Inhibitory effects of sesquiterpene lactones from the Indonesian marine sponge Lamellodysidea cf. herbacea on bone morphogenetic protein-induced osteoblastic differentiation.

A new unique sesquiterpene lactone, bicyclolamellolactone A (1), was isolated together with two known monocyclofarnesol-type sesquiterpenes, lamellolactones A (2) and B (3), from the Indonesian marine sponge Lamellodysidea sp. (cf. L. herbacea). The planar structure of 1 was assigned based on its spectroscopic data (1D and 2D NMR, HRESIMS, UV, and IR spectra). The relative and absolute configuration of 1 was determined by comparison of its calculated and experimental electronic circular dichroism spectra in combination with NOESY correlations. Compounds 1-3 inhibited bone morphogenic protein (BMP)-induced alkaline phosphatase activity in mutant BMP receptor-carrying C2C12 cells with IC50 values of 51, 4.6, and 20 µM, respectively.

Screening for Small Molecule Inhibitors of BMP-Induced Osteoblastic Differentiation from Indonesian Marine Invertebrates.

Fibrodysplasia ossificans progressiva (FOP) is a rare congenital disorder with heterotopic ossification (HO) in soft tissues. The abnormal activation of bone morphogenetic protein (BMP) signaling by a mutant activin receptor-like kinase-2 (ALK2) leads to the development of HO in FOP patients, and, thus, BMP signaling inhibitors are promising therapeutic applications for FOP. In the present study, we screened extracts of 188 Indonesian marine invertebrates for small molecular inhibitors of BMP-induced alkaline phosphatase (ALP) activity, a marker of osteoblastic differentiation in a C2C12 cell line stably expressing ALK2(R206H) (C2C12(R206H) cells), and identified five marine sponges with potent ALP inhibitory activities. The activity-guided purification of an EtOH extract of marine sponge Dysidea sp. (No. 256) resulted in the isolation of dysidenin (1), herbasterol (2), and stellettasterol (3) as active components. Compounds 1-3 inhibited ALP activity in C2C12(R206H) cells with IC50 values of 2.3, 4.3, and 4.2 µM, respectively, without any cytotoxicity, even at 18.4-21.4 µM. The direct effects of BMP signaling examined using the Id1WT4F-luciferase reporter assay showed that compounds 1-3 did not decrease the reporter activity, suggesting that they inhibit the downstream of the Smad transcriptional step in BMP signaling.

Production of an α-pyrone metabolite and microbial transformation of isoflavones by an Indonesian Streptomyces sp.

A benzyl-α-pyrone metabolite, streptpyrone A (1), was obtained together with three known isoflavonoids, daidzein-7-O-α-l-rhamnoside (2), genistein-7-O-α-l-rhamnoside (3), and daidzein (4), from the culture broth of an Indonesian actinomycete Streptomyces sp. TPU1401A. The structure of 1, elucidated based on its spectroscopic data, has been reported as a synthetic compound. However, this is the first report of the isolation of 1 as a metabolite of microbial origin. Strain TPU1401A exhibited the ability to transform the isoflavone aglycones 4 and genistein (5) into the 7-O-glycosides 2 and 3, respectively. Compounds 2 and 3 promoted the growth of strain TPU1401A more effectively than compounds 4 and 5. These results suggest that strain TPU1401A utilizes isoflavone glycosides to promote growth by transforming isoflavones through microbial glycosidation.

Callyspongiamides A and B, sterol O-acyltransferase inhibitors, from the Indonesian marine sponge Callyspongia sp.

Callyspongiamides A (1) and B (2), two new sterol O-acyltransferase (SOAT) inhibitors, were isolated from the Indonesian marine sponge Callyspongia sp. together with a known congener, dysamide A (3). The structures of 1 and 2 were elucidated to be polychlorine-containing modified dipeptides based on their spectroscopic data. Compounds 1-3 inhibited both of the SOAT isozymes, SOAT1 and SOAT2, in cell-based and enzyme-based assays.

Cladosporamide A, a new protein tyrosine phosphatase 1B inhibitor, produced by an Indonesian marine sponge-derived Cladosporium sp.

Cladosporamide A (1), a new protein tyrosine phosphatase (PTP) 1B inhibitor, was isolated together with a known prenylated flavanone derivative (2) from the culture broth of an Indonesian marine sponge-derived Cladosporium sp. TPU1507 by solvent extraction, ODS column chromatography, and preparative HPLC (ODS). The structure of 1 was elucidated based on 1D and 2D NMR data. Compound 1 modestly inhibited PTP1B and T-cell PTP (TCPTP) activities with IC50 values of 48 and 54 µM, respectively. The inhibitory activity of 2 against PTP1B (IC50 = 11 µM) was approximately 2-fold stronger than that against TCPTP (IC50 = 27 µM).

