RESUMO
The young leaves of Phyllanthus acidus (Euphorbiaceae) are commonly used as edible vegetables in Indonesia, Thailand, and India, and their water infusions as dieting aids for people trying to remain slim. However, it is regarded as a poisonous plant in Malaya, and current researches are insufficient to provide a conclusion on its toxicity and safety under large doses. In this study, we firstly found that the refined nonpolar extracts of P. acidus leaves showed significant cytotoxic effect against BEAS-2B and L02 normal cell lines with IC50 values of 2.15 and 1.64 mg/mL, respectively. Further bioactivity-guided isolation produced four new rare dichapetalins (pacidusins A-D) from the most active fraction. Their structures including absolute configurations were elucidated by extensive spectroscopic data and X-ray diffraction analysis. All the isolated dichapetalins exhibited moderate cytotoxicity against, BEAS-2B and L02 normal cell lines with IC50 values ranging from 12.44 to 22.55 µM, as well as five human cancer cell lines with IC50 values ranging from 3.38 to 22.38 µM. Furthermore, the content of the main dichapetalins in the leaves were determined by analytical HPLC, which showed that the leaves contained a very high amount of the four isolated dichapetalins with a total yield of 0.488 mg/g of dry plant material. These toxic dichapetalins may lead to adverse health effects in higher doses. Our findings indicate that the dichapetalin containing leaves may not be suitable for consumption in large quantities as food, but demonstrate their potency as anti-cancer agents for new drug discovery.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Phyllanthus/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Relação Estrutura-AtividadeRESUMO
Ten previously undescribed glycosides, carissaedulosides A-J (1-10) referring to six apiosylated phenylpropanoids (1-6), one coumarin-secoiridoid hybrid (7), and three furofuran lignans (8-10) were isolated from the root barks of Carissa edulis, together with 13 known analogues (11-23). Their structures were elucidated by spectroscopic analysis, ECD computational methods, and chemical derivations for configurations of sugar moieties. The new lignan bisdesmoside, 10, exhibited significant cytotoxicity against A549 (IC50 = 3.87 ± 0.03 µM) and MCF-7 (IC50 = 9.231 ± 0.290 µM) cell lines, while the known lignan monodesmoside, 12, showed impressive cytotoxic efficacy (IC50 = 5.68 ± 0.180 µM) against only MCF-7 cell line. It is noted that a known cardenolide, 11, displayed strong cytotoxic potency against HL-60, A549, MCF-7 and SW480 cell lines with IC50 values ranging from 0.023 to 0.137 µM. Moreover, compound 11 induced dose-dependent apoptosis on SW480 cell, but not explicit dose-dependent apoptosis on HL-60 cells.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apocynaceae/química , Glicosídeos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Glicosídeos/química , Glicosídeos/isolamento & purificação , Humanos , Estrutura Molecular , Raízes de Plantas/química , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Management errors during pre-hospital care, triage process and resuscitation have been widely reported as the major source of preventable and potentially preventable deaths in multiple trauma patients. Common tools for defining whether it is a preventable, potentially preventable or non-preventable death include the Advanced Trauma Life Support (ATLS®) clinical guideline, the Injury Severity Score (ISS) and the Trauma and Injury Severity Score (TRISS). Therefore, these surrogated scores were utilized in reviewing the study's trauma services. METHODS: Trauma data were prospectively collected and retrospectively reviewed from January 1, 2018, to December 31, 2018. All cases of trauma death were discussed and audited by the Hospital Trauma Committee on a regular basis. Standardized form was used to document the patient's management flow and details in every case during the meeting, and the final verdict (whether death was preventable or not) was agreed and signed by every member of the team. The reasons for the death of the patients were further classified into severe injuries, inappropriate/delayed examination, inappropriate/delayed treatment, wrong decision, insufficient supervision/guidance or lack of appropriate guidance. RESULTS: A total of 1913 trauma patients were admitted during the study period, 82 of whom were identified as major trauma (either ISS > 15 or trauma team was activated). Among the 82 patients with major trauma, eight were trauma-related deaths, one of which was considered a preventable death and the other 7 were considered unpreventable. The decision from the hospital's performance improvement and patient safety program indicates that for every trauma patient, basic life support principles must be followed in the course of primary investigations for bedside trauma series X-ray (chest and pelvis) and FAST scan in the resuscitation room by a person who meets the criteria for trauma team activation recommended by ATLS®. CONCLUSION: Mechanisms to rectify errors in the management of multiple trauma patients are essential for improving the quality of trauma care. Regular auditing in the trauma service is one of the most important parts of performance improvement and patient safety program, and it should be well established by every major trauma center in Mainland China. It can enhance the trauma management processes, decision-making skills and practical skills, thereby continuously improving quality and reducing mortality of this group of patients.
