28-deacetylbelamcandal, a tumor-promoting triterpenoid from Iris tectorum

Rearranged iridal-type triterpenoids from Iris tectorum

Three new iridal-type triterpenoids (1-3) featuring a rearranged homofarnesylside chain were isolated from the rhizomes of Iris tectorum. Compounds 2 and 3 were found to be a pair of epimers. Their structures were elucidated on the basis of comprehensive spectroscopic analysis. A possible biosynthetic pathway for them was postulated. Moreover, the mixture of compounds 2 and 3 exhibited moderate neuroprotective activity against serum deprivation-induced PC12 cell death.

Iridal-type triterpenoids with anti-HBV activity from Iris confusa

Five new iridal-type triterpenoids, named as spirioiridoconfal A-C (1-3), isobelamcandal (4) and 17-hydroxyl-27-ene-iridal (5), along with one known compound (6) were isolated from the whole plant of Iris confusa. Their structures were determined by extensive spectroscopic analyses. Compounds 3 and 6 showed moderate activity against HBV DNA replication in vitro with the IC₅₀ value at 84.6 ± 24.9 (SI = 2.1) and 58.6 ± 6.1 (SI = 12.7) μM relatively.

Polycycloiridals with a Cyclopentane Ring from Iris tectorum

Six new iridal-type triterpenoids containing an unprecedented cyclopentane ring, polycycloiridals E-J (1-6), were isolated from a large-scale re-extraction of Iris tectorum. A possible biosynthesis pathway is postulated. The known spirioiridotectal D (7) was also obtained in the current investigation, and its structure was unequivocally defined using X-ray diffraction data. Compound 7 suppressed LPS-activated NO production in the BV2 cell line with an IC₅₀ value of 0.54 μM.

The unprecedented iridal lactone and adducts of spiroiridal and isoflavonoid from Belamcanda chinensis

Five novel iridal-type triterpenoid derivatives have been isolated from the rhizomes of Belamcanda chinensis, along with five known compounds. Their structures were elucidated by extensive spectroscopic analysis.

Polycycloiridals A-D, Four Iridal-Type Triterpenoids with an α-Terpineol Moiety from Iris tectorum

Polycycloiridals A-D, four novel iridals with an unprecedented α-terpineol moiety resulting from cyclization of the homofarnesylside chain, were isolated from the ethanol extract of rhizomes of Iris tectorum. Their structures were elucidated on the basis of comprehensive spectroscopic analysis. The absolute configuration of 1 was determined by the modified Mosher's method and comparison of experimental and calculated electronic circular dichroism (ECD) spectrum. A possible biosynthetic pathway was postulated.

Tissue-specific metabolites profiling and quantitative analyses of flavonoids in the rhizome of Belamcanda chinensis by combining laser-microdissection with UHPLC-Q/TOF-MS and UHPLC-QqQ-MS

The rhizome of Belamcanda chinensis (L.) DC. is a traditionally used medicinal material in China. Due to increasing demand, B. chinensis has been cultivated widely, and thus the study on its rational utilization of medicinal part and guidelines for the optimal cultivation and harvest is an important issue. Considering flavonoids were the main bioactive secondary metabolites of B. chinensis, fluorescence microscopy, laser microdissection (LMD), ultra-high performance liquid chromatography-quadrupole/time-of-flight-mass spectrometry (UHPLC-Q/TOF-MS), and UHPLC coupled with triple quadrupole mass spectrometer (UHPLC-QqQ-MS) were applied to profile and determine flavonoids in various tissues in this study. Consequently, 43 peaks were detected by UHPLC-Q/TOF-MS, and 26 flavonoid compounds combined with seven triterpene compounds were identified or tentatively identified in the tissue extractions. The results indicated that the hydrophobic compounds, especially flavonoid or isoflavonoid aglycones and xanthone mainly accumulated in the cork, whereas the hydrophilic compounds, namely the flavonoid and isoflavonoid glycosides were usually found in the cortex or center (the part inside of endodermis). Samples of rhizomes from different growth ages and origins were simultaneously analyzed. It was shown that the bulb or lateral part of the rhizome generally possessed more total flavonoids than the vertical part or the primordium. The present study established a new practical method to evaluate the quality of the rhizome of B. chinensis and to explore the relationship between distribution patterns of secondary metabolites and growth years of plants, thus important information for cultivation and processing was provided.

