and indirubin levels. The findings of this study lay the groundwork for enhancing in vitro production of indigotin and indirubin in Isatis species through NP applications, and for developing high-capacity production strategies by determining optimal dosages in scale-up studies. [Display omitted] • AgNP and SA-CNP are effective for indole alkaloid biosynthesis. • Genes responsible for indole alkaloid biosynthesis were upregulated by NPs. • NPs increased indigotin and indirubin in parallel with It-TSA and CYP79B2 gene. • NPs are new alternative route for the production of indol alkaloids. • The effect of NPs differed in I. tinctoria and I. ermenekensis. [ABSTRACT FROM AUTHOR]

NAC (NAM, ATAF1/2 and CUC2) transcription factors (TFs) are a class of TFs families unique to plants, which not only play an important role in the growth and developmental stages of plants but also function in response to stress and regulation of secondary metabolite biosynthesis. However, there are few studies on NAC genes in the medicinal plant Isatis indigotica. In this study, 96 IiNAC genes were identified based on the whole-genome data of I. indigotica , distributed in seven chromosomes and three contigs. IiNAC genes were structurally conserved and divided into 15 subgroups. Cis -elements were identified in the promoter region of the IiNAC gene in response to plant growth and development, abiotic stresses and hormones. In addition, transcriptome and metabolome data of I. indigotica leaves under salt stress were analyzed to construct a network of IiNAC gene co-expression and metabolite association. Ten differentially expressed IiNAC genes were co-expressed with 109 TFs, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that most of these genes were associated with plant growth and development and abiotic stress responses. Eleven IiNAC genes were positively associated with 72 metabolites. Eleven IiNAC genes were positively or negatively associated with 47 metabolites through 37 TFs. Commonly associated secondary metabolites include two terpenoids, abscisic acid and bilobalide, two flavonoids, dihydrokaempferol and syringaldehyde, a coumarin, 7-methoxycoumarin, an alkaloid, lupinine, and quinone dihydrotanshinone I. This study provides important data to support the identification of the NAC gene family in I. indigotica and the regulatory functions of IiNAC genes in metabolites under salt stress. • A total of 96 IiNAC transcription factors were identified in Isatis indigotica and classified into 15 subfamilies. • The expression profile of the IiNAC genes under salt stress was established. • Construction of a co-expression network of IiNAC genes under salt stress • Establishment of a network for the regulation of metabolites by IiNAC and other transcription factors under salt stress [ABSTRACT FROM AUTHOR]

Greenhouse gases (GHGs, particularly carbon dioxide (CO 2 )) emissions from soil under wheat production are a significant source of agricultural carbon emissions that have not been mitigated effectively. A field experiment and a static incubation study in a lab were conducted to stimulate wheat growth and investigate its potential to reduce CO 2 emissions from soil through intercropping with a traditional Chinese medicinal herb called Isatis indigotica . This work was conducted by adding I. indigotica root exudates based on the quantitative real-time PCR (qPCR) analysis of the DNA copy number of the rhizosphere or bulk soil microbial populations. This addition was performed in relation to the CO 2 formation by cellulolytic microorganisms ( Penicillium oxalicum , fungi and Ruminococcus albus ) to elucidate the microbial ecological basis for the molecular mechanism that decreases CO 2 emissions from wheat fields using I. indigotica . The results showed that the panicle weight and full grains per panicle measured through intercropping with I. indigotica (NPKWR) increased by 39% and 28.6%, respectively, compared to that of the CK (NPKW). Intercropping with I. indigotica significantly decreased the CO 2 emissions from soil under wheat cultivation. Compared with CK, the total CO 2 emission flux during the wheat growth period in the I. indigotica (NPKWR) intercropping treatment decreased by 29.26%. The intensity of CO 2 emissions per kg of harvested wheat grain declined from 7.53 kg CO 2 /kg grain in the NPKW (CK) treatment to 5.55 kg CO 2 /kg grain in the NPKWR treatment. The qPCR analysis showed that the DNA copy number of the microbial populations of cellulolytic microorganisms ( P. oxalicum , fungi and R. albu s) in the field rhizosphere around I. indigotica or in the bulk soil under laboratory incubation was significantly lower than that of CK. This finding indicated that root exudates from I. indigotica inhibited the activity and number of cellulolytic microbial populations, which led to decreased CO 2 emissions, suggesting this plant's potential role in mitigating agricultural GHGs and in supporting agroecology. [ABSTRACT FROM AUTHOR]