Assuntos
Traumatismo Múltiplo/mortalidade , Melhoria de Qualidade , Adolescente , Adulto , Cuidados de Suporte Avançado de Vida no Trauma , Idoso , Feminino , Humanos , Escala de Gravidade do Ferimento , Masculino , Auditoria Médica , Pessoa de Meia-Idade , Traumatismo Múltiplo/terapia , Segurança do Paciente , Estudos Retrospectivos , Adulto JovemRESUMO
Arsenic (As) can be easily enriched in atmospheric particulate matters (PMs), especially in fine particulate matters (PM2.5). In this study, thirty two PM2.5 samples were collected in four seasons in Baoding, China, where the haze pollution was very serious in recent years. The total contents, species and bioavailability of arsenic in PM2.5 samples were investigated. Species of arsenic in the PM2.5 samples were discriminated as five fractions using a sequential extraction method: non-specifically sorbed fraction (F1), specifically-sorbed fraction (F2), amorphous and poorly-crystalline hydrous oxides of Fe and Al fraction (F3), well-crystallized hydrous oxides of Fe and Al fraction (F4) and residual fraction (F5). Bioavailabilities of arsenic in the PM2.5 samples were evaluated by in vitro tests using both solubility bioavailability research consortium (SBRC) and Gamble's solution extraction methods. The total volume concentrations of As in PM2.5 were significantly higher in winter than the other seasons. However, the highest mass concentration of As was found in spring. Scanning electron microscopy (SEM) characterization indicated that the physical morphology of the particles varied in different seasons. Significant differences of fraction distribution and BFs were found between different seasons. Arsenic in PM2.5 samples mainly presented in F1 with high bioavailability factor (BF), especially for the samples in summer. In vitro tests indicated that arsenic in PM2.5 could be dissolved more easily in gastric phase rather than intestinal and lung phases. There was a significant correlation between species and in vitro tests. Interestingly, a synergy effect was found between F2 and F3. Health risk assessment indicated that arsenic in PM2.5via inhalation exposure for both children and adults could cause adverse effects. Principal component analysis suggested that the arsenic in PM2.5 was from the similar sources between summer and autumn, winter and spring, respectively.
Assuntos
Poluentes Atmosféricos/análise , Arsênio/análise , Monitoramento Ambiental/métodos , Exposição por Inalação/análise , Material Particulado/análise , Adulto , Disponibilidade Biológica , Criança , China , Cidades , Humanos , Tamanho da Partícula , Estações do AnoRESUMO
Sixty-three amide alkaloids, including three new, piperflaviflorine A (1), piperflaviflorine B (2), and sarmentamide D (4), and two previously synthesized ones, (1E,3S)-1-cinnamoyl-3- hydroxypyrrolidine (3) and N-[7'-(4'-methoxyphenyl)ethyl]-2-methoxybenzamide (5), were isolated from the aerial parts of Piper flaviflorum and Piper sarmentosum. Their structures were elucidated by detailed spectroscopic analysis and, in case of 3, by single-crystal X-ray diffraction. Most of the isolates were tested for their antifungal and antibacterial activities. Ten amides (6-15) showed antifungal activity against Cryptococcus neoformans ATCC 90â113 with IC50 values in the range between 4.7 and 20.0 µg/mL.
Assuntos
Alcaloides/farmacologia , Amidas/farmacologia , Antifúngicos/farmacologia , Cryptococcus neoformans/efeitos dos fármacos , Estrutura Molecular , Piper/química , Alcaloides/química , Alcaloides/isolamento & purificação , Amidas/química , Amidas/isolamento & purificação , Antifúngicos/química , Antifúngicos/isolamento & purificação , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Difração de Raios XRESUMO
Two new compounds, (Z,R)-1-phenylethylcinnamate (1) and (1R,2R,3R,6S)-pipoxide (2) were isolated from the aerial part of Piper hainanense, along with 12 known compounds, including nine benzene derivatives (4-11), one isobutylamide (12), and two polyoxygenated cyclohexene derivatives (13-14). Their structures were elucidated on the basis of the HRESIMS, 1D and 2D NMR spectroscopic analyses, and ECD in cases of 2 and 3. The absolute configuration of ellipeiopsol B (3) was determined for the first time. All these compounds 1-14 were reported from the titled plant for the first time. Most of the isolates were tested for their cytotoxicities against five human cancer cell lines. Four of which, 2, 3, 9, 14 showed moderate bioactivities. Among them, the new compound 2 showed potential cytotoxicity against SMMC-7721, MCF-7, and SW-480 with IC50 values of 9.7, 15.0, and 13.2 µM, respectively.
