Lyconadins C and F, new Lycopodium alkaloids from Lycopodium complanatum

New Lycopodium alkaloids, lyconadins C (1) and F (2), were isolated from the club moss Lycopodium complanatum. Lyconadin C (1) is a new C₁₆N₂-type Lycopodium alkaloid possessing unique fused-tetracyclic ring system consisting of a cycloheptene ring fused to a decahydroquinoline and pyridone rings. Lyconadin F (2) possesses a primary amide moiety in its molecular, which is the first example of Lycopodium alkaloids. Biogenetically, lyconadins C (1) and F (2) might be related to lyconadins A (4) and B (5). The structures and relative stereochemistry of 1 and 2 were elucidated on the basis of spectroscopic data. The absolute stereochemistry of 2 was elucidated by chemical correlations with lyconadin B (5) through hemiaminal form of lyconadin F (3).     

Five novel norcembranoids from Sinularia leptoclados and S. parva

Three new norcembrane-based diterpenoids, leptocladolides A (1), B (4) and C (5), along with five known metabolites 6-10, have been isolated from the dichloromethane extract of a Taiwanese soft coral Sinularia leptoclados. Furthermore, a chemical investigation on the dichloromethane extract of S. parva has resulted in the isolation of two new related isomers, 1-epi-leptocladolide A (2) and 7E-leptocladolide A (3), in addition to 1 and 7. The structures of new metabolites 1-5 were elucidated on the basis of extensive spectroscopic analyses and their relative stereochemistries were determined by NOESY experiments. The new metabolites 1 and 3 have been shown to exhibit significant cytotoxic activity against KB and Hepa59T/VGH cancer cell lines.     

Daphniglaucins D-H, J, and K, new alkaloids from Daphniphyllum glaucescens

Five new fused-hexacyclic alkaloids, daphniglaucins D (1), E (2), F (3), G (4), and H (5), and two new yuzurimine-type alkaloids, daphniglaucins J (6) and K (7), have been isolated from the leaves of Daphniphyllum glaucescens, and the structures and relative stereochemistry were elucidated on the basis of spectroscopic data and chemical means.     

Three new diterpenoids, tricalysiolide H and tricalysiones A and B, from Tricalysia dubia

Three new diterpenoids, tricalysiolide H (1) and tricalysiones A (2) and B (3), with novel structural features were isolated from the wood of Tricalysia dubia, together with a known compound, cafestol (4). The structures of 1-3 were elucidated on the basis of 2D NMR spectroscopy and X-ray crystallographic analysis.     

New norditerpenoids from Cespitularia hypotentaculata

Four new norditerpenoids, designated as cespihypotins A (1), B (2), C (3) and D (4), were isolated from Cespitularia hypotentaculata Roxas (Xeniidae) that was collected in Taiwan. Compounds 1 and 2 are unprecedented structures having 13- and 14-membered lactone ring, respectively. Their structures were elucidated on the basis of extensive spectroscopic analysis. A plausible biogenetic pathway for compounds 1-4 was also proposed.     

Two novel sesquiterpenes from the roots of Taiwania cryptomerioides Hayata

Two novel 3,4-secocadinane and 4,5-seco-8(7→6)-abeoguaiane skeletons, namely taiwaninones A (1) and B (2), together with khusinodiol (3) and 4β,6β-dihydroxy-1α,5β(H)-guai-9-ene (4) were isolated from the roots of Taiwania cryptomerioides. Their structures were elucidated by the spectral methods. The biotransformations of 1 and 2 were proposed from 3 and 4, respectively.     

The first sorbicillinoid alkaloids, the antileukemic sorbicillactones A and B, from a sponge-derived Penicillium chrysogenum strain

The saltwater culture of a Penicillium chrysogenum strain isolated from the Mediterranean sponge Ircinia fasciculata yielded three new sorbicillin-derived compounds (1-3), whose structures were elucidated mainly by 2D NMR and mass spectrometry. Among them, sorbicillactones A (1) and B (2) are the first sorbicillinoid natural products that contain nitrogen. Compound 1 is anti-HIV active and it exhibits a strong cytotoxic activity against L5178y leukemic cells, combined with a relatively low toxicity to cervical carcinoma HeLa S3 cells and pheochromocytoma PC 12 cells. The absolute configurations of 1 and 2 were elucidated by quantum chemical calculation of circular dichroism (CD) spectra. Another compound isolated, sorbivinetone (3), might be an artifact derived from sorbicillinol (4) by Diels-Alder reaction with ethyl vinyl ether. Furthermore, the known sorbicillinoid fungal metabolites oxosorbicillinol (5), sorbicillin (6), and bisvertinolone (7) were identified, as well as the alkaloids meleagrine and roquefortine C. The biosynthetic origin of sorbicillactone A (1) from acetate, alanine, and methionine was investigated by feeding experiments with ¹³C-labeled precursors.     

