Search

Two new bisanthraquinones, glabraquinone A and B (1–2) were isolated from the root of Prismatomeris glabra (Korth.) Valeton. In addition to the new glabraquinones, six known anthraquinones, that is, 1-hydroxy-2-methoxy-6-methylanthraquinone (3), 1,2-dimethoxy-7-methylanthraquinone (4), lucidin (5), nordamnacanthal (6), damnacanthal (7) and 2-carboxaldehyde-3-hydroxyanthraquinone (8)) and an aromatic compound, that is, catechol diethyl ether (9) were isolated and characterized in this study. Compounds 1, 4 and 9 showed mild activity, reducing N2A cell viability to 77%, 82% and 77%, respectively, in anti-neuroblastoma assay. [ABSTRACT FROM AUTHOR]

Chemical investigation of the extracts obtained from the red thallus tips from Cetraria laevigata resulted in the isolation of five known quinoid pigments identified by FT-IR, UV, NMR, MS methods and by comparison with literature data (skyrin (1), 3-ethyl-2,7-dihydroxynaphthazarin (2), graciliformin (3), cuculoquinone (4) and islandoquinone (5)). An antioxidant capacity of compounds 1–5 were evaluated and compared with quercetin using a lipid peroxidation inhibitory assay and superoxide radical (SOR), nitric oxide radical (NOR), 1,1-diphenyl-2-picrylhydrazine (DPPH), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) scavenging assays. Compounds 2, 4 and 5 were far more active: they demonstrated the antioxidant capacity in various test assays with the IC50 values 5–409 µM comparable to the flavonoid quercetin. While, the isolated quinones (1–5) exhibited weak cytotoxicity in human cancer cell line A549 assessed by MTT assay. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the rhyzomes of Rumex abyssinicus (Polygonaceae) afforded six anthraquinones viz chrysophanol (1), physcion (2), emodin (3), mixture of physcion-8-O-β,D-glucopyranoside (4) and chrypsophanol-8-O-β,D-glucopyranoside (5), and emodin-8-O-β,D-glucopyranoside (6). All the compounds were characterised and identified by comparison of their MS and NMR data with available literature data. The isolated compounds were evaluated for their antileishmanial activity. Emodin (3) was the most active compounds with IC50 13.82 and 0.26 µg/mL against Leishmania donovani amastigotes and promastigotes, respectively. Emodin-8-O-β,D-glucopyranoside (6) also showed a moderate activity with IC50 27.53 and 37.08 µg/mL. This is the first report of antileishmanial compounds from R. abyssinicus and the antileishmanial activities of compounds 2, 4, 5 and 6 are here reported for the first time. [ABSTRACT FROM AUTHOR]

The phytochemical investigation on the fruits of Morinda citrifolia led to the isolation and characterization of a new anthraquinone, moricitrifone (1), along with seven known anthraquinones (2–8). The chemical structure of 1 was elucidated by extensive spectral analyses. The known compounds (2–8) were identified by comparing their spectral data with those reported in the literature. The antiproliferative activities of all isolated anthraquinones (1–8) against five human cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7 and SW480 were evaluated in vitro. Compounds 1–8 exhibited remarkable antiproliferative activities with IC50 values ranging from 0.26 ± 0.05 to 16.58 ± 0.18 μM, which were comparable to those of doxorubicin. [ABSTRACT FROM AUTHOR]

A new anthraquinone, asperquinone A (1), and four known anthraquinone derivatives 2–5 were isolated from the mangrove endophytic fungus Aspergillus sp. 16-5C. These structures were elucidated by spectroscopic analysis and the absolute configuration of 1 was unambiguously determined by ECD calculation. Compounds 1–5 showed no significant inhibitory effect against Mycobacterium tuberculosis protein tyrosine phosphatase B (MptpB). [ABSTRACT FROM AUTHOR]

