Agariblazeispirols A and B, an unprecedented skeleton from the cultured mycelia of the fungus, Agaricus blazei

Agariblazeispirols A and B, which have a unique steroidal skeleton, have been isolated from the cultured mycelia of Agaricus blazei (Agaricaceae). The absolute structure of Agariblazeispirol A was established to be (20S,22R,23R,24S)-13β,22:22,25-diepoxy-5-methoxy-14β-methyl-18-nor-des-A-ergosta-5,7,9,11-tetraen-23-ol by extensive 1D and 2D NMR spectral data, and X-ray analysis. The structure of Agariblazeispirol B was elucidated to be a stereoisomer of agariblazeispirol A at its carbon 22, (20S,22S,23R,24S)-13β,22:22,25-diepoxy-5-methoxy-14β-methyl-18-nor-des-A-ergosta-5,7,9,11-tetraen-23-ol by comparison of extensive 1D and 2D NMR spectral data with those of agariblazeispirol A. Both compounds showed a moderate circumvention of drug resistance on mouse leukemia P388/VCR cells.     

Suffruticosine, a novel octacyclic alkaloid with an unprecedented skeleton from Securinegasuffruticosa (Pall.) Rehd.

A novel securinega alkaloid, suffruticosine (1), was isolated from the leaves and barks of Securinegasuffruticosa. The structure of 1, characterized by a fused complex octacyclic system, was elucidated by combined spectroscopic techniques, especially 2D NMR and CD spectral analyses.     

Two novel tricyclic diterpenoids from Isodon rubescens var. taihangensis

Two novel tricyclic diterpenoids rubescensins U (1) and V (2) were isolated from the leaves of Isodon rubescens var. taihangensis. They were elucidated as a 8,15-seco-ent-kauranoid and an ent-abietanoid, respectively, by 1D and 2D NMR spectra, and single crystal X-ray analysis. Compound 1 is the first example of an 8,15-seco-ent-kaurane from the plants genus Isodon. A discussion of their biogenesis is described.     

Five new isocoumarins from Sonoran desert plant-associated fungal strains Paraphaeosphaeria quadriseptata and Chaetomium chiversii

Five new isocoumarins, paraphaeosphaerins A-C and chaetochiversins A and B, biogenetically related to monocillin I and radicicol, have been isolated from solid agar cultures of Paraphaeosphaeria quadriseptata and Chaetomium chiversii, two fungal strains living in association with the Sonoran desert plants, Opuntia leptocaulis and Ephedra fasciculata, respectively. A new chroman-4-one, aposphaerin C, was also isolated from P. quadriseptata. Their structures and stereochemistry were elucidated using a combination of ¹H and ¹³C homo- and hetero-nuclear 2D NMR techniques, ¹H NMR analysis of Mosher's esters, and chemical correlations.     

Novel pyridino-α-pyrone sesquiterpene type pileotin produced by a sea urchin-derived Aspergillus sp.

A new metabolite, pileotin A, was isolated from a strain of Aspergillus fumigatus originally obtained from the sea urchin Toxopneustes pileolus together with the known compound oxalicine B. The relative stereostructure of pileotin A was elucidated based on spectroscopic analyses, including 1D and 2D NMR techniques. This unique pyridino-α-pyrone sesquiterpene type metabolite has spiro-δ-lactone at C-4.     

Infectopyrone, a potential mycotoxin from Alternaria infectoria

A new metabolite, infectopyrone (1), has been isolated from the filamentous fungus Alternaria infectoria. The structure of 1 was elucidated by analysis of 2D NMR spectroscopic data. Compound 1 is an α-pyrone resembling known toxins, and is a useful phenotaxonomic marker for the A. infectoria species-group. Infectopyrone (1) was also produced by species within Stemphyllium and Ulocladium, and found in mouldy food.     

A novel polyprenylated phloroglucinol, garcinialone, from the roots of Garcinia multiflora

A novel polyprenylated phloroglucinol garcinialone (1) along with a known compound isoxanthochymol (2) have been isolated from the roots of Garcinia multiflora. The structures of 1 and 2 were elucidated spectroscopically, by 1D and 2D NMR and mass spectrometry.     

An unusual diterpene glycoside from the nuts of almond (Prunus amygdalus Batsch)

A new unusual kauranoid diterpene glycoside, named amygdaloside, was isolated from the nuts of almond (Prunus amygdalus). It's structure was established as 17-O-β-D-glucopyranoside ent-6,7-epoxy-6-hydroxyl-6,7-secokaur-19-oic acid, 6,19-lactone 16β17-diol on the basis of high-resolution 1D and 2D NMR spectral studies.     

Kingamide A, a new indole alkaloid from the ascidian Leptoclinides kingi

Chemical investigation of the CH₂Cl₂/MeOH extract from the Australian ascidian Leptoclinideskingi led to the isolation of a new brominated indole alkaloid, kingamide A (1). The planar structure of kingamide A was elucidated following the interpretation of 1D/2D NMR and MS data, and the absolute configuration was determined using Marfey’s method. This is the first report of a natural product from L. kingi.     

