In vitro antioxidant,cholinesterase and tyrosinase inhibitory activities of Calophyllum symingtonianum and Calophyllum depressinervosum(Guttiferae)

Objective:To screen the antioxidant,cholinesterase and tyrosinase enzymatic inhibition activities of the leaves and heartwood of Calophyllum symingtonianum(C.symingtonianum),and the bark of Calophyllum depressinervosum(C.depressinervosum).Methods:Samples of leaves and heartwood of C.symingtonianum and bark of C.depressinervosum were tested for their total phenolic content and in vitro antioxidant assay by 2,2-diphenyl-1-picrylhydrazyl radical scavenging and β-carotene bleaching.Cholinesterase inhibition by Ellman’s method and tyrosinase inhibition using L-3,4-dihydroxyphenylalanine as a substrate were also tested.Results:All methanol extracts were found to exhibit strong 2,2-diphenyl-1-picrylhydrazyl radical scavenging effects.Extracts from the heartwood of C.symingtonianum gave a low IC50(5.17±0.04)μg/mL followed by bark of C.depressinervosum[(7.30±0.14)μg/mL]and C.symingtonianum leaves[(15.70±1.43)μg/mL].The methanol extract of C.depressinervosum bark showed 95.08%inhibition ofβ-carotene bleaching.All extracts showed moderate inhibition towards tyrosinase activity with an IC50 of more than 100μg/mL.The methanol extract of C.depressinervosum stem bark showed the highest inhibition(78.46%)against butyrylcholinesterase.Conclusions:These results showed that both Calophyllum species are potential sources of antioxidant and cholinesterase inhibitors.Further study is needed for the isolation and characterization of the active metabolites responsible for both activities.

山竹果皮中异戊烯基双苯吡酮类成分

从山竹(Garcinia mangostana)的果皮中分离得到22个双苯吡酮类化合物,经波谱数据分析分别鉴定为:1,3,7-三羟基𠮿酮(1)、1,3,6,7-四羟基-8-异戊烯基𠮿酮(2)、1,3,5-三羟基-4-异戊烯基𠮿酮(3)、8-deoxygartanin(4)、cudraxanthone G(5)、gartanin(6)、6-脱氧-γ-倒捻子素(7)、γ-倒捻子素(8)、α-倒捻子素(9)、1,3-二羟基-6,7-二甲氧基-2,8-二异戊烯基𠮿酮(10)、β-倒捻子素(11)、garcinone D(12)、garcinone B(13)、mangostenone D(14)、3-O-methylmangostenone D(15)、9-hydroxycalabaxanthone(16)、11-羟基-1-异倒捻子素(17)、brasilixanthone B(18)、garcimangosxanthone D(19)、BR-xanthone A(20)、tovophyllin A(21)和1,3,6-trihydroxy-2,5-bis(3-methylbut-2-enyl)-6',6'-dimethyl-4',5'-dihydropyrano[2,3':7,8]xanthone(22)。其中化合物2~22为异戊烯基双苯吡酮类,且化合物3和15属首次从山竹中分离。在小鼠海马神经元HT22细胞上测试了所有化合物对谷氨酸诱导的细胞死亡的保护活性。

Apoptosis,antimicrobial and antioxidant activities of phytochemicals from Garcinia malaccensis Hk.f

Objective:To study the chemical constituents of stembark of Garcinia malaccenm（G.malaccenm） together with apoptotic.antimicrobial and antioxidant activities.Methods:Purification and structure elucidation were carried out by chromatographic and spectroscopic techniques, respectively.MTT and trypan blue exclusion methods were performed to study the cytotoxic activity.Antibacterial activity was conducted by dise diffusion and microdilulion methods, whereas antioxidant activities were done by ferric thiocyanate method and DPPH radical scavenging.Results:The phylochemical study led lo the isolation ofα,β-mangostin and cycloarl-24-en-3β-ol.α-Mangostin exhibited cytotoxic activity against HSC-3 cells with an IC50 of 0.33μM.β- andα-mangostin showed activity against K562 cells with IC50 of 0.40μM and 0.48μM,respectively,α-Mangostin was active against Gram-positive bacteria, Staphylococcus aureus（S.aureus） and Bacilus anthracis（B.anthmcis） with inhibition zone and MIC value of（19 mm;0.02S mg/mL） and（20 mm;0.013 mg/mL）,respectively.In antioxidant assay,α-mangostin exhibited activity as an inhibitor of lipid peroxidation.Conclusions:G.malaccenm presenceα- andβ-mangostin and cycloart-24-en-3β-ol.β-Mangostin was found very active against H.SC-3 cells and KS62.The results suggest that mangoslins derivatives have the potential to inhibit the growth of cancer cells by inducing apoptosis.In addition,α-andβ-mangostin was found inhibit the growth of Cram-positive pathogenic bacteria and also showed the activity as an inhibitor of lipid peroxidation.

A New Xanthone Derivative from Hypericum Erectum

A new xanthone, 1,2-dihydro-3,6,8-trihydroxy-1,1-bis (3-methylbut -2-enyl)-5-(1, 1-dimethylprop-2-enyl)xanthen-2,9-dione (1), has been isolated from the aerial part of Hypericum erectum.

Hypercohones D–G,New Polycyclic Polyprenylated Acylphloroglucinol Type Natural Products from Hypericum cohaerens

Four new polycyclic polyprenylated acylphloroglucinol type metabolites,hypercohones D–G(1–4),along with four known analogues(5–8),were isolated from the aerial parts of Hypericum cohaerens.The structures of these isolates were elucidated by extensive spectroscopic methods.The inhibitory activities of these isolates against five human cancer cell lines in vitro were also tested.

New Phloroglucinol Glycosides from Hypericum japonicum

Two new phloroglucinol glycosides, 2,6-dihydroxy-3,5-dimethyl-1-isobutyrylbenzene-4-O-beta-D-glucoside and 2,6-dihydroxy-3,5-dimethyl-1-(2-methylbutyryl) benzene-4-O-beta-D-glucoside were isolated from Hypericum japonicum. Their structures were determined by spectroscopic and chemical methods.

Hyperinoids A and B,two polycyclic meroterpenoids from Hypericum patulum

Hyperinoids A(1)and B(2),two prenylated acylphloroglucinol related meroterpenoids,were isolated from Hypericum patulum.Compound 1 incorporates an unprecedented 11,12-dioxatetracyclo[5.4.3.01,7.04,14]tetradecane system,while 2 possesses a unique 10,11-dioxatetracyclo[5.3.3.01,7.04,13]tridecane syste m.Their structures were established by spectro scopic analysis and X-ray crystallographic data.Compounds 1 and 2 were identified as potent NF-κB inhibitors and suppressed the LPS-induced inflammatory responses in RAW 246.7 macrophages and primary mouse BMDM cells.