Anthraquinones (AQ), unveiling large structural diversity, among polyketides demonstrate a wide range of applications. The hydroxy anthraquinones (HAQ), a group of anthraquinone derivatives, are secondary metabolites produced by bacteria and eukaryotes. Plant-based HAQ are well–studied unlike bacterial HAQ and applied as herbal medicine for centuries. Bacteria are known to synthesize a wide variety of structurally diversified HAQ through polyketide pathways using polyketide synthases (I, II & III) principally through polyketide synthase-II. The actinobacteria especially the genus Streptomyces and Micromonospora represent a rich source of HAQ, however novel HAQ are reported from the rare actinobacteria genera (Salinospora, Actinoplanes, Amycoloptosis, Verrucosispora, Xenorhabdus, and Photorhabdus. Though several reviews are available on AQ produced by plants and fungi, however none on bacterial AQ. The current review focused on sources of bacterial HAQ and their structural diversity and biological activities along with toxicity and side effects. [ABSTRACT FROM AUTHOR]

One new anthraquinone, questinlin (1), four known anthraquinones (2–5), together with three known benzophenone derivatives (6–8) were isolated from a wetland fungus Aspergillus flavipes PJ03-11. Their structures were elucidated on the basis of detailed spectroscopic analysis, including 1D, 2D NMR (HMQC, HMBC), mass spectrometry, and optical rotation and IR spectra. In addition, the cytotoxic activities against three human cancer cell lines (HepG2, Caco-2 and A549) were evaluated. In this article, Aspergillus flavipes PJ03-11, a wetland soil fungus isolated from Honghaitan, Panjin city, Liaoning province, was used to study the secondary metabolites through one strain many compounds (OSMAC) methods. By changing the culture medium and adding the substance stimulating the metabolism of the strain into the fermentation medium, the peak type and amount of ethyl acetate extract in the fermentation medium were studied by HPLC. Finally, 2 mM MgCl2 was added into the rice solid medium for the expansion fermentation. [ABSTRACT FROM AUTHOR]

Three new isochroman derivatives, penicitrisochromans A-C ( 1 - 3 ), together with 25 known polyketides were isolated from the marine-derived fungus Penicillium citrinum PSU-MF100. Their structures were elucidated by extensive spectroscopic analysis. The absolute configurations of 1 and 2 were established by comparison of specific rotations and electronic circular dichroism (ECD) data with those of the known co-metabolite whereas those of 3 were assigned based on the ECD calculation and biosynthetic consideration. Among the isolated polyketides, three known anthraquinone derivatives, ω -hydroxyemodin, penicillanthranin A and emodin, displayed moderate to strong antibacterial activity against methicillin-resistant Staphylococcus aureus with MIC values of 32, 16 and 4  µ g/mL, respectively. For antifungal activity, two known benzopyranones, coniochaetones A and C, exhibited moderate antifungal activity against Candida albicans NCPF3153 and Cryptococcus neoformans ATCC90112 with the respective MIC values of 16 and 64  µ g/mL.

This paper investigates the optimum processing conditions of microwave assisted extraction (MAE) of anthraquinone (aloe emodin, AE) and flavonoids (kaempferol 3-gentiobioside, K3G and kaempferol, KA) from Senna alata (L.) Roxb. The kinetic study indicates that MAE showed a greater extraction rate, compared to ultrasonic-assisted and maceration, due to the enhanced power which altered the leaf microstructures. The optimisation was undertaken using one-factor-at-a-time, two-level factorial design and central composite design were used to maximise the yield of the target compounds. The optimum yield of K3G (4.27 mg/g DW), KA (8.54 mg/g DW) and AE (0.86 mg/g DW) was obtained at 90.5% ethanol, microwave power of 18.6 W/mL with a desirability of 0.82. In addition, the yield of K3G and KA is correlated positively with the antioxidant activity. [ABSTRACT FROM AUTHOR]