Novel trichothecanes, paecilomycine A, B, and C, isolated from entomopathogenic fungus, Paecilomyces tenuipes

Paecilomycine A (1), B (2), and C (3) were isolated from cultivated fruiting bodies of Paecilomyces tenuipes (Isaria japonica), which is a popular entomopathogenic fungus used in folk medicine and health foods in China, Korea, and Japan. The structures of 1-3 were deduced from their spectroscopic data and their absolute configurations were elucidated by preparing their MPA esters. Compound 1 showed activity in the neurotrophic factor biosynthesis in glial cells.     

Halichonadins G-J, new sesquiterpenoids from a sponge Halichondria sp.

Three new dimeric sesquiterpenoids, halichonadins G-I (1-3), and one new eudesmane sesquiterpenoid possessing a 1-phenethyl urea moiety, halichonadin J (4), were isolated from a marine sponge Halichondria sp. Halichonadins G (1) and H (2) are homo-dimers of eudesmane sesquiterpenoid, linked through a methyl 2-{1-(2-amino-2-oxoethyl)ureido}acetate fragment and a 2-hydroxymalonamide fragment, respectively, while halichonadin I (3) is a new hetero-dimer of eudesmane sesquiterpenoid linked through a urea fragment. The structures of 1-4 were elucidated on the basis of spectroscopic data.     

Polyhydroxy pregnanes from Dregea volubilis

Three new polyhydroxy pregnanes named dregealol (1), volubilogenone (2) and volubilol (3) were isolated from the flowers of Dregea volubilis, and their structures elucidated from extensive 2D NMR analysis. The structure of volubilol (3) was confirmed by X-ray crystallographic studies. The known pregnane derivatives drevogenin D, iso-drevogenin P and 17α-marsdenin were also isolated.     

New phlegmarane-type, cernuane-type, and quinolizidine alkaloids from two species of Lycopodium

Two new phlegmarane-type alkaloids, cermizines A (1) and B (2), three new quinolizidine alkaloids, cermizine C (3) and senepodines G (4) and H (5), and a new C₁₆N₂ type alkaloid consisting of a quinolizidine and a piperidine ring, cermizine D (6), as well as two new cernuane-type alkaloids, cernuine N-oxide (7) and lycocernuine N-oxide (8), have been isolated together with cernuine (9) and lycocernuine (10) from the club moss Lycopodium cernuum and L. chinense. The relative stereochemistry of 1-4 and 6, and the absolute stereochemistry of 5, 7, and 8 were elucidated by combination of NOESY correlations, modified Mosher's method, chemical transformations, and computational methods. Cermizine D (6) might be a biosynthetic intermediate of cernuane-type alkaloids such as 7-10.     

New pyridoacridine alkaloids from the purple morph of the ascidian Cystodytes dellechiajei

Two new pyridoacridine alkaloids, 13-didemethylaminocycloshermilamine D (1) and demethyldeoxyamphimedine (2), were isolated from the purple chromotype of the Western Mediterranean ascidian Cystodytes dellechiajei. This morph also contained the known shermilamine B (3), kuanoniamine D (4), N-deacetylshermilamine B (5), N-deacetylkuanoniamine D (6), styelsamines C (7), and D (8). The structures of new compounds were elucidated on the basis of spectroscopic data. A hypothetic biosynthetic pathway from the tetracyclic styelsamine D (8) was proposed for both compounds 1 and 2 and their antimicrobial potential was evaluated.     

