New bioactive diterpene polyesters from Euphorbia decipiens

A reinvestigation with a modified extraction procedure of Euphorbia decipiens resulted in the isolation and structure elucidation of three new myrsinane-type diterpene esters (1-3). The structures of compounds 1-3 were elucidated by spectroscopic data interpretation. Compound 1 showed inhibitory activity against prolyl endopeptidase (PEP), whereas compound 2 exhibited DNA-damaging activity in a mutant yeast bioassay.     

Sesquiterpene coumarins from Ferula gumosa

A new sesquiterpene coumarin, gumosin (1), two new sesquiterpene coumarin glycosides, gumosides A (2) and B (3), and 10 known compounds, namely, cauferoside (4), feselol (5), conferoside, ferilin, ferocaulidin, ligupersin A, conferol, and daucosterol, and the phenolic compounds acantrifoside E and 4-hydroxybenzoic acid 4-(6-O-sulfo)glucopyranoside, were isolated from a methanolic extract of Ferula gumosa roots. The structures of 1-3 were elucidated by spectroscopic data interpretation. The cytotoxic activity of the sesquiterpene coumarin derivatives was evaluated against a small panel of cancer cell lines.     

New bioactive peroxides from marine sponges of the family plakiniidae

In our continuing program to identify compounds with antifungal properties, the ethanol extracts of two sponges of the family Plakinidae were found to inhibit the growth of the fungal pathogens Candida albicans and Aspergillus fumigatus. From these organisms three new compounds and five known compounds have been identified. A new 1,2-dioxane ring peroxide acid, 1, has been isolated from the sponge Plakortis halichondrioides along with five known compounds. Two new 1,2-dioxolane peroxide acids, 3 and 4, have been isolated from the sponge Plakinastrella onkodes. The structures were established by interpretation of spectral data. The three new compounds exhibit moderate activity against the fungal pathogen C. albicans with MICs of 5, 1.6, and 1.6 microg/mL respectively, for 1, 3, and 4. Compound 1 also showed in vitro inhibition of the fungal pathogen A. fumigatus with an IC(90) value of 5.6 microg/mL.     

New bioactive clerodane diterpenoids from the bark of Casearia grewiifolia

Bioactivity-guided fractionation of hexane and dichloromethane extracts of the bark of Casearia grewiifolia afforded four new clerodane diterpenes, caseargrewiins A-D (1-4), and two known clerodane diterpenes, rel-(2S,5R,6R,8S,9S,10R,18S,19R)-18,19-diacetoxy-18,19-epoxy-6-methoxy-2-(2-methylbutanoyloxy)cleroda-3,13(16),14-triene (5) and rel-(2S,5R,6R,8S,9S,10R,18S,19R)-18,19-diacetoxy-18,19-epoxy-6-hydroxy-2-(2-methylbutanoyloxy)cleroda-3,13(16),14-triene (6). The structures of 1-4 were established on the basis of the interpretation of their 1D and 2D NMR spectral data. The absolute configuration of 4 was determined by the modified Mosher's method. All compounds exhibited promising antimalarial and antimycobacterial activities but also cytotoxicity against three cancer cell lines.     

New bioactive prenylflavonoids and dibenzocycloheptene derivative from roots of Dendrolobium lanceolatum

Two new flavanones (1 and 2), a new flavan (3), and a new rare dibenzocycloheptene derivative (4) together with a known flavan, 4'-hydroxy-2' ',2' 'dimethyl-pyranoflavan (5), were isolated from the roots of Dendrolobium lanceolatum. Their structures were established on the basis of spectral evidence, and an X-ray analysis was performed to confirm the structure of 4. Compounds 1-3 exhibited antimalarial activity with IC50 values of 2.6, 3.3, and 3.1 microg/mL, respectively. Compounds 1-5 showed moderate antimycobacterial activity with MIC values of 6.3, 12.5, 25, 25, and 50 microg/mL, respectively. In addition, 1 showed strong cytotoxicity against cancer cell lines KB, BC, and NCI-H187 with IC50 values of 1.2, 1.6, and 0.6 microg/mL, respectively, while 2 showed moderate cytotoxicity against the NCI-H187 cell line with an IC50 value of 8.1 microg/ mL.     

New bioactive sulfated metabolites from the Mediterranean tunicate Sidnyum turbinatum.

In addition to the known sodium 3,7,11,15-tetramethylhexadeca-1,19-diyl sulfate (4), the BuOH extract of the Mediterranean tunicate Sidnyum turbinatum was shown to contain four new metabolites: 1-heptadecanyl sulfate (1), 1-octadecanyl sulfate (2), sodium (2S)-2,6,10,14-tetramethylpentadeca-1,18-diyl sulfate (3), and 1-hexyl sulfate (5). Their structures were determined by spectroscopic and chemical methods. Compounds 1-5 exhibited in vitro antiproliferative activity estimated on the WEHI 164 cell line.     