Three glycosylated stilbenes (1–3), two anthraquinones (4, 5), one lignan (6), five tannins (7–11), two amino acids (12, 13), and one auronol (14) were isolated from the root of Ampelopsis japonica. All compounds, except for 4, 6, and 11 were obtained from this species for the first time. Compounds 6–9 could notably inhibit ROS generations in HaCaT keratinocyte cells with IC50 values of 5.28, 4.83, 0.87, and 1.66 μM, respectively. Compounds 8–10 showed potent DPPH free radical scavenging effects with IC50 values of 14.37, 16.08, and 12.11 μM, individually. In anti-melanogenesis assay, only 8 and 9 could decrease 7.93% and 11.66% melanin contents induced by α-MSH in B16F10 melanoma cells at 40 μM and moderately inhibit tyrosinase activities. By far, galloylhamameloses 8 and 9 were found to exhibit both antioxidant and anti-melanogenesis properties that could be further developed as cosmeceutical agents for skin disorders. [ABSTRACT FROM AUTHOR]

Vismia gracilis extracts were tested against Aedes aegypti to assess mortality and behavioural effects. The leaf hexanic extract (L-Hex) presented increased larvicidal activity with exposure period: LC50 46.48 µg/mL (24 h) and LC50 20.57 µg/mL (48 h). Eight compounds were annotated/isolated from the L-Hex active extract, 4 benzophenones and 4 anthraquinones. Considering chemometric findings, the benzophenone moiety, tested as the commercial benzophenone, promoted larval mortality (LC50 16.35 µg/mL). Both the L-Hex extract and benzophenone induced intestinal damage in larvae. Benzophenone also promoted toxicity and behavioural effects in female adults. These findings highlighted the potential use of this class of compounds for developing vector-control products. [ABSTRACT FROM AUTHOR]

Chemical investigation of the chloroform extract of heartwood of Tectona grandis L. f. led to the isolation of three new naphthoquinone derivatives, tectonaquinones A (1), B (2) and C (3), along with six known compounds: barleriaquinone-I (4), tectoquinone (5), tecomaquinone I (6), lapachol (7), obtusifolin (8) and 2-hydroxy-3-methyl anthraquinone (9). The structures of the new compounds were elucidated by spectroscopic methods including 2 D NMR experiments. Tectonaquinone B is the first natural compound that has a hexa-cyclic dinaphthofuran-dione scaffold. Tectonaquinone C has a bicyclic acetal motif that is unusual in nature. [ABSTRACT FROM AUTHOR]

7-Methyl juglone as a naturally occurring naphthoquinone showed striking antibacterial, antifungal, antivirus and anticancer activity. Its derivatives had also been characterized as key intermediates in the preparation of natural naphthoquinones and anthraquinones. Herein, we reported a regioselective synthesis of 7-methyl juglone via the construction of fused polycyclic systems. The key steps of the strategy involved Stobbe condensation of 2,5-dimethoxy benzaldehyde with diethyl succinate, intramolecular cyclization, reduction, acid-facilitated debenzylation and further cerium(IV) ammonium nitrate-mediated oxidation. Compared with the reported methods employing Birch conditions in liquid ammonia or Friedel-Crafts cycloacylation with melting heat of aluminum salts, the reaction conditions in the new synthetic route were milder and suitable for large scale preparations. In addition, all of the starting materials in the synthesis were readily available. It has great implications for the design and synthesis of structurally asymmetric naphthoquinones derivatives. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the roots of Morinda coreia led to the isolation of one new bianthraquinone, morindaquinone (1), together with 12 known compounds, soranjidiol (2), rubiadin-1-methyl ether (3), 2-methoxy-1,3,6-trihydroxyanthraquinone (4), 1-hydroxy-2-methylanthraquinone (5), tectoquinone (6), nordamnacanthal (7), damnacanthal (8), 2-formylanthraquinone (9), 3-hydroxy-2-hydroxymethylanthraquinone (10), lucidin-ω-methyl ether (11), scopoletin (12) and (+)-mellein (13). The structures of these compounds were determined on the basis of extensive spectroscopic analyses, as well as by comparison with literature reports. Compound 1 was the first example of bianthraquinone found in the genus Morinda, whereas compound 13 was firstly isolated from this genus. Among them, compounds 2, 7, 8 and 10 exhibited moderate to weak cytotoxicity against human cervical (HeLa), human colon (HT 29) and human breast (MCF-7) cell lines, while compounds 6 and 9 – 11 showed weak anti-acetylcholinesterase activity. [ABSTRACT FROM AUTHOR]

