Metabolomics analysis reveals the metabolite profiles of Rheum tanguticum grown under different altitudinal gradients.

BACKGROUND: Plant growth and quality are often affected by environmental factors, including geographical location, climate, and soil. In this study, we describe the effect of altitudinal differences on the growth and active ingredients in Rheum tanguticum Maxim. ex Balf. (R. tanguticum), a traditional Chinese medicinal herb known for its laxative properties. RESULTS: The results showed that plants grown at lower altitudes had better growth performances than those in higher altitude areas. The yield varied by 2.45-23.68 times with altitude, reaching a maximum of 102.01 t/ha. In addition, total anthraquinone and total sennoside contents decreased with increasing altitude, whereas total tannins increased with increasing altitude. The total anthraquinone content of the indicator compound reached 5.15% at five experimental sites, which exceeded the Chinese Pharmacopoeia standard by 70.87%. The content of the other two categories of active ingredients reached a maximum value of 0.94% (total sennosides) and 2.65% (total tannins). Redundancy analysis revealed that annual rainfall, annual average temperature, annual sunshine hours, and pH significantly affected growth and active ingredients. Moreover, key metabolites, such as flavonoids, amino acids and their derivatives, phenolic acids, lipids, and terpenes, were differentially expressed between samples from low- and high-altitude cultivation areas. These metabolites were enriched in the flavonoid and flavonol biosynthetic pathway and the monoterpene biosynthetic pathway. CONCLUSIONS: These results suggest that high anthraquinone content was observed in the lowest-latitude cultivation area due to low rainfall and alkaline soil pH. Key metabolites were significantly upregulated in high-latitude cultivation areas. These results provide a scientific basis for quality control and the systematic cultivation of R. tanguticum.

DNA Interaction and Cleavage Modes of Anthraquinone-Fused Enediynes: A Study on Tiancimycins, Yangpumicins, and Their Semisynthetic Analogues.

Dynemicin A has been the sole prototypical anthraquinone-fused enediyne (AFE) explored since its discovery in 1989. This study investigates the distinct DNA binding and cleavage mechanisms of emerging AFEs, represented by tiancimycins and yangpumicins, along with semisynthetic analogues. Our findings reveal their potent cytotoxicity against various tumor cell lines, while 18-methoxy tiancimycin A treatment could significantly suppress breast tumor growth with minimal toxicity. One of the most potent AFEs, i.e., tiancimycin A, preferentially targets DNA sequences 5'-ATT, 5'-CTT, 5'-GAA, 5'-GAT, and 5'-TTA. Molecular dynamics simulations suggest that emerging AFEs intercalate deeper into AT-rich DNA base pairs compared to dynemicin A. Importantly, tiancimycin A may equilibrate between insertional and intercalative modes without deintercalation, enabling selective cleavage of T and A bases. This study underscores how subtle structural variations among AFEs significantly influence their DNA recognition and cleavage, facilitating future design of novel AFEs as potent and selective payloads for antibody-drug conjugates.

Morindone as a potential therapeutic compound targeting TP53 and KRAS mutations in colorectal cancer cells.

There is an increasing demand for anticancer agent in treating colorectal cancer (CRC) with frequently mutated TP53 and KRAS genes. Phytochemical compounds are suitable as chemoprevention for CRC since dietary factor is a major risk factor. Anthraquinones from Morinda citrifolia L. were previously reported with various pharmacological properties. Various in vitro experiments were conducted to investigate the effects of two anthraquinones: damnacanthal and morindone on the cell proliferation, cell cycle, apoptosis, gene expression and protein expression in two CRC cells: HCT116 and HT29. Real-time monitoring of CRC cells showed that both anthraquinones exerted significant anti-proliferative effects in a dose- and time-dependent manner. Next, cell cycle analysis revealed an increase in the percentage of CRC cells in the G1 phase under anthraquinones treatment. Fluorescence microscopy also showed an increment of apoptotic cells under anthraquinones' treatment. siRNA transfection was conducted to evaluate the mediating effect of gene knockdown on mutated TP53 and KRAS in CRC cells. Before transfection, qRT-PCR analysis showed that only morindone downregulated the gene expression of mutated TP53 and KRAS and then further downregulated them after transfection. Both damnacanthal and morindone treatments further downregulated the expression of these two genes but upregulated at the protein expression level. Furthermore, gene knockdown also sensitised CRC cells to both damnacanthal and morindone treatments, resulting in lowered IC50 values. The accumulation of cells at the G1 phase was reduced after gene knockdown but increased after damnacanthal and morindone treatments. In addition, gene knockdown has increased the number of apoptotic cells in both cell lines and further increment was observed after anthraquinone treatment. In conclusion, morindone could be a competitive therapeutic agent in CRC by exhibiting multiple mechanism of anti-cancer actions.