Six new indole alkaloid sulfonic acids ( 1 – 6 ), together with two analogues ( 7 and 8 ) that were previously reported as synthetic products, were isolated from an aqueous extract of the Isatis indigotica root. Their structures including the absolute configurations were determined by spectroscopic data analysis, combined with enzyme hydrolysis and comparison of experimental circular dichroism and calculated electronic circular dichroism spectra. In the preliminary assay, compounds 2 and 4 showed antiviral activity against Coxsackie virus B3 and influenza virus A/Hanfang/359/95 (H3N2), respectively. [ABSTRACT FROM AUTHOR]

The root of Isatis tinctoria L. is highly appreciated as a Traditional Chinese herbal medicine for the prevention and adjuvant treatment of respiratory diseases caused by coronaviruses viruses such as SARS and COVID-19. I. tinctoria hairy root cultures (ITHRCs) provide a better alternative to field cultivation for the production of antiviral flavonoids. For the first time, ITHRCs were exposed to different colors of LED lights i.e. , red, green, blue, red/green/blue (1/1/1, RGB), and white, in an attempt to promote the root growth and enhance the production of bioactive flavonoids. Results revealed that the biomass productivity (7.15 ± 0.63 g/L) in ITHRCs with an initial inoculum size of 0.2% cultured for 50 days under blue light increased by 1.86-fold relative to that under dark (control), and yields of rutin (320.49 ± 27.56 μg/g DW), quercetin (388.75 ± 9.17 μg/g DW), kaempferol (787.90 ± 83.43 μg/g DW), and isorhamnetin (269.11 ± 20.08 μg/g DW) increased by 4.15-fold, 9.31-fold, 9.09-fold, and 2.88-fold as compared with control, respectively. Interestingly, the emergence of adventitious buds was noticed in ITHRCs under all light treatments. Additionally, the enhanced densities of chloroplasts and root hairs were found in blue-light grown ITHRCs as against control, which might account for the elevated biomass productivity. Moreover, blue light induced oxidative stress in ITHRCs in terms of the overproduction of oxidation products and the enhancement of antioxidant enzyme activity. Furthermore, blue light significantly activated photoreceptor (CRY1) and key regulator of light signaling (HY5), thus leading to the up-regulated expression of MYB4 and structural genes (such as CHS and FLS) responsible for flavonoid biosynthesis. And, the transcriptional activation of CUC1 was likely related to the formation of adventitious buds in ITHRCs. Overall, the simple supplementation of blue LED light makes ITHRCs more attractive as plant factories for obtaining higher productivity of biomass and medicinally important flavonoids. [Display omitted] • Blue light promoted morphogenesis and flavonoid synthesis in Isatis tinctoria hairy root cultures. • Flavonoid augmentation was a protective response to photooxidation under blue light. • CRY-mediated light signal transduction contributed to boosting flavonoid production. • CUC1 activation was likely to be correlated with the formation of adventitious buds. [ABSTRACT FROM AUTHOR]

