Four New Isocoumarins from the Mangrove Fungus Alternaria Malorum with Antimicrobial Activities.

Four new isocoumarins, alternariethers A-C (1-3) and alternariester (4) were separated from the fermentation of the fungus Alternaria malorum FL39, purified from Myoporum bontioides. Their structures were ascertained using NMR and HR-ESI-MS spectroscopy. For compound 4, the absolute configuration was solved with the help of ECD calculation and the DP4+ method. Compared with the positive control triadimefon, compound 1 showed more potent antifungal effects on Colletotrichum musae. The antifungal effects of compounds 1, 2, and 3 on Fusarium oxysporum and Fusarium graminearum, of compound 4 on F. oxysporum, were equal to those of triadimefon. Except for compound 4 which was inactive against Escherichia coli with O78 serotype, all compounds showed moderate or weak antibacterial activity against Staphylococcus aureus ATCC 6538 and E. coli with O6 or O78 serotype.

Furanosesquiterpenes and Related Natural Products from Myoporum Species: Isolation and Semisynthesis.

Myoporum species are recognized as toxic plants. Essential oils from the leaves of these species contain furanosesquiterpenes, which comprise the active toxins. In this report, natural products isolation studies of three Myoporum species (M. insulare, M. parvifolium, and M. montanum) afforded two previously unreported furanosesquiterpenes (24 and 25) and three unprecedented γ-lactone-containing analogues (26-28), along with nine previously reported furanosesquiterpenes and five other natural products. Among the 14 furanosesquiterpenes and related compounds isolated in this study, we observed three distinct types of furanosesquiterpene structures isolated from each of these Myoporum species. Semisyntheses of four sesquiterpene natural products were completed from (-)-ngaione over two steps in each case. This included the synthesis of the lactam-containing sesquiterpene myoporumine A.

HPLC Analysis and Molecular Docking Study of Myoporum serratum Seeds Extract with Its Bioactivity against Pathogenic Microorganisms and Cancer Cell Lines.

Natural constituents have been utilized to avoid humanity from various diseases, such as microbial infection and cancer, over several decades due to bioactive compounds. Myoporum serratum seeds extract (MSSE) was formulated via HPLC for flavonoid and phenolic analysis. Moreover, antimicrobial via well diffusion method, antioxidant via 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, anticancer activities against HepG-2 cells (human hepatocellular cancer cell line), and MCF-7 cells (human breast cancer cell line), and molecular docking of the main detected flavonoid and phenolic compounds with the cancer cells were performed. The phenolic acids, including cinnamic acid (12.75 µg/mL), salicylic acid (7.14 µg/mL), and ferulic (0.97 µg/mL), while luteolin represents the main detected flavonoid with a concentration of 10.74 µg/mL, followed by apegenin 8.87 µg/mL were identified in MSSE. Staphylococcus aureus, Bacillus subtilis, Proteus vulgaris, and Candida albicans were inhibited by MSSE with 24.33, 26.33, 20.67, and 18.33 mm of inhibition zone, respectively. MSSE exhibited a low inhibition zone of 12.67 mm against Escherichia coli while showing no inhibitory activity against Aspergillus fumigatus. The values of MIC ranged from 26.58 to 136.33 µg/mL for all tested microorganisms. MBC/MIC index and cidal properties were attributed to MSSE for all tested microorganisms except E. coli. MSSE demonstrated anti-biofilm 81.25 and 50.45% of S. aureus and E. coli, respectively. IC50 of the antioxidant activity of MSSE was 120.11 µg/mL. HepG-2 and MCF-7 cell proliferation were inhibited with IC50 140.77 ± 3.86 µg/mL and 184.04 µg/mL, respectively. Via Molecular docking study, luteolin and cinnamic acid have inhibitory action against HepG-2 and MCF-7 cells, supporting the tremendous anticancer of MSSE.

[Metabolites of endophytic fungus Nigrospora sphaerica S5 from Myoporum bontioides].