Thiadiazole-, selenadiazole- and triazole-fused anthraquinones as G-quadruplex targeting anticancer compounds.

G-quadruplex (G4) ligands attract considerable attention as potential anticancer therapeutics. In this study we proposed an original scheme for synthesis of azole-fused anthraquinones and prepared a series of G4 ligands carrying amino- or guanidinoalkylamino side chains. The heterocyclic core and structure of the terminal groups strongly affect on binding to G4-forming oligonucleotides, cellular accumulation and antitumor potency of compounds. In particular, thiadiazole- and selenadiazole- but not triazole-based ligands inhibit the proliferation of tumor cells (e.g. K562 leukemia) and stabilize primarily telomeric and c-MYC G4s. Anthraselenadiazole derivative 11a showed a good affinity to c-MYC G4 in vitro and down-regulated expression of c-MYC oncogene in cellular conditions. Further studies revealed that anthraselenadiazole 11a provoked cell cycle arrest and apoptosis in a dose- and time-dependent manner inhibiting K562 cells growth. Taken together, this work gives a valuable example that the closely related heterocycles may cause a significant difference in biological properties of G4 ligands.

Synthesis and antitumor activity of cyclopentane-fused anthraquinone derivatives.

In our pursuit of developing novel analogs of anthracyclines with enhanced antitumor efficacy and safety, we have designed a synthesis scheme for 4,11-dihydroxy-5,10-dioxocyclopenta[b]anthracene-2-carboxamides. These newly synthesized compounds exhibit remarkable antiproliferative potency against various mammalian tumor cell lines, including those expressing activated mechanisms of multidrug resistance. The structure of the diamine moiety in the carboxamide side chain emerges as a critical determinant for anticancer activity and interaction with key targets such as DNA, topoisomerase 1, and ROS induction. Notably, the introduced modification to the doxorubicin structure results in significantly increased lipophilicity, cellular uptake, and preferential distribution in lysosomes. Consequently, while maintaining an impact on anthracyclines targets, these novel derivatives also demonstrate the potential to induce cytotoxicity through pathways associated with lysosomes. In summary, derivatives of cyclic diamines, particularly 3-aminopyrrolidine, can be considered a superior choice compared to aminosugars for incorporation into natural and semi-synthetic anthracyclines or new anthraquinone derivatives, aiming to circumvent efflux-mediated drug resistance.

Antitumoral photoinduced effects of crude extract, fractions, and naphthoquinones from Sinningia magnifica (Otto & A. Dietr.) Wiehler (Gesneriaceae) in a bioguided study.

Photodynamic therapy (PDT) has been used for various purposes, including as an antitumor resource in a noninvasive therapy with minimal side effects. Sinningia magnifica (Otto & A. Dietr.) Wiehler is a rupicolous plant found in rock crevices in Brazilian tropical forests. Initial studies indicate the presence of phenolic glycosides and anthraquinones in species of the genus Sinningia (Generiaceae family). It is known that anthraquinones are natural photosensitizers with potential PDT applications. This led us to investigate the potential compounds of S. magnifica for use as a natural photosensitizer against the melanoma (SK-MEL-103) and the prostate cancer (PC-3) cell lines in a bioguided study. Our results showed that singlet oxygen production by the 1,3-DPBF photodegradation assay greatly increased in the presence of crude extract and fractions. The biological activity evaluation showed photodynamic action against melanoma cell line SK-MEL-103 and prostate cell line PC-3. These results suggest the presence of potential photosensitizing substances, as demonstrated in this in vitro antitumor PDT study by the naphthoquinones Dunniol and 7-hydroxy-6-methoxy-α-dunnione for the first time. Naphthoquinones, anthraquinones and phenolic compounds were identified in the crude extract by UHPLC-MS/MS analysis, motivating us to continue with the bioguided phytochemical study aiming to discover more photochemically bioactive substances in Gesneriaceae plants.