Lignans are a major class of secondary metabolites distributed widely in the plant kingdom that are derived from coupling of phenylpropanoid (C6-C3) units. Most lignans are 8–8'-linked, and are often found in their glycosylated forms, which are catalyzed by UDP-dependent glycosyltransferase (UGT). Up to now, all UGTs involved in lignans biosynthesis are determined with substrate promiscuity. Here, IiUGT71B2 is reported from Isatis indigotica that specific catalyzes 4- O and 4′- O glycosylation of furan (lariciresinol) and dibenzylbutyrolactone (matairesinol) type lignans. Transcriptional profile of IiUGT71B2 indicates its involvement in lignan glycosides biosynthesis, which is co-expressed with other lignan biosynthetic genes, and is consistent with metabolic distribution of lignans in organs and tissues as well. Both in vitro and in vivo experiments demonstrate IiUGT71B2 catalyzes the mono- and di- glycosylation of lariciresinol and mono-glycosylation of matairesinol. The ligand docking and site-directed mutagenesis suggest Asn261, Ser289, Ala356, and Tyr395 as key residues, which may determine its catalytic efficiency together with the narrow binding pocket of IiUGT71B2. This study provides insights into lignan metabolism and functional diversity of plant UGTs. [Display omitted] • IiUGT71B2 specifically catalyzes glycosylation of lariciresinol and matairesinol. • The substrates promiscuity of lignan UGTs is driven by positive selection. • A precise metabolic distribution of lignans in roots section was visualized. [ABSTRACT FROM AUTHOR]

Nine tetrahydrofuran lignans, including three undescribed spiro-lignans, were isolated from Isatis indigotica Fortune (Brassicaceae). Extensive spectroscopic analyses achieved the structure elucidation of these tetrahydrofuran lignans, and quantum chemical calculation combined with the MAE ΔΔ δ parameter. Notably, isatispironeols A-B have a unique spiro[dienone-tetrahydrofuran] molecular core. These spiro[dienone-tetrahydrofuran] lignans showed comparable neuroprotective effects as the positive control in the H 2 O 2 -induced SH-SY5Y cells model. In addition, (−)-(7 R, 8 S, 1 ′R, 7 ′R, 8 ′R)-isatispironeol A possessed more significant AChE inhibitory activity, further interact sites were also predicted by the in silico assay. Nine tetrahydrofuran lignans, including three undescribed spiro-lignans, were isolated from Isatis indigotica Fortune (Brassicaceae). These undescribed spiro-lignans with a unique spiro[dienone-tetrahydrofuran] molecular core. [Display omitted] • Three undescribed spiro-lignans were isolated from Isatis indigotica Fortune. • The structure elucidation was achieved by quantum chemical calculation. • Isatispironeols A-B have a unique spiro[dienone-tetrahydrofuran] molecular core. • These spiro-lignans showed comparable neuroprotective effects. • (−)-isatispironeol A possessed greater AChE inhibitory activity. [ABSTRACT FROM AUTHOR]

The present work was undertaken to investigate chemical constituents and chemotaxonomic significance from the seeds of Raphanus sativus L. As a result, sixteen compounds including sinapoyl derivatives (1 – 7) and indoles (8 – 16) were yielded, and their chemical structures were elucidated by 1H NMR and 13C NMR spectroscopic methods, along with the comparison with relevant literature data. Of note, ethyl 2,3-dihydro-2-oxo-1H-indole-3-acetate (compound 11) was a new natural product. Three compounds (12 , 13 , and 16) were first isolated from the genus Raphanus ; while five compounds (5 , 9 , 10 , 14, and 15) were first reported from the family Brassicaceae. In addition, the chemotaxonomic significance of isolated compounds was also discussed. • One new natural product was unveiled in this work. • Five compounds were isolated from the family Brassicaceae for the first time. • Three compounds were first reported from the genus Raphanus. • The close relationship between Raphanus and Isatis species was revealed in chemotaxonomic investigation. [ABSTRACT FROM AUTHOR]

Adjuvants can enhance vaccine immunogenicity and induce long-term enhancement of immune responses. Thus, adjuvants are important for vaccine research. Polysaccharides isolated from select Chinese herbs have been demonstrated to possess various beneficial functions and excellent adjuvant abilities. In the present study, the polysaccharides IIP-A-1 and IIP-2 were isolated from Isatis indigotica root and compared with the common vaccine adjuvant aluminum hydroxide via intramuscular co-administration of inactivated rabies virus rCVS-11-G into mice. Blood was collected to determine virus neutralizing antibody (VNA) titers and B and T lymphocyte activation status. Inguinal lymph node samples were collected and used to measure B lymphocyte proliferation. Splenocytes were isolated, from which antigen-specific cellular immune responses were detected via ELISpot, ELISA and intracellular cytokine staining. The results revealed that both types of polysaccharides induce more rapid changes and higher VNA titers than aluminum hydroxide. Flow cytometry assays revealed that the polysaccharides activated more B lymphocytes in the lymph nodes and more B and T lymphocytes in the blood than aluminum hydroxide. Antigen-specific cellular immune responses showed that IIP-2 strongly induced T lymphocyte proliferation in the spleen and high levels of cytokine secretion from splenocytes, whereas aluminum hydroxide induced proliferation in only a small number of lymphocytes and the secretion of only small quantities of cytokines. Collectively, these data suggest that the polysaccharide IIP-2 exhibits excellent adjuvant activity and can enhance both cellular and humoral immunity. [ABSTRACT FROM AUTHOR]