Six new anthraquinones named lasianthuoside F (1), G (2), H (3), I (4), J (5), K (6) were isolated from an acetone extract of the root of Lasianthus acuminatissimus. Their structures were elucidated by physical and chemical evidence and spectral analysis. [ABSTRACT FROM AUTHOR]

Two new bis anthraquinones, glabraquinone A and B ( 1 - 2 ) were isolated from the root of Prismatomeris glabra (Korth.) Valeton. In addition to the new glabraquinones, six known anthraquinones, that is, 1-hydroxy-2-methoxy-6-methylanthraquinone ( 3 ), 1,2-dimethoxy-7-methylanthraquinone ( 4 ), lucidin ( 5 ), nordamnacanthal ( 6 ), damnacanthal ( 7 ) and 2-carboxaldehyde-3-hydroxyanthraquinone ( 8 )) and an aromatic compound, that is, catechol diethyl ether ( 9 ) were isolated and characterized in this study. Compounds 1 , 4 and 9 showed mild activity, reducing N2A cell viability to 77%, 82% and 77%, respectively, in anti-neuroblastoma assay.

Rumex lunaria L. is a Canarian medicinal plant, belonging to Polygonaceae. The potential antidiabetic activity of the methanolic extract of the leaves was investigated. For this purpose, the inhibition of α-glucosidase and albumin glycation by the extract was studied. Further, the anti-radical activity and the phytochemical composition were detected. The reduction of α-glucosidase activity was significant from 3 µg/mL, while the BSA glycation inhibition started from 100 µg/mL. Moreover, the extract exhibited a significant free-radical scavenger activity. Its phytochemical characterization showed the presence of carotenoids, phenolic and flavonoid compounds, whereas anthraquinones were not detected. C-flavonoid glycosides were identified and quercetin-O-hexoside-O-deoxyhexoside was the most detected (22.67 ± 0.02 mg/g). The findings indicate that the methanolic R. lunaria leaf extract has significant anti-α-glucosidase, anti-radical and anti-glycation activities. This research is the first showing the potential antidiabetic activity of R. lunaria. [ABSTRACT FROM AUTHOR]

The aim of this work is to characterize the active constituents present in the ethyl acetate fraction of Senna tora, L. Roxb. seeds. Due to the fact that the main biological activity of S. tora, L seeds is attributed to its phenolic compounds which are mainly isolated from Ethyl acetate fraction, to avoid repetition of work and to save time, it was deemed necessary to confirm the identity of these phenolic compounds. This was done by GC-MS and LC-MS analysis of the ethyl acetate fraction where the structures of the isolated compounds were established on the basis of molecular ion peak and their fragmentation pattern. They were identified as Chrysophanol, Chrysarobin, 10-hydroxy-5-methoxy-2-methyl-1, 4-anthracenedione, Rubrofusarin, Parietin, Griseoxanthone-B, Isotorachrysone, and Cumbiasin B. [ABSTRACT FROM AUTHOR]

Tectona grandis Linn (Teak), is locally known as Sagwan, belongs to Lamiaceae family. It is one of the most valuable timber in the world, due to its beautiful surface and its resistance to termite and fungal damage. The main active ingredient compounds that are responsible for these action are tectoquinone, lapachol and deoxylapachol. Naphthoquinones, anthraquinones and isoprenoid quinones are abundant metabolites in teak. In addition to these, teak contains several other phytochemicals such as triterpenoids, steroids, lignans, fatty esters and phenolic compounds. Pharmacologically, the plant has been investigated for antioxidant, anti-inflammatory, anti-pyretic, cytotoxic, analgesic, hypoglycemic, wound healing and antiplasmodial activities. The present review highlights the phytochemical and pharmacological aspects of teak. [ABSTRACT FROM AUTHOR]