Assuntos
Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Cinamatos/isolamento & purificação , Cinamatos/farmacologia , Cicloexenos/isolamento & purificação , Cicloexenos/farmacologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Piper/química , Antineoplásicos Fitogênicos/química , Cinamatos/química , Cicloexenos/química , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Triterpenos/químicaRESUMO
The roots of Panax notoginseng, an important Chinese medicinal plant, have been used traditionally in both the raw and processed forms, due to the different chemical constituents and bioactivities found. Thirty-eight dammarane-type triterpenoid saponins were isolated from the steam-processed roots of P. notoginseng, including 18 new substances, namely, notoginsenosides SP1-SP18 (1-18). The structures of 1-18 were determined on the basis of spectroscopic analysis and acidic hydrolysis. The absolute configuration of the hydroxy group at C-24 in 1-4, 19, and 20 was determined in each case by Mo2(AcO)4-induced circular dichroism. The new compounds were found to feature a diversity of highly oxygenated side chains, formed by hydrolysis of the C-20 sugar moiety followed by dehydration, dehydrogenation, epoxidation, hydroxylation, or methoxylation of the main saponins in the raw roots. The new saponins 1, 2, 6-8, 14, and 17 and the known compounds 20-27 showed promoting effects on the differentiation of PC12 cells, at a concentration of 10 µM.
Assuntos
Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Panax notoginseng/química , Plantas Medicinais/química , Saponinas/isolamento & purificação , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Medicamentos de Ervas Chinesas/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Células PC12 , Raízes de Plantas/química , Ratos , Saponinas/química , Saponinas/farmacologia , Triterpenos/química , DamaranosRESUMO
Nineteen new highly oxygenated norbisabolane sesquiterpenoids, phyllanthacidoid acid methyl ester (1), and C-T (4-21), were isolated from Phyllanthus acidus Skeels, together with two known ones, phyllanthusols A (2) and B (3), whose sugar moiety was revised as glucosamine-N-acetate, rather than the previously assigned mannosamine-N-acetate. Compounds 2 and 3 were renamed respectively as phyllanthacidoids A (2) and B (3) to avoid confusion. All of the isolates except for 1 are glycosides, whose saccharide moieties possess a pentaoxy cyclohexane (scyllo quercitol) connecting with glucosamine-N-acetate or glucosyl moieties, which are first examples in natural products. Phyllanthacidoids N-R (15-19) with 8R configurations and/or 5,8-diketal skeleton, are unprecedented structures among norbisabolane sesquiterpenoids. Phyllanthacidoids S (20) and T (21) have the unusual tricyclo [3.1.1.1] oxygen bridge skeleton formed by a diketal system, of which the relative configurations of the aliphatic chain were assigned on the basis of heteronuclear coupling constants. The absolute configurations of compounds (1-21) were established by means of calculated electronic circular dichroism (ECD) and coupling constants. Compounds 1-5, 7-9, 10, and 14 displayed potential anti-hepatitis B virus (HBV) activities, with IC50 values of 0.8-36 µM against HBV surface antigen (HBsAg) and HBV excreted antigen (HBeAg), and the results indicated that the 5-ketal group and sugar moieties had contributions to the selectivity of HBsAg and HBeAg.