Oleanane triterpenes with protein tyrosine phosphatase 1B inhibitory activity from aerial parts of Lantana camara collected in Indonesia and Japan.

During the search for new protein tyrosine phosphatase (PTP) 1B inhibitors, EtOH extracts from the aerial parts of Lantana camara L. (lantana) collected at Manado (Indonesia) and two subtropical islands in Japan (Ishigaki and Iriomote Islands, Okinawa) exhibited potent inhibitory activities against PTP1B in an enzyme assay. Four previously undescribed oleanane triterpenes were isolated together with known triterpenes and flavones from the Indonesian lantana. The EtOH extracts of lantana collected in Ishigaki and Iriomote Islands exhibited different phytochemical profiles from each other and the Indonesian lantana. Triterpenes with a 24-OH group were isolated from the Indonesian lantana only. Five known triterpene compounds were detected in the Ishigaki lantana, and two oleanane triterpenes with an ether linkage between 3ß and 25 were the main components together with five known triterpenes as minor components in the Iriomote lantana. The structures of previously undescribed compounds were assigned on the basis of their spectroscopic data. Among the compounds obtained in this study, oleanolic acid exhibited the most potent activity against PTP1B, and is used as a positive control in studies on PTP1B.

Anti-mycobacterial alkaloids, cyclic 3-alkyl pyridinium dimers, from the Indonesian marine sponge Haliclona sp.

Three new dimeric 3-alkyl pyridinium alkaloids, named haliclocyclamines A-C (1-3), were isolated together with five known congeners, cyclostellettamines A (4), B (5), C (6), E (7), and F (8), from the Indonesian marine sponge Haliclona sp. The structures of 1-3 were assigned based on their spectroscopic data (1D and 2D NMR, HRFABMS, ESIMS/MS, UV, and IR). Compounds 1-8 exhibited antimicrobial activities against Mycobacterium smegmatis with inhibition zones of 17, 10, 13, 14, 8, 8, 12, and 12mm, respectively, at 10µg/disc. Compounds 3 and 8 also modestly inhibited the activity of vaccinia H-1-related phosphatase (VHR), a dual-specificity phosphatase, at 17-18µM.

A new biphenyl ether derivative produced by Indonesian ascidian-derived Penicillium albobiverticillium.

A new biphenyl ether derivative, 2-hydroxy-6-(2'-hydroxy-3'-hydroxymethyl-5-methylphenoxy)-benzoic acid (1), was isolated together with the known benzophenone derivative, monodictyphenone (2), from a culture broth of Indonesian ascidian-derived Penicillium albobiverticillium TPU1432 by solvent extraction, ODS column chromatography, and preparative HPLC (ODS). The structure of 1 was elucidated based on NMR experiments. Compound 2 exhibited moderate inhibitory activities against protein tyrosine phosphatase (PTP) 1B, T cell PTP (TCPTP), and CD45 tyrosine phosphatase (CD45), whereas compound 1 modestly inhibited CD45 activity.

An anti-mycobacterial bisfunctionalized sphingolipid and new bromopyrrole alkaloid from the Indonesian marine sponge Agelas sp.

In the course of our studies on anti-mycobacterial substances from marine organisms, the known dimeric sphingolipid, leucettamol A (1), was isolated as an active component, together with the new bromopyrrole alkaloid, 5-bromophakelline (2), and twelve known congeners from the Indonesian marine sponge Agelas sp. The structure of 2 was elucidated based on its spectroscopic data. Compound 1 and its bis TFA salt showed inhibition zones of 12 and 7 mm against Mycobacterium smegmatis at 50 µg/disk, respectively, while the N,N'-diacetyl derivative (1a) was not active at 50 µg/disk. Therefore, free amino groups are important for anti-mycobacterial activity. This is the first study to show the anti-mycobacterial activity of a bisfunctionalized sphingolipid. Compound 13 exhibited weak PTP1B inhibitory activity (29% inhibition at 35 µM).

Lissoclibadin 1, a Polysulfur Aromatic Alkaloid from the Indonesian Ascidian Lissoclinum cf. badium, Induces Caspase-Dependent Apoptosis in Human Colon Cancer Cells and Suppresses Tumor Growth in Nude Mice.

Lissoclibadins, polysulfur aromatic alkaloids, were isolated from the Indonesian ascidian Lissoclinum cf. badium. Lissoclibadins 1 (1), 3 (2), 4 (3), 7 (4), 8 (5), and 14 (6) inhibited the growth of four human solid cancer cell lines: HCT-15 (colon adenocarcinoma), HeLa-S3 (cervix adenocarcinoma), MCF-7 (breast adenocarcinoma), and NCI-H28 (mesothelioma). Lissoclibadin 1 (1) exerted the most potent cytotoxic effects in vitro and mainly promoted apoptosis through an intrinsic pathway with the activation of a caspase-dependent pathway in HCT-15 cells. In vivo studies demonstrated that 1 suppressed tumor growth in nude mice carrying HCT-15 cells without significant secondary adverse effects. In conclusion, the results obtained in the present study demonstrate that 1 has potential as a chemotherapeutic candidate for preclinical investigations.

