Triterpenes and xanthones from the stem bark of Garcinia tetralata

A new compound, 3β,18,19β-trihydroxylupane, was isolated from Garcinia tetralata, along with five known compounds, garcinexanthone B, morolic acid acetate, toxyloxanthone A, 6,11-dihydroxy-2,2-dimethylpyrano[3,2-c]xanthen-7(2H)-one, and 1,4-dihydroxy-5,6-dimethoxy-xanthone. The structure of the new compound was established by extensive spectroscopic techniques.     

Three new biphenyls from the twigs of Garcinia tetralata and their anti-tobacco mosaic virus activity

Phytochemical investigations on the ethanol extract of the twigs of Garcinia tetralata resulted in the isolation of three new biphenyls, tetralatabiphenyls A–C (1–3), along with three known biphenyl derivatives (4–6). Structural elucidations of 1–3 were performed by spectroscopic methods such as 1D and 2D NMR spectra, in addition to high-resolution mass spectra. Compounds 1–6 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compound 3 showed high anti-TMV activity with inhibition rate of 31.1%. Compounds 1, 2, and 4–6 also showed modest anti-TMV activities with inhibition rates in the range of 18.9–24.5%, respectively.     

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).     

Antioxidant compounds from the stem bark of Garcinia atroviridis

A new xanthone, namely garcinexanthone G (1), along with eight known compounds, stigmasta-5,22-dien-3β-ol (2), stigmasta-5,22-dien-3-O-β-glucopyranoside (3), 3β-acetoxy-11α,12α-epoxyoleanan-28,13β-olide (4), 2,6-dimethoxy-p-benzoquinone (5), 1,3,5-trihydroxy-2-methoxyxanthone (6), 1,3,7-trihydroxyxanthone (7), kaempferol (8) and quercetin (9), were isolated from the stem bark of Garcinia atroviridis. Their structures were elucidated based on spectroscopic methods including nuclear magnetic resonance (NMR-1D and 2D), UV, IR, and mass spectrometry. All the isolated compounds were evaluated for their antioxidant properties based on the DPPH radical scavenging activities. Results showed that 1,3,7-trihydroxyxanthone and quercetin showed significant antioxidant activities with EC₅₀ values of 16.20 and 12.68 μg/ml, respectively, as compared to the control, ascorbic acid (7.4 μg/ml).     

Antibacterial caged-tetraprenylated xanthones from the stem bark of Garcinia scortechinii

Five new caged-tetraprenylated xanthones, scortechinones L - P (1-5), together with six known scortechinones (A, B, D, F, I and J) and one known xanthone, 4 ',5 '-dihydro-1,5-dihydroxy-6 ',6 '-dimethylpyrano(2 ',3 ':6,7)-4 ',4 ',5 '-trimethylfurano(2 ',3 ':3,4)- xanthone, were isolated from the crude methanol extract of the stem bark of Garcinia scortechinii. The structures were elucidated by analysis of spectroscopic data and comparison of the NMR data with those reported previously. The antibacterial activity of all caged-polyprenylated xanthones, isolated from the latex and stem bark of G. scortechinii, was evaluated. Scortechinone B (6) exhibited significant antibacterial activity against a methicillin-resistant Staphylococcus aureus strain with an MIC value of 2 microg/mL. From the MIC values, some structure-antibacterial activity relationships were established.     

A new furanoxanthone from Garcinia mangostana

Our phytochemical study on the stem bark of Garcinia mangostana has led to the discovery of a new furanoxanthone, mangaxanthone A (1), together with five known analogs. The five known analogs that were isolated are α-mangostin (2), β-mangostin (3), cowagarcinone B (4), and dulcisxanthone F (5). The structural elucidations of these compounds were carried out by interpreting their spectroscopic data, mainly 1D and 2D NMR spectra and MS.     

Trypanocidal constituents in plants 2.xanthones from the stem bark of Garcinia subelliptica

The constituents of the stem bark of Garcinia subelliptica (Guttiferae) were investigated based on its trypanocidal activity against epimastigotes of Trypanosoma cruzi, the etiologic agent for Chagas' disease. As the active components, nine xanthones were isolated including two new ones, 4-hydroxybrasilixanthone B and 1,3,5,6-tetrahydroxy-4,7,8-tri(3-methyl-2-butenyl)xanthone. Their structures were determined by spectroscopic analysis. Trypanocidal activity against trypomastigotes, an infectious form of T. cruzi, was also estimated as well as cytotoxic activity. Fukugetin, the major component of the bark, showed no activity.     

Two new xanthones and cytotoxicity from the bark of Garcinia schomburgkiana

Journal of Natural Medicines - Two new xanthone derivatives, named schomburgones A (1) and B (2), along with eight known compounds, including xanthones (3–8) and anthraquinones (9–10)...     

A new furanoxanthone from the stem bark of Calophyllum inophyllum

The stem bark extracts of Calophyllum inophyllum furnished one new furanoxanthone, inophinnin (1), in addition to inophyllin A (2), macluraxanthone (3), pyranojacareubin (4), 4-hydroxyxanthone, friedelin, stigmasterol, and betulinic acid. The structures of these compounds were determined by spectroscopic analysis of 1D and 2D NMR spectral data (¹H, ¹³C, DEPT, COSY, HMQC, and HMBC) while EI-MS gave the molecular mass. The new xanthone, inophinnin (1), exhibited some anti-inflammatory activity in nitric oxide assay.     

