Daphnodorin B

Phytochemistry. 2014 Oct;106:61-68.

Phytotoxic flavonoids from roots of Stellera chamaejasme L. (Thymelaeaceae).[Pubmed: 25096753 ]

Allelopathy, the negative effect on plants of chemicals released to the surroundings by a neighboring plant, is an important factor which contributes to the spread of some weeds in plant communities. In this field, Stellera chamaejasme L. (Thymelaeaceae) is one of the most toxic and ecologically-threatening weeds in some of the grasslands of north and west China.
METHODS AND RESULTS:
Bioassay-guided fractionation of root extracts of this plant led to the isolation of eight flavonoids 1-8, whose structures were elucidated by spectroscopic analysis. All compounds obtained, except 7-methoxylneochaejasmin A (4) and (+)-epiafzelechin (5), showed strong phytotoxic activity against Arabidopsis thaliana seedlings. Seedling growth was reduced by neochamaejasmin B (1), mesoneochamaejasmin A (2), chamaejasmenin C (3), genkwanol A (6), Daphnodorin B (7) and dihydroDaphnodorin B (8) with IC50 values of 6.9, 12.1, 43.2, 74.8, 7.1 and 27.3μg/mL, respectively, and all of these compounds disrupted root development. Endogenous auxin levels at the root tips of the A. thaliana DR5::GUS transgenic line were largely reduced by compounds 1, 2 and 6-8, and were increased by compound 4. Moreover, the inhibition rate of A. thaliana auxin transport mutants pin2 and aux1-7 by compounds 1-8 were all lower than the wild type (Col-0). The influence of these compounds on endogenous auxin distribution is thus proposed as a critical factor for the phytotoxic effect. Compounds 1, 2, 4 and 8 were found in soils associated with S. chamaejasme, and these flavonoids also showed phytotoxicity to Clinelymus nutans L., an associated weed of S. chamaejasme.
CONCLUSIONS:
These results indicated that some phytotoxic compounds from roots of S. chamaejasme may be involved in the potential allelopathic behavior of this widespread weed.

Planta Med. 2000 Aug;66(6):564-7.

Antifungal, antimitotic and anti-HIV-1 agents from the roots of Wikstroemia indica.[Pubmed: 10985087]

METHODS AND RESULTS:
With guidance of Pyricularia oryzae bioassay, daphnoretin (1), (+)-nortrachelogenin (2), genkwanol A (3), wikstrol A (4), wikstrol B (5) and Daphnodorin B (6) were isolated from the roots of Wikstroemia indica. Compounds 1-6 induced morphological deformation of P. oryzae mycelia with MMDC values of 68.4 +/- 1.3, 31.3 +/- 1.8, 45.8 +/- 0.5, 70.1 +/- 2.4, 52.3 +/- 0.9 and 73.7 +/- 1.6 microM, respectively. Compounds 3-6 showed moderate activity against microtubule polymerization with IC50 values of 112 +/- 4, 131 +/- 3, 184 +/- 6 and 142 +/- 2 microM in vitro, respectively. Compounds 2, 3, 5 and 6 were moderately active against HIV-1 in vitro.
CONCLUSIONS:
The findings of bioactivity of 1-6 support the antifungus, antimitosis and anti-HIV-1 uses for W. indica roots.

Biochem Biophys Res Commun. 2001 May 18;283(4):831-6.

Inhibitory mechanism of daphnodorins for human chymase.[Pubmed: 11350059 ]

METHODS AND RESULTS:
We investigated the inhibitory mechanisms of daphnodorins for human chymase using three-dimensional molecular modeling. In daphnodorin A-human chymase complex, daphnodorin A was fixed to the active site via hydrogen bonds with Ala177, Phe29, and Gly199 in human chymase, and it formed hydrogen bonds with Ser182 and Gly180, and this complex was formed stably. In Daphnodorin B-human chymase complex, Daphnodorin B formed hydrogen bonds with Lys28 and Phe29 in human chymase, but it could not form hydrogen bonds with Gly199, Ala177, and Lys179. The phenyl group of Daphnodorin B shifted from the P1 hole in human chymase in comparison with that of daphnodorin A.
CONCLUSIONS:
For the inhibition of human chymase by daphnodorins, we indicated that it was significant whether daphnodorins formed hydrogen bonds with Ala177 located in the P1 hole, Ser182 located in the active site, Gly180 located in the anion hole, and with Gly199, Phe29, and Lys28 in human chymase.

Int. Immunopharmacol., 2007 Feb;7(2):128-34.

Antitumor activity of daphnodorins from Daphne genkwa roots.[Pubmed: 17178378 ]

Daphne genkwa root has been traditionally used as an effective remedy to treat various tumors. However, the active constituents for its antitumor potency have not been well documented. During the screening for antitumor constituents, it was found that daphnodorins were responsible for the inhibition of tumor growth and metastasis.
METHODS AND RESULTS:
In this study, six daphnodorins including Daphnodorin B (1),daphnodorin G (2), daphnodorin H (3), daphnodorin H-3''-methylether (4),daphnodorin H-3-methylether (5) and daphnodorin G-3''-methylether (6) were investigated for the protection against LLC-induced reduction of lymphoid organs and peripheral lymphocytes, and for the activities against tumor growth and metastasis. The six daphnodorins showed selective cytotoxicity to a number of tumor cell lines. Treatment of LLC-bearing mice with Daphnodorin B and/or daphnodorin complex evidently protected peripheral lymphocytes from tumor-induced reduction, increased lymphocyte proliferation potential and inhibited tumor progression and metastasis at doses of 40 and 80 mg/kg.
CONCLUSIONS:
These results indicated that Daphnodorin B or daphnodorin complex inhibited tumor growth and metastasis by protecting host immunocyte viability and proliferation potential, and selectively inhibiting tumor cell proliferation.