Three new anthraquinones, lasianthurin B (1), C (2), lasianthuoside D (3), a new benzochromene, lasianthurin D (4), and a new furfural glycoside, lasianthuoside E (5), together with one known compound 4- hydroxymethyl-2-furaldehyde (6) were isolated from an alcohol extract of the root of Lasianthus acuminatissimus. Their structures were elucidated on the basis of extensive spectroscopic data analysis (including 1D, 2D NMR, X-ray, and MS experiments) and comparsion to literature data. [ABSTRACT FROM AUTHOR]

A new anthraquinone, altermodinacid A ( 1 ), and five known derivatives, pachybasic acid ( 2 ), emodic acid ( 3 ), emodin ( 4 ), phomarin ( 5 ), and 1,7-dihydroxy-3-methylanthracene-9,10-dione ( 6 ), were discovered from a halotolerant fungus Alternaria sp. X112 isolated from a marine fish Gadus macrocephalus . Their structures were determined by analysing MS and NMR data. The cytotoxic effect, antiagricultural pathogens activity, antibacterial activity and quorum sensing inhibitory potential of new compound 1 were evaluated.

A new anthraquinone, morinquinone, together with 18 known anthraquinones were isolated from the stems ofMorinda ellipticaRidl. Their structures were elucidated on the basis of spectroscopic data. They each showed weak inhibitory activity against a susceptible strain ofStaphylococcus aureusand a methicillin-resistantS. aureus. Damnacanthal was effective againstMicrosporum gypseum(MIC 1 μg/mL). Lucidin was active againstEntamoeba histolytica(MIC 31.25 μg/mL) andGiardia intestinalis(MIC 7.8 μg/mL). [ABSTRACT FROM PUBLISHER]

As a continuation of our ongoing studies aimed to reveal the presence of oxyprenylated anthraquinones in plants claimed to have a laxative effect, in this article, we describe the extraction and HPLC separation of madagascin (3-isopentenyloxyemodin) and 3-geranyloxyemodine from dried leaves and fruits of Senna alexandrina Mill. (Leguminosae) and leaves and gel of Aloe vera (L.) Burm. F. (Xanthorrhoeaceae). Both compounds are described herein for the first time as components of extracts of the title plants. [ABSTRACT FROM AUTHOR]

Eight anthraquinones (1–8), three xanthones (11–13) and two phenols (9–10) were isolated fromAspergillussp. associated withPanax notoginseng, and their structures were determined as ziganein-1-methyl ether (1), 8-O-methylchrysophanol(2), averythrin (3), averufin (4), 8-O-methyl averufin (5), versicolorin B (6), averantin (7), methyl-averantin (8), arugosin C (9), diorcinol (10), sterigmatocystin (11), demethylsterigmatocystin (12) and dihydrosterigmatocystin (13) by spectroscopic analyses. Compounds1,2and5were the novel isolates from genusAspergillus. Compounds3,6and7exhibited antifungal activity againstFusariumsolani, pathogenic fungus ofP. notoginseng, with minimum inhibitory concentrations (MICs) of 16–32 μg/mL, and compounds1,3,4,7and9showed antibacterial activity againstBacillussubtiliswith MICs of 64–128 μg/mL, 16–32 μg/mL, 8–16 μg/mL, 16–32 μg/mL and 64–128 μg/mL, respectively. The metabolites showed the potential value in the research of antifungal agents, especially in searching for a biocontrol of diseases ofP. notoginseng. The preliminary structure–activity relationships have been discussed for some of the compounds. [ABSTRACT FROM PUBLISHER]

