Effect of Amino Acids on the Generation of Ginsenoside Rg3 Epimers by Heat Processing and the Anticancer Activities of Epimers in A2780 Human Ovarian Cancer Cells

Ginsenosides are the active components of Panax ginseng. Many research studies indicate that these deglycosylated, less-polar ginsenosides have better bioactivity than the major ginsenosides. In the present study, we sought to verify the enhanced anticancer effect of P. ginseng extract after undergoing the Maillard reaction as well as elucidate the underlying mechanism of action. The effects of 9 amino acids were tested; among them, the content of 20(S)-Rg3 in the ginseng extract increased to more than 30, 20, and 20% when processed with valine, arginine, and alanine, respectively, compared with that after normal heat processing. The ginseng extract that was heat-processed with arginine exhibited the most potent inhibitory effect on A2780 ovarian cancer cell proliferation. Therefore, the generation of 20(S)-Rg3 was suggested to be involved in this effect. Moreover, the inhibitory effect of 20(S)-Rg3 on A2780 cell proliferation was significantly stronger than that of 20(R)-Rg3. Protein expression levels of cleaved caspase-3, caspase-8, caspase-9, and PARP in the A2780 ovarian cancer cells markedly increased, whereas the expression of BID decreased after 20(S)-Rg3 treatment. Therefore, we confirmed that the anticancer effects of the products of ginseng that was heat-processed with arginine are mediated mainly via the generation of the less-polar ginsenoside 20(S)-Rg3

Densazalin, a New Cytotoxic Diazatricyclic Alkaloid from the Marine Sponge Haliclona densaspicula

Densazalin, a polycyclic alkaloid, was isolated from the marine sponge Haliclona densaspicula collected in Korea. The complete structure of the compound was determined by spectroscopic methods, including 1D and 2D nuclear magnetic resonance techniques, high-resolution mass spectrometry, and comparison of the calculated and measured electronic circular dichroism spectra. Densazalin possesses a unique 5,11-diazatricyclo[7.3.1.02,7]tridecan-2,4,6-triene moiety, which is connected by two linear carbon chains. This compound was derived from the biogenetic precursor bis-1,3-dialkylpyridnium. Densazalin exhibited cytotoxic activity on two human tumor cell lines (AGS and HepG2) in the Cell Counting Kit-8 (CCK-8) bioassay, with IC50 values ranging from 15.5 to 18.4 μM

Bacillus velezensis: A Valuable Member of Bioactive Molecules within Plant Microbiomes

Bacillus velezensis is an aerobic, gram-positive, endospore-forming bacterium that promotes plant growth. Numerous strains of this species have been reported to suppress the growth of microbial pathogens, including bacteria, fungi, and nematodes. Based on recent phylogenetic analysis, several Bacillus species have been reclassified as B. velezensis. However, this information has yet to be integrated into a well-organized resource. Genomic analysis has revealed that B. velezensis possesses strain-specific clusters of genes related to the biosynthesis of secondary metabolites, which play significant roles in both pathogen suppression and plant growth promotion. More specifically, B. velezensis exhibits a high genetic capacity for synthesizing cyclic lipopeptides (i.e., surfactin, bacillomycin-D, fengycin, and bacillibactin) and polyketides (i.e., macrolactin, bacillaene, and difficidin). Secondary metabolites produced by B. velezensis can also trigger induced systemic resistance in plants, a process by which plants defend themselves against recurrent attacks by virulent microorganisms. This is the first study to integrate previously published information about the Bacillus species, newly reclassified as B. velezensis, and their beneficial metabolites (i.e., siderophore, bacteriocins, and volatile organic compounds)

Characterization and Anti-inflammatory Effects of Iodinated Acetylenic Acids Isolated from the Marine Sponges <i>Suberites mammilaris</i> and <i>Suberites japonicus</i>

The previously unknown compounds <b>1</b>–<b>4</b>, acetylenic acids with one or two iodine atom(s), were isolated from the marine sponges <i>Suberites mammilaris</i> and <i>Suberites japonicus</i>. Their complete structures were determined using NMR and mass spectrometry. The methylated compounds <b>1a</b> and <b>2a</b> exhibited a strong NO inhibitory effect on RAW264.7 cells, while methylated <b>3a</b> and <b>4a</b> were inactive in RAW264.7 cells, but highly active in BV2 microglia cells

Effect of Amino Acids on the Generation of Ginsenoside Rg3 Epimers by Heat Processing and the Anticancer Activities of Epimers in A2780 Human Ovarian Cancer Cells