The endophytic fungus Nigrospora sphaerica S5 derived from the semi-mangrove plant Myoporum bontioides was fermented. Its metabolites were purified by column chromatography. Nine compounds were obtained and identified as terezine P(1), 3-(1-hydroxyethyl)-4-methyl dihydrofuran-2(3H)-one(2), methylhydroheptelidate(3), hydroheptelidic acid(4), 5, 7-dimethoxy-4, 6-dimethylphthalide(5),(3R,4S)-(-)-4-hydroxymellein(6), pestalopyrone(7), indole-3-formaldehyde(8) and p-hydroxybenzaldehyde(9) by spectroscopic techniques. Terezine P(1) was a new alkaloid belonging to the terezine class with a pyrazine ring. Compounds 2-7 were lactones, of which 3 and 4 belonged to sesquiterpenes. Compounds 8 and 9 were indole alkaloids and phenols, respectively. Compounds 3-6 were purified from Nigrospora sp. for the first time. These compounds showed different degrees of antibacterial activity against Staphylococcus aureus, Escherichia coli of O6 serotype and E. coli of O78 serotype.

Four New Isocoumarins and a New Natural Tryptamine with Antifungal Activities from a Mangrove Endophytic Fungus Botryosphaeria ramosa L29.

Four new isocoumarin derivatives, botryospyrones A (1), B (2), C (3), and D (4), and a new natural tryptamine, (3aS, 8aS)-1-acetyl-1, 2, 3, 3a, 8, 8a-hexahydropyrrolo [2,3b] indol-3a-ol (5), were isolated from a marine mangrove endophytic fungus Botryosphaeria ramosa L29, obtained from the leaf of Myoporum bontioides. Their structures were elucidated using spectroscopic analysis. The absolute configurations of compounds 3, 4, and 5 were determined by comparison of their circular dichroism (CD) spectra with the calculated data. The inhibitory activities of compound 1 on Fusarium oxysporum, of compounds 2 and 3 on F. oxysporum and Fusarium graminearum, and of compound 5 on F. oxysporum, Penicillium italicum, and F. graminearum were higher than those of triadimefon, widely used as an agricultural fungicide. Compound 5 was produced after using the strategy we called "using inhibitory stress from components of the host" (UISCH), wherein (2R, 3R)-3, 5, 7-trihydroxyflavanone 3-acetate, a component of M. bontioides with weak growth inhibitory activity towards B. ramosa L29, was introduced into the culture medium.

Anti-MRSA Sesquiterpenes from the Semi-Mangrove Plant Myoporum bontioides A. Gray.

The striking rise of methicillin-resistant Staphylococcus aureus (MRSA) infections has become a serious threat to public health worldwide. In an effort to search for new anti-MRSA agents from natural products, a bioassay-guided phytochemical study was conducted on the semi-mangrove plant Myoporum bontioides A. Gray, which led to the isolation of two new sesquiterpene alkaloids (1 and 2) and six known furanosesquiterpenes (3⁻8). Their structures were elucidated on the basis of extensive analysis of their 1D, 2D NMR and mass spectroscopic data. These two new alkaloids (1 and 2) displayed potent anti-MRSA activity with MIC value of 6.25 µg/mL. This is the first report of sesquiterpene alkaloids from the plants of Myoporum genus and their anti-MRSA activity.

Structure Elucidation and Botanical Characterization of Diterpenes from a Specific Type of Bee Glue.

Investigation of the single plant source bee glue type originating from Southern Australia resulted in the isolation and structure elucidation of major serrulatane diterpenes, novel 7,8,18-trihydroxyserrulat-14-ene (1), along with its oxidized product, 5,18-epoxyserrulat-14-en-7,8-dione (3) and known (18RS)-5,18-epoxyserrulat-14-en-8,18-diol (2). Exploration into the botanical origin revealed Myoporum insulare R. Br, as the plant source of the bee glue materials. This discovery was made through comparative analysis of the myoporum bee glue samples collected from the beehives, analyses of plant resinous exudate, and resin carried on the hind legs of bees foraging for bee glue.

A Flavone Constituent from Myoporum bontioides Induces M-Phase Cell Cycle Arrest of MCF-7 Breast Cancer Cells.

Myoporum bontioides is a traditional medicinal plant in Asia with various biological activities, including anti-inflammatory and anti-bacterial characteristics. To identify the bioactive constituents from M. bontioides, a newly-identified flavone, 3,4'-dimethoxy-3',5,7-trihydroxyflavone (compound 1), along with eight known compounds, were investigated in human MCF-7 breast cancer, SCC4 oral cancer, and THP-1 monocytic leukemia cells. Among these compounds, compound 1 exhibited the strongest antiproliferative activity with half-maximal inhibitory concentration (IC50) values ranging from 3.3 µM (MCF-7) to 8.6 µM (SCC4). Flow cytometric analysis indicated that compound 1 induced G2/M cell cycle arrest in MCF-7 cells. Mechanistic evidence suggests that the G2/M arrest could be attributable to compound 1's modulatory effects on the phosphorylation and expression of numerous key signaling effectors, including cell division cycle 2 (CDC2), CDC25C, and p53. Notably, compound 1 downregulated the expression of histone deacetylase 2 (HDAC2) and HDAC4, leading to increased histone H3 acetylation and p21 upregulation. Together, these findings suggest the translational potential of compound 1 as a breast cancer treatment.