Cofactorless oxygenases guide anthraquinone-fused enediyne biosynthesis.

The anthraquinone-fused enediynes (AFEs) combine an anthraquinone moiety and a ten-membered enediyne core capable of generating a cytotoxic diradical species. AFE cyclization is triggered by opening the F-ring epoxide, which is also the site of the most structural diversity. Previous studies of tiancimycin A, a heavily modified AFE, have revealed a cryptic aldehyde blocking installation of the epoxide, and no unassigned oxidases could be predicted within the tnm biosynthetic gene cluster. Here we identify two consecutively acting cofactorless oxygenases derived from methyltransferase and α/ß-hydrolase protein folds, TnmJ and TnmK2, respectively, that are responsible for F-ring tailoring in tiancimycin biosynthesis by comparative genomics. Further biochemical and structural characterizations reveal that the electron-rich AFE anthraquinone moiety assists in catalyzing deformylation, epoxidation and oxidative ring cleavage without exogenous cofactors. These enzymes therefore fill important knowledge gaps for the biosynthesis of this class of molecules and the underappreciated family of cofactorless oxygenases.

Two new anthraquinone derivatives from Saprosma crassipes H. S. Lo.

Two new anthraquinone derivatives sapranquinones A and B (1 and 2) together with two known biogenetically related anthraquinone derivatives (3 and 4) were isolated from the stems of Saprosma crassipes H. S. Lo. The structures of these compounds were elucidated using comprehensive spectroscopic methods. Compounds 1-4 were evaluated for their antibacterial activities and compounds 1 and 3 had a broad spectrum antibacterial activity against Staphylococcus albus, Escherichia coli, Bacillus cereus, Micrococcus tetragenus, and Micrococcus luteus with MIC values ranging from 1.25 to 5 µg/mL.

Exploring natural anthraquinones as potential MMP2 inhibitors: A computational study.

OBJECTIVE: Matrix metalloproteinase-2 (MMP2) plays a significant role in cleaving extracellular matrix components, leading to many cancer cells' progression and invasion behavior. Therefore, MMP2 inhibition may hold promise for cancer treatment. Anthraquinones have shown antineoplastic effects, some of which have been used in clinical practice as anticancer drugs. This study used a computational drug discovery approach to assess the possible inhibitory effects of selected anthraquinones on MMP2. The results were then compared with that of Captopril, which was considered a standard drug. METHODS: This study used the AutoDock 4.0 tool to evaluate the binding affinity of 21 anthraquinones to the MMP2 catalytic domain. The most favorable scores based on the Gibbs free binding energy scores were given to the highest-ranked ligands. The Discovery Studio Visualizer tool illustrated interactions between MMP2 residues and top-ranked anthraquinones. RESULTS: A total of 12 anthraquinones were identified with ΔGbinding scores less than - 10 kcal/mol. Pulmatin (Chrysophanol-8-glucoside) was the most potent MMP2 inhibitor, with a ΔGbinding score of - 12.91 kcal/mol. This anthraquinone was able to restrict MMP2 activity within a picomolar range. CONCLUSION: MMP2 inhibition by anthraquinones, notably Pulmatin, may be a useful therapeutic approach for cancer treatment.

A Review on Bioactive Anthraquinone and Derivatives as the Regulators for ROS.

Anthraquinones are bioactive natural products, which are often found in medicinal herbs. These compounds exert antioxidant-related pharmacological actions including neuroprotective effects, anti-inflammation, anticancer, hepatoprotective effects and anti-aging, etc. Considering the benefits from their pharmacological use, recently, there was an upsurge in the development and utilization of anthraquinones as reactive oxygen species (ROS) regulators. In this review, a deep discussion was carried out on their antioxidant activities and the structure-activity relationships. The antioxidant mechanisms and the chemistry behind the antioxidant activities of both natural and synthesized compounds were furtherly explored and demonstrated. Due to the specific chemical activity of ROS, antioxidants are essential for human health. Therefore, the development of reagents that regulate the imbalance between ROS formation and elimination should be more extensive and rational, and the exploration of antioxidant mechanisms of anthraquinones may provide new therapeutic tools and ideas for various diseases mediated by ROS.

Quinones: Biosynthesis, Characterization of 13 C Spectroscopical Data and Pharmacological Activities.

