Malyngamide 4, a new lipopeptide from the Red Sea marine cyanobacterium Moorea producens (formerly Lyngbya majuscula)

In our continuing effort to discover new drug leads from Red Sea marine organisms, a sample of the marine cyanobacterium Moorea producens (previously Lyngbya majuscula) was investigated. Bioassay-directed purification of a tumor cell-growth inhibitory fraction of the organic extract of the Red Sea cyanobacterium afforded a new compound, malyngamide 4 (1), together with five previously reported compounds, malyngamide A (2) and B (3), (S)-7-methoxytetradec-4(E)-enoic acid (lyngbic acid, 4), aplysiatoxin (5) and debromoaplysiatoxin (6). Assignment of the planar structures of these compounds was based on extensive analysis of one- and two-dimensional NMR spectra and high-resolution mass spectrometric data. The isolated compounds were evaluated for their inhibitory activity against three cancer cell lines. In addition, the antibacterial activity of the compounds against Mycobacterium tuberculosis H₃₇Rv ATCC 27294 (H₃₇Rv) was evaluated. Lyngbic acid (4) was the most active against M. tuberculosis, while malyngamides 4 (1) and B (3) moderately inhibited the cancer cell lines. The other compounds were deemed inactive at the test concentrations.     

Benzoate esters and flavonoids from Desmos pedunculosus

The genus Desmos (Annonaceae) is comprised of about thirty-three species of trees and shrubs found in southern Asia, Indonesia, and northern Australia. The chemistry of many of these species is largely unreported. Phytochemical investigation of a methanol extract of the aerial parts of D. pedunculosus led to the isolation of two flavonoids and eight benzoate ester derivatives. Three of these benzoate esters are new compounds, while two others are known synthetic compounds reported here as natural products for the first time. The compounds were characterized by mass spectrometry and 1D and 2D NMR spectroscopy. Based on a comparison of extracts of D. chinensis and D. pedunculosus from Vietnam, several of the compounds we report may serve as marker compounds to chemically distinguish these similar species.     

Identification of oxylipins with antifungal activity by LC–MS/MS from the supernatant of Pseudomonas 42A2

In microorganisms hydroxy fatty acids are produced from the biotransformation of unsaturated fatty acids. Such compounds belong to a class of oxylipins which are reported to perform a variety of biological functions such as anti-inflammatory or cytotoxic activity. These compounds have been found in rice and timothy plants after being infected by specific fungus. When grown in submerged culture with linoleic acid, Pseudomonas 42A2 accumulated in the supernatant several hydroxy fatty acids. In this work LC–MS/MS has been used to elucidate the structure of the components form the organic extract: 9-hydroxy-10,12-octadecadienoic acid; 13-hydroxy-9,11-octadecadienoic acid; 7,10-dihydroxy-8E-octadecenoic acid; 9,10,13-trihydroxy-11-octadecenoic acid and 9,12,13-trihydroxy-10-octadecenoic acid. Antimicrobial activity against several pathogenic fungal strains is presented: MIC (μg/mL) Verticillium dhaliae, 32; Macrophonia phaesolina, 32; Arthroderma uncinatum, 32; Trycophyton mentagrophytes, 64.     

Hydroxylation of long chain fatty acids by CYP147F1, a new cytochrome P450 subfamily protein from Streptomyces peucetius

Cytochrome P450 (CYP) 147F1 from Streptomyces peucetius is a new CYP subfamily of that has been identified as ω-fatty acid hydroxylase. We describe the identification of CYP147F1 as a fatty acid hydroxylase by screening for the substrate using a substrate binding assay. Screening of substrates resulted in the identification of fatty acid groups of compounds as potential hits for CYP147F1 substrates. Fatty acids from C_10:0 to C_18:0 all showed type I shift spectra indicating their potential as substrates. Among several fatty acids tested, lauric acid, myrsitic acid, and palmitic acid were used to characterize CYP147F1. CYP147F1 activity was reconstituted using putidaredoxin reductase and putidaredoxin from Pseudomonas putida as surrogate electron transfer partners. Kinetic parameters, including the dissociation constant, K_m, NADH consumption assay, production formation rate, and coupling efficiency for CYP147F1 were also determined.     

