A methylflavan with free radical scavenging properties from Pancratium littorale

Tyrosinase Inhibitors Derived from Chemical Constituents of Dianella ensifolia

Dianella ensifolia is a perennial herb with thickened rhizome and is widely distributed in tropical and subtropical regions of Asia, Australia, and the Pacific islands. This plant has the potential to be used as a source of herbal medicine. This study investigated further phytochemistry and tyrosinase inhibitory effect of some constituents isolated from D. ensifolia. Four new flavans, (2S)-4’-hydroxy-6,7-dimethoxyflavan (1), (2S)-3’,4’-dihydroxy-7-methoxy-8-methylflavan (2), (2S)-2’-hydroxy-7-methoxyflavan (3), and (2S,1′S)-4-hydroxy-4-(7-methoxy-8-methylchroman-2-yl)-cyclohex-2-enone (4), together with 67 known compounds, including 10 flavans (5−14), 5 flavanones (15−19), 3 flavone (20−22), 5 chalcones (23−27), 3 chromones (28−30), 15 aromatics (31−45), 7 phenylpropanoids (46−52), one lignan (53), 7 steroids (54−60), one monoterpene (61), one diterpene (62), 4 triterpenes (63−66), a carotenoid (67), 2 alkaloids (68 and 69), and 2 fatty acids (70 and 71) were isolated from D. ensifolia. Their structures were elucidated on the basis of physical and spectroscopic data analyses. Moreover, compounds 1−4, 8, 10−15, 20, 21, and 41 were evaluated for their mushroom tyrosinase inhibitory effect. Compounds 11 and 14 strongly inhibited mushroom tyrosinase activity with IC50 values of 8.6 and 14.5 μM, respectively.

Biological Investigation of Amaryllidaceae Alkaloid Extracts from the Bulbs of Pancratium trianthum Collected in the Senegalese Flora

Amaryllidaceae plants are rich in alkaloids with biological properties. Pancratium trianthum is an Amaryllidaceae species widely used in African folk medicine to treat several diseases such as central nervous system disorders, tumors, and microbial infections, and it is used to heal wounds. The current investigation explored the biological properties of alkaloid extracts from bulbs of P. trianthum collected in the Senegalese flora. Alkaloid extracts were analyzed and identified by chromatography and mass spectrometry. Alkaloid extracts from P. trianthum displayed pleiotropic biological properties. Cytotoxic activity of the extracts was determined on hepatocarcinoma Huh7 cells and on acute monocytic leukemia THP-1 cells, while agar diffusion and microdilution assays were used to evaluate antibacterial activity. Antiviral activity was measured by infection of extract-treated cells with dengue virus (DENV_GFP) and human immunodeficiency virus-1 (HIV-1_GFP) reporter vectors. Cytotoxicity and viral inhibition were the most striking of P. trianthum’s extract activities. Importantly, non-cytotoxic concentrations were highly effective in completely preventing DENV_GFP replication and in reducing pseudotyped HIV-1_GFP infection levels. Our results show that P. trianthum is a rich source of molecules for the potential discovery of new treatments against various diseases. Herein, we provide scientific evidence to rationalize the traditional uses of P. trianthum for wound treatment as an anti-dermatosis and antiseptic agent.

Saccharpiscinols A-C: Flavans with Potential Anti-Inflammatory Activities from One Actinobacteria Saccharomonospora piscinae

Phytochemical investigation and chromatographic separation of extracts from the actinobacteria strain Saccharomonospora piscinae that was isolated from dried fishpond sediment of Kouhu township, in the south of Taiwan, led to the isolation of three new compounds, saccharpiscinols A-C (1-3, respectively), and three new natural products, namely (2S)-5,7,3',4'-tetrahydroxy-6,8-dimethylflavanone (4), methyl-4-hydroxy-2-methoxy-6-methylbenzoate (5), and (±)-7-acetyl-4,8-dihydroxy-6-methyl-1-tetralone (6). Compounds 4-6 were reported before as synthesized products, herein, they are reported from nature for the first time. The structures of the new compounds were unambiguously elucidated on the basis of extensive spectroscopic data analysis (1D- and 2D-NMR, MS, and UV) and comparison with literature data. The effect of some isolates on the inhibition of NO production in lipopolysaccharide-activated RAW 264.7 murine macrophages was evaluated. Saccharpiscinol A showed inhibitory activities against LPS-induced NO production.