Ginsenosides are the active components of Panax ginseng. Many research studies indicate that these deglycosylated, less-polar ginsenosides have better bioactivity than the major ginsenosides. In the present study, we sought to verify the enhanced anticancer effect of P. ginseng extract after undergoing the Maillard reaction as well as elucidate the underlying mechanism of action. The effects of 9 amino acids were tested; among them, the content of 20(S)-Rg3 in the ginseng extract increased to more than 30, 20, and 20% when processed with valine, arginine, and alanine, respectively, compared with that after normal heat processing. The ginseng extract that was heat-processed with arginine exhibited the most potent inhibitory effect on A2780 ovarian cancer cell proliferation. Therefore, the generation of 20(S)-Rg3 was suggested to be involved in this effect. Moreover, the inhibitory effect of 20(S)-Rg3 on A2780 cell proliferation was significantly stronger than that of 20(R)-Rg3. Protein expression levels of cleaved caspase-3, caspase-8, caspase-9, and PARP in the A2780 ovarian cancer cells markedly increased, whereas the expression of BID decreased after 20(S)-Rg3 treatment. Therefore, we confirmed that the anticancer effects of the products of ginseng that was heat-processed with arginine are mediated mainly via the generation of the less-polar ginsenoside 20(S)-Rg3

Ostreol A: A new cytotoxic compound isolated from the epiphytic dinollagellate Ostreopsis cf. ovata from the coastal waters of Jeju Island, Korea

Ostreol A was isolated from cultures of the epiphytic dinoflagellate Ostreopsis cf. ovata from the coastal waters of Jeju Island, Korea. The compound, a non-palytoxin derivative, has a polyhydroxy chain ending with the primary amino group and contains an amide bond, along with two tetrahydropyran rings in the chain. Its chemical structure was elucidated by nuclear magnetic resonance (NMR) spectroscopy methods and confirmed by mass analysis. The compound exhibited significant cytotoxicity in the brine shrimp lethality test at a concentration of 0.9 mu g/mL. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.N

Densanins A and B, New Macrocyclic Pyrrole Alkaloids Isolated from the Marine Sponge <i>Haliclona densaspicula</i>

Densanins A (<b>1</b>) and B (<b>2</b>) were isolated from the sponge <i>Haliclona densaspicula</i>. On the basis of spectral data and the Mosher ester method, the complete structures were characterized as hexacyclic diamine alkaloids, which were probably derived from 3-alkylpyridine. Compounds <b>1</b> and <b>2</b> showed relatively potent inhibitory effects on lipopolysaccharide-induced nitric oxide production in BV2 microglial cells with IC₅₀ values of 1.05 and 2.14 μM, respectively

Acuminolide A: Structure and Bioactivity of a New Polyether Macrolide from Dinoflagellate <i>Dinophysis acuminata</i>

Acuminolide A (<b>1</b>), along with pectenotoxin II (PTX-2), dinophysistoxin I (DTX-1), okadaic acid (OA), and 7-<i>epi</i>-PTX-2 <i>seco</i> acid, was isolated from a large-scale cultivation of the dinoflagellate <i>Dinophysis acuminata</i>. The new 33-membered macrolide <b>1</b> was characterized by detailed analysis of 2D NMR and MS data. Its relative stereochemistry was elucidated on the basis of ROESY correlations and <i>J</i>-based analysis. In contrast to the other well-known toxins that were isolated, <b>1</b> showed no cytotoxicity against four cancer cell lines but caused potent stimulation of actomyosin ATPase activity

Determination of the Absolute Configuration of Polyhydroxy Compound Ostreol B Isolated from the Dinoflagellate <i>Ostreopsis</i> cf. <i>ovata</i>

Following isolation of the polyhydroxy compound, ostreol B, from cultivated cells of the toxic dinoflagellate Ostreopsis cf. ovata collected in South Korea, 1D and 2D NMR spectroscopy were employed to determine the planar chemical structure of this compound, which contained a tetrahydropyran ring, two terminal double bonds, and 21 hydroxyl groups. The absolute configurations of all stereogenic carbon centers in ostreol B were then determined through a combination of the <i>J</i>-based configuration analysis, rotating frame Overhauser effect correlations, and the modified Mosher method following cleavage of the 1,2-diol bonds. Ostreol B was also found to exhibit moderate cytotoxicity in HepG2, Neuro-2a and HCT-116 cells