Cytotoxic meroterpenoids from the macroalga Cystoseira abies-marina

Two new meronorsesquiterpenes (cystoazorones A and B) and two new meroditerpenes (cystoazorols A and B), along with benzoic acid were isolated from the brown macroalga Cystoseira abies-marina. The structures of the new compounds were established by 1D and 2D NMR as well as HRMS spectral analysis. The in vitro cytotoxicity and antioxidant activity of the isolated compounds were also evaluated. Cystoazorones A and B, and cystoazorol A exhibited in vitro growth inhibitory activity against HeLa cells. The HeLa cell line in log phase was found to be more sensitive to cystoazorol A than when it was in lag phase. Cystoazorol A also showed a selectivity index higher than taxol, which was used as a positive control. Cystoazorols A and B were found to be the strongest antioxidants among the compounds tested.     

Flower scent composition in Dianthus and Saponaria species (Caryophyllaceae) and its relevance for pollination biology and taxonomy

Floral fragrance compounds of seven Dianthus species (D. arenarius, D. armeria, D. barbatus, D. deltoides, D. monspessulanus, D. superbus, and D. sylvestris) and one Saponaria species (S. officinalis) (Caryophyllaceae) were studied using headspace adsorption technique followed by gas chromatography massspectrometry (GC-MS). The number of compounds (fatty acid derivatives, benzenoids, phenyl propanoids, isoprenoids, and nitrogen containing compounds) identified in the floral odors ranged from 18 to 51 but all were dominated by only 1–3 compounds. Most of the compounds identified in this study have been previously reported in floral scents from species of the closely related genus Silene L. However, the phenyl propanoids eugenol, methyleugenol, methylisoeugenol, cis-asarone, and trans-asarone have formerly not been found in Silene. Based on the measurement of Sørensen’s index of similarity (I_s) nonmetric multidimensional scaling (MDS) was used to detect meaningful underlying dimensions and to visualize similarities between the investigated species. The MDS analysis showed three groups of species, (1) the diurnal D. armeria, D. barbatus, and D. deltoides are characterized by the predominance of fatty acid derivatives, (2) the closely related nocturnal D. monspessulanus, and D. superbus by high relative amounts of isoprenoids such as cis-β-ocimene and β-caryophyllene, and (3) the species D. arenarius, D. sylvestris and S. officinalis by a predominance of benzenoids, especially methylbenzoate. The results are discussed in relation to pollination, especially by butterflies, moths, and hawkmoths.     

New derivatives from the aerial parts of Boerhaavia diffusa L. (Nyctaginaceae)

Boerhaavia diffusa L. is used in the traditional medicine of several Asian countries. The isolation and identification of five new compounds, together with 11 known compounds, from the ethyl acetate extract of the aerial part of B. diffusa grown Vietnam is reported. The structure of the new compounds was established by 1D and 2D NMR spectroscopy, and high resolution ESI-MS analysis. New compounds are two rotenoids: 9,11-dihydroxy-6,10-dimethoxy[1]benzopyrano[3,4-b][1]benzopyran-12(6H)-one (boeravinone P, 3) and 3-[2-(β-d-glucopyranosyloxy)-3-hydroxyphenyl]-5-hydroxy-2-hydroxymethyl-7-methoxy-6-methyl-4H-1-benzopyran-4-one (boeravinone Q, 9), an atropisomeric mixture of two rotenoid glycosides (3′,5-dihydroxy-2-hydroxymethyl-7-methoxy-6-methylisoflavone 2′-O-β-d-glucopyranoside, 11), a sesquiterpene lactone (4,10-dihydroxy-8-methoxyguai-7(11)-en-8,12-olide, 5) and a new phenylpropanoid glycoside (boerhaavic acid, 15).     

Resin glycosides from the aerial parts of Operculina turpethum

Three glycosidic acids, turpethic acids A−C, and two intact resin glycosides, turpethosides A and B, all having a common pentasaccharide moiety and 12-hydroxy fatty acid aglycones of different chain lengths, were obtained from the aerial parts of Operculina turpethum. Their structures were elucidated by spectroscopic analyses and chemical correlations. The aglycones were characterized as 12-hydroxypentadecanoic acid in two compounds, 12-hydroxyhexadecanoic acid in two other components, and 12-hydroxyheptadecanoic acid in the fifth compound, which were all confirmed by synthesis. The absolute configurations of these aglycones were all established as S by Mosher’s method. These compounds represent the first examples of resin glycosides with a monohydroxylated 12-hydroxy fatty acid as an aglycone, and one compound is the first described resin glycoside having a hydroxylated C₁₇ fatty acid as its aglycone.     

