Antifungal chromans inhibiting the mitochondrial respiratory chain of pea seeds and new xanthones from Calophyllum caledonicum

Two new xanthones, caledonixanthone M 1 and caloxanthone L 2, and one new acid, caledonic acid 6 were isolated from the hexane-soluble extract of the stem bark of Calophyllum caledonicum. In the course of this phytochemical study, seven other known compounds - calothwaitesixanthone, calozeyloxanthone, allanxanthone, isoapetalic acid 3, calolongic acid 4, apetalic acid 5 and isocalolongic acid 7 - were isolated. Their antifungal activity against the growth of the human pathogenic fungus Aspergillus fumigatus was then investigated. The results indicated that the crude extract, calolongic acid 4 and isocalolongic acid 7 exhibited strong inhibitory effects with MIC (80) values of 8, 4, 2 microg/mL, respectively. Besides, calolongic acid 4, its lactone derivative 4a and isocalolongic acid 7 markedly reduced the respiration of pea seed mitochondria.     

Cytotoxic prenylated xanthones from Calophyllum inophyllum

A new prenylated xanthone (1), named caloxanthone N, together with two known constituents, gerontoxanthone C (2) and 2-hydroxyxanthone (3), was isolated from the ethanolic extract of the twigs of Calophyllum inophyllum. Their structures were completely elucidated using a combination of 1D, 2D NMR techniques (COSY, HMQC, HMBC, and ROESY) and HR-ESI-MS analyses. Compounds 1 and 2 exhibited cytotoxicity against chronic myelogenous leukemia cell line (K562) with IC₅₀ values of 7.2 and 6.3 μg ml^? 1, respectively.     

Cytotoxic and antifungal isoprenylated xanthones and flavonoids from Cudrania fruticosa

A new isoprenylated xanthone, cudrafrutixanthone A, was isolated from the roots of Cudrania fruticosa, together with 18 known compounds. Their structures were elucidated by spectroscopic methods. Most isoprenylated xanthones exhibited cytotoxicity against HCT-116, SMMC-7721, SGC-7901, and BGC-823 cell lines with IC (50) values of 1 - 5 microg/mL. Toxyloxanthone C and wighteone showed antifungal activity against Candida albicans with MICs of 25 and 12.5 microg/mL, respectively.     

Two new xanthones from the root of Thai Calophyllum inophyllum and their toxicity against colon and liver cancer cells

Journal of Natural Medicines - Two new xanthones, 1,3,6,7-tetrahydroxy-5-methoxy-4-(1′,1′-dimethyl-2′-propenyl)-8-(3″,3″-dimethyl-2″-propenyl)-xanthone (1) and...     

Secoiridoids and xanthones from Gentianella nitida

From Gentianella nitida twelve known metabolites were isolated and identified by HPLC-UV and/or by spectroscopic methods as secologanoside, amaroswerin, amarogentin (secoiridoids), isoorientin (C-glucosylflavone), mangiferin, demethylbellidifolin 8-O-glucoside, norswertianine 1-O-glucoside, swertianine 1-O-primeveroside, swertianine 8-O-glucoside, norswertianine, demethylbellidifolin, and swertianine (xanthone glycosides and aglycones). Secologanoside is reported here for the first time in Gentianaceae species; the antioxidant mangiferin was obtained as the major compound in good yield.     

Investigation of the antifungal activity of caledonixanthone E and other xanthones against Aspergillus fumigatus

Among the different xanthones previously isolated from the stem bark of Calophyllum caledonicum, caledonixanthone E presented the strongest activity (MIC (80) = 8 microg/mL) in acidic conditions (pH 3) against the human pathogenic fungus Aspergillus fumigatus. Phase-contrast microscopy studies suggested the assembly or synthesis of cell wall components as the target of the drug. Moreover, the use of fluorescent lectins further supported an impact of caledonixanthone E on the synthesis of chitin, the major structural polysaccharide of the fungal wall. These results suggest that caledonixanthone E may be an interesting model for the design of new antifungal drugs.     

Secoiridoids and xanthones from Tylophora secamonoides Tsiang

A new secoiridoid, secamonoide A (1), and a new xanthone glycoside, secamonoide B (2), together with nine known compounds, were isolated from the aerial parts of Tylophora secamonoides Tsiang. Their structures were elucidated on the basis of spectroscopic methods. An antimicrobial bioassay showed that secamonoides A and B exhibited weak activities (MIC values greater than 100 mg/ml) against some hospital bacteria in vitro.     

Secoiridoids and xanthones from Tylophora secamonoides Tsiang

A new secoiridoid, secamonoide A (1), and a new xanthone glycoside, secamonoide B (2), together with nine known compounds, were isolated from the aerial parts of Tylophora secamonoides Tsiang. Their structures were elucidated on the basis of spectroscopic methods. An antimicrobial bioassay showed that secamonoides A and B exhibited weak activities (MIC values greater than 100 mg/ml) against some hospital bacteria in vitro.     

Two new xanthones from Polygala crotalarioides

Two new xanthones, 1,6,8-trihydroxy-7-methoxy-2,3-methylenedioxyxanthone (1) and 1,6-dihydroxy-7,8-dimethoxy-2,3-methylenedioxyxanthone (2), have been isolated from the roots of Polygala crotalarioides. Their structures were elucidated by spectral and chemical methods.     

Two new xanthones from Artocarpus obtusus

Two new xanthones, pyranocycloartobiloxanthone A (1) and dihydroartoindonesianin C (2), were isolated from the stem bark of Artocarpus obtusus Jarrett by chromatographic separation. Their structures were determined by using spectroscopic methods and comparison with known related compounds. Pyranocycloartobiloxanthone A (1) showed strong free radical scavenging activity by using DPPH assay as well as cytotoxicity towards K562, HL-60, and MCF7 cell lines.     

