Aminocadambines A and B, two novel indole alkaloids from Neolamarckia cadamba

Two novel monoterpenoid indole alkaloids, aminocadambines A (1) and B (2), characterized by tetrahydrofuran and 1,2,3,4-tetrahydropyridine rings, were isolated from the leaves of Neolamarckia cadamba. Their structures were elucidated on the basis of spectroscopic and computational methods. The absolute configuration of 1 was established by CD analysis. A plausible biosynthetic pathway for 1 and 2 is proposed.     

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.     

New oxindole and indole alkaloids from Gelsemium rankinii

Six new humantenine-type (1-6) and two new gelsemine-type (7, 8) oxindole alkaloids and one new indole alkaloid (9) were isolated from the leaves and branches of Gelsemium rankinii. The structures of the new alkaloids were determined by spectroscopic analyses. Among them, 6-hydroxyhumantenine (5) is the first example of a Gelsemium alkaloid with an oxygen function at C-6 position, and is a plausible biogenetic precursor of gelsemine-type alkaloids.     

Four new colchicinoids, gloriosamines A-D, from Gloriosa rothschildiana

Four new colchicinoids, gloriosamines A-D, were isolated from the aerial parts of Gloriosa rothschildiana. The structure of gloriosamine A, including the absolute configuration, was determined by chemical conversion from colchicine.     

Xylomexicanins E-H,new limonoids from Xylocarpus granatum

Four novel tetranortriterpenoids, xylomexicanins E–H (1–4), were isolated from the seeds of the Chinese mangrove, Xylocarpus granatum. Among them, xylomexicanin E (1) represents the first example of limonoid with azaspiro skeleton between B (pyrrolidine) and C rings, whose biosynthetic pathways were proposed. The structures were elucidated on the basis of one- and two-dimensional NMR (including ¹H, ¹³C NMR, DEPT, ¹H–¹H COSY, HSQC, HMBC, and NOESY) and confirmed by high-resolution mass spectrometry. Compound 2, the second example of a limonoid with a C-9–C-30 linkage, showed moderate activity against the A549 and RERF cell line with IC₅₀ value of 18.83 and 15.83 μM,     

Cannabioxepane, a novel tetracyclic cannabinoid from hemp, Cannabis sativa L.

Apart from large amounts of cannabidiol, the known stilbenoids 1-4 and the oxylipins 7 and 8, a fibre cultivar of Cannabis sativa derived from the historical Carmagnola variety gave the novel spiranic stilbenoid isocannabispiradienone (5) and the biphenyl-type cannabinoid cannabioxepane (CBX, 6), a tetracyclic compound characterized by an unprecedented C-5/C-8′ oxygen bridge and devoid of cannabinoid activity. Structures were established by analysis of MS and NMR data, and the biogenetic derivation of the new compounds is discussed.     

New humantenine-type indole alkaloids with iridoid unit from Gelsemium species

Two new oxindole alkaloids, rankiniridine (1) and humanteniridine (2), having a nitrogen-carbon linkage between a humantenine-type monoterpenoid indole alkaloid and a monoterpene unit with an iridoid skeleton, were isolated from Gelsemium rankinii and Gelsemium elegans, respectively.     

Psoracorylifols A-E, five novel compounds with activity against Helicobacter pylori from seeds of Psoralea corylifolia

Five novel compounds, psoracorylifols A-E (1-5) with important activity against Helicobacter pylori have been isolated from a well-known traditional Chinese medicine (TCM), the seeds of Psoralea corylifolia. The structures of compounds 1-5, including their absolute configurations, were established on the basis of spectral methods and biogenetic reason. The structure of 1 was confirmed by a single-crystal X-ray diffraction. Psoracorylifols D and E (4 and 5) represent an unprecedented carbon skeleton. The biogenetic origin of psoracorylifols A-E (1-5) was also postulated.     

Four new ginkgolic acids from Ginkgo biloba

Four new compounds, 2-hydroxy-6-(12′-hydroxyheptadec-13′(E)-en-1-yl)benzoic acid (1), 2-hydroxy-6-(13′-hydroxyheptadec-11′(E)-en-1-yl)benzoic acid (2), 2-hydroxy-6-(10′-hydroxypentadec-11′(E)-en-1-yl)benzoic acid (3), and 2-hydroxy-6-(11′-hydroxypentadec-9′(E)-en-1-yl)benzoic acid (4) were isolated from the leaves of Ginkgo biloba and the structures of new ginkgolic acids were deduced on the basis of spectroscopic methods and chemical means. Compounds 1 and 2, and 3 and 4 examined as an inseparable mixture of hydroxyl and double bond positional isomers, were ultimately defined by total synthesis. Compounds 1–4 showed moderate lipid droplets accumulation inhibitory activity on mouse pre-adipocyte cell line, MC3T3-G2/PA6.     

Kansuinone, a novel euphane-type triterpene from Euphorbia kansui

Kansuinone (1), a rearranged euphane triterpenoid containing a spiro [5,6] ring system, was isolated from the roots of Euphorbia kansui. Its structure and stereochemistry were elucidated on the basis of spectroscopic, CD, and computational methods. Kansuinone (1) exhibited inhibitory activity against human and mouse 11β-HSD1 (11β-hydroxysteroid dehydrogenase type 1), with IC₅₀ values of 1.12 and 1.08 μM, respectively.     

