Bioactive Naphthoquinones from Higher Plants

Hook, Ingrid; Mills, Clive; Sheridan, Helen

doi:10.1016/b978-0-444-63294-4.00005-x

Cited by 36 publications

(29 citation statements)

References 294 publications

(177 reference statements)

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“…Many species within the genus Impatiens are known to produce 1,4‐NQs (Hook, Mills, & Sheridan, ), and recent evidence suggests that these compounds function to chemically mediate interactions with other plants and fungi in the rhizosphere (Ruckli, Hesse, et al., ). The observation by Lobstein et al.…”

Section: Resultsmentioning

confidence: 99%

Specialized naphthoquinones present in Impatiens glandulifera nectaries inhibit the growth of fungal nectar microbes

2019

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The invasion success of Impatiens glandulifera (Himalayan balsam) in certain parts of Europe and North America has been partially attributed to its ability to compete for bee pollinators with its rich nectar and due to its capacity to produce and release allelopathic 1,4‐naphthoquinones (1,4‐ NQ s) from its roots and leaves. Given that other 1,4‐ NQ s present in the digestive fluids of certain carnivorous plants are proposed to control microbial colonization, we investigated the potential for the 1,4‐ NQ s, 2‐methoxy‐1,4‐naphthoquinone (2‐ MNQ ) and lawsone, to fulfill an analogous role in the nectaries of I. glandulifera . Both 2‐ MNQ and lawsone were detected in the floral nectaries of I. glandulifera at levels comparable to leaves and roots, but were discovered to be at significantly higher levels in its extra‐floral nectaries ( EFN s) and to be present in EFN nectar itself. Nectar microbe inhibition assays revealed that the common nectar bacteria Gluconobacter oxydans and Asaia prunellae are not inhibited by 2‐ MNQ or lawsone, although both compounds were found to inhibit the growth of the common fungal nectar microbes Metschnikowia reukaufii and Aureobasidium pullulans . Taken together, these findings suggest that 2‐ MNQ and lawsone could serve to protect the rich nectar of I. glandulifera against fungal growth. The high abundance of 2‐ MNQ and lawsone in I. glandulifera EFN s may also point to an unsuspected mechanism for how allelopathic 1,4‐ NQ s are leached into the soil where they exhibit their known allelopathic effects.

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Section: Resultsmentioning

confidence: 99%

Specialized naphthoquinones present in Impatiens glandulifera nectaries inhibit the growth of fungal nectar microbes

2019

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“…Naphthoquinones are a group of widely distributed phenolics of plant origin and are classified to ortho and para-naphthoquinones. Ortho-naphthoquinones are particularly known for their cytotoxic effects among other biological activities such as anti-bacterial, anti-fungal and antiparasitic and acetylcholine esterase inhibitory effects [ 1 ]. Mansonones are a group of sesquiterpene-derived ortho-naphthoquinones occurring in different genuses in the plant kingdom such as Hibiscus, Mansonia and Thespesia [ 2 ].…”

Section: Introductionmentioning

confidence: 99%

Anticancer Profiling for Coumarins and Related O-Naphthoquinones from Mansonia gagei against Solid Tumor Cells In Vitro

et al. 2018

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Napthoquinones and coumarins are naturally occurring compounds with potential anticancer activity. In the current study, two O-naphthoquinons (mansonone-G and mansonone-N) and six coumarins (mansorin-A, mansorin-B, mansorin-C, mansorins-I, mansorin-II, and mansorin-III) were isolated from the heartwood of Mansonia gagei family Sterculariaceae. Isolated compounds were examined for their potential anticancer activity against breast (MCF-7), cervix (HeLa), colorectal (HCT-116) and liver (HepG2) cancer cells using Sulfarhodamine-B (SRB) assay. Mansorin-II and mansorin-III showed relatively promising cytotoxic profile in all cell lines under investigation with inhibitory concentrations (IC50s) in the range of 0.74 µM to 36 µM and 3.95 µM to 35.3 µM, respectively. In addition, mansorin-B, mansorin-C, mansorin-II and mansorin-III significantly increased cellular entrapment of the P-glycoprotein (P-gp) substrate, doxorubicin, in colorectal cancer cells expressing the P-gp pump. The inhibitory effect of the isolated compounds on P-gp pump was examined using human recombinant P-gp molecules attached to ATPase subunit. Mansorin-B and mansonone-G were found to inhibit the P-gp attached ATPase subunit. On the other hand, mansorin-C, mansorin-III and mansorin-II inhibited P-gp pump via dual action (P-gp related ATPase subunit inhibition and P-gp substrate binding site occupation). However, mansorin II was examined for its potential chemomodulatory effect to paclitaxel (PTX) against colorectal cancer cells (HCT-116 and CaCo-2). Mansorin-II significantly reduced the IC50 of PTX in HCT-116 cells from 27.9 ± 10.2 nM to 5.1 ± 1.9 nM (synergism with combination index of 0.44). Additionally, Mansorin-II significantly reduced the IC50 of PTX in CaCo-2 cells from 2.1 ± 0.8 µM to 0.13 ± 0.03 µM (synergism with combination index of 0.18). Furthermore, cell cycle analysis was studied after combination of mansorin-II with paclitaxel using DNA flow cytometry analysis. Synergism of mansorin-II and PTX was reflected in increasing apoptotic cell population in both HCT-116 and CaCo-2 cells compared to PTX treatment alone. Combination of mansorin-II with PTX in CaCo-2 cells significantly increased the cell population in G2/M phase (from 2.9 ± 0.3% to 7.7 ± 0.8%) with reciprocal decrease in G0/G1 cell fraction from 52.1 ± 1.1% to 45.5 ± 1.0%. Similarly in HCT-116 cells, mansorin-II with PTX significantly increased the cell population in G2/M phase (from 33.4 ± 2.8% to 37.6 ± 1.3%) with reciprocal decrease in the S-phase cell population from 22.8 ± 1.7% to 20.2 ± 0.8%. In conclusion, mansorin-II synergizes the anticancer effect of paclitaxel in colorectal cancer cells, which might be partially attributed to enhancing its cellular entrapment via inhibiting P-gp efflux pump.

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“…Convergent evolution at the metabolic level entails different lineages independently evolving pathways to produce identical or nearly identical compounds. Classic examples include the independent evolution of betalain biosynthesis in basidiomycete fungi and Caryophyllales (Musso, ; Mueller et al., ), caffeine biosynthesis in Malvaceae, Rubiceae and Theaceae (Yoneyama et al., ; Denoeud et al., ), and specialized 1,4‐naphthoquinones spread across several disparate plant orders (Kumara et al., ; Hook et al., ). In a few cases, the genes responsible for these convergent gains have been identified.…”

Section: Genetic Mechanisms Of Biochemical Diversificationmentioning

confidence: 99%