Phytochemical study of the aerial parts of Cassiaitalica Mill. (family: Fabaceae) growing in Saudi Arabia afforded one new cycloartane triterpene, named (22E)-3-β-hydroxycycloart-22-en-24-one (2), together with eight known compounds: β-sitosterol (1), uvaol (3), daucosterol (4), methyl 3,4-dihydroxybenzoate (5), emodin (6), 4-hydroxypheny-O-β-D-glucopyranoside (7), aloin (8) and rutin (9). The structure of the isolated compounds was determined by physical, chemical and spectral data (UV, IR, MS, 1D (1H, 13C and DEPT) and 2D (1H–1H COSY, HSQC and HMBC) NMR), as well as by comparing with authentic samples. Compounds 3–5 and 7–9 were isolated for the first time from the plant. Compound 2 was evaluated for its cytotoxic activity against the L5178Y and PC12 cell lines. The total methanolic extract and compounds 5–9 exhibited free radical-scavenging activity using DPPH assay. [ABSTRACT FROM AUTHOR]

Thielavia species (Chaetomiaceae) are a wealthy source of enzymes such as laccases, cutinases, glucuronoyl esterases, feruloyl esterases, 1,4-β-endoglucanase and lytic polysaccharide monooxygenases that reported to have various biotechnological and industrial applications in dye decolorization, bio-refinery, biomass utilization, ester biosynthesis and biodegradation. Different metabolites have been reported from this genus as depsides, azaphilones, pyrazines, naphthodianthrones and anthraquinones derivatives. These metabolites have attracted research interest due to their fascinating structures and diverse bioactivities, including antimicrobial, cytotoxic, antioxidant, anti-diabetic, and superoxide anion generation, phospholipase, prostaglandins synthesis and proteasome inhibitory activities. Therefore, these compounds can be taken into account as candidates for the development of effective and novel pharmaceutical leads. The current review represents the relevant information for the Thielavia genus, in particular, its phytoconstituents and their pharmacological activities, as well as the biotechnological applications of Thielavia species published from 1981 till now. More than 40 metabolites are described and - 71 references are cited. [Formula: see text].

A new chromone, 5,7-dihydroxy-2 -(hydroxymethyl)-6,8-dimethyl-chromen-4-one, named melachromone, together with 12 known compounds, including chromones, anthraquinone, flavonoids, flavonoid glycosides, benzene derivatives, ellagic acids and terpenes, were isolated from the leaves ofMelaleuca cajuputiPowell. Their structures were characterised by spectroscopic methods. [ABSTRACT FROM PUBLISHER]

The aim of this study was to evaluate the anxiolytic-like effect of chrysophanol (CHRY), isolated from hexane extract of Senna cana stem and its possible mechanism of action. CHRY was obtained through chromatographic treatments and its identity was confirmed by uni and bidimensional RMN 1 H and RMN 13 C. Adult zebrafish (n = 6/group) were treated (with CHRY (4.0 or 12.0 or 40.0 mg/Kg; 20 µL; intraperitoneally) and submitted to acute toxicity and open field tests. Subsequently, other groups (n = 6/each) received CHRY for the analysis of its effect on the Light & Dark Test. The participation of the GABAergic system was also assessed using the diazepam (GABA A receptor agonist) and flumazenil (GABA A receptor antagonist). CHRY was considered non-toxic, it did not reduce the locomotor activity, and showed an anxiolytic-like effect. This effect was reduced by pre-treatment with flumazenil. The results suggest that CHRY is an anxiolytic-like agent mediated via the GABAergic system.

There is an urgent need to replace highly polluting pesticides with environmentally friendly green pesticides of high efficiency and low toxicity, because of the growing concern for quality and safety of agricultural products. To discover new pesticides with diverse chemical structures from natural products, a series of rhein derivatives 3a-9b were designed, synthesized, and evaluated for their antifungal activity and insecticidal activity. The bioassay showed that some compounds exhibited moderate antifungal activity against Rhizoctonia solani , but lower activity against the other five pathogens. Surprisingly, most compounds displayed potent insecticidal activity against Spodoptera litura and Tetranychus cinnabarinus at a concentration of 2 μmol/mL. In particular, compounds 3a , 5a and 3 b exhibited potent insecticidal activities against S. litura at 72 h, with mortality rates of 100%, 100% and 92.1%, respectively, which were equivalent to that of the insecticide fipronil (100%). Their structure-activity relationships were also discussed. The findings of this experiment provide helpful research ideas for the development of these rhein derivatives as novel natural product-based pesticides in crop protection.