Assuntos
Antivirais/química , Antivirais/isolamento & purificação , Antivirais/farmacologia , Benzofuranos/química , Benzofuranos/farmacologia , Dissacarídeos/química , Dissacarídeos/farmacologia , Glicosídeos/química , Antígenos de Superfície da Hepatite B/química , Antígenos E da Hepatite B/química , Vírus da Hepatite B/química , Vírus da Hepatite B/efeitos dos fármacos , Phyllanthus/química , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Compostos de Espiro/química , Compostos de Espiro/farmacologia , Benzofuranos/isolamento & purificação , Dissacarídeos/isolamento & purificação , Antígenos de Superfície da Hepatite B/imunologia , Antígenos E da Hepatite B/imunologia , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Teoria Quântica , Compostos de Espiro/isolamento & purificação , EstereoisomerismoRESUMO
During the process exploring anti-viral compounds from Phyllanthus species, eight new highly oxygenated bisabolane sesquiterpenoid glycoside phyllaemblicins G1G8 (18) were isolated from Phyllanthus emblica, along with three known compounds, phyllaemblicin F (9), phyllaemblic acid (10) and glochicoccin D (11). Phyllaemblicin G2 (2), bearing a tricyclo [3.1.1.1] oxygen bridge ring system, is an unusual sesquiterpenoid glycoside, while phyllaemblicins G6G8 (68) are dimeric sesquiterpenoid glycosides with two norbisabolane units connecting through a disaccharide. All the structures were elucidated by the extensive analysis of HRMS and NMR data. The relative configuration of phyllaemblicin G2 was constructed based on heteronuclear coupling constants measurement, and the absolute configurations for all new compounds were established by calculated electronic circular dichroism (ECD) using time dependent density functional theory. The sesquiterpenoid glycoside dimers 69 displayed potential anti-hepatitis B virus (HBV) activities, especially for the new compound 6 with IC50 of 8.53 ± 0.97 and 5.68 ± 1.75 µM towards the HBV surface antigen (HBsAg) and HBV excreted antigen (HBeAg) secretion, respectively.
Assuntos
Antivirais/química , Glicosídeos/química , Vírus da Hepatite B/efeitos dos fármacos , Phyllanthus emblica/química , Sesquiterpenos/química , Antivirais/isolamento & purificação , Antivirais/farmacologia , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Células Hep G2 , Antígenos de Superfície da Hepatite B/análise , Antígenos E da Hepatite B/análise , Vírus da Hepatite B/fisiologia , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Extratos Vegetais/química , Raízes de Plantas/química , Teoria Quântica , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia , Terpenos/química , Terpenos/isolamento & purificação , Terpenos/farmacologiaRESUMO
OBJECTIVE: To investigate the clinical significance of transforming growth factor-beta 1 (TGF-ß1) in children with primary IgA nephropathy (IgAN). METHODS: Thirty children who were diagnosed with primary IgAN by renal biopsy between May 2008 and October 2012 were included in the study. Thirty healthy children were used as the control group. Urinary and blood TGF-ß1 levels were measured using enzyme-linked immunosorbent assay, and the protein expression of TGF-ß1 in the renal tissue was measured by immunohistochemistry. The correlation between TGF-ß1 levels in blood, urine, and renal tissue and their relationship with clinical indices were analyzed. RESULTS: Children with primary IgAN had significantly higher urinary and blood TGF-ß1 levels than the control group (P<0.01). Urinary TGF-ß1 level was positively correlated with the pathological grade of renal tissue (r=0.557, P=0.001), and a significant positive correlation was also found between the TGF-ß1 expression in the renal tissue and the pathological grade of renal tissue (r=0.682, P<0.01). There was no correlation between TGF-ß1 levels in blood and renal tissue (r=0.038, P=0.844). CONCLUSIONS: Urinary TGF-ß1 level is significantly positively correlated with the pathological severity of disease in children with primary IgAN. Clinical measurement of urinary TGF-ß1 may be of great practical value in predicting the progression and prognosis of chronic nephropathy.