Furanoterpenes, new types of protein tyrosine phosphatase 1B inhibitors, from two Indonesian marine sponges, Ircinia and Spongia spp.

Protein tyrosine phosphatase (PTP) 1B negatively regulates the insulin and leptin signaling pathways, and, thus, the clinical application of PTP1B inhibitors to the prevention and treatment of type 2 diabetes and obesity is expected. During our studies on PTP1B inhibitors, two furanosesterterpenes and a C21 furanoterpene were obtained as new types of PTP1B inhibitors from two Indonesian marine sponges. (7E, 12E, 20Z, 18S)-Variabilin (1) and (12E, 20Z, 18S)-8-hydroxyvariabilin (2) from Ircinia sp. and furospongin-1 (3) from Spongia sp. inhibited PTP1B activity with IC50 values of 1.5, 7.1, and 9.9µM, respectively. The inhibitory activity of compound 1 against T-cell PTP (TCPTP) was approximately 2-fold that against PTP1B, whereas the vaccinia H-1-related phosphatase (VHR) inhibitory effects of 1 were 4-fold weaker than that of its PTP1B inhibitory activity. Compounds 1-3 at 50µM did not show cytotoxicity against two human cancer cell lines, hepatoma Huh-7 and bladder carcinoma EJ-1. Compound 1 did not enhance the phosphorylation level of Akt, a key downstream effector of the cascade, in Huh-7 cells.

A tetramic acid derivative with protein tyrosine phosphatase 1B inhibitory activity and a new nortriterpene glycoside from the Indonesian marine sponge Petrosia sp.

During the search for protein tyrosine phosphatase 1B (PTP1B) inhibitors from marine organisms, the known tetramic acid derivative, melophlin C (1), was isolated as an active component together with the new nortriterpenoid saponin, sarasinoside S (2), and three homologues: sarasinosides A1 (3), I1 (4), and J (5), from the Indonesian marine sponge Petrosia sp. The structure of 2 was elucidated on the basis of its spectroscopic data. Compound 1 inhibited PTP1B activity with an IC50 value of 14.6µM, while compounds 2-5 were not active at 15.2-16.0µM. This is the first study to report the inhibitory effects of a tetramic acid derivative on PTP1B activity.

Verruculides A and B, two new protein tyrosine phosphatase 1B inhibitors from an Indonesian ascidian-derived Penicillium verruculosum.

Two new merosesquiterpenes, verruculides A (1) and B (2), were isolated from a culture broth of the Indonesian ascidian-derived Penicillium verruculosum TPU1311, together with three known congeners, chrodrimanins A (3), B (4), and H (5). The structures of 1 and 2 were assigned on the basis of their spectroscopic data (1D and 2D NMR, HRMS, UV, CD, and IR). Compound 2 had a linear sesquiterpene moiety and was considered to be the derivative of the biosynthetic precursor for 1 and 3-5. Compounds 1, 3, and 5 inhibited the activity of protein tyrosine phosphatase 1B (PTP1B) with IC50 values of 8.4, 8.5, and 14.9 µM, respectively. Compound 2 showed 40% inhibition at 23.1 µM, while 4 was not active at 20.7 µM.

A polybromodiphenyl ether from an Indonesian marine sponge Lamellodysidea herbacea and its chemical derivatives inhibit protein tyrosine phosphatase 1B, an important target for diabetes treatment.

The ethanol extract of an Indonesian marine sponge Lamellodysidea herbacea inhibited the activity of protein tyrosine phosphatase 1B (PTP1B), an important target enzyme for the treatment of type II diabetes. Bioassay-guided isolation yielded a known polybromodiphenyl ether (1) as a sole bioactive component. The structure of 1 was confirmed by spectroscopic data for 1 and its methyl ether derivative (2). Compound 1 markedly inhibited the PTP1B activity (IC50 = 0.85 µM) and showed a moderate cytotoxicity against two human cancer cell lines, HCT-15 (colon) and Jurkat (T-cell lymphoma) cells. On the other hand, compound 2 maintained potent inhibitory activity against PTP1B (IC50 = 1.7 µM) but did not show apparent cytotoxicity at 18 µM against these cancer cells. Four ester derivatives [acetyl (3), butyryl (4), hexanoyl (5), and benzoyl (6)] were prepared from 1 and their activities evaluated against PTP1B and two cancer cell lines to investigate the structure-activity relationships. Although compounds 3-6 exhibited potent inhibitory effects against PTP1B activity, cytotoxicity against HCT-15 and Jurkat cells was observed as a similar efficacy to that of 1. From these results, compound 2 was found to be the best inhibitor of PTP1B with no apparent cytotoxicity. Therefore, 2 may be a lead compound for making a new type of PTP1B inhibitor. Moreover, compound 2 did not inhibit the cell growth of Huh-7 cells (hepatoma). Hepatocytes are one of the locations of PTP1B, and Huh-7 cells are used to study the mechanism of action of compound 2.

