Antibacterial C-geranylflavonoids from Paulownia tomentosa Fruits

Eight C-6-geranylflavonoids ( 1- 8) were isolated from an ethanol extract of Paulownia tomentosa fruits. Tomentodiplacone ( 1), 3'- O-methyl-5'-hydroxydiplacone ( 2), 3'- O-methyl-5'- O-methyldiplacone ( 3), and tomentodiplacone B ( 4) were obtained as new compounds, and 3'- O-methyldiplacol ( 5) was isolated for the first time from a natural source. The structures of these new compounds were determined by using mass spectrometry (including HRMS) and 1D and 2D NMR spectroscopy, and the absolute configurations of the compounds were determined by circular dichroism. The antibacterial activities of 1- 8 against seven bacteria and yeast were evaluated.     

Immunosuppressive decalin derivatives from red yeast rice

Five new decalin derivatives (1-5), together with two known compounds (6 and 7), were isolated from the ethyl acetate extract of red yeast rice. Their structures were elucidated by means of NMR and mass spectroscopic analyses. Monascusic lactone A (1) is the first reported naturally occurring decalin derivative possessing a spiro lactone at the C-1 position. The immunosuppressive effects of all these isolates (1-7) on human T cell proliferation were investigated, and all, especially monascusic acids B (2), C (3), D (4), and A (6) and heptaketide (7), suppressed human T cell proliferation in a dose-dependent manner from 10 to 100 μM. This is the first report on the immunosuppressive activity of decalin derivatives.     

Labdane and kaurane diterpenoids from Plectranthus fruticosus

Six new diterpenoids, three labdane and three kaurane derivatives, have been isolated from an acetone extract of Plectranthus fruticosus together with other already known substances. The structures of these compounds (1-5 and 7) were established mainly by spectroscopic means, particularly by 1D and 2D NMR studies, as well as by some chemical correlations with known diterpenoids. The physical and spectroscopic data of the derivative 11, obtained by hydrolysis of the labdane 2, were identical to those reported for a compound previously isolated from Croton joufra, to which structure 12 had been established erroneously by other authors. Several of the isolated compounds were tested as antimicrobial agents against three bacteria strains and one yeast strain, but only 4 showed a moderate inhibitory activity against Staphylococcus aureus.     

Two novel cyclic peptides with antifungal activity from the cyanobacterium Tolypothrix byssoidea (EAWAG 195).

Two novel cyclic tridecapeptides, tolybyssidins A (1) and B (2), were isolated from the culture medium of mass cultured cyanobacterium Tolypothrix byssoidea (EAWAG 195) by means of bioguided isolation. The gross structures of these peptides were determined by 1D and 2D NMR experiments and tandem mass spectrometry. Both peptides contain the nonnatural amino acid dehydrohomoalanine (Dhha) as well as proteinogenic amino acids albeit with D- or L-configuration. The compounds exhibit moderate antifungal activity against the yeast Candida albicans.     

Batzelline D and isobatzelline E from the indopacific sponge Zyzzya fuliginosa

Two new pyrroloquinoline alkaloids, isobatzelline E (1) and batzelline D (2), together with the known compounds batzelline C (3), isobatzelline C (4), and makaluvamine D (5), were isolated from an Indopacific collection of the marine sponge Zyzzya fuliginosa; the known compounds makaluvamines A (9), H (10), J (7), K (8), and P (6) were obtained from Z. fuliginosa collected in Papua New Guinea. The structures were elucidated by interpretation of 1D (1)H and (13)C NMR spectra and 2D HSQC and HSQC-LR spectra. Compounds 1-10 were isolated because the crude extracts of both Zyzzya species inhibited HIV-1 envelope-mediated cell fusion. However, the inhibition profile observed for the pure compounds 1-10 mirrors that reported for the inhibition of topoisomerase II by other pyrroloquinolines, leaving open the possibility that the activity results from interactions with DNA-modifying enzymes.     