Dictyotadimer A, a new dissymmetric bis-diterpene from a brown alga of the genus Dictyota

A phytochemical investigation of a Mediterranean brown alga (Dictyota sp.) led to the isolation of a novel C₄₀bis-diterpene, named dictyotadimer A. The chemical structure of this unusual dissymmetric dimer, characterized by a C-C linkage between two different xenicane units, was elucidated by 1D and 2D NMR analyses together with HR-ESI mass spectrometry. The relative configuration of the two diterpenoid components was determined by NOESY NMR correlations and molecular modeling. A plausible biogenetic pathway of dictyotadimer A was also proposed.     

The first A-nor-hippuristanol and two novel 4,5-secosuberosanoids from the Gorgonian Isis hippuris

The first A-nor-hippuristanol, A-nor-22-epi-hippurin-2α-carboxylic acid (1), and two 4,5-secosuberosane sesquiterpenoids, isishippuric acids A and B (2 and 3), have been isolated from the gorgonian coral Isis hippuris. Those structures were deduced by extensive 1D and 2D NMR studies. The structure of 1 was further supported by a single crystal X-ray diffraction analysis. Isishippuric acid B has been shown to exhibit potent cytotoxicity toward a limited panel of cancer cells.     

Jaspolides G and H, unique bisisomalabaricanes from the Chinese marine sponge Jaspis sp.

Two unique bisisomalabaricanes jaspolides G (1) and H (2) were isolated from the marine sponge Jaspis sp. Their structures were elucidated on the basis of extensive spectroscopic data (IR, MS, and 1D and 2D NMR) analyses. A possible biogenetic pathway via Diels-Alder dimerization for jaspolides G and H was also proposed.     

Salviatalin A and salvitrijudin A, two diterpenes with novel skeletons from roots of Salvia digitaloides and anti-inflammatory evaluation

Salviatalin A (1) and salvitrijudin A (2), two diterpenes with novel skeletons, were isolated from the roots of Salvia digitaloides. Their structures were determined using 1D, 2D NMR, and HRESI-MS spectroscopic analyses. Salviatalin A (1) from bioassay-guided fractionation showed a potent inhibitory effect on superoxide anion production in GMLP/CB-activated human neutrophils as well as other anti-inflammatory effects. A plausible biosynthetic pathway is also discussed.     

Multidione, a novel diterpenoid from Jatropha multifida

A novel diterpenoid, multidione, has been isolated from the stems of Jatropha multifida and its structure has been settled from 1D and 2D NMR spectra. The compound possesses a phenolic moiety and a long side chain, structurally similar to the B ring of other lathyrane-diterpenoids in seco-form.The compound has possibly been derived biogenetically from a related lathyrane-diterpenoid.     

Cebulactams A1 and A2, new macrolactams isolated from Saccharopolyspora cebuensis, the first obligate marine strain of the genus Saccharopolyspora

The new macrolactams cebulactams A1 and A2 were isolated from an extract of the first obligate marine strain of the genus Saccharopolyspora. Their constitutionally identical structures, each bearing a six-membered cyclic ether as part of the macrocycle, and their relative configurations were elucidated by MS methods and by 1D and 2D NMR techniques.     

Trigonoines A and B, two novel alkaloids from the leaves of Trigonostemon lii

Two novel alkaloids, trigonoine A containing a 2,8-diazabicyclo[3.3.1]nonane ring system and trigonoine B formed by a combination of a 2,3-dihydroquinolin-4-one and 3H-pyrrolo[2,3-c]quinoline rearranged from β-carboline skeleton were isolated from the leaves of Trigonostemon lii. Their structures were elucidated by 1D and 2D NMR spectroscopic methods.     

Panaxfuraynes A and B, two new tetrahydrofuranic polyacetylene glycosides from Panax ginseng C. A. Meyer

Panaxfurayne A (1), a tetrahydrofuranic polyacetylene glycoside, was isolated from the roots of Panax ginseng C. A. Meyer (Araliaceae) together with panaxfurayne B (2) as a geometric isomer of 1. The chemical structures of these two compounds were ascertained by UV, Mass, 1D, and 2D NMR experiments. During these experiments, these tetrahydrofuranic polyacetylene compounds proved to be of biogenetically novel type.     

Novel ent-kaurane dimers from Isodon rubescens var. rubescens

Three novel asymmetric ent-kaurane dimers xindongnins M-O (1-3) were isolated from Isodon rubescens var. rubescens. Their structures were elucidated by spectroscopic methods including 2D NMR analysis. The relative stereochemistry of 1 was determined by single crystal X-ray diffraction, which also confirmed the unique linkage of a single carbon-carbon bond between the two subunits of this dimer. A biogenetic pathway was proposed for the formation of these dimers.     

Amarusine A,a new dioxaspiro[4.4]nonane derivative with a butyrolactone ring from Pleioblastus amarus

Amarusine A (1), a new polyketide derivative possessing an unusual dioxaspiro[4.4]nonane derivative with a butyrolactone ring, was isolated from the leaves of Pleioblastus amarus. The structure and absolute stereochemistry of compound 1 were rigorously determined using UV, IR, HRESIMS, and 1D and 2D NMR techniques and by comparing experimental and calculated electronic circular dichroism (ECD) spectra. Amarusine A (1) exhibits a good antioxidant activity for scavenging the DPPH radical. A possible biosynthetic pathway was postulated.