New cytotoxic coumarins and prenylated benzophenone derivatives from the bark of Ochrocarpos punctatus from the Madagascar rainforest

Bioassay-guided fractionation of a CH2Cl2-MeOH extract of the bark of Ochrocarpos punctatus resulted in the isolation of seven new coumarins, ochrocarpins A-G (1-7), three new benzophenone derivatives, ochrocarpinones A-C (8-10), and five known coumarins, mammea A/AC cyclo F (11), mammea A/AD cyclo D (12), mammea A/AB cyclo F (13), mammea A/AA cyclo F (14), mammea A/AB cyclo D (15), and 15,16-dihydro-16-hydroperoxyplukenetione (16). The structures of compounds 1-10 were established on the basis of extensive 1D and 2D NMR spectroscopic data interpretation. All compounds exhibited cytotoxicity against the A2780 ovarian cancer cell line.     

Biologically active sesquiterpene coumarins from Ferula species

Extracts from different species of the genus Ferula (Apiaceae) have had various biomedical applications for many centuries. Many biological features of this genus such as cytotoxicity, antibacterial, antiviral, P-glycoprotein (P-gp) inhibitory and antiinflammatory activity have been attributed to sesquiterpene coumarins; structures containing a common coumarin group and a sesquiterpene moiety. This both highlights the importance of sesquiterpene coumarins as biologically active natural products and necessitates further studies on these compounds. Taking into account the versatile biological properties of compounds isolated from Ferula and the unprecedented interest in the application of natural products as a new generation of therapeutics, the present review will discuss reports on biological activities of sesquiterpene coumarins of the genus Ferula, from 1990 onwards.     

Sesquiterpene coumarins and related derivatives from Ferula pallida

Six new compounds-two sesquiterpene coumarins, pallidones A and B (1, 2), and four related derivatives, pallidones C-F (3-6), as well as two known sesquiterpene coumarins, feselol (7) and conferol (8), have been isolated from the EtOAc extracts of the roots of Ferula pallida. All structures of these compounds were determined on the basis of spectral evidence, especially 2D NMR ((1)H-(1)H COSY, HSQC, HMBC, and NOESY) and HRMS. The possible biosynthetic pathway of pallidones C-F (3-6) is discussed.     

Mammea coumarins from the flowers of Mammea siamensis

Four new mammea coumarins, mammea E/BA cyclo D (1), mammea E/BC cyclo D (2), mammea E/BD cyclo D (3), and mammea E/AC cyclo D (4), were isolated from the flowers of Mammea siamensis, along with six known coumarins. Extensive 1D and 2D NMR experiments and other spectroscopic studies, as well as chemical transformations, were employed to determine the structures of 1-4.     

New bioactive metabolites from a freshwater isolate of the fungus Kirschsteiniothelia sp.

The new cytotoxic naphthoquinone dimer kirschsteinin [5], two new chlorinated diphenyl ethers 8 and 9, three known naphthoquinone derivatives 1, 2, and 7, a monoacetyl derivative of 2, and the (-)-enantiomer of O-methylasparvenone [4], have been isolated from a previously undescribed species of Kirschsteiniothelia. The structures of these compounds were assigned primarily by nmr studies and by spectral comparisons.     

Effects of the Kielmeyera coriacea extract on energy metabolism in the rat liver

Kielmeyera coriacea Mart is a medicinal plant of the Clusiacea (Guttiferae) family used by the native population of Brazil in the treatment of several tropical diseases such as malaria, schistosomiasis, leishmaniasis, and fungal or bacterial infections. Kielmeyera coriacea is also effective as an antidepressant drug. Extracts of the plant are rich in xanthones. Compounds of this class have been reported to inhibit mitochondrial energy metabolism. For this reason the action of the Kielmeyera coriacea extract on hepatic energy metabolism was investigated in the present work, using isolated rat liver mitochondria and the perfused rat liver. In perfused livers the extract (20-80 microg/ml) caused stimulation of oxygen consumption, inhibition of gluconeogenesis and stimulation of glycogenolysis and glycolysis. In isolated mitochondria the Kielmeyera coriacea extract (5-20 microg/ml) stimulated state IV respiration, reduced the ADP/O ratio and decreased the respiratory coefficient. The activities of succinate-oxidase, NADH-oxidase, NADH dehydrogenase and succinate dehydrogenase were inhibited. The ATPase of intact mitochondria was stimulated and the ATPase of uncoupled mitochondria was inhibited. The results of this investigation suggest that the Kielmeyera coriacea extract impairs the hepatic energy metabolism by acting as mitochondrial uncoupler and inhibitor of enzymatic activities linked to the respiratory chain. The impairment of mitochondrial energy metabolism could lead to adverse metabolic effects by the use of the crude extract, but it could equally be the basis of its antiprotozoan and antifungal effects.     