Identification and Bioactivity of Compounds from the Mangrove Endophytic Fungus Alternaria sp.

Racemic new cyclohexenone and cyclopentenone derivatives, (±)-(4R*,5S*,6S*)-3-amino-4,5,6-trihydroxy-2-methoxy-5-methyl-2-cyclohexen-1-one (1) and (±)-(4S*,5S*)-2,4,5-trihydroxy-3-methoxy-4-methoxycarbonyl-5-methyl-2-cyclopenten-1-one (2), and two new xanthone derivatives 4-chloro-1,5-dihydroxy-3-hydroxymethyl-6-methoxycarbonyl-xanthen-9-one (3) and 2,8-dimethoxy-1,6-dimethoxycarbonyl-xanthen-9-one (4), along with one known compound, fischexanthone (5), were isolated from the culture of the mangrove endophytic fungus Alternaria sp. R6. The structures of these compounds were elucidated by analysis of their MS (Mass), one and two dimensional NMR (nuclear magnetic resonance) spectroscopic data. Compounds 1 and 2 exhibited potent ABTS [2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)] scavenging activities with EC50 values of 8.19 ± 0.15 and 16.09 ± 0.01 µM, respectively. In comparison to Triadimefon, compounds 2 and 3 exhibited inhibitory activities against Fusarium graminearum with minimal inhibitory concentration (MIC) values of 215.52 and 107.14 µM, respectively, and compound 3 exhibited antifungal activity against Calletotrichum musae with MIC value of 214.29 µM.

Three new resveratrol derivatives from the mangrove endophytic fungus Alternaria sp.

Three new resveratrol derivatives, namely, resveratrodehydes A-C (1-3), were isolated from the mangrove endophytic fungus Alternaria sp. R6. The structures of these compounds were elucidated by analysis of their MS, 1D and 2D NMR spectroscopic data. All compounds showed broad-spectrum inhibitory activities against three human cancer cell lines including human breast MDA-MB-435, human liver HepG2, and human colon HCT-116 by MTT assay (IC50 < 50 µM). Among them, compounds 1 and 2 both exhibited marked cytotoxic activities against MDA-MB-435 and HCT-116 cell lines (IC50 < 10 µM). Additionally, compounds 1 and 3 showed moderate antioxidant activity by DPPH radical scavenging assay.

A new di-O-prenylated flavone from an actinomycete Streptomyces sp. MA-12.

A new di-O-prenylated flavone, named 7,3'-di-(γ,γ-dimethylallyloxy)-5-hydroxy-4'-methoxyflavone (1), was isolated from the culture broth of the endophytic actinomycete Streptomyces sp. MA-12 isolated from the root of the semi-mangrove plant Myoporum bontioides A. Gray. The structure of 1 was determined by comprehensive spectroscopic methods, including 1D and 2D NMR experiments (COSY, HMQC, and HMBC). Primary bioassays showed that 1 at concentration of 0.25 mM had moderate inhibitory activity against three plant pathogenic fungi including Colletotrichum musae, Gibberella zeae (Schweinitz) Petch, and Penicillium citrinum Thom.

Citeromyces hawaiiensis sp. nov., an ascosporic yeast associated with Myoporum sandwicense.

Citeromyces hawaiiensis sp. nov. (NRRL Y-11581(T)  = CBS 12303(T), type strain) is described from 12 strains isolated from flux of the sandalwood (Myoporum sandwicense) and adjacent soil in Hawaii, USA. Analyses of gene sequences from the D1/D2 domains of nuclear large subunit rRNA, internal transcribed spacer (ITS), mitochondrial small-subunit rRNA and translation elongation factor-1α each separated the proposed novel species from Citeromyces matritensis and Citeromyces siamensis, the other known species of the genus Citeromyces. The three species are morphologically similar but they can be separated by growth reactions in standard assimilation tests. An additional strain of Citeromyces siamensis (NRRL Y-11788), a species previously known only from Thailand, was obtained from spoiled condensed milk in Ohio, USA.