Cytotoxic diacetylenic spiroketal enol ethers from Plagius flosculosus

Three new diacetylenic spiroketal enol ethers named flosculins A (1), B (2), and C (3), along with five known compounds (4-8) of the same structural class, were isolated from the leaves of Plagius flosculosus. The structures were deduced by extensive 1D and 2D NMR spectroscopy and mass spectrometry. All isolated compounds exhibited significant cytotoxic activity against leukemia cells (Jurkat T and HL-60). Compounds 5-8 induced apoptosis in HL-60 cells with corresponding IC(50) values ranging from 4 to 6 microM.     

15,21-Cyclowithanolides from Jaborosa bergii

Six new withanolides (1-6) were isolated from the aerial parts of Jaborosa bergii plants and characterized by spectroscopic methods (1D and 2D NMR, MS). Five of the new compounds presented a novel norbornane-type structure in ring D of the steroid nucleus (1-5), resulting from a carbon-carbon bond between C-15 and C-21. The sixth withanolide isolated was the 5alpha-chloro-6beta-hydroxy analogue (6) of 2,3-dehydrojaborosalactol M (7), previously isolated from this plant. Compound 1 showed selective phytotoxicity toward monocotiledoneous and dicotiledoneous species.     

Absolute structures of new briarane diterpenoids from junceella fragilis

Four new diterpenoids with the briarane skeleton, (-)-4-deacetyljunceellolide D (2), (+)-11alpha, 20alpha-epoxyjunceellolide D (3), (-)-11alpha, 20alpha-epoxy-4-deacetyljunceellolide D (4), and (-)-11alpha, 20alpha-epoxy-4-deacetoxyjunceellolide D (5), (+)-junceellolide A (6) [the antipodal derivative of the known (-)-junceellolide A], along with three known briaranes, (-)-junceellolide D (1), (-)-junceellin (7), and (-)-praelolide (8), were isolated from the Indonesian gorgonian Junceella fragilis. The structures of the new compounds were established on the basis of extensive NMR studies and by comparison with the spectral data from other briarane compounds. The absolute configurations for four of the compounds were determined by the modified Mosher method and by unambiguous chemical interconversions.     

蜈蚣草化学成分的研究

目的 研究蜈蚣草Pteris vittataL.的化学成分.方法 蜈蚣草全草60%乙醇提取物采用大孔吸附树脂、硅胶、凝胶、C18色谱柱等进行分离纯化,根据理化性质及波谱数据鉴定所得化合物的结构.结果 从中分离得到11个化合物,分别鉴定为芦丁(1)、山柰酚-3-O-β-D-葡萄糖苷(2)、山柰酚-3-O-芸香糖苷(3)、山柰酚-3-O-β-D-葡萄糖醛酸苷(4)、淫羊藿次苷B6 (5)、ethyl β-D-xylopyranoside (6)、苯乙烯-4-O-β-D-吡喃葡萄糖苷(7)、苯丙氨酸(8)、phenyl-β-D-glucopyranoside (9)、4-羟基-2-甲氧基-苯基-β-D-葡萄糖苷(10)、松脂醇-4”-吡喃葡萄糖苷(11).结论 化合物2~11为首次从该植物中分离得到.     

Bioactive saponins from Swartzia schomburgkii from the suriname rainforest

Bioassay-guided fractionation of the MeOH extract of Swartzia schomburgkii using the engineered yeast strains 1138, 1140, and 1353 as the bioassay tool resulted in the isolation of five active (2, 4-7) and three inactive (1, 3, 8) saponins. Saponins 4 and 6 are previously unreported. The structures of all of the saponins were established based on 1D and 2D NMR spectral analysis, on acid and alkaline hydrolysis followed by TLC and GC-MS, and by comparison with literature data for known compounds. Three of the isolated compounds (4-6) showed weak cytotoxicity against the M-109 cell line.     