Three pairs of enantiomerically pure alkaloids with diverse structure features, named isatindigoticoic acid A and epiisatindigoticoic acid A [( − )- 1 and (+)- 1 ], phaitanthrin A and epiphaitanthrin A [( − )- 2 and (+)- 2 ], and isatindopyrromizol A and epiisatindopyrromizol A [(−)- 3 and (+)- 3 ], respectively, were isolated from an aqueous extract of the roots of Isatis indigotica . Racemic and scalemic mixtures of these enantiomers were separated by HPLC on a chiral semi-preparative column. Their structures including absolute configurations were determined by extensive spectroscopic analysis in conjunction with the calculation of electronic circular dichroism (ECD) spectra. The enantiomer pairs possess parent structures of 2-oxo-1,2,3,4-tetrahydroquinoline-4-carboxylic acid, indolo[2,1- b ]quinazolinone, and 3-thioxohexahydro-1 H -pyrrolo[1,2- c ]imidazol-1-one, respectively. Except for phaitanthrin A [( − )- 2 ] which the configuration was previously undetermined, these compounds are new enantiomeric natural products. [ABSTRACT FROM AUTHOR]

Jasmonates (JAs) act as conserved elicitors of plant secondary metabolism. JAs perception triggers extensive transcriptional reprogramming leading to activation of the entire metabolic pathways. The family of basic helix-loop-helix (bHLH) transcription factors (TFs) has essential roles in JA signaling; however, little is known about their roles in regulation of secondary metabolites in Isatis indigotica . In this study, we identified 78 putative IibHLH sequences using the annotation of I. indigotica transcriptome. The identified proteins were characterized based on phylogenetic and conserved motif analyses. Using RNA sequencing, 16 IibHLHs showed significant positive response to MeJA (methyl jasmonate) at 1 h, indicating their roles as early signaling events of JA-mediated transcriptional reprogramming. Ten IibHLHs presented co-expression pattern with biosynthetic pathway genes, suggesting their regulating role in secondary metabolite synthesis. These gene expression profiling data indicate that bHLHs can be used as candidate genes in molecular breeding programs to improve metabolite production in I. indigotica . [ABSTRACT FROM AUTHOR]

Since ancient times, indigo has been one of the most widely used natural pigments for textile dyeing. In Europe, the only source of indigo dye was from woad (Isatis tinctoria). Woad leaves were processed to obtain an insoluble indigo pigment, which had to be reduced to leuco-indigo to dye textiles. Today, most indigo comes from the chemical industry, the production of which raises public health and ecological problems. For the past few years, renewed interest in natural pigments has led to the revival of I. tinctoria cultivation for indigo pigment production. However, the woad blue is still obtained with uncontrolled and inconsistent yields. The aim of the following paper is to provide an overview of what is known about the production of the woad blue pigment, from the leaves of I. tinctoria to its use as a dye, from medieval times to the present day. Despite numerous studies, the behaviour of the woad indigogenic precursors and the mechanisms leading to indigo formation remain unclear. • Overview of the indigo precursors from Isatis tinctoria. • Investigation of the indigo precursors variability within the plant and during harvesting. • Comparative review of traditional and modern indigo productions from Isatis tinctoria. • Recent advances on eco-sustainable indigo production and reduction for dyeing. [ABSTRACT FROM AUTHOR]