Dietary verbascoside supplementation in donkeys: effects on milk fatty acid profile during lactation,and serum biochemical parameters and oxidative markers

Various uses of donkeys’ milk have been recently proposed for human consumption on the basis of its nutritional characteristics. Improvements in milk fatty acid profile and animal oxidative status can be induced through dietary supplementation of phenolic compounds. The study aimed to evaluate in donkeys the effects of dietary supplementation with verbascoside (VB) on: (i) the fatty acid profile and vitamins A and E contents of milk during a whole lactation, and (ii) blood biochemical parameters and markers of oxidative status of the animals. At foaling, 12 lactating jennies were subdivided into two groups (n 6): control, without VB supplement; VB, receiving a lipid-encapsulated VB supplement. Gross composition, fatty acid profile and vitamins A and E contents in milk were assessed monthly over the 6 months of lactation. Serum total cholesterol, high-density lipoproteins cholesterol and low-density lipoproteins cholesterol, tryglicerides, non-esterified fatty acid, bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase, reactive oxygen metabolites, thiobarbituric acid reactive substances (TBARs), vitamin A and vitamin E were evaluated at 8 days after foaling (D0) and then at D90, D105 and D120 of lactation. In milk, the VB supplementation decreased the saturated fatty acids (P<0.05) and increased the monounsaturated fatty acids (P<0.05), and vitamins A and E (P<0.01) values. On the serum parameters, the VB supplementation decreased total cholesterol (P<0.01), tryglicerides, bilirubin, ALT and TBARs, and increased (P<0.01) vitamin E. In conclusion, the VB dietary supplementation affects the nutritional quality of donkey’s milk with a benefit on the oxidative status and serum lipidic profile of the animals.     

Biotransformation of oleic acid by alcaligenes sp. 5–18, a bacterium tolerant to high concentrations of oleic acid

We isolated from soil 160 bacterial strains which are tolerant to high concentrations of oleic acid, and examined their ability to transform oleic acid to new fatty acid derivatives. One of the isolated strains, Alcaligenes sp. 5–18, produced several compounds from oleic acid: 3-hydroxyoleic acid, 3-hydroxyhexadecenoic acid, octadecadienoic acid, hexadecadienoic acid, and tetradecadienoic acid. These compounds are intermediates in the β-oxidation pathway of oleic acid, and their accumulation is probably due to defective β-oxidation of oleic acid in the microorganism. Neither hydroxy nor enoic derivatives of fatty acids with a carbon chain length shorter than 14 were produced.     

Fatty acids and global metabolites profiling of Dunaliella tertiolecta by shifting culture conditions to nitrate deficiency and high light at different growth phases

In this study, Dunaliella tertiolecta cells were shifted to nitrate-deficient (ND) and/or high light (HL) conditions at different growth phases. Profiling of global metabolites and fatty acids of D. tertiolecta cells were performed by shifting cultivation condition at exponential (EX) and stationary (ST) phases. ND and/or HL induced saturation of fatty acids by increasing saturated fatty acid and monounsaturated fatty acid and decreasing polyunsaturated fatty acid in D. tertiolecta cultures. The relative levels of metabolites like proline, valine, isoleucine, and myoinositol, which act as osmolytes, and ergosterol and glycerol, which are related to the osmoregulatory mechanism, decreased to a greater extent by ND than HL shifts. In addition, the effects of these shifts at the EX phase were observed to be more significant in most of the fatty acids. The results of this research might be applicable to the interpretation of metabolic synthesis and fatty acid production, and to the optimization of cultivation conditions for the use of D. tertiolecta and other microalgae as biofuels or nutraceutical sources.     

Secondary metabolites from Hypericum trichocaulon Boiss. & Heldr., growing wild in the island of crete

Eleven compounds were isolated from the aerial blooming parts of Hypericum trichocaulon Boiss. & Heldr., a narrow endemic plant of the island of Crete (Greece). These compounds comprise one previously undescribed prenylated phloroglycinol derivative (adhyperfoliatin), together with ten known compounds, procyanidin A₂, hyperixanthone A, (E)-chlorogenic acid, trans-phytol, five flavonoids, i.e. I3,II8-biapigenin, quercitrin, hyperoside, rutin, myricitrin and one fatty acid. The structures of the isolated compounds were established by means of 1D and 2D NMR, as well as MS spectral analyses. Phloroglucinol derivatives are recognized as chemophenetic markers for the genus Hypericum, and the isolation of adhyperfoliatin contributes to the characterization of the section Drosocarpium Spach, where the under-investigation taxon belongs. Moreover, the investigation of the methanol extract led to the isolation of myricitrin in high amounts, a specialized metabolite which also serves as a marker for this section.     