狭叶薰衣草化学成分的研究

目的 研究狭叶薰衣草Lavandula angustifolia Mill.的化学成分.方法 狭叶薰衣草95%乙醇提取物乙酸乙酯部位采用RP-HPLC、TLC、硅胶、MCI树脂等进行分离纯化,根据理化性质及波谱数据鉴定所得化合物的结构.结果 从中分离得到11个化合物,分别鉴定为(-)-isolariciresinol-9-O-glucopyranoside (1)、threo-3,3'-dimethoxy-4,8'-oxyneoligna-9,4',7',9'-tetraol-7 (8)-ene (2)、1-(4-hydroxy-3-meth-oxyphenyl)-2-[4-(3-hydroxy-propyl)-2-methoxyphenoxy]-propane-1,3-diol (3)、(E)-ferulic acid 4-O-β-D-glucoside (4)、eugenyl-O-β-apiofuranosyl(1”-6')-O-β-glucopyranoside(5)、2-methoxy-4-(2-propen-1-yl) penyl-β-D-glucopyranoside(6)、4-O-β-D-glucopyranosylconiferyl aldehyde (7)、dimethylconiferin (8)、methylconiferin (9)、2-苯乙基-O-β-D-吡喃葡萄糖苷(10)、zansimuloside A(11).结论 所有化合物均为首次从该植物中分离得到.     

Phenolic constituents from Dalbergia cochinchinensis

Three new phenolic compounds (1-3), along with five known phenolics, 4'-hydroxy-2'-methoxychalcone (4), latinone (5), dalbergiphenol (6), 7-hydroxyflavanone, and dalbergin (7), have been isolated from the stems of Dalbergia cochinchinensis. The structures of 1-3 were established by spectroscopic techniques including 1D and 2D NMR methods. The inhibitory activity against testosterone 5 alpha-reductase, which causes androgen-dependent diseases, was also examined for selected compounds.     

Steroids and flavonoids from Physalis alkekengi var. franchetii and their inhibitory effects on nitric oxide production

Four new steroidal compounds possessing a rare 13,14-seco-16,24-cycloergostane skeleton, physalin Y ( 1), physalin Z ( 2), physalin I ( 6), and physalin II ( 7), were isolated from the 80% EtOH extract of calyces from Physalis alkekengi var. franchetii together with 11 known steroids ( 3- 5 and 8- 15) and eight flavonoids ( 16- 23). The structures of the new compounds were elucidated primarily on the basis of 1D and 2D NMR and mass spectroscopic studies. The relative configuration of the 3-OH group of 3, 4, and 5 was also established or re-established. The inhibitory effects of compounds 1- 23 on nitric oxide production in lipopolysaccaride-activated macrophages were evaluated.     

Three new sesquiterpenes from roots of Curcuma longa

Objective: To study the chemical constituents from the roots of Curcuma longa. Methods: The structures of the new compounds were elucidated based on extensive spectral analysis, including 1D and 2D NMR, MS, UV, and CD analysis. Results: Two new sesquiterpene compounds (1S,2R,5R,7S,8R)-2,8-epoxy-5-hydroxybisabola-3,10-dioen-9-one (1), (1R,2R,5R,7S,8R)-2,8-epoxy-5-hydroxybisabola-3,10-dioen-9-one (2), and a new natural product 6-(4-Hydroxymethylphenyl)-2-methyl-hept-2-ene-4-one (3) together with three known compounds ar-turmerone (4), 2-methyl-6-(4-hydroxyphenyl-3-methyl)-2-hepten-4-one (5) and 2-methyl-6-(4-hydroxyphenyl)-2-hepten-4-one (6) were isolated from C. longa root extract with 95% ethanol. Conclusion: In the study, three new compounds were isolated from C. longa, and their absolute configurations were determined.     