In order to promote the application of high-quality varieties and explore the diversity of cultivated resources of Isatis indigotica Fort., the source of medicinal Banlangen, 10 germplasms were planted in Heilongjiang (HLJ) and Shanxi (SX) provinces to analyze two-year agronomic traits, yields and active ingredient contents in this study. The results showed that germplasm no. 2 had the highest yields in both HLJ (236.54 kg/mu) and SX (368.68 kg/mu), and it had the highest Epigoitrin (RSG) content in HLJ in 2020 (0.8946 %). In addition, the polysaccharide (IRPS) content of germplasm no. 2 was the highest in HLJ (up to 39.100 mg/g), and ranked second in SX (30.767 mg/g). It was the only germplasm with IRPS content that exceeded 30 mg/g in both areas. The yield and RSG content of germplasm no. 6 was slightly lower than that of germplasm no. 2. The germplasms no. 2 and 6 had remarkable advantages in yield and active component content which were worthy of promotion as excellent cultivars in planting industry. Germplasm no. 5 and 10 had advantages in root width and IRPS content, respectively, which could be used as breeding germplasms. Screening germplasm with excellent traits and promoting its cultivation will help to ensure the quality stability of medicinal materials, and to improve economic efficiency of Banlangen production. [Display omitted] • Two high-yield and -quality Banlangen germplasms, no.2 and 6, were obtained. • One germplasm, no. 2, displayed high stress resistance. • Polysaccharides was stable in most germplasms while monosaccharide ratios varied. • Content of Epigoitrin environmentally varied highly in most germplasms. • Banlangen yield was significantly and positively correlated with lower root width. [ABSTRACT FROM AUTHOR]

Isatis indigotica Fortune is an herbaceous plant belonging to the Brassicaceae family, whose leaves and roots are rich in active compounds popularly used as natural dyes and/or for their pharmacological activity. Few studies are available on its seeds production and chemical composition. This study evaluated the seed yield and active compounds of I. indigotica Fortune (Chinese woad) with the aim to investigate its intra-species chemotypic, phenotypic and productive variations. A field experiment was carried out in Central Italy under Mediterranean climate, comparing four I. indigotica accessions. The plant phenological, morphological and productive characteristics (siliculas and seed yields) have been evaluated and the seeds analysed for fatty acid composition and glucosinolate patterns. The four accessions, grown as winter annual crop, showed similar phenological development but a different percentage of plants that turn to flower. All the genotypes showed good adaptability to the environmental conditions and good agronomical performances, with good siliculas yield (1.36 ± 0.08 t ha −1 ) and oil content (36.8 ± 0.82% w/w). Significant differences among the accessions were observed for the fatty acid and glucosinolate profiles. The oil was rich in mono- and polyunsaturated fatty acid (58% and 32% as mean value, respectively) with major differences for the oleic and α-linolenic acids. The erucic acid content ranged from 16 to 21%. In relation to the glucosinolates, the major differences were recorded for progoitrin, epi -progoitrin, gluconapin and glucobrassicin. The high polyunsaturated fatty acid concentration of I. indigotica seeds, together with its interesting glucosinolate content, open new perspectives for sustainable biobased production. [ABSTRACT FROM AUTHOR]

Land use optimization is a prerequisite for sustainable development, regardless the characteristics of the zone before and after industrial intervention. In order to determine the questions “what to do?” and “where should be done the proposed application?” multi-criteria analysis is used. Various algorithms, software, meteorological stations, satellite images, aerial photographs, sun-photometers and other instruments and equipment were employed in the studied area. For the purpose of this research, three variables were included in the Multi-criteria analysis: groundwater, evapotranspiration and subsurface models information. Those variables will determine if the land is desirable for agriculture, for forestry, or artificial wetlands purposes. The results show special need for developing artificial wetlands (42%), followed by Agriculture (23%) and Forestry (12%). The results for “Do Nothing” (23%) relate to the actual situation of the recovered zone after mining intervention with agriculture applications which had been proved to be successful in attaining Sustainable Development. [ABSTRACT FROM AUTHOR]