Longipedlactones A-I, nine novel triterpene dilactones possessing a unique skeleton from Kadsura longipedunculata

Nine novel triterpene dilactones with an unprecedented rearranged pentacyclic skeleton, longipedlactones A-I (1-9), have been isolated from the leaves and stems of Kadsura longipedunculata Finet et Gagnep (Schisandraceae). Their structures were determined on the basis of comprehensive spectroscopic analysis and single-crystal X-ray structure determination. A biogenetic pathway for longipedlactone A (1) was also proposed. Compounds 1-3, 6, and 8 showed significant cytotoxicity against A549, with HT-29 and K562 cell lines having IC₅₀ values of 0.84-11.38 μM in vitro.     

Evolving trends in the dereplication of natural product extracts. 3: further lasiodiplodins from Lasiodiplodia theobromae, an endophyte from Mapania kurzii

Two further lasiodiplodins, (3R,4R)-4-hydroxy-de-O-methyl-lasiodiplodin and (E)-9-etheno-de-O-methyl-lasiodiplodin, together with three known lasiodiplodins from a cytotoxic extract obtained from a culture of Lasiodiplodia theobromae, an endophyte from the root tissues of Mapania kurzii (Cyperaceae) from the Malaysian rain forest, were characterized on microgram scale.     

Coelodiol and coeloic acid, ent-isocopalane diterpenes from the Indonesian sponge Coelocarteria cfr. singaporensis

Two novel ent-isocopalane diterpenes, coelodiol (1) and coeloic acid (2), the latter characterized by an unique oxidative degradation of ring A, have been isolated from the Indonesian sponge Coelocarteria cfr. singaporensis. The stereostructure of these metabolites has been established through interpretation of NMR data and application of the exciton chirality CD method. Coelodiol (1) and coeloic acids (2) were found to inhibit the growth of MKN-45 cell line (human gastric adenocarcinoma).     

Cinnacassides A-E, five geranylphenylacetate glycosides from Cinnamomum cassia

Cinnacassides A-E (1-5), five novel glycosides with a unique geranylphenylacetate carbon skeleton, were isolated from the stem bark of Cinnamomum cassia. Each of the cinnacassides A-D (1-4) possesses one of the four stereoisomers in the aglycone. Their structures were established by extensive spectroscopic analysis and chemical and chiroptical methods. A plausible biosynthetic route to 1-5 was also proposed.     

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.     

Isolation of a polysaccharide with anticancer activity from Auricularia polytricha using high-speed countercurrent chromatography with an aqueous two-phase system

Polysaccharides from a crude extract of Auricularia polytricha were separated by high-speed countercurrent chromatography (HSCCC). The separation was performed with an aqueous two-phase system of PEG1000–K₂HPO₄–KH₂PO₄–H₂O (0.5:1.25:1.25:7.0, w/w). The crude sample (2.0 g) was successfully separated into three polysaccharide components of AAPS-1 (192 mg), AAPS-2 (137 mg), and AAPS-3 (98 mg) with molecular weights of 162, 259, and 483 kDa, respectively. These compounds were tested for growth inhibition of transplanted S180 sarcoma in mice. AAPS-2 had an inhibition rate of 40.4%. The structure of AAPS-2 was elucidated from partial hydrolysis, periodate oxidation, acetylation, methylation analysis, and NMR spectroscopy (¹H, ¹³C). These results showed AAPS-2 is a polysaccharide with a backbone of (1 → 3)-linked-β-d-glucopyranosyl and (1 → 3, 6)-linked-β-d-glucopyranosyl residues in a 2:1 ratio, and has one terminal (1→)-β-d-glucopyranosyl at the O-6 position of (1→3, 6)-linked-β-d-glucopyranosyl of the main chain.     

Seven new prenylated indole diketopiperazine alkaloids from holothurian-derived fungus Aspergillus fumigatus

Seven new prenylated indole diketopiperazine alkaloids, including compound 1, 3 spirotryprostatins C-E (2-4), 2 derivatives of fumitremorgin B (5 and 6), and 13-oxoverruculogen (7), have been isolated from the holothurian-derived fungus Aspergillus fumigatus, along with 12 known ones (8-19). The structures of the new compounds were determined on the basis of extensive spectroscopic data and amino acid analysis. All new compounds were evaluated for their cytotoxic activities on MOLT-4, A549, HL-60, and BEL-7420 cell lines by the MTT and SRB methods.     

Makomotines A to D from Makomotake, Zizania latifolia infected with Ustilago esculenta

Four novel compounds, makomotines A to D (1–4), along with two known ones (5, 6) were isolated from Makomotake, Zizania latifolia infected with Ustilago esculenta. The structures were determined or identified by the interpretation of spectroscopic data. Compound 1 suppressed the formation of osteoclast without toxicity.     

Laetiporic acid, a new polyene pigment from the wood-rotting basidiomycete Laetiporus sulphureus (Polyporales, Fungi)

A new pigment, laetiporic acid, has been isolated from fruit-bodies of the wood-rotting fungus Laetiporus sulphureus (sulfur shelf). Structure elucidation by application of extensive 2D NMR techniques permitted its identification as a polyene of non-isoprenoid origin. Laetiporic acid, which represents the main pigment in L. sulphureus basidiocarps, bears an unprecedented decaene skeleton as part of its chromophore and, interestingly, contains double bonds with a stable cis configuration.     

Novel grayanane diterpenoids from Rhododendron principis

Six new grayanane diterpenoids, principinols A–F (1–6), were isolated from Rhododendron principis. Compounds 1 and 2 possess unprecedented 6,10-epoxy and 5α-OH moieties, and 1 and 3 are the first two examples of 9α-H in grayanoids. Their structures were determined by extensive spectroscopic analysis, and the absolute configurations of 1–4 were assigned by single-crystal X-ray crystallography. Compounds 4 and 5 inhibit PTP1B phosphatase activity in vitro. A preliminary structure–activity relationship discussion is presented.