Papuamine and haliclonadiamine, obtained from an Indonesian sponge Haliclona sp., inhibited cell proliferation of human cancer cell lines.

The extract of an Indonesian marine sponge Haliclona sp. showed potent cytotoxicity against human solid cancer cell lines, MCF-7 (breast), LNCap (prostate), Caco-2 (colon) and HCT-15 (colon) cells. Study on nuclear morphological changes and flow cytometric analysis suggested that the component(s) in the extract would induce an apoptosis to these cancer cells. Bioassay-guided isolation yielded two pentacyclic alkaloids, papuamine (1) and haliclonadiamine (2), which inhibited cell proliferation of six human cancer cell lines with IC50 values of 0.93-1.50 and 1.00-4.44 µM, respectively. Compounds 1 and 2 accumulated lymphoma U937 cells at sub-G1 phase and induced a condensation of chromatin and fragmentation of nucleus.

Two new tryptamine derivatives, leptoclinidamide and (-)-leptoclinidamine B, from an Indonesian ascidian Leptoclinides dubius.

Two new tryptamine-derived alkaloids, named as leptoclinidamide (1) and (-)-leptoclinidamine B (2), were isolated from an Indonesian ascidian Leptoclinides dubius together with C²-α-D-mannosylpyranosyl-L-tryptophan (3). The structure of 1 was assigned on the basis of spectroscopic data for 1 and its N-acetyl derivative (4). Compound 1 was an amide of tryptamine with two ß-alanine units. Although the planar structure of 2 is identical to that of the known compound (+)-leptoclinidamine B (5), compound 2 was determined to be the enantiomer of 5 based on amino acid analysis using HPLC methods. Compounds 1 to 4 were evaluated for cytotoxicity against two human cancer cell lines, HCT-15 (colon) and Jurkat (T-cell lymphoma) cells, but none of the compounds showed activity.

(25S)-cholesten-26-oic acid derivatives from an Indonesian soft coral Minabea sp.

(25S)-3-Oxocholesta-1,4-dien-26-oic acid (1) and a new (25S)-18-acetoxy-3-oxocholesta-1,4-dien-26-oic acid (2) were isolated from a soft coral Minabea sp. (cf. aldersladei) collected in North Sulawesi, Indonesia, together with two known cholic-acid-type compounds, 3-oxochol-1,4-dien-24-oic acid (3) and 3-oxochol-4-en-24-oic acid (4). The structures of these compounds were determined on the basis of their spectroscopic data. The absolute stereochemistry at C-25 of 2 was determined by comparative (1)H NMR study using chiral anisotropic reagents [(S)- and (R)-phenylglycine methyl esters]. This is the first to report compound 1 as a natural product.

Tetrahydrobostrycin and 1-deoxytetrahydrobostrycin, two new hexahydroanthrone derivatives, from a marine-derived fungus Aspergillus sp.

Two new hexahydroanthrones, tetrahydrobostrycin (1) and 1-deoxytetrahydrobostrycin (2), were isolated from a marine-derived fungus Aspergillus sp. strain 05F16 collected at the coral reef of Manado, Indonesia, together with bostrycin and abscisic acid. The structures of new compounds were determined on the basis of their spectral data. Compound 1 showed weak antibacterial activity against Staphylococcus aureus and Escherichia coli and 2 against S. aureus.

Polymorphism in Nucleotide Sequence of Mitochondrial Intergenic Region in Scleractinian Coral (Galaxea fascicularis).

A region of 826 bp that is unlikely to code for a protein, ribosomal RNA, or transfer RNA was identified between the cytochrome b and NADH-ubiquinone oxidoreductase chain 2 loci in the mitochondrial DNA of the scleractinian reef coral Galaxea fascicularis. Nucleotide sequences were determined in a part (625 bp) of this intergenic region in 95 individuals collected at 9 sites in the Ryukyu Archipelago in southwestern Japan. A total of 8 haplotypes were found, and a deletion of 290 bp was found in 3 of them. Significant differences were found in frequencies of the haplotypes at 3 sampling sites. The presence or absence of the deletion was highly correlated with the hard or soft morphotype. The deletion was found in the majority of hard-type colonies, but in a small fraction of soft-type individuals.