3,5,7,3′,5′-Pentahydroxyflavan and 3α-methoxyfriedelan from Humboldtia laurifolia

The leaf, bark and timber extractives of Humboldtia laurifolia were investigated and the following compounds have been isolated: O-acetyloleanolic aldehyde, a sitosteryl ester, lupeol, sitosterol, a fatty acid, 5,7,4′-trihydroxyflavone (apigenin), (2R,3R)-3,5,7,3′,5′-pentahydroxyflavan and 3α-methoxyfriedelan. The latter two compounds are new natural products.     

Antibacterial metabolites from the Actinomycete <Emphasis Type="Italic">Streptomyces</Emphasis> sp. P294

The Actinomycete strain P294 was isolated from soil and identified as Streptomyces sp. based upon the results of 16S rRNA sequence analysis. Three compounds obtained from the solid fermentation products of this strain have been determined by 1D, 2D NMR and HRMS experiments. These compounds include two new compounds angumycinones C (1) and D (2), and the known compound X-14881 E (3). All compounds were assayed for antibacterial and nematicidal activity. The results showed the three compounds had different degrees of inhibitory activity against several target bacteria but no significant toxicity against the nematode Caenorhabditis elegans.     

Cyclohexene long-chain fatty acid esters from Uvaria dulcis (Dunal)

Two new cyclohexene long-chain fatty acid esters, namely Dulcisenes A and B, were isolated from the twigs of the Uvaria dulcis together with seven known compounds, uvarigranol E, (−)-zeylenol, ellipeiopsol B, 5,7-dihydroxyflavone, 8-hydroxy-5,7-dimethoxyflavanone, lupeol, and benzyl benzoate. The structures of the isolated compounds were elucidated by spectroscopic and mass-spectrometric analyses, including 1D, 2D NMR and HR TOF MS. Several of these metabolites were tested for cytotoxicity against HepG2, A549, S102, HuCCA-1, HeLa, MDA-MB-231, T47D, HL-60, and P388 cell lines.     

Fatty Acid Esters of Phloridzin Induce Apoptosis of Human Liver Cancer Cells through Altered Gene Expression

Phloridzin (phlorizin or phloretin 2′-O-glucoside) is known for blocking intestinal glucose absorption. We have investigated the anticarcinogenic effect of phloridzin and its novel derivatives using human cancer cell lines. We have synthesised novel acylated derivatives of phloridzin with six different long chain fatty acids by regioselective enzymatic acylation using Candida Antarctica lipase B. The antiproliferative effects of the new compounds were investigated in comparison with the parent compounds, phloridzin, aglycone phloretin, the six free fatty acids and chemotherapeutic drugs (sorafenib, doxorubicin and daunorubicin) using human hepatocellular carcinoma HepG2 cells, human breast adenocarcinoma MDA-MB-231 cells and acute monocytic leukemia THP-1 cells along with normal human and rat hepatocytes. The fatty acid esters of phloridzin inhibited significantly the growth of the two carcinoma and leukemia cells while similar treatment doses were not toxic to normal human or rat hepatocytes. The antiproliferative potency of fatty esters of phloridzin was comparable to the potency of the chemotherapeutic drugs. The fatty acid esters of phloridzin inhibited DNA topoisomerases IIα activity that might induce G₀/G₁ phase arrest, induced apoptosis via activation of caspase-3, and decreased ATP level and mitochondrial membrane potential in HepG2 cells. Based on the high selectivity on cancer cells, decosahexaenoic acid (DHA) ester of phloridzin was selected for gene expression analysis using RT²PCR human cancer drug target array. Antiproliferative effect of DHA ester of phloridzin could be related to the down regulation of anti-apoptotic gene (BCL2), growth factor receptors (EBFR family, IGF1R/IGF2, PDGFR) and its downstream signalling partners (PI3k/AKT/mTOR, Ras/Raf/MAPK), cell cycle machinery (CDKs, TERT, TOP2A, TOP2B) as well as epigenetics regulators (HDACs). These results suggest that fatty esters of phloridzin have potential chemotherapeutic effects mediated through the attenuated expression of several key proteins involved in cell cycle regulation, DNA topoisomerases IIα activity and epigenetic mechanisms followed by cell cycle arrest and apoptosis.     