Chemical Constituents from a Mangrove-Derived Actinobacteria Isoptericola chiayiensis BCRC 16888 and Evaluation of Their Anti-NO Activity

Cultivation of the actinobacteria strain Isoptericola chiayiensis, a mangrove-derived actinobacteria that was isolated from a mangrove soil collected in Chiayi County, resulted in the isolation of one new 2-furanone derivative, isopterfuranone (1), one new sesquiterpenoid, isopterchiayione (2), one new benzenoid derivative, isopterinoid (3), five new flavonoids, chiayiflavans A-E (4-8), and 4 metabolites isolated for the first time from nature source, methyl 3-(4-methyl-2,5-dioxopyrrolidin-3-yl)propanoate (9), 3-ethyl-4-methylpyrrolidine-2,5-dione (10), chiayiensol (11) and chiayiensic acid (12). Their structures were determined through in-depth spectroscopic and mass-spectrometric analyses. Most of the isolates showed potent inhibitory effects on NO production in LPS-stimulated RAW 264.7 murine macrophages cells with IC₅₀ values ranging from 9.36 to 40.02 μM. Of these isolates, 4 and 5 showed NO inhibitory activity with IC₅₀ values of 17.14 and 9.36 μM, stronger than the positive control quercetin (IC₅₀ =36.95 μM). This is the first report on flavan metabolites from the genus Isoptericola.

Bioactive Compounds from Medicinal Plants in Myanmar

Myanmar is a country with rich natural resources and of these, medicinal plants play a vital role in the primary health care of its population. The people of Myanmar have used their own system of traditional medicine inclusive of the use of medicinal plants for 2000 years. However, systematic and scientific studies have only recently begun to be reported. Researchers from Japan, Germany, and Korea have collaborated with researchers in Myanmar on medicinal plants since 2000. During the past two decades, over 50 publications have been published in peer-reviewed journals. Altogether, 433 phytoconstituents, including 147 new and 286 known compounds from 26 plant species consisting of 29 samples native to Myanmar, have been collated. In this contribution, phytochemical and biological investigations of these plants, including information on traditional knowledge are compiled and discussed.

Flavonoids and alkaloids from the rhizomes of Zephyranthes ajax Hort. and their cytotoxicity

A new flavanol derivative, (2R,3R)-3-acetoxy-7-hydroxy-3′,4′-methylenedioxyflavan (1), was co-isolated from the rhizomes of Zephyranthes ajax Hort. with the following seven known compounds: 7-hydroxyflavan (2), 7,4′-dihydroxyflavan (3), 7,4′-dihydroxy-8-methylflavan (4), 7,3′-dihydroxy-4′-methoxyflavan (5), 5,4′-dihydroxy-7-methoxy-6-methylflavan (6), 7-hydroxy-3′,4′-methylenedioxyflavanone (7) and haemanthamine (8). Their structures were elucidated by combining 1D-/2D-NMR, CD, UV and HRESIMS data, and comparisons with reported data in literature were made. Among these known compounds, 2, 3, 4, 6 and 7 were isolated from the genus Zephyranthes for the first time. In addition, the cytotoxicity assay indicated that compound 8 has potent cytotoxic activity against human hepatocellular carcinoma (the HepG2 cell line), human lung carcinoma (the SK-LU-1 cell line), human carcinoma in the mouth (the KB cell line), human colon carcinoma (the SW480 cell line) and human stomach gastric adenocarcinoma (the AGS cell line), with IC₅₀ values ranging from 4.4 to 11.3 µM. This is the first study reporting the cytotoxicity of compound 8 against the SK-LU-1 cancer cell lines.

Three new flavanoids from artificially induced dragon's blood of Dracaena cambodiana

Three new flavanoids, (2R)-7,4'-dihydroxy-8-methylflavan (1), (2R)-7,4'-dihydroxy-6-methylflavan (2), and (3R)-7,3',4'-trihydroxyhomoisoflavan (3), together with seven known compounds (4-10), were isolated from artificially induced dragon's blood of Dracaena cambodiana, and their structures were determined based on HR-ESI-MS and extensive spectroscopic techniques (UV, IR, 1D-, and 2D-NMR). Compound 2 exhibited weak cytotoxicity against BEL-7402 cells line with the IC₅₀ value of 39.2 μM. In addition, compound 3 showed significant acetylcholinesterase (AChE) inhibitory activity.

Isolation and chatacterization of homoisoflavonoids from Dracaena cochinchinensis and their osteogenic activities in mouse mesenchymal stem cells