Isatis indigotica Fort. (Cruciferae) is a biennial medicinal plant. In order to protect the decreasing natural genetic resources of I. indigotica , three candidate DNA barcodes (ITS2, trnL-F and rbc L) were employed to establish an accurate and effective identification system for I. indigotica . The results demonstrated that all three candidate DNA barcodes have performed very well in I. indigotica . The interspecific genetic distances were obviously greater than the intraspecific distance among I. indigotica as indicated by ITS2, trnL-F and rbc L. Sequence alignment analysis of I. indigotica genotypes revealed that four SNPs (54, 108, 146 and 181 bp) located in ITS2, three (2, 30, 709 bp) in trnL-F and one (531 bp) in rbc L, respectively. UPGMA phylogenetic tree constructed from trnL-F and rbc L could allote I. indigotica to the correct corresponding genus, whereas rbc L could not distinguish I. indigotica from its adulterants. Meanwhile, UPGMA tree of ITS2 could accurately identify I. indigotica from its adulterants according to the corresponding species. Consequently, it can be concluded that ITS2 is a more suitable and accurate DNA barcode for identifying I. Indigotica and its adulterants than trnL-F and rbc L. [ABSTRACT FROM AUTHOR]

Highlights: [•] Spaceflight was an effective method to create new germplasm of Isatis indigotica. [•] Chemical changes of Isatis indigotica seeds after spaceflight were determined. [•] FTIR and 2DIR correlation spectroscopy were used in analysis. [•] Spaceflight caused chemical changes of Isatis indigotica seeds. [ABSTRACT FROM AUTHOR]

Abstract: In order to further exploit the by-products of Isatis indigotica Fort., the seed oil was studied for its extraction and physicochemical properties. Ultrasound-assisted extraction (UAE) was used, and the parameters affecting seed oil recovery were optimized through response surface methodology (RSM). The optimum conditions were as follows: solvent-to-sample, 24:1; particle size, 110 meshes; extraction temperature, 49°C; and extraction time, 44min. Which resulted in a maximum oil recovery of 81.20±0.21% (n =3). Furthermore, the effects of UAE on the yield, fatty acid compositions, physicochemical properties, and microstructure of the seed powder were also investigated by calculating the recovery rate, utilizing a gas chromatograph fitted with a mass spectrometer (GC–MS), and performing scanning electron microscopy, respectively. The results show that UAE was an effective method for the seed oil extraction and the high content of unsaturated fatty acids (93.81%) demonstrates the oil has potential benefits for the cosmetics, edible products, or pharmaceutical industries. [Copyright &y& Elsevier]

Abstract: Systematics of the genus Isatis (Brassicaceae) is difficult and controversial, and previous studies were based solely on morphological characters. Sequence variation of the internal transcribed spacer (ITS) regions and the 5.8S gene of nuclear ribosomal DNA (nrDNA) were analyzed using parsimony and Bayesian methods. Twenty-eight taxa of Isatis and related genera of the tribe Isatideae were sampled, including 20 Isatis species representing almost all major morphological lineages, all three species of Pachypterygium, two of nine species of Sameraria, and monospecific Boreava, Myagrum, and Tauscheria. Two well-supported clades were resolved in the ITS tree, and they demonstrate the artificiality of the present delimitation of the tribe. One clade includes I. emarginata, I. minima, I. trachycarpa, P. brevipes, P. multicaule, P. stocksii, and T. lasiocarpa. The second clade includes I. buschiana, the polymorphic I. cappadocica with five subspecies, I. gaubae, I. kotschyana, I. leuconeura, I. pachycarpa, I. takhtajanii, I. tinctoria, and S. armena. Pachypterygium is polyphyletic and, together with Boreava, Sameraria, and Tauscheria, all are nested within Isatis. This study is a continuation of our recent systematic survey based on seed-coat microsculpturing (. Flora 202, 447–454) and reveals that fruit characters mapped onto the molecular tree show considerable convergence. The reliance on fruit characters alone in the delimitation of genera may well lead to erroneous phylogenetic results and thus to incorrect taxonomic conclusions. [Copyright &y& Elsevier]