Genetic Architecture of Palm Oil Fatty Acid Composition in Cultivated Oil Palm (Elaeis guineensis Jacq.) Compared to Its Wild Relative E. oleifera (H.B.K) Cortés

We searched for quantitative trait loci (QTL) associated with the palm oil fatty acid composition of mature fruits of the oil palm E. guineensis Jacq. in comparison with its wild relative E. oleifera (H.B.K) Cortés. The oil palm cross LM2T x DA10D between two heterozygous parents was considered in our experiment as an intraspecific representative of E. guineensis. Its QTLs were compared to QTLs published for the same traits in an interspecific Elaeis pseudo-backcross used as an indirect representative of E. oleifera. Few correlations were found in E. guineensis between pulp fatty acid proportions and yield traits, allowing for the rather independent selection of both types of traits. Sixteen QTLs affecting palm oil fatty acid proportions and iodine value were identified in oil palm. The phenotypic variation explained by the detected QTLs was low to medium in E. guineensis, ranging between 10% and 36%. The explained cumulative variation was 29% for palmitic acid C16:0 (one QTL), 68% for stearic acid C18:0 (two QTLs), 50% for oleic acid C18:1 (three QTLs), 25% for linoleic acid C18:2 (one QTL), and 40% (two QTLs) for the iodine value. Good marker co-linearity was observed between the intraspecific and interspecific Simple Sequence Repeat (SSR) linkage maps. Specific QTL regions for several traits were found in each mapping population. Our comparative QTL results in both E. guineensis and interspecific materials strongly suggest that, apart from two common QTL zones, there are two specific QTL regions with major effects, which might be one in E. guineensis, the other in E. oleifera, which are independent of each other and harbor QTLs for several traits, indicating either pleiotropic effects or linkage. Using QTL maps connected by highly transferable SSR markers, our study established a good basis to decipher in the future such hypothesis at the Elaeis genus level.     

Effects of Substituted Pyridazinones (San 6706, San 9774, San 9785) on Glycerolipids and Their Associated Fatty Acids in the Leaves of Vicia faba and Hordeum vulgare

The fatty acids of the major glycerolipids from the leaves of Vicia faba and Hordeum vulgare plants treated with three different concentrations of pyridazinone derivatives were analyzed. These compounds showed multiple effects on the levels of lipids and pigments. At low concentrations, the primary effect of San 9785 was on the level of linolenic acid (18:3) in the galactolipids of V. faba, whereas the effect of San 6706 was primarily on the trans-Δ³-hexadecenoic acid (16:1) content in phosphatidylglycerol. At higher concentrations, the two compounds reduced the content of both fatty acids in the leaves. The results appear to indicate a differential effect of these herbicides on fatty acid accumulation and a difference in susceptibility of two fatty acids in the species examined. Electron microscopic studies revealed that two herbicides caused different abnormalities in V. faba chloroplast ultrastructure.     

Enhanced production of fatty acids in three strains of microalgae using a combination of nitrogen starvation and chemical inhibitors of carbohydrate synthesis

Microalgae are attracting much attention as superior biodiesel producers. In particular, under stressful conditions, they accumulate organic compounds consisting entirely of carbon and hydrogen. The aim of this work was to increase intracellular fatty acid content in Dunaliella tertiolecta (Chlorophyceae), Nannochloropsis oculata (Eustigmatophyceae), and Porphyridium cruentum (Rhodophyceae) using a combination of nitrogen starvation and chemical inhibitors of carbohydrate biosynthesis. These microalgae were subjected to nitrogen starvation and their physiological changes were then observed over time. In D. tertiolecta, no significant change in total fatty acid content was detected on day 3.5 relative to the initial total fatty acid content (day 0), while total carbohydrate content dramatically increased as the nitrogen starvation period was extended. In N. oculata, total fatty acid content rapidly increased, reaching up to nearly 40% of the DCW at day 3.5. However, total carbohydrate content exhibited a gradual reduction throughout the experiment. In P. cruentum, total carbohydrate content increased up to 43% of DCW on day 3.5 and total fatty acid content increased slightly under nitrogen depletion. These data suggest that different eukaryotic microalgae use different storage products under stressful conditions. Among the three strains, D. tertiolecta showed decreased total carbohydrate content and enhanced total fatty acid content following inhibition of carbohydrate synthesis by dichlorophenyl dimethylurea and cyclohexane diamine tetra acetic acid. The results demonstrate the possibility of furthering our understanding of the fatty acid and carbohydrate biosynthesis metabolic network that responds to environmental changes in microalgae.