Quinones are natural products widely distributed in nature, which are involved in stages of several vital biological processes, with mostly having a variety of pharmacological properties. The main groups comprising most of these compounds are benzoquinones, naphthoquinones, anthraquinones, and phenanthraquinones. Quinone isolation has been a focus of study around the world in recent years; for this reason, this study approaches the junction of natural quinones identified by 13 C Nuclear Magnetic Resonance (NMR) spectroscopic analytical techniques. The methodology used to obtain the data collected articles from various databases on quinones from 2000 to 2022. As a result, 137 compounds were selected, among which 70 were characterized for the first time in the period investigated; moreover, the study also discusses the biosynthetic pathways of quinones and the pharmacological activities of the compounds found, giving an overview of the various applications of these compounds.

TLC-MS-Bioautographic Identification of Antityrosinase Compounds and Preparation of a Topical Gel Formulation from a Bioactive Fraction of an RSM-Optimized Alcoholic Extract of Rubia Cordifolia L. stem.

BACKGROUND: Rubia cordifolia L., Rubiaceae, is globally reported to treat skin-related problems. The study aimed to assess the antityrosinase potential of Rubia cordifolia (ARC) and the development of gel formulation. METHODS: The AutoDock Vina (version V.1.2.0) program package was used for molecular docking to check for the binding affinity of ligands with protein. Response surface methodology (RSM) software was used to optimize extraction parameters for an alcoholic extract of Rubia cordifolia (ARC). The developed HPTLC method for the quantification of purpurin in ARC was validated as per the International Conference on Harmonization (ICH) guidelines. A bioautographic study for the evaluation of antityrosinase effects was performed; an anthraquinone-enriched fraction (AEF)-loaded gel formulation developed and evaluated physicochemically which could be used to reduce skin pigmentation. RESULTS: Purpurin showed optimum binding affinity (-7.4 kcal/mol) with the molecular target (tyrosinase) when compared to that of standard kojic acid (-5.3 kcal/mol). Quantification of purpurin in ARC, optimized by RSM software, was validated and physiologically significant results were observed for the antityrosinase potential of an AEF, along with TLC-MS-bioautographic identification for antityrosinase compounds: purpurin (m/z 256.21) and ellagic acid (m/z 302.19). Evaluation of an AEF-loaded gel formulation by in vitro and ex vivo permeation studies was performed. CONCLUSION: ARC extraction parameters optimized by RSM, and a bioautographic study helped identify antityrosinase compounds. The development of a gel formulation could be a cost-effective option for the treatment of depigmentation in the future. HIGHLIGHTS: A TLC-MS-Bioautography-based Identification of Antityrosinase Compounds and development of AEF-loaded Topical Gel formulation from a Bioactive Fraction of an RSM-Optimized Alcoholic Extract of Rubia Cordifolia L. stem, which could help with promising results in reducing skin pigmentation and maintaining even tone.

Normal and Aberrant Methyltransferase Activities Give Insights into the Final Steps of Dynemicin A Biosynthesis.

The naturally occurring enediynes are notable for their complex structures, potent DNA cleaving ability, and emerging usefulness in cancer chemotherapy. They can be classified into three distinct structural families, but all are thought to originate from a common linear C15-heptaene. Dynemicin A (DYN) is the paradigm member of anthraquinone-fused enediynes, one of the three main classes and exceptional among them for derivation of both its enediyne and anthraquinone portions from this same early biosynthetic building block. Evidence is growing about how two structurally dissimilar, but biosynthetically related, intermediates combine in two heterodimerization reactions to create a nitrogen-containing C30-coupled product. We report here deletions of two genes that encode biosynthetic proteins that are annotated as S-adenosylmethionine (SAM)-dependent methyltransferases. While one, DynO6, is indeed the required O-methyltransferase implicated long ago in the first studies of DYN biosynthesis, the other, DynA5, functions in an unanticipated manner in the post-heterodimerization events that complete the biosynthesis of DYN. Despite its removal from the genome of Micromonospora chersina, the ΔdynA5 strain retains the ability to synthesize DYN, albeit in reduced titers, accompanied by two unusual co-metabolites. We link the appearance of these unexpected structures to a substantial and contradictory body of other recent experimental data to advance a biogenetic rationale for the downstream steps that lead to the final formation of DYN. A sequence of product-forming transformations that is in line with new and existing experimental results is proposed and supported by a model reaction that also encompasses the formation of the crucial epoxide essential for the activation of DYN for DNA cleavage.