Two new homoisoflavonoids, dracaeconolide A (1) and dracaeconolide B (2), together with ten known compounds, namely (3R)-7,4'-dihydroxy-8-methoxyhomoisoflavane (3), (3R)-7-hydroxy-3-(4-hydroxybenzyl)chromane (4), (3R)-7,4'-dihydroxy-5-methoxy-homoisoflavane (5), (3R)-6,4'-dihydroxy-8-methoxyhomoisoflavan (6), 7,4'-dihydroxy-8-methylflavan (7), (2R)-7,4'-dihydroxy-5-methoxy-8-methylflavan (8), 5,4'-dihydroxy-7-methoxy-6-methylflavane (9), 7,4'-dihydroxy-3'-methoxyflavan (10), 7,4'-dihydroxyflavan (11), 4,4'-dihydroxy-2,6-dimethoxydihydrochlcone (12), were isolated from the red resin of Dracaena cochinchinensis (dragon's blood, DB). All the compounds were then evaluated for their effects on mouse bone marrow-derived mesenchymal stem cells (MSCs) proliferation using CCK8 assay and their abilities in promoting MSCs differentiating into osteoblast through the assay of alkaline phosphatase (ALP) activity in vitro. Compounds 2, 3, 4, 7, 9, and 11, at a concentration of 10μM with no cytotoxicity, significantly promoted MSC osteogenic differentiation by increasing the levels of ALP activity to percents of 159.6±5.9, 167.6±10.9, 162.0±1.4, 151.3±4.0, 171.0±8.2, and 169.9±7.3 in relative to the control, respectively. The results of ALP staining were in accordance to that of ALP activity.

Chalcane-stilbene conjugates and oligomeric flavonoids from Chinese Dragon's Blood produced from Dracaena cochinchinensis

A detailed chemical investigation of Chinese Dragon's Blood, which is a traditional medicine produced form the red resin of Dracaena cochinchinensis, yielded two chalcane-stilbene conjugates, named cochinchinenenes G and H, together with 25 known compounds. The structures of these compounds were determined by spectroscopic examination. HPLC analysis of the resin indicated that the major constituents were a complex mixture of oligomeric polyphenols, which were detected as a broad hump on the base line of a HPLC chromatogram. (13)C NMR analysis indicated that the oligomers were mainly composed of oxygenated chalcane units. This suggestion was supported by the results of a thiol degradation experiment with mercaptoethanol, which yielded a thioether of 4-[(4-hydroxyphenyl)propyl]-3-methoxyphenol. Furthermore, methylation followed by electrospray ionization mass spectroscopic analysis of the resulting fractions established the presence of at least one heptamer of chalcane units.

Comparative analysis of lycorine in wild plant and callus culture samples of Hymenocallis littoralis by HPLC-UV method

The Hymenocallis littoralis, an ornamental and medicinal plant, had been traditionally used for wound healing. In the present study, an analytical method using HPLC with ultraviolet detection was developed for the quantification of lycorine in the extracts of different parts of wild plant and tissue culture samples of H. littoralis. The separation was achieved using a reversed-phase column. The method was found to be accurate, repeatable, and sensitive for the quantification of minute amount of lycorine present in the samples. The highest lycorine content was found in the bulb extract (2.54 ± 0.02 μg/mg) whereas the least was in the root extract (0.71 ± 0.02 μg/mg) of the wild plants. Few callus culture samples had high content of lycorine, comparable to that of wild plants. The results showed that plant growth regulators, 2,4-dichlorophenoxyacetic acid (2,4-D) alone at 4.5 μM (2.58 ± 0.38 μg/mg) or a combination of 2,4-D at 9.00 μM with 4.5 μM of 6-benzylaminopurine (BAP), were the optimum concentrations for the production of high lycorine (2.45 ± 0.15 μg/mg) content in callus culture. The present analytical method could be of value for routine quantification of lycorine in the tissue culture production and standardization of the raw material or extracts of H. littoralis.

Biochemical modulation of cell energy by 2-deoxyglucose and malonate in 7,12-dimethylbenz(a)anthracene-induced carcinogenesis in rats

The goal of this study was to explore the impact of 2-deoxglucose or malonate individually or in combination on the level of cell energy (adenosine-5'-triphosphate) and oxidative stress in 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary proliferation in rats. A total of 60 adult female Sprague Dawley rats were randomly divided into five groups (12 rats each): group I serves as the control group. Rats in groups (II-V) were administrated intragastrically a single dose of 50 mg/kg body weight (bw) of DMBA. A day after DMBA administration, rats in group III were injected intraperitoneally (ip) with 100 mg 2-deoxyglucose (2-DG)/kg bw daily. Rats in group IV were injected ip with 10 mg sodium malonate/kg bw daily. Rats in group V were injected ip with 100 mg 2-DG/kg bw and 10 mg sodium malonate/kg bw (treatment for 90 days). The results obtained showed that DMBA induced oxidative stress by decreasing the activities of glutathione reductase (GRase) and superoxide dismutase (SOD), glutathione peroxidase (GPx) and elevating the levels of malondialdehyde (MDA) and nitric oxide (NO) in mammary tissues when compared with control. The combined treatment protected against the previous deleterious changes by a significant elevation in the activities of GRase and SOD, GPx and lowering the levels of MDA and NO more potentially when compared with individual treatment. Apoptosis, as indicated by a significant release of cytochrome c from mitochondria into the cytosol, observed in DMBA-injected rats was positively significantly correlated with the elevation of the level of NO. These data explained the possible additive effect of 2-DG and malonate by depleting the cell energy by their protective effects against the earlier stages of carcinogenesis.