Myobontioids A-D and antifungal metabolites from the leaves of Myoporum bontioides A. Gray.

A new sesquiterpene glucoside (1), two new norsesquiterpenes (2, 3), and a new homomonoterpene (4), named myobontioids A-D respectively, along with twelve known flavonoids and lignans (5-16) were isolated from Myoporum bontioides A. Gray. Flavanones 5-11 specifically inhibited Phytophthora capsici and Magnaoeporthe grisea at the concentrations of 125, 250 and 500 µg.mL-1. Notably, the new compound 4 possessed a strong activity against Phytophthora capsici with IC50 below 63.5 µg.mL-1 and 90.4% inhibition at 125 µg.mL-1.

Host Plant Recognition and Performance of Klambothrips myopori (Thysanoptera: Phlaeothripidae) Across Myoporum Cultivars in Southern California.

Myoporum spp. (Lamiales: Scrophulariaceae) native to Australia and New Zealand have been introduced into North America and have been widely planted as shrubs and ground covers in the California urban landscape. The invasive thrips, Klambothrips myopori Mound and Morris, invaded California in 2005 and feed exclusively on Myoporum. However, some commercial cultivars have suffered extensive damage, whereas others have not. In field studies and laboratory feeding tests of six different potential host species or cultivars, Myoporum laetum and Myoporum 'Pacificum' were identified as most suitable host plants of K. myopori. In laboratory trials, K. myopori failed to complete development on M. 'Clean n Green' and M. 'Putah Creek'. Of the six varieties of Myoporum tested, K. myopori damage was only observed on M. laetum and M. 'Pacificum'. Although K. myopori can successfully colonize and reproduce on several varieties of Myoporum, they demonstrated a preference for M. laetum and M. 'Pacificum' in laboratory and field trials.

Chlorine-containing iridoid and iridoid glucoside, and other glucosides from leaves of Myoporum bontioides.

Sixteen compounds were isolated from the MeOH extract of leaves of Myoporum bontioides. The five compounds hitherto unknown, were elucidated to be a chlorine-containing iridoid, named myopochlorin, and an iridoid glucoside, an acylated iridoid glucoside, a linear acetogenin glucoside, and an acyclic monoterpene glucoside, named myobontiosides A-D, respectively, by means of spectroscopic analyses.

Inhibitory activity against plant pathogenic fungi of extracts from Myoporum bontioides A. Gray and indentification of active ingredients.

BACKGROUND: In order to understand the bioactivity of Myoporum bontioides A. Gray against plant pathogens and determine its active ingredients, the inhibitory activities of methanol extracts from M. bontioides against Fusarium oxysporum f. sp. niveum (E. F. Smith) Snyder & Hansen, Pestalotia mangiferae P. Henn., Thielaviopsis paradoxa (De Seynes) v. Hohnel, Colletotrichum musae (Berk. & M. A. Curtis) v. Arx, Alternaria alternata (Fr.) Keissler, Mycosphaerella sentina (Fr.) Schroter and Sphaceloma fawcettii Jenk. were evaluated using a growth rate method, and the active ingredient was isolated by activity-directed isolation and identified by determination and analysis of IR, (1)H NMR, (13)C NMR and mass spectra and correlative physical constants. RESULTS: The results showed that the extracts from stems and leaves of M. bontioides exhibited inhibitory activity against the seven fungi, with > 58% inhibition at 10 g L(-1) after 72 h. The active compound was isolated and identified as (-)-epingaione, and showed inhibitory activity against the above seven fungi. The inhibitory activity against P. mangiferae was the highest, with an EC(50) value of 77 mg L(-1). The EC(50) values against the other six fungi were 147-245 mg L(-1). (-)-Epingaione also inhibited spore germination of F. oxysporum f. sp. niveum, T. paradoxa and S. fawcettii. CONCLUSION: (-)-Epingaione demonstrated broad-spectrum inhibitory activity against plant pathogenic fungi and is promising for exploitation as a fungicide.

A new genus and twenty new species of Australian jumping plant-lice (Psylloidea: Triozidae) from Eremophila and Myoporum (Scrophulariaceae: Myoporeae).