A New Bis-indole Alkaloid, Spermaocymine A, and an Anthraquinone from Spermacoce ocymoides.

A phytochemical study on Spermacoce ocymoides has led to the isolation of a novel bis-indole alkaloid, spermaocymine A (2), together with the known alkaloid 4-methyl-borreverine (1), as well as an anthraquinone, 8-hydroxy-2-(hydroxymethyl)-1-methoxyanthracene-9,10-dione (3). The structures of the isolated compounds were elucidated by analyzing spectroscopic and spectrometric data, including one-dimensional (1D)- and 2D-NMR and high resolution (HR)-MS. Newly isolated alkaloid 2 was a C-3,14-stereoisomer of 1, the first natural stereoisomer of related bis-indoles containing an indeno[1,2-b]indole skeleton with an epiminoethano bridge. When 1-3 were assayed against five tumor cell lines including multi-drug resistant cells, compound 1 exhibited potent antiproliferative activity with IC50 values of 6.2-11.5 µM.

Characterization and antimicrobial evaluation of anthraquinones and triterpenes from Rubia cordifolia.

Chemical investigation of roots of the plant, Rubia cordifolia Linn, led to the isolation of an undescribed anthraquinone, cordifoquinone R, determined as 1,2-dihydroxy-6-methoxyanthracene-9,10-dione (6) based on the 1D and 2D NMR analyses and HRESIMS. Ten other known compounds viz.1,4-dihydroxy-2-methoxyanthracene-9,10-dione (1), rubiadin (2), xanthopurpurin (3), 1-methoxy-3-hydroxy-2-carbomethoxy-9,10-anthraquinone (4), alizarin (5), ß-sitosterol glucoside (7), scopoletin (8), oleanolic acid, (9), pomolic acid (10), queretaroic acid (11) were also isolated. Out of these compounds, 4, 10, and 11 are first reported from this plant species. Compounds 2, 3, 6, 7, and 10 showed activity in the range of 16-32 µg/ml against S. aureus ATCC 29213.

Anthraquinone Removal from Cassia obtusifolia Seed Water Extract Using Baking, Stir-Frying, and Adsorption Treatments: Effects on the Chemical Composition, Physicochemical Properties of Polysaccharides, and Antioxidant Activities of the Water Extract.

Safety issues of the controversial anthraquinones from Cassia obtusifolia seed water extracts (CWEs) limit its application. This work aimed to remove the anthraquinones of CWEs by baking treatment (BT), stir-frying treatment (ST), and adsorption treatment (AT). Effects of these treatments on the chemical composition, physicochemical properties of polysaccharides, and antioxidant activities of CWEs were analyzed and compared. Results indicated that AT exhibited the best removal effect on the total anthraquinone among the three treatments. After AT, the contents of rhein, emodin, aloe-emodin, and aurantio-obtusin of the CWE were below the limit of detection. In addition, AT increased the contents of neutral sugars in CWEs in comparison to BT and ST. None of the treatments had an obvious influence on the structural characteristics of polysaccharides. However, AT decreased the antioxidant activity of CWEs due to their lower anthraquinone content. In summary, AT was considered as an efficient and simple method to remove anthraquinones, while retaining the features of polysaccharides.

Antiulcer Activity of Anthraquinone-Flavonoid Complex of Rumex tianschanicus Losinsk.

The composition of an ethanol extract from the roots of Rumex tianschanicus Losinsk of the Trans-Ili Alatau wild flora was studied in order to determine its antiulcer activity. The phytochemical composition of the anthraquinone-flavonoid complex from (AFC) R. tianschanicus revealed the presence of numerous polyphenolic compounds, the most abundant of which are anthraquinones (1.77%), flavonoids (6.95%), and tannins (13.39%). The use of column chromatography (CC) and thin-layer chromatography (TLC) in conjunction with UV, IR, NMR spectroscopy, and mass spectrometry data allowed the researchers to isolate and identify the major components of the anthraquinone-flavonoid complex's polyphenol fraction: physcion, chrysophanol, emodin, isorhamnetin, quercetin, and myricetin. The gastroprotective effect of the polyphenolic fraction of the anthraquinone-flavonoid complex (AFC) of R. tianschanicus roots was examined in an experimental model of rat gastric ulcer induced by indomethacin. The preventive and therapeutic effect of the anthraquinone-flavonoid complex at a dose of 100 mg/kg was analyzed using intragastric administration per day for 1 to 10 days, followed by a histological examination of stomach tissues. It has been demonstrated that prophylactic and prolonged use of the AFC R. tianschanicus in laboratory animals resulted in significantly less pronounced hemodynamic and desquamative changes in the epithelium of gastric tissues. The acquired results thus offer fresh insight into the anthraquinone and flavonoid metabolite component composition of R. tianschanicus roots, and they imply that the examined extract can be used to develop herbal medicines with antiulcer activity.