Two new xanthones from the stems of Cratoxylum cochinchinense

Two new xanthones, 6-hydroxy-3,7-dimethoxy-8-(3-methylbut-2-enyl)-6′,6′-dimethyl-5′-hydroxy-4′,5′-dihydropyrano(2′,3′:1,2)xanthone (1) and 6-hydroxy-3,7-dimethoxy-8-(2-oxo-3-methylbut-3-enyl)-6′,6′-dimethyl-5′-hydroxy-4′,5′-dihydropyrano(2′,3′:1,2)xanthone (2), have been isolated from the stems of Cratoxylum cochinchinense (Lour.) Blume. Their structures were established on the basis of spectroscopic analysis.     

Anti-inflammatory activity of mangostins from Garcinia mangostana.

The fruit hull of Garcinia mangostana Linn (Guttiferae) is used as an anti-inflammatory drug in Southeast Asia. Two xanthones, alpha- and gamma-mangostins, were isolated from the fruit hull of G. mangostana, and both significantly inhibited nitric oxide (NO) and PGE(2) production from lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The IC(50) values for the inhibition of NO production by alpha- and gamma-mangostins were 12.4 and 10.1 microM, respectively. After iNOS enzyme activity was stimulated by LPS for 12 h, treatment with either alpha- or gamma-mangostin at 5 microg/ml (12.2 and 12.6 microM, respectively) for 24 h did not significantly inhibit NO production. The data show that the inhibitory activities of alpha- and gamma-mangostins are not due to direct inhibition of iNOS enzyme activity. On the other hand, expression of iNOS was inhibited by alpha- and gamma-mangostins in LPS-stimulated RAW 264.7 cells, but not by COX-2. However, the level of PGE(2) production was reduced by the two xanthones. In an in vivo study, alpha-mangostin significantly inhibited mice carrageenan-induced paw edema. In conclusion, alpha- and gamma-mangostins from G. mangostana are bioactive substances with anti-inflammatory effects.     

岭南山竹子树皮化学成分研究

目的研究藤黄属植物岭南山竹子树皮中的化学成分。方法利用硅胶、Sephadex LH-20等色谱法对山竹子树皮中的化学成分进行分离以及根据所获单体化合物的理化性质和光谱数据（紫外、核磁共振、质谱）鉴定其结构。结果从山竹子树皮中分离得到7个单体化合物,经鉴定分别为10-hydroxybotryococcene（1）、peplusol（2）、stigmast-4-en-3-one（3）、parvifiol（4）、1,2-benzenedicarboxylic acid bis（2-methyl heptyl）ester（5）、camboginol（6）、pedunxanthone C（7）。结论化合物1～7均为首次从该种植物中分离得到。     

Cytotoxic xanthones and biphenyls from the root of Garcinia linii

Three new xanthones, linixanthones A-C, two new biphenyls, garcibiphenyls A and B, and a new benzopyran, garcibenzopyran, together with twelve known xanthones and a known biphenyl have been isolated from the root of Garcinia linii. The structures of these new compounds were determined through spectral analyses. Among the isolates, five compounds exhibited cytotoxicities (ED50 values < 4 microg/mL) against P-388 and HT-29 cell lines in vitro.     

Quantitative and qualitative determination of six xanthones in Garcinia mangostana L. by LC-PDA and LC-ESI-MS

A new method was developed for the simultaneous analysis of six naturally occurring xanthones (3-isomangostin, 8-desoxygartanin, gartanin, alpha-mangostin, 9-hydroxycalabaxanthone and beta-mangostin). The quantitative determination was conducted by reversed phase high performance liquid chromatography with photodiode array detector (LC-PDA). Separation was performed on a Phenomenex Luna C18(2) (150 mm x 3.00 mm, 5 microm) column. The xanthones were identified by retention time, ultraviolet (UV) spectra and quantified by LC-PDA at 320 nm. The precision of the method was confirmed by the relative standard deviation (R.S.D.), which was < or =4.6%. The recovery was in the range from 96.58% to 113.45%. A good linear relationship was established in over two orders of magnitude range. The limits of detection (LOD) for six xanthone compounds were < or =0.248 microg/mL. The identity of the peaks was further confirmed by high performance liquid chromatography with time-of-flight mass spectrometry (LC-TOF MS) system coupled with electrospray ionization (ESI) interface. The developed methods were applied to the determination of six xanthones in Garcinia mangostana products. The satisfactory results showed that the methods are effective for the analysis of real samples.     

Triterpenes from Campanula lactiflora

One new triterpene compound, 3β-acetoxylup-20(30)-en-29-al (1) and two known 3-acetylptiloepoxide (2) and 3β-acetoxylup-20(29)-ene (3) were isolated for the first time from the leaves of Campanula lactiflora and their structures were deduced by high field 1D and 2D 400 MHz NMR, EI-MS and (+) LC-MS/MS spectra.     

Triterpenes from Campanula lactiflora

One new triterpene compound, 3β-acetoxylup-20(30)-en-29-al (1) and two known 3-acetylptiloepoxide (2) and 3β-acetoxylup-20(29)-ene (3) were isolated for the first time from the leaves of Campanula lactiflora and their structures were deduced by high field 1D and 2D 400 MHz NMR, EI-MS and (+) LC-MS/MS spectra.     

Four new xanthones and their cytotoxicity from the stems of Garcinia schomburgkiana

Journal of Natural Medicines - Four new xanthones, named schomburgones C-F (1‒4), along with six known xanthones (5‒10) were isolated from the stems of Garcinia schomburgkiana. Their...     

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.