Iridal-type triterpenoids with neuroprotective activities from Iris tectorum

Six novel iridal-type triterpenoids with a previously unreported 3,6-dihydro-2H-pyran moiety, named spirioiridotectals A-F (1-6), were isolated from the ethanol extract of the rhizomes of Iris tectorum. Their structures were elucidated on the basis of extensive spectroscopic analysis. Furthermore, in in vitro bioactivity assays, compounds 1, 2, and 6 exhibited neuroprotective activities against serum-deprivation-induced PC12 cell damage.

Two isoflavones and bioactivity spectrum of the crude extracts of Iris germanica rhizomes

In vitro biological activities including bactericidal, fungicidal and insecticidal activities as well as phytotoxicity and brine shrimp toxicity of the petroleum ether, chloroform and ethyl acetate extracts of Iris germanica L. were determined. The bactericidal activity of the extracts was assayed by the agar well diffusion test. In the fungicidal test, the agar tube dilution method was used. The insecticidal activity was determined by the exposure method. The toxicity of the extracts was evaluated by the phytotoxicity test as well as the brine shrimp toxicity test. The chloroform and ethyl acetate extracts of I. germanica rhizomes exhibited bactericidal activity, while the petroleum ether extract did not exhibit any bactericidal, fungicidal and insecticidal activities. It was also inactive in the brine shrimp toxicity test, whereas it showed significant phytotoxicity against the plant Lemna aequinoctialis Welv. Two known isoflavones were isolated from the chloroform extract of the plant.

Protein kinase C activation by iridal type triterpenoids

Eleven iridal type triterpenoids from Iris tectorum and Belamcanda chinensis were examined for protein kinase C (PKC) activation and binding activity to PKC. Among the tested compounds, nine iridals showed dose-dependent activities, and a mutual relation between the two activities was also observed. 28-Deacetylbelamcandal, which has been found to be a new class 12-O-tetradecanoylphorbol 13-acetate type tumor promoter, showed the most potent activity in both tests. The structural requirements of the iridals inducing these activities were as follows: 1) a hydrophobic side-chain, 2) an E-methylidene aldehyde group at the C-1 position, and 3) a hydroxyl group at the C-26 position.

Iridals from Iris tectorum and Belamcanda chinensis

Three iridals, iridotectorals A and B, and iridobelamal. A, were isolated from rhizomes of Iris tectorum and Belamcanda chinensis, respectively, along with five known iridals. Their structures were elucidated on the basis of spectral evidence. The human promyelocytic leukemia (HL-60) cell-adhesion activity of the eight iridals is also discussed.

Inhibitory effect of euphol, a triterpene alcohol from the roots of Euphorbia kansui, on tumour promotion by 12-O-tetradecanoylphorbol-13-acetate in two-stage carcinogenesis in mouse skin

The anti-inflammatory activity of euphol, twelve other triterpene alcohols and sitosterol-beta-D-glucopyranoside, isolated from the dichloromethane extract of the roots of Euphorbia kansui, has been evaluated in mice with inflammation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). TPA (1.7 nmol; 1.0 microg/ear) was dissolved in acetone and 10 microL delivered to the inner and outer surfaces of the right ear of ICR mice. A triterpene alcohol, sterol glucoside or vehicle (20 microL; chloroform-methanol 1:1), was applied topically approximately 30 min before each TPA treatment. The ear thickness was measured before treatment and then oedema was measured 6 h after TPA treatment. For the two-stage carcinogenesis experiment, initiation was accomplished by administration of a single topical application of 7,12-dimethylbenz[a]anthracene (DMBA; 195 nmol; 50 microg/mouse) to the shaved backs of mice. Promotion was with 1.7 nmol (1.0 microg) TPA, applied twice weekly to the same shaved area, begun one week after the initiation. Euphol (2.0 micromol; 853 microg), or its vehicle (acetone-dimethylsulphoxide, 9:1; 100 microL), was applied topically 30 min before each TPA treatment. The number and diameter of skin tumours were measured every other week for 20 weeks. All the compounds were found to possess marked inhibitory activity and their 50% inhibitory dose for TPA-induced inflammation was 0.2-1.0 mg/ear. Topical application of euphol (2.0 micromol; 853 microg/mouse) markedly suppressed the tumour-promoting effect of TPA (1.7 nmol; 1.0 microg/mouse) in mouse skin initiated with DMBA.