Additional bioactive heptenes from Melodorum fruticosum

Four additional new bioactive heptenes, melodorinol [2], homomelodienone [4], 7-hydroxy-6-hydromelodienone [5], and homoisomelodienone [7] have been isolated from Melodorum fruticosum. These compounds were slightly to significantly cytotoxic to human tumor cell lines. Their structures have been determined by comparison of their 1H-nmr, 13C-nmr, and mass spectral data with those of prototype compounds (acetylmelodorinol [1], melodienone 3, and isomelodienone [6]).     

大果藤黄中2个新的香豆素类化学成分

目的 研究大果藤黄Garcinia pedunculata果实的化学成分,以期发现新的活性化合物.方法 运用硅胶、Sephadex LH-20、Chromatorex C18、Diol silica gel、MCI gel CHP-20P以及反相半制备型高效液相等各种现代色谱分离技术进行系统的分离纯化,根据化合物的光谱...     

甘草废渣中1个新的香豆素类化合物

目的研究甘草Glycyrrhiza uralensis废渣的化学成分。方法采用硅胶吸附柱色谱、Sephadex LH-20柱色谱、高效液相色谱等分离手段进行分离纯化,根据化合物的理化性质和波谱数据鉴定化合物的结构。结果从新疆产甘草废渣75%乙醇提取物中分离得到了5个化合物,分别鉴定为槐香豆素C(1)、3β-O-对羟基-反-肉桂酰-齐墩果酸(2)、3-羰基甘草次酸(3)、3β,18-O-异丙叉-8(14),15-异右松脂烷二烯(4)、3β,18-O-异丙叉-7,15-异右松脂烷二烯(5)。结论化合物1为新的香豆素类化合物,命名为槐香豆素C;化合物2、4、5为首次从该属植物中分离得到。     

Terpenylated coumarins as SIRT1 activators isolated from Ailanthus altissima

Four new terpenylated coumarins (1-4) were isolated from the stem bark of Ailanthus altissima by bioactivity-guided fractionation using an in vitro SIRT1 deacetylation assay. Their structures were identified as (2'R,3'R)-7-(2',3'-dihydroxy-3',7'-dimethylocta-6'-enyloxy)-6,8-dimethoxycoumarin (1), 6,8-dimethoxy-7-(3',7'-dimethylocta-2',6'-dienyloxy)coumarin (2), (2'R,3'R,6'R)-7-(2',3'-dihydroxy-6',7'-epoxy-3',7'-dimethyloctaoxy)-6,8-dimethoxycoumarin (3), and (2'R,3'R,4'S,5'S)-6,8-dimethoxy-7-(3',7'-dimethyl-4',5'-epoxy-2'-hydroxyocta-6'-enyloxy)coumarin (4). Compounds 1-4 strongly enhanced SIRT1 activity in an in vitro SIRT1-NAD/NADH assay and an in vivo SIRT1-p53 luciferase assay. These compounds also increased the NAD-to-NADH ratio in HEK293 cells. The present results suggest that terpenylated coumarins from A. altissima have a direct stimulatory effect on SIRT1 deacetylation activity and may serve as lead molecules for the treatment of some age-related disorders.     

Paecilosetin, a new bioactive fungal metabolite from a New Zealand isolate of Paecilomyces farinosus

A new tetramic acid derivative, paecilosetin (1), along with a recently characterized N-hydroxypyridone, farinosone B (2), was isolated from the fungus Paecilomyces farinosus. Each compound showed activity against the P388 cell line with IC50 values of 3.1 and 1.1 microg/mL, respectively. Paecilosetin was also active against the microorganisms Bacillus subtilis, Trichophyton mentagrophytes, and Cladosporium resinae.     

New bioactive rosigenin analogues and aromatic polyketide metabolites from the freshwater aquatic fungus Massarina tunicata

Four new rosigenin analogues (massarigenins A-D; 1-4) and two new aromatic polyketide-derived secondary metabolites (massarinins A and B; 6, 7) and have been isolated from the freshwater aquatic fungus Massarina tunicata. The structures of these compounds were determined primarily by analysis of NMR data, and that of compound 1 was verified by X-ray crystallography. The known compound 4-(2-hydroxybutynoxy)benzoic acid (11) was also obtained, and its absolute stereochemistry was assigned. Several of these metabolites showed antibiotic activity against Gram-positive bacteria.