Polygonum cuspidatum is a potent anti-oxidant herb that is well known for its various bioactivities. The current study investigates which compound group is most effective, to establish the key compound groups for quality assessment, especially in terms of neuroprotective effects. The roots of P. cuspidatum were extracted with 85% methanol and fractionated with hexane, ethyl acetate, n-butanol and water. Each fraction was applied to an in vitro radical scavenging assay, a lipid peroxidation assay in brain homogenates and an in vivo assay using a transient focal cerebra ischemia model induced by a middle cerebral artery occlusion in a Sprague-Dawley rat. The ethyl acetate fraction was the most effective fraction in both in vitro and in vivo assays, having the highest stilbene and anthraquinone contents. These results suggest that stilbenes and anthraquinones may be key compound groups for the quality assessment of the anti-oxidative and neuroprotective effects of P. cuspidatum. [ABSTRACT FROM AUTHOR]

The isolation, characterisation and quantification of anthraquinones, from hypogeal apparatus of Rubia peregrina L. (Wild Madder) growing wild in Sardinia (Italy) are described. The present study allowed us to perform an easy and fast HPLC analytical method for the detection of anthraquinones in all underground parts of plant. Concentrations of these compounds are variable in the different hypogeal parts before and after hydrolysis of the crude methanolic extracts. Before hydrolysis, we found that pseudopurpurin was 0.18% in rhizomes, alizarin 0.02% in rhizomes and principal stolons, and purpurin 0.56% in stolons of second order. Rubiadin is the major constituent of R. peregrina and reached a higher concentration in principal stolons of up to 4.8%. After hydrolysis, we found some drastic changes: an increase of purpurin in rhizomes (0.04%) and pseudopurpurin in all hypogeal parts (around 0.57%), and a decrease of purpurin in all parts of hypogeal apparatus. The most important change was found in rubiadin concentration, which reached its maximum in principal stolons (11.3%). No anthraquinones were found in the aerial parts of the plant. [ABSTRACT FROM AUTHOR]

An investigation of Morinda citrifolia roots afforded a new anthraquinone, 2-ethoxy-1-hydroxyanthraquinone (1), along with five other known anthraquinones: 1-hydroxy-2-methylanthraquinone (2), damnacanthal (3), nordamnacanthal (4), 2-formyl-1-hydroxyanthraquinone (5) and morindone-6-methyl-ether (6). This is the first report on the isolation of morindone-6-methyl-ether (6) from this plant. The structures of these compounds were elucidated based on spectroscopic analyses such as NMR, MS and IR. Biological evaluation of five pure compounds and all the extracts against the larvae of Aedes aegypti indicated 1-hydroxy-2-methylanthraquinone (2) and damnacanthal (3) were the extracts to exhibit promising larvicidal activities. [ABSTRACT FROM AUTHOR]

The chemical constituents and biological activities of leaves and roots of Aloe hijazensis, collected in Saudi Arabia, are reported here for the first time. Twenty-two compounds were obtained, among them eight hydroxyquinones: aloe-emodin (1), emodin (2), chrysophanol (3), aloesaponarin II 3-methyl ether (4), ziganein (5), ziganein-5-methyl ether (6a), aloesaponarin I (7) and chrysophanein (8), the dihydro-isocoumarin feralolide (9), 4,7-dichloro-quinoline (10), the triterpene lupeol (11), the anthrone aloin (12), three aloenin derivatives, aloenin (13) ethylidene-aloenin (14), and aloenin B (15), four flavonoids, quercetin (16), kaempferol (17) cosmosiin (18) and isovitexin (19), and cinnamic acid (20) and two further analogues, caffeic acid (21) and ferulic acid (22). While 15 of the isolated compounds were found in the leaves, 12 were isolated from roots of the plant. Compounds 6a and 10 are reported as new natural constituents, while the compounds 4, 5, 8, and 18 are reported here for the first time from Aloe spp. The structures of the compounds were deduced by intensive studies of their UV, NMR, MS data and by comparison with related structures. The biological activity of plant extracts was studied against various microbial strains, and potent anti-bacterial and anti-fungal activities were found. [image omitted] [image omitted] [ABSTRACT FROM AUTHOR]