Abstract: Aim of the study: Isatis indigotica (I. indigotica), Cruciferae, has been used in Chinese medicine for anti-leukemia and anti-severe acute respiratory syndrome (SARS). The aim of this study was to evaluate the cytotoxicity of Isatis indigotica extracts on human leukemia cell line (HL-60) and the antiviral activity on swine pseudorabies virus (PrV) in in vitro assays. Materials and methods: Extracts and derived fractions of Isatis indigotica were prepared from root (R) and leaf (L) using methanol (M), ethyl acetate (E) and distilled water (D). The cytotoxic effect of extracts on swine peripheral blood mononuclear cells (PBMCs) and HL-60 was assessed by MTT method. The cytopathic effect (CPE) reduction, plaque reduction and inhibition assays on viral replication, and virucidal activity were further conducted to investigate the anti-PrV activity. Results: Indirubin, one of the biological active compounds of Isatis indigotica, had the most significant cytotoxicity on HL-60 cells and inhibitory effect on PrV replication. Extracts from roots and leaves of Isatis indigotica also presented CPE inhibition either before or after infection of PrV on porcine kidney (PK-15) cells. Leaf extracts had better virucidal activity than roots, and ethyl acetate extracts exhibited the highest efficacy among extracts tested. Conclusion: Isatis indigotica posses a valuable virucidal effect in disease control of pseudorabies virus infection in swine. [Copyright &y& Elsevier]

Abstract: A novel method based on ultra-performance liquid chromatography with photo diode array and electrospray ionization tandem mass spectrometry detection (UPLC-PDA-ESI-MS/MS) was developed for the qualitative and quantitative analysis of flavonoids in the leaves of Isatis indigotica Fort. (Daqingye). The separation was carried out on an Acquity UPLC BEH C18 column with 0.1% formic acid and methanol as the mobile phase under gradient conditions. Eight flavone C-glucosides were identified and their mass spectrometric fragmentation patterns were studied. Among them, the fragmentation pathways of three flavone 6-C-diglucosides with the rare 1→3 interglycosidic linkage were investigated for the first time. In addition, a quantitative analytical method for six flavone C-glucosides in Daqingye by UPLC-ESI-MS/MS was established and applied for the determination of commercial Daqingye samples from different resources. [Copyright &y& Elsevier]

Abstract: In order to examine the systematic application of seed-coat microsculpturing in Isatis, seed surfaces of 23 species (41 populations) in four genera of tribe Isatideae were examined using scanning electron microscopy (SEM). Eight types of basic ornamentation patterns were recognized among the studied specimens. Of these, the reticulate–areolate type was the most common and was found in the genera Isatis, Pachypterygium, Samerari and Tauscheria and 15 species (e.g., I. cappodocica, I. kotschyana and I. tinctoria). The reticulate type, the second most frequent, occurred in 7 species while other types each were represented by only one or 2 species. Although different populations of a given species show similar seed-surface sculpturing in most cases, in some polymorphic species like I. cappadocica and I. kotschyana these patterns were variable among populations. To some extent the variation corresponds to infraspecific taxa for some species, but the differences are not significant enough to be useful in the delimitation of the subspecies recognized by previous workers. Moreover, seed-coat characters do not support the separation of genera Isatis, Pachypterygium, Sameraria and Tauscheria. [Copyright &y& Elsevier]

Abstract: A rapid, selective, and sensitive LC-APCI-MS method is developed in this study for detecting and analyzing tryptanthrin, indigo, and indirubin in Daqingye and Banlangen, which are, respectively, the leaves and roots of Isatis indigotica and Strobilanthes cusia in traditional Chinese medicine. The detection of the three active components is linear in concentrations ranging from 100 to 1500ng/mL, the squared correlation coefficient is higher than 0.996, the precision as measured by the relative standard deviation is no larger than 9.5%, and the recovery is greater than 86.6%. The analysis of the 21 Banlangen samples led to considerably different conclusions on the contents of tryptanthrin, indigo, and indirubin in fresh leaves versus those in dried leaves. These results should shed some light on future plant selection and breeding. Compared with the traditional TLC and HPLC-UV methods, the new LC-APCI-MS approach has proven to be an optimal tool for detecting and analyzing the three marker compounds in the Chinese herbal medicines of Daqingye and Banlangen. [Copyright &y& Elsevier]