The Triozidae is a diverse, cosmopolitan family of jumping plant-lice (Hemiptera: Psylloidea) from an exceptionally diverse range of plant families, but with few described Australian species. As a direct outcome of the Australian Biological Resources Study Bush Blitz species discovery program, many new Psylloidea from novel host plants in remote localities have been revealed. In this study a new genus Myotrioza Taylor gen. nov. and 20 new species are described from southern and central Australia which also establishes the first host plant records from Eremophila and Myoporum (Scrophulariaceae: Myoporeae). New species, delineated using a combination of morphological and mitochondrial COI sequence data, are: Myotrioza clementsiana sp. nov., M. darwinensis sp. nov., M. desertorum sp. nov., M. eremi sp. nov., M. eremophili sp. nov., M. flindersiana sp.nov., M. gawlerensis sp. nov., M. insularis sp. nov., M. interioris sp. nov., M. interstantis sp. nov., M. longifoliae sp. nov., M. markmitchelli sp. nov., M. myopori sp. nov., M. oppositifoliae sp. nov., M. pantonii sp. nov., M. platycarpi sp. nov., M. remota sp. nov., M. scopariae sp. nov., M. serrulatae sp. nov., and M. telowiensis sp. nov. Genetic divergence data, host associations, biogeographic data, diagnoses and a key to species are presented. Myotrioza appears to be particularly diverse in ephemeral southern Australia, especially in inland Western Australia and South Australia, matching regions of high diversity of the host genera; some species are likely to be short range endemics.

Effects of salinity on anatomical features and physiology of a semi-mangrove plant Myoporum bontioides.

The effect of different concentrations of NaCl, 0, 100, 200, 300 and 400 mM, on the anatomical features and physiology of Myoporum bontioides was investigated. The photosynthetic rates (Pn) were significantly reduced by salt stress, with the lowest values at 400 mM NaCl. The content of malondialdehyde (MDA), proline and soluble sugar, as well as the activities of peroxidase (POD) and catalase (CAT) increased at the beginning, but became similar to the control as the experiment proceeded. The NaCl effect on superoxide dismutase (SOD) was different from the other parameters, with a significant reduction at 400 mM NaCl at Day 7. Salt glands were found in both upper and lower epidermis, and the ratios of the thickness of palisade to spongy mesophyll tissues increased with NaCl concentrations. The medullary ray was clearly damaged by NaCl at levels of 200 and 300 mM. These results demonstrated that M. bontioides could adapt to a relatively low salinity, and was not a halophilous species.

[Bioactivity of volatile oils from Myoporum bontioides on Plutella xylostella].

This study showed that the volatile oils from Myoporum bontioides had a significant repellent action on Plutella xylostella. When Plutella xylostella adults entered into the 4-arm selective olfactometer, the preferred times and average staying duration, in the order from more to less, were 3, 1, 4, and 2 arms, which showed a tendency of keeping away from the treatment arms. The males were more sensitive to the volatile oils than the females, when the velocity of flow was 200 ml.min-1. On the first day of the 3rd bioassay, the oviposition deterrent rate and IIPC of the volatile oils on Plutella xylostella adults was 94.48% and 0.0552, respectively. A liquid component of the volatile oils from Myoporum bontioides was isolated, purified, and identified as myoporone.

[Bioactivity of Myoporum bontioides extracts to Plutella xylostella].

The bioactivity of Myoporum bontioides extracts to Plutella xylostella was studied with IIPC as evaluated index. The results showed that petroleum ether and chloroform extracts had a higher activity than ethyl acetate and alcohol extracts. At 0.01 gDW x ml(-1), the ODR of petroleum ether and chloroform extracts was 84.69% and 79.90%, and 76.47% and 45.70% after treated 1d and 3d, while the IIPC was 0.1565 and 0.2055, respectively. Provided with a higher concentration of 0.05 gDW x ml(-1), the ODR was 88.52% and 72.25%, and 87.33%, 58.37%, while the IIPC was 0.1125 and 0.2620, respectively. From the chloroform extract of Myopdrum Bontioides, three flavonoids, 2, 3-dihydro-5, 7-dihydroxy-2-phenyl-4H-1-Benzopyran-4-one (I), 3, 5, 7-trihydroxy-2-phenyl-4H-1-Benzopyran-4-one (II) and 5, 7-dihydroxy-3-methoxy-2-(4-methoxyphenyl)-4H-1-Benzopyran-4-one (III), were isolated, and their structure were identified based on the analyses of physical and spectrum data. Among these compounds, (II) had a better bioactivity to Plutella xylostella.