Three novel nortriterpenoids from Notochaete hamosa Benth. (Labiatae)

Three nortriterpenoids, notohamosin A (1), B (2) and C (3) with novel skeleton, and eight known compounds were isolated from the ethanol extract of the whole plants of Notochaete hamosa Benth. (Labiatae). On the basis of spectral evidence including 1D, 2D NMR, IR and MS data, their structures were elucidated. The relative configurations of compounds 1, 2 and 3 were determined according to NOESY experiments.     

Unusual enniatins produced by the insect pathogenic fungus Verticillium hemipterigenum: isolation and studies on precursor-directed biosynthesis

Two new enniatins H (3) and I (4), whose substituents on 2-hydroxycarboxylic acid moieties were different from those of known compounds, were isolated, together with known enniatins B (1) and B₄ (2), from the insect pathogenic fungus Verticillium hemipterigenum BCC 1449. Structures of these compounds were elucidated by spectroscopic means. Studies on precursor-directed biosynthesis with strain BCC 1449 led to the production and identification of three analogs, enniatins G (5), C (6) and MK1688 (7), as well as the stereochemical elucidation of 3 and 4. Enniatins 1-7 were evaluated for their antiplasmodial and antimycobacterial activities.     

Complanadine B, obscurumines A and B, new alkaloids from two species of Lycopodium

A new dimer of C₁₆N₂ type alkaloid, complanadine B (1), and two new C₁₆N type alkaloids, obscurumines A (2) and B (3), have been isolated from the club moss Lycopodium complanatum and L. obscurum, respectively. The structures and stereochemistry of 1-3 were elucidated by combination of 2D NMR spectra and chemical transformation. Complanadine A (4) isolated together with 1 induced secretion of neurotrophic factors from human astrocytoma cells.     

Kehokorins A-C, novel cytotoxic dibenzofurans isolated from the myxomycete Trichia favoginea var. persimilis

Kehokorins A (1)-C (3), three novel dibenzofurans, have been isolated from field-collected fruit bodies of the myxomycete, Trichia favoginea var. persimilis, and their structures were elucidated by spectral data. Kehokorin A (1) was a α-l-rhamnopyranoside of kehokorin B (2), while kehokorin C (3) was a 1-demethoxy analog of 2. Kehokorin A (1) was cytotoxic against HeLa cells with an IC₅₀ value of 1.5 μg/mL.     

Three novel 3,4-seco-podocarpane trinorditerpenoids from Aleurites moluccana

Three novel 3,4-seco-podocarpane-type trinorditerpenoids, moluccanic acid (1), moluccanic acid methyl ester (2), and 6,7-dehydromoluccanic acid (3), were isolated from the twigs and leaves of Aleurites moluccana. Their structures were elucidated by spectroscopic methods including 2D NMR analysis. The cytotoxicity of compounds 1-3 was evaluated.     

Three novel pregnane glycosides from Epigynum auritum

Three novel pregnane glycosides with an unusual aglycone (Epigynumgenane), named Epigynosides A (1), B (2) and C (3), were isolated from the aerial part of Epiginum auritum. Their structures were elucidated by spectral means and confirmed by X-ray diffraction analysis.     

Aigialomycins and related polyketide metabolites from the mangrove fungus Aigialus parvus BCC 5311

Reinvestigation of the secondary metabolites from the marine mangrove fungus Aigialus parvus BCC 5311 led to the isolation of six new nonaketide metabolites, aigialomycins F (4) and G (5a/5b), 7′,8′-dihydroaigialospirol (7), 4′-deoxy-7′,8′-dihydroaigialospirol (8), and rearranged macrolides 9 and 10, along with six previously described compounds, hypothemycin (1), aigialomycins A (2) and B (3), aigialospirol (6), 4-O-demethylhypothemycin (11), and aigialone (12). The structures of the new compounds were elucidated by analyses of the NMR spectroscopic and mass spectrometry data in combination with chemical means.     

Two novel diterpenoids from Isodon rubescens var. lushanensis

Two novel diterpenoids, luanchunins A (1) and B (2), along with their precursor, kamebakaurin (3), had been isolated from the stems and leaves of Isodon rubescens var. lushanensis. Their structures were elucidated on the basis of extensive spectroscopic analyses. Compounds 1 and 2 showed potent cytotoxic activity against HL-60 with IC₅₀ values of 4.81 μM and 3.52 μM, respectively. Plausible pathways for the biosynthesis of 1 and 2 were also postulated.