Abstract: The 3C-like protease (3CLpro) of SARS-coronavirus mediates the proteolytic processing of replicase polypeptides 1a and 1ab into functional proteins, becoming an important target for the drug development. In this study, Isatis indigotica root extract, five major compounds of I. indigotica root, and seven plant-derived phenolic compounds were tested for anti-SARS-CoV 3CLpro effects using cell-free and cell-based cleavage assays. Cleavage assays with the 3CLpro demonstrated that IC50 values were in micromolar ranges for I. indigotica root extract, indigo, sinigrin, aloe emodin and hesperetin. Sinigrin (IC50: 217μM) was more efficient in blocking the cleavage processing of the 3CLpro than indigo (IC50: 752μM) and beta-sitosterol (IC50: 1210μM) in the cell-based assay. Only two phenolic compounds aloe emodin and hesperetin dose-dependently inhibited cleavage activity of the 3CLpro, in which the IC50 was 366μM for aloe emodin and 8.3μM for hesperetin in the cell-based assay. [Copyright &y& Elsevier]

Abstract: The aim was to establish a method for extraction and chemical fingerprinting of extracts of Isatis indigotica roots (“Ban–Lan–Gen”) and to apply the method developed to 18 Ban–Lan–Gen samples. RP-HPLC with gradient elution was performed on authentic reference standards of powdered I. indigotica roots, indigotin and indirubin purchased from the National Institute for the Control of Pharmaceutical and Biological Products (NICPBP) of China. Eighteen “Ban–Lan–Gen” samples (including the reference powdered herb) were bought from Singapore and different regions in China. Comparisons of the chromatograms showed that the samples can be divided into three groups. The chromatograms of the extracts of five samples were found to be similar to that of the extract of the authentic sample. Eight other samples had similar peaks as the authentic sample but the intensities of the peaks were generally lower, except for the peaks between retention times of 10–40min. Peaks in these regions were more intense than those found in the extract of the authentic sample. Forty-five characteristic peaks could be found in the extracts of all the above samples. Peaks at retention times 52 and 53min were determined to be indigotin and indirubin, respectively. The remaining four samples had similar chemical fingerprints to each other but were different from that of the authentic sample. Hierarchical clustering analysis gave similar results as the visual comparison. The RP-HPLC method developed allows simple identification and comparisons of I. indigotica roots. This is the first report of hierarchical clustering analysis of I. indigotica root. [Copyright &y& Elsevier]

Abstract: The present phytochemical investigations of Isatis indigotica Fort. resulted in the isolation of seven lignans (1–7), three aromatic glycosides (8–10), three nucleosides (11–13) and two bis-indole alkaloids (14–15). Among them, compounds 5, 6 and 9 were obtained from this genus for the first time. The chemotaxonomic importance of these compounds was also summarized. [Copyright &y& Elsevier]

5-Hydroxyoxindole is a recently identified endogenous compound. Its physiological role remains unclear but certain evidence exists, that it may share some regulatory properties with isatin, a known endogenous inhibitor of monoamine oxidase (MAO) type B (MAO-B). In this study several oxidized indoles were tested for their in vitro inhibition of MAO type A (MAO-A) and B of rat brain non-synaptic mitochondria. 5-Hydroxyoxindole was less potent MAO-A inhibitor (ic50 56.8 μM) than isatin (31.8 μM) and especially 5-hydroxyisatin (6.5 μM), but it was the only highly selective MAO-A inhibitor among the all compounds studied (ic50 MAO-A:ic50 MAO-B=0.044). Thus, the in vitro data suggest that MAO-A may represent potential target for 5-hydroxyoxindole. [Copyright &y& Elsevier]

3-Methyleneoxindole is a cytotoxic metabolite of indole-3-acetic acid with potential for use in cancer therapy. This species and ring-substituted analogues are conveniently synthesised from the corresponding isatins via a Peterson olefination. [Copyright &y& Elsevier]