大叶藤黄中三个新《口山》酮类成分

为了研究大叶藤黄树皮中<口山>酮类成分,运用正相和反相硅胶柱色谱法对大叶藤黄树皮乙酸乙酯萃取物进行分离纯化,并用波谱技术鉴定化合物结构.共分离得到3个新<口山>酮类化合物,其结构分别鉴定为1,2,5-三羟基-6-甲氧基<口山>酮(1),1,4,6-三羟基-5-甲氧基<口山>酮(2),1,2,7-三羟基-4-(1,1-二甲基烯丙基)<口山>酮(3).     

Two new xanthones from Swertia angustifolia

Two new xanthones, angustins A and B (1 and 2), were isolated from the aerial parts of Swertia angustifolia together with six known compounds (3-8). The structures of these two xanthones were elucidated by extensive analysis of the spectroscopic data. In addition, compounds 3 and 6-8 were isolated from this plant for the first time.     

Two new xanthones from Polygala crotalarioides

Two new xanthones, 1,6,8-trihydroxy-7-methoxy-2,3-methylenedioxyxanthone (1) and 1,6-dihydroxy-7,8-dimethoxy-2,3-methylenedioxyxanthone (2), have been isolated from the roots of Polygala crotalarioides. Their structures were elucidated by spectral and chemical methods.     

New antifungal agents and preparations

In neutropenic patients amphotericin B remains the drug of choice for the treatment of systemic fungal infections. On the basis of a superior efficacy in combination with a lower toxicity, the triazoles have superseded the older azoles. Regularly, amphotericin B and a triazole are used simultaneously without any evidence from clinical trials that such a strategy is safe and efficacious. Liposomal preparation, lipid complex or colloidal dispersion of amphotericin B have been produced successfully to reduce toxicity. However, there is only one small randomised study that hints at the superiority of liposomal amphotericin B over amphotericin B deoxycholate. Promising new agents like candins, sordarins, high dose oral terbinafine, the third generation azoles, and liposomal nystatin are under development. The first phase II study on voriconazole in the treatment of pulmonary aspergillosis has produced encouraging results. The major promise of the new candins lies in the activity against Candida species, including those resistant to the azoles and polyenes, and in a mechanism of action totally different from the established antifungals. Cytokines and colony stimulating factors are theoretically very promising but there are no clinical studies that warrant routine use.     

New antifungal pyranoisoflavone from Ficus tikoua Bur

建立苗药地瓜藤的UHPLC指纹图谱,研究其与抗氧化活性的谱效关系,筛选抗氧化活性成分群。

采用UHPLC建立地瓜藤指纹图谱,运用《中药指纹图谱相似度评价系统》(2012版)进行相似度评价并指认共有峰,运用SPSS 16.0、SIMCA 14.1软件进行聚类分析(hierarchical cluster analysis,HCA) 和主成分分析(principal component analysis,PCA);采用1,1-二苯基-2-三硝基苯肼自由基清除法、2,2’-联氮-二(3-乙基苯并噻唑啉-6-磺酸)二铵盐自由基清除法和总抗氧化能力测定法评价16批地瓜藤抗氧化活性;运用灰色关联度分析(grey relational analysis,GRA)、双变量相关分析、偏最小二乘回归(partial least squares regression,PLSR)3种分析方法研究谱效关系。

建立了16批地瓜藤的UHPLC指纹图谱并标定13个共有峰,相似度为0.613~0.996,同时指认出峰9为芦丁、峰10为异槲皮素、峰12为水仙苷,HCA结果显示样品共聚为两类,与PCA结果一致;16批地瓜藤均有不同程度抗氧化活性。GRA结果显示13个共有峰与抗氧化活性之间的关联度>0.8,均具有高关联性,双变量相关性分析及PLSR分析结果表明峰5、峰9(芦丁)、峰10(异槲皮素)、峰11、峰12(水仙苷)的相关系数及回归系数与抗氧化活性呈正相关,且贡献度较大(变量重要性投影>1),为抗氧化活性的主要有效成分。

16批地瓜藤均具有较好的抗氧化活性,其发挥抗氧化作用是内部抗氧化成分群协同作用的结果,而共有峰5,9,10,11,12所对应的成分与其抗氧化活性密切相关,揭示了地瓜藤抗氧化活性的药效物质基础。

     

Five novel prenylated xanthones from Resina Garciniae

Fourteen prenylated xanthone derivatives were isolated from gamboge, the dry latex of Garcinia hanburyi, and their structures were elucidated by a detailed spectroscopic analysis. Five of them, isogambogenic acid (1), desoxymorellinin (2), 10-methoxygambogenic acid (3), 10-methoxygambogic acid (4) and 10-ethoxy gambogic acid (5), are new compounds. All of them showed potent cytotoxicity against HL-60, SMMC-7721 and BGC-83 cells.     

Five novel prenylated xanthones from Resina Garciniae

Fourteen prenylated xanthone derivatives were isolated from gamboge, the dry latex of Garcinia hanburyi, and their structures were elucidated by a detailed spectroscopic analysis. Five of them, isogambogenic acid (1), desoxymorellinin (2), 10-methoxygambogenic acid (3), 10-methoxygambogic acid (4) and 10-ethoxy gambogic acid (5), are new compounds. All of them showed potent cytotoxicity against HL-60, SMMC-7721 and BGC-83 cells.