Assuntos
Glomerulonefrite por IGA/patologia , Fator de Crescimento Transformador beta1/fisiologia , Adolescente , Criança , Feminino , Glomerulonefrite por IGA/metabolismo , Humanos , Rim/química , Rim/patologia , Masculino , Fator de Crescimento Transformador beta1/análise , Fator de Crescimento Transformador beta1/urinaRESUMO
Quantitative analysis of Rumex nepalensis var. remotiflorus revealed that its roots contain rich anthraquinones, which has emodin, chrysophanol, and physcion contents of up to 0.30, 0.67, and 0.98 mg/g, respectively. Further phytochemical study led to the isolation and purification of seven undescribed phenolic constituents, including one flavan derivative with a 13-membered ring, polygorumin A (1), two dianthrone glucosides, polygonumnolides F and G (2, 3), two diphenylmethanones, rumepalens A and B (4, 5), and a pair of epimeric oxanthrone C-glucosides, rumejaposides K and L (6a, 6b) from the roots of R. nepalensis var. remotiflorus. Furthermore, 1 undescribed natural product, 1-ß-D-glucoside-6'-[(2E)-3-(4-hydroxy-3-methoxyphenyl)-2-propenoate]-3-hydroxy-5-methylphenyl (19), and 21 known phenolic compounds were obtained from the aforementioned plant for the first time. Their structures were elucidated through extensive spectroscopic data analysis. Notably, compounds 1, 4-5, and 7-9 exhibited inhibitory activity on α-glucosidase with IC50 values ranging from 1.61 ± 0.17 to 32.41 ± 0.87 µM. In addition, the isolated dianthrone, chrysophanol bianthrone (14), showed obvious cytotoxicity against four human cancer cell lines (HL-60, SMMC-7721, A-549, and MDA-MB-231) with IC50 values ranging from 3.81 ± 0.17 to 35.15 ± 2.24 µM. In silico target prediction and molecular docking studies demonstrated that the mechanism of the anticancer activity of 14 may be related to the interaction with protein kinase CK2.
Assuntos
Antineoplásicos Fitogênicos , Inibidores de Glicosídeo Hidrolases , Fenóis , Rumex , alfa-Glucosidases , Humanos , Fenóis/farmacologia , Fenóis/química , Fenóis/isolamento & purificação , Inibidores de Glicosídeo Hidrolases/farmacologia , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/isolamento & purificação , Rumex/química , alfa-Glucosidases/metabolismo , alfa-Glucosidases/efeitos dos fármacos , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Estrutura Molecular , Ensaios de Seleção de Medicamentos Antitumorais , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Linhagem Celular Tumoral , Raízes de Plantas/química , Relação Dose-Resposta a Droga , Proliferação de Células/efeitos dos fármacosRESUMO
Six new bisbenzylisoquinoline alkaloids (1-6) and seven known compounds (8-14) were isolated from the tubers of Stephania epigaea, in addition to the major alkaloid, cepharanthine (7). The structures of 1-6 were elucidated by combined spectroscopic data analysis and chemical methods, with their configurations determined from their optical rotation values and confirmed using circular dichroism. Compounds 1-6 belong to the oxyacanthine type of bisbenzylisoquinoline alkaloids and have a rare methylenedioxy substituent. Compound 1, a dimer composed of benzylisoquinoline and seco-aristolactam units, represents a new type of bisbenzylisoquinoline alkaloid, while compounds 3-6 are bisbenzylisoquinoline N-oxides. These compounds were evaluated for their in vitro cytotoxicities against six human cancer cell lines (A-549, ECA109, HL-60, MCF-7, SMMC-7721, and SW480). Cepharanthine (7), the major component of S. epigaea, exhibited cytotoxicity against all of these cancer cell lines except ECA109, while its known analogue, 10, displayed cytotoxicity against all six cancer cell lines.
Assuntos
Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Benzilisoquinolinas/isolamento & purificação , Benzilisoquinolinas/farmacologia , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Stephania/química , Alcaloides/química , Antineoplásicos Fitogênicos/química , Benzilisoquinolinas/química , Dicroísmo Circular , Ensaios de Seleção de Medicamentos Antitumorais , Medicamentos de Ervas Chinesas/química , Espectroscopia de Ressonância de Spin Eletrônica , Células HL-60 , Humanos , Isoquinolinas/farmacologia , Estrutura Molecular , Tubérculos/químicaRESUMO
Four new phenolic compounds, including two naphthalenes, musizin-8-O-ß-D-(6'-O-malonyl-3''-methoxy)glucopyranoside (1) and 2-acetyl-3-methyl-1,4-naphtho-quinone-8-O-ß-D-glucopyranoside (2), one chromone, (2'R)-7-hydroxy-2-(2'-hydroxypropyl)-5-methyl acetate chromone (3), and one xanthone, 2,8-dimethyl-3,6-dihydroxyxanthone (4) were isolated from the roots of Rumex dentatus L. (Polygonaceae). In addition, five known including four naphthalenes (5-8) and one chromone (9) were also obtained. Their structures were determined by means of extensive spectroscopic analysis and acidic hydrolysis. Compound 1 showed moderate antifungal activity against Epidermophyton floccosum, with inhibitory rate of 39.539 ± 0.412% at a concentration of 100 µM.