Pinpointing pseurotins from a marine-derived Aspergillus as tools for chemical genetics using a synthetic lethality yeast screen

A new compound of mixed polyketide synthase-nonribosomal peptide synthetase (PKS/NRPS) origin, 11- O-methylpseurotin A ( 1), was identified from a marine-derived Aspergillus fumigatus. Bioassay-guided fractionation using a yeast halo assay with wild-type and cell cycle-related mutant strains of Saccharomyces cerevisiae resulted in the isolation of 1, which selectively inhibited a Hof1 deletion strain. Techniques including 1D and 2D NMR, HRESIMS, optical rotation, J-based analysis, and biosynthetic parallels were used in the elucidation of the planar structure and absolute configuration of 1. A related known compound, pseurotin A ( 2), was also isolated and found to be inactive in the yeast screen.     

Tasnemoxides A-C, new cytotoxic cyclic norsesterterpene peroxides from the Red Sea sponge Diacarnus erythraenus

Tasnemoxides A-C (1-3), three new cytotoxic cyclic norsestertepene peroxides, were isolated from the Red Sea sponge Diacarnus erythraenus, together with the known compound sigmosceptrellin B (4). The structural determination of the isolated compounds was based on extensive 1D and 2D NMR studies and mass spectral determinations. Compounds 1-3 showed moderate cytotoxicity against three cancer cell lines.     

Cytotoxic isomalabaricane triterpenes from the marine sponge Rhabdastrella globostellata

Fourteen isomalabaricane triterpenes were isolated from the marine sponge Rhabdastrella globostellata. In addition to the known compounds globostellatic acids A (1) and D (4) and stelliferin riboside (13), 11 of the compounds were new natural products, which included globostelletin (3), eight new globostellatic acid congeners, F to M (2, 5-11), and two new stelliferin ribosides (12 and 14). The isolated compounds were tested against three different cancer cell lines, L5178Y (mouse lymphoma), HeLa (human cervix carcinoma), and PC-12 (rat pheochromocytoma). The isomalabaricane derivatives were found to be selectively active toward the mouse lymphoma cell line L5178Y. The structures were determined by 1D and 2D NMR data and by comparison with spectroscopic data of known related compounds.     

Nematicidal epipolysulfanyldioxopiperazines from Gliocladium roseum

Five new verticillin-type epipolysulfanyldioxopiperazines, gliocladine A (1), B (2), C (3), D (4), and E (5), were isolated from wheat solid-substrate fermentation of Gliocladium roseum 1A, along with four known compounds, verticillin A (6), 11'-deoxyverticillin A (7), Sch52900 (8), and Sch52901 (9). Their structures were elucidated by extensive 1D and 2D NMR studies, MS, and chemical transformations. In vitro immersion tests showed that all nine compounds exhibited antinematodal activity against Caenorhabditis elegans and Panagrellus redivivus. The monomeric epipolysulfanydioxopiperazines (3-5), with the indole moiety, were found to be less active than the dimeric compounds (1, 2, 6-8).     

Labdane diterpenes of Leonurus sibiricus

Seven new labdane diterpenes, sibiricinones A-E (1-4, 6) and 15-epi-sibiricinones D and E (5 and 7), and the flavone genkwanin were isolated from the aerial parts of Leonurus sibiricus. Sibiricinone D (4) and 15-epi-sibiricinone D (5), and sibiricinone E (6) and 15-epi-sibiricinone E (7), respectively, were isolated as C-15 epimeric pairs. These secondary metabolites were identified on the basis of 1D and 2D NMR including (1)H-(1)H COSY, HSQC, and HMBC spectroscopic techniques. The stereochemical configurations of compounds 4-7 were assigned through 2D T-ROESY and selective NOE experiments.     

Phomadecalins A-D and phomapentenone A: new bioactive metabolites from Phoma sp. NRRL 25697, a fungal colonist of Hypoxylon stromata

Five new natural products, phomadecalins A-D (1-4) and phomapentenone A (5), have been obtained from cultures of Phoma sp. (NRRL 25697), a fungal colonist isolated from the stromata of Hypoxylon sp. The structures of these compounds were elucidated through a series of 1D and 2D NMR experiments. Compounds 1-4 display activity against Gram-positive bacteria.