A novel anthraquinone, 1,3-dihydroxy-5,6-dimethoxy-2-methoxymethyl-9,10-anthraquinone (9) and a new natural product, 2-hydroxymethyl-1-methoxy-9,10-anthraquinone (8) were isolated from the roots of Prismatomeris malayana together with seven known anthraquinones, tectoquinone (1), 1-hydroxy-2-methyl-9,10-anthraquinone (2), rubiadin (3), rubiadin-1-methyl ether (4), 1,3-dihydroxy-5,6-dimethoxy-2-methyl-9,10-anthraquinone (5), nordamnacanthal (6), and damnacanthal (7). Their structures were determined on the basis of spectroscopic data. Some of the anthraquinones were tested for anticancer, antifungal, and antimalarial activities. [ABSTRACT FROM AUTHOR]

Two new anthraquinones, 1,6-dihydroxy-5-methoxy-2-methoxymethylanthraquinone (1) and 1,5,7-trihydroxy-6-methoxy-2-methoxymethylanthraquinone (2), and one new lignan isoamericanoic acid A (3) were isolated from the fruits of Morinda citrifolia along with 11 known compounds scopoletin, luteolin, americanin A, americanin D, 3,3'-bisdemethylpinoresinol, p-cresol, p-hydroxybenzoic acid, p-hydroxybenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde, 4-hydroxy-3-methoxycinnamaldehyde, and 2,5-dihydroxy-4-methoxybenzaldehyde. The structures of all compounds were elucidated by spectroscopic analysis. [ABSTRACT FROM AUTHOR]

Three anthraquinones, Cdc25B phosphatase inhibitors, were isolated from the methanolic extract of the roots of Polygonum multiflorum Thunb. (Polygonaceae). Anthraquinones, physcion (1), emodin (2), and questin (3), inhibited the enzymatic activity of Cdc25B phosphatase with IC50 values of 62.5, 30, and 34 µg mL-1, respectively. Emodin (2) and questin (3) strongly inhibited the growth of human colon cancer cells, SW620 with GI50 values of 6.1 and 0.9 µg mL-1, respectively. Commercially available anthraquinones, chrysophanol (4), and rhein (5) also inhibited Cdc25B phosphatase with IC50 values of 10.7 and 22.1 µg mL-1, respectively. [ABSTRACT FROM AUTHOR]

Studies on the chemical constituents of the stem of Morinda citrifolia, Linn. have led to the isolation of two new compounds, morindicinone (=2-hydroxy-1,8-dimethoxy-7-methoxymethylanthraquinone, 1) and morindicininone (=4-hydroxymethyl-1,3-dimethoxyanthraquinone, 2), as well as two known constituents, 2-hydroxyanthraquinone (3) and 2-methoxyanthraquinone (4). Their structures were elucidated by spectral analysis including 2D-NMR techniques. [ABSTRACT FROM AUTHOR]

Colleflaccinosides A and B, two chiral bianthraquinone glycosides from the two geographical varieties of lichen Collema flaccidum collected in Russia and Israel have been isolated as new natural products. Their structures were elucidated using UV, CD, IR, MS, 1D and 2D NMR spectral data, and chemical degradation. The colleflaccinosides B had significant antitumor activity in the crown gall tumor inhibition test. [ABSTRACT FROM AUTHOR]

A new α-methylanthraquinone glucoside, laccaic acid D 8- o -β-D-glucoside, and six known anthraquinones have been isolated from the aqueous alcoholic extract of Emex spinosus (L.) Campd. ( Polygonaceae ), together with two known flavonol glycosides. The structures were determined by conventional analytical methods and confirmed by MS and NMR spectral analysis, including 2D experiments for the new compound. [ABSTRACT FROM AUTHOR]