Assuntos
Polygonaceae , Rumex , Estrutura Molecular , Polygonaceae/química , Raízes de Plantas/química , NaftalenosRESUMO
Eleven flavonoids including one new flavonol glycoside, quercetin-3-O-(2-α-L-rhamnopyranosyl)-ß-D-glucuronopyranosyl methyl ester (1), were isolated for the first time from the fruits of Phyllanthus acidus (L.) Skeels (Phyllanthaceae). Their structures were determined by extensive spectroscopic data. The known flavonoids, quercetin-3-O-ß-D-glucuronide methyl ester (3), quercetin-3-O-(2''-α-L-rhamnopyranosyl-6''-O-α-L-rhamno pyranosyl)-ß-D-glucopyranoside (5), myricetin (9), and 6-methoxy-naringenin (11) were isolated for the first time from the genus Phyllanthus. Flavonoids 4, 6 and 9 (IC50 = 6.01, 6.32, and 7.84 µM, respectively) showed stronger α-glucosidase inhibitory activities than the positive control, acarbose (IC50 = 306.45 µM). The fruits of P. acidus might be further developed as an anti-diabetic food supplement.
Assuntos
Phyllanthus , Quercetina , Quercetina/análise , Frutas/química , Phyllanthus/química , Flavonoides/química , GlucosidasesRESUMO
Panax notoginseng (PN) is a well-known traditional Chinese medicine, with dammarane-type triterpenoid saponins characterized as major component and active ingredients, together with amino acids, flavonoids, polysaccharides, and polyacetylenes. The roots of PN are susceptible to root rot disease, which causes a huge loss and changes in the chemical components of this precious resource. In this study, sub-fractions of rot PN root extracts were preliminarily found to have admirable cytotoxicity on two human cancer cells. Further bioassay-guided isolation discovered nine new non-triterpenoids, including two novel N-methylacetamido-1-oxotetrahydropyrimidine alkaloids (1, 2), five 2H-furanones or 2H-pyranones (3-7), and two polyacetylenic alcohols (8, 9). Their structures were illuminated by extensive spectroscopic data, calculated ECD, and X-ray diffraction analysis. Among them, 3-7 were considered to be transformed from panaxatriol through the intermediates (8, 9). The new alkaloids (1, 2) displayed noteworthy cytotoxicity against five human cancer cells with IC50 values ranging from 14 to 24 µM. In silico target prediction and molecular docking studies showed that 1 and 2 may interact with EGFR, and were verified by the experimental inhibitory effect on EGFR tyrosine kinase.
RESUMO
Camellia taliensis (W. W. Smith) Melchior, belonging to the genus Camellia sect. Thea., is mainly distributed from northern Myanmar to western and southwestern Yunnan province of China, and its leaves have been used to make various teas by the locals of its growing regions. The chemical constituents of C. taliensis are significantly related to those of cultivated tea plants, C. sinensis and C. sinensis var. assamica. The HPLC-ESI-MS analysis of black tea prepared from the leaves of C. taliensis showed a rich existence of polyphenols. Further comprehensive chemical study led to the separation and recognition of 32 compounds (1-32), including one new hydrolyzable tannin, 1-O-galloyl-4,6-tetrahydroxydibenzofurandicarboxyl-ß-D-glucopyranose (1), and one new natural product (24). The known compounds referred to seven hydrolyzable tannins (2-8), 10 flavonols and glycosides (9-18), and 14 simple phenolics (19-32). Their structures were elucidated by comprehensive spectroscopic analyses. Among them, 20 compounds (2, 3, 6, 7, 8, 15, 17, 18, 20-22, 24-32) were isolated from black tea for the first time. Most isolates displayed obvious antioxidant activities on DPPH and ABTS+ assays, and the hydrolyzable tannins 1, 3-5, 7, and 8 exhibited stronger inhibitory activities on α-glycosidase than quercetin and acarbose (IC50 = 5.75 and 223.30 µM, respectively), with IC50 values ranging from 0.67 to 2.01 µM.