Cytotoxic constituents of Soymida febrifuga from Myanmar

The 70% ethanol extract of Soymida febrifuga was found to kill PANC-1 human pancreatic cancer cells preferentially under nutrition-deprived conditions at a concentration of 10 microg/mL. Phytochemical investigation led to the isolation of 27 compounds including four new compounds [(3R)-6,4'-dihydroxy-8-methoxyhomoisoflavan (1), (2R)-7,4'-dihydroxy-5-methoxy-8-methylflavan (2), 7-hydroxy-6-methoxy-3-(4'-hydroxybenzyl)coumarin (3), and 6-hydroxy-7-methoxy-3-(4'-hydroxybenzyl)coumarin (4)]. 2',4'-Dihydroxychalcone (8) displayed the most potent preferential cytotoxicity (PC(50) 19.0 microM) against PANC-1 cells. In addition, the cytotoxic activity against colon 26-L5 carcinoma (colon 26-L5), B16-BL6 melanoma (B16-BL6), lung A549 adenocarcinoma (A549), cervix HeLa adenocarcinoma (HeLa), and HT-1080 fibrosarcoma (HT-1080) cell lines and their structure-activity relationship are discussed. The cytotoxic activity of 4'-hydroxy-3,5-dimethoxystilbene (6) against colon 26-L5 (IC(50) 2.96 microM) was found to be stronger than the positive control, doxorubicin, at IC(50) 3.12 microM.

A new cytotoxic homoisoflavonoid from Dracaena cambodiana

A new homoisoflavonoid, named cambodianol (1), together with the two known flavanes, (2S)-7,3'-dihydroxy-4'-methoxy-8-methylflavane (2) and (2R)-7,4'-dihydroxy-8-methylflavane (3), were isolated from the stems of Dracaena cambodiana. Their structures were determined based on HR-ESI-MS and spectroscopic techniques (UV, IR, 1D-, and 2D-NMR). Compound 1 exhibited significant cytotoxic activities against K562 and SGC-7901 with the IC(50) values of 1.4 and 2.9 microg/ml, respectively.

Anti-Helicobacter pylori and thrombin inhibitory components from Chinese dragon's blood, Dracaena cochinchinensis

Chemical studies on the constituents of Dracaena cochinchinensis led to the discovery of eight new flavonoid derivatives ( 1- 8) along with 14 known compounds ( 9- 22). The identification and structural elucidation of these isolates were based on spectral analyses. All isolates were tested for antibacterial activities against Helicobacter pylori (ATCC43504) and thrombin inhibitory effects. As a result, new flavonoid derivatives 6 and 7 and (2 S)-4',7-dihydroxy-8-methylflavan ( 11) were found to be most efficacious against H. pylori (ATCC43504) with MIC values of 29.5, 29.5, and 31.3 microM, respectively, and the seven new flavonoid derivatives ( 1- 7) and one known biflavonoid ( 9) were observed to exhibit moderate thrombin inhibitory activity.

Anti-tumor promoting potential of luteolin against 7,12-dimethylbenz(a)anthracene-induced mammary tumors in rats

In this study, we evaluated the anti-tumor potential of luteolin (30mg/kg, p.o.), combined with cyclophosphamide (10mg/kg, i.p.) (LU+CYC) orally administered for 20 days; and CYC individually for 10 days against 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinogenesis in Wistar rats. Combination treatment (LU+CYC) inhibited the incidence rate of tumors and decreased tumor volume significantly without changing the total body weight of the animals. Long-term treatment did not show any apparent toxicity in rats. The CYC-treated group showed potential reduction of tumor volume (74%), severe toxicity, and loss of body weight. In order to elucidate the anticancer mechanism of luteolin, antioxidant activities such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) generation in the liver, kidney and breast, as well as protein profiles, were also examined. Biochemical analysis of the combination-treated group showed significant (P<0.01; P<0.05) inhibition of lipid peroxide (LPx) formation (oxygen-free radicals), the level and the activity of SOD, CAT and GPx were found to be very high than the LU and CYC individually treated rats at a 30mg/kg dose. 2D gel electrophoresis analysis revealed that (56kDa) high molecular weight protein was detected in tumors of rats receiving combination treatment than the cancer controls. The biological significance of that protein involved for the dysfunction of cancer cells and induces apoptosis. Histopathological changes also confirmed the formation of tumor tubules and neovascularization after the treatment. Overall, these results suggest that the combination treatment provided antioxidant defense with strong chemopreventive activity against the genesis of DMBA-induced mammary tumors.