A discrete intermediate for the biosynthesis of both the enediyne core and the anthraquinone moiety of enediyne natural products.

The enediynes are structurally characterized by a 1,5-diyne-3-ene motif within a 9- or 10-membered enediyne core. The anthraquinone-fused enediynes (AFEs) are a subclass of 10-membered enediynes that contain an anthraquinone moiety fused to the enediyne core as exemplified by dynemicins and tiancimycins. A conserved iterative type I polyketide synthase (PKSE) is known to initiate the biosynthesis of all enediyne cores, and evidence has recently been reported to suggest that the anthraquinone moiety also originates from the PKSE product. However, the identity of the PKSE product that is converted to the enediyne core or anthraquinone moiety has not been established. Here, we report the utilization of recombinant E. coli coexpressing various combinations of genes that encode a PKSE and a thioesterase (TE) from either 9- or 10-membered enediyne biosynthetic gene clusters to chemically complement ΔPKSE mutant strains of the producers of dynemicins and tiancimycins. Additionally, 13C-labeling experiments were performed to track the fate of the PKSE/TE product in the ΔPKSE mutants. These studies reveal that 1,3,5,7,9,11,13-pentadecaheptaene is the nascent, discrete product of the PKSE/TE that is converted to the enediyne core. Furthermore, a second molecule of 1,3,5,7,9,11,13-pentadecaheptaene is demonstrated to serve as the precursor of the anthraquinone moiety. The results establish a unified biosynthetic paradigm for AFEs, solidify an unprecedented biosynthetic logic for aromatic polyketides, and have implications for the biosynthesis of not only AFEs but all enediynes.

Soluble Protein Content, Bioactive Compounds and the Antioxidant Activity in Seeds of Ten Rheum tanguticum Lines from Qinghai-Tibet Plateau.

Rheum tanguticum (Rh. tanguticum) is a Chinese medicinal plant traditionally used in the treatment of constipation. As a byproduct, the seeds of this plant are rich in nutrients and phytochemicals. This study aimed to determine and assess seed germination ability, seed physical characteristics, soluble protein content, chemical constituents and antioxidant capacity from different breeding lines, to promote the development and utilization of seed resources. Significant differences were observed for the soluble protein content and antioxidant assays among the ten lines. The contents of aloe-emodin, rhein and catechins accumulated in seeds were extremely low and significantly different from those in roots. In contrast, emodin and chrysophanol were abundant in seeds, and significant differences were observed between seeds and roots. It was found that associations between gallic acid and catechins were not significant for either soluble protein or antioxidant capacity. There was a significantly positive correlation between the contents of four anthraquinones (aloe-emodin, rhein, emodin and chrysophanol) and soluble protein. Seeds have potent antioxidative capacity and relatively high levels of soluble protein content. The rich chemical composition of seeds can be widely used in the medical industry for further development.

Production of anthraquinones from cell and organ cultures of Morinda species.

Since ancient times, Morinda species, particularly Morinda citrifolia, have been used for their therapeutic benefits. Iridoids, anthraquinones, coumarins, flavonoids, lignans, phytosterols, and carotenoids are examples of natural substances with bioactivity. Anthraquinone derivatives are the most significant of these chemicals since they are utilized as natural coloring agents and have a wide range of medicinal functions. Utilizing cell and organ cultures of Morinda species, various biotechnological methods have been developed for the bioproduction of anthraquinone derivatives. The generation of anthraquinone derivatives in cell and organ cultures is summarized in this article. The methods used to produce these chemicals in bioreactor cultures have also been examined. KEY POINTS: • This review investigates the potential of cell and organ cultures for anthraquinone synthesis. • The overproduction of anthraquinones has been addressed using a variety of techniques. • The use of bioreactor technologies for anthraquinone manufacturing is highlighted.