RESUMO
Three new phenolic compounds, eucalmaidin F (1), (3S)-5-guaiacyl-3-hydroxypentanoic acid (2), and 8-ß-C-glucopyranosyl-5,7-dihydroxy-2-isobutylchromone (3), were isolated from the branches of E. maideni, together with 30â known compounds, including four phenylpropanoids, three lignans, four phloroglucinol glucosides, five dihydroflavonoids, seven simple phenolic compounds, six terpenoids, and glycerol. The new structures were established by spectroscopic studies (MS, and 1D- and 2D-NMR), chemical degradation, and modified Mosher's method. Compounds 3, guaiacylglycerol, 3-hydroxy-1-(4-hydroxyphenyl)propan-1-one, caffeic acid, (2E)-3-(4-hydroxyphenyl)prop-2-enoic acid, (7'S,8R,8'R)-lyoniresinol, (+)-lyoresinol 3α-O-α-L-rhamnopyranoside, garcimangosone, phlorocetophenone 2'-glucopyranoside, (+)-taxifolin 3α-O-α-L-rhamnopyranoside, (+)-aromadendrin, (+)-taxifolin, resveratrol, piceatannol, 3,4,5-trihydroxyphenol. Tachiaside, gallic acid, macrocapals A und G, and oleuropeic acid were evaluated for their cytotoxicities against five human cancer cell lines. Resveratrol, piceatannol, gallic acid, and macrocapal G exhibited moderate inhibitory effects on human myeloid heukemia HL-60 cell, with IC(50) values of 22.05, 22.05, 7.75, and 31.93â µM, respectively; and only macrocapal G showed inhibitory effect on hepatocellular carcinoma SMMC-7721 cell, with an IC(50) value of 26.75â µM.
Assuntos
Cromonas/química , Eucalyptus/química , Flavonas/química , Fenóis/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cromonas/isolamento & purificação , Cromonas/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Flavonas/isolamento & purificação , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Conformação Molecular , Fenóis/isolamento & purificação , Fenóis/farmacologia , Caules de Planta/químicaRESUMO
Fuzhuan brick tea, a kind of dark tea consumed mainly in the border regions of Southwestern and Northwestern China since the 1860s, is produced from the leaves of Camellia sinensis var. sinensis by microbial fermentation. From this special fermented tea, a new norisoprenoid, 3R,9R-oxido-5-megastigmene, was isolated, together with α-linolenic acid, strictin, isovitexin, astragalin, (+)-catechin, (-)-epicatechin, (-)-epicatechin gallate, (+)-gallocatechin, (-)-epigallocatechin, (-)-epigallocatechin gallate and gallic acid. The structures of the compounds were identified by spectroscopic means. The new compound didn't show any inhibition activity against the tested enteric pathogenic microorganisms at a concentration of 800 µg/mL by the hole plate diffusion method.
Assuntos
Camellia sinensis/química , Antibacterianos/química , Antibacterianos/farmacologia , Apigenina/análise , Apigenina/farmacologia , Catequina/análogos & derivados , Catequina/análise , Catequina/farmacologia , Escherichia coli Enteropatogênica/efeitos dos fármacos , Ácido Gálico/análise , Ácido Gálico/farmacologia , Estrutura Molecular , Norisoprenoides/análise , Norisoprenoides/farmacologia , Ácido alfa-Linolênico/análise , Ácido alfa-Linolênico/farmacologiaRESUMO
The broad learning system (BLS) is an emerging flat network, which has demonstrated its outstanding performance in classification and regression problems. The regularization plays an important role in the performance of the BLS. In real applications, since the BLS network is usually expanded dynamically, a predetermined regularization parameter may reduce the performance of the network. Using a fixed regularization in some cases, the classification accuracy of the BLS decreases dramatically when we expand the network. To alleviate this problem, we propose a method that automatically finds appropriate regularization parameters for different datasets, which is based on the weighted generalized cross-validation (WGCV). The experimental results indicate that the WGCV method improves the performance of the BLS, and alleviates the accuracy decrease of the incremental learning algorithm.
Assuntos
AlgoritmosRESUMO
Deep neural networks have achieved breakthrough improvement in various application fields. Nevertheless, they usually suffer from a time-consuming training process because of the complicated structures of neural networks with a huge number of parameters. As an alternative, a fast and efficient discriminative broad learning system (BLS) is proposed, which takes the advantages of flat structure and incremental learning. The BLS has achieved outstanding performance in classification and regression problems. However, the previous studies ignored the reason why the BLS can generalize well. In this article, we focus on the interpretation from the viewpoint of the frequency domain. We discover the existence of the frequency principle in BLS, i.e., the BLS preferentially captures low-frequency components quickly and then fits the high frequencies during the incremental process of adding feature nodes and enhancement nodes. The frequency principle may be of great inspiration for expanding the application of BLS.