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Two terpenes; cneorubin X (1), (-)-gymnomitr-3(15)-en-4β-ol (2) as well as one benzoic compound; caffeic acid (3) were isolated from Bazzania harpago collected from Mt. Trus Madi, Sabah, Malaysia. The structures of these secondary metabolites were elucidated based on spectroscopic data (Infra-Red (IR), 1D and 2D Nuclear Magnetic Resonance (NMR), and Mass Spectrum (MS)). This is the first record that cneorubin X (1) was isolated from non-vascular plants and it exhibited active anti-fungal activity against Haliphthoros sabahensis and Haliphthoros milfordensis. Chemosystematics finding suggests that the Marchantiophyta (liverworts) genus Bazzania might have a closer chemical relationship to its sister group Bryophyta (mosses) genus Brachythecium, Kindbergia and Mnium, as well as Anthocerophyta (hornworts) genus Anthocerosin their evolutionary history.

The aquaculture industry is growing rapidly throughout the world, but due to intensification, fish hatcheries are often faced with infestations of parasites, which can lead to economic loss. Among these parasites, the leech Zeylanicobdella arugamensis (Hirudinea: Piscicolidae) has been reported to impact hybrid groupers and other hosts. The objective of this study was to test the antiparasitic potential of chromatographic fractions of a crude methanolic extract of the tropical shrub Dillenia suffruticosa. The phytochemical composition of the shrub was determined using high-resolution liquid chromatography (LC)–quadrupole time-of-flight (QTOF)–mass spectrometry (MS) to narrow down the metabolites responsible for its antiparasitic properties. Seven fractions of a methanolic extract of D. suffruticosa were obtained through flash column chromatography. Various concentrations of the fractions were prepared and tested against Z. arugamensis. In the bioassay conducted with fresh leeches, significant mortality was induced by fraction 6 at 31.66 ± 4.88 min, followed by fraction 5 (39.58 ± 2.94 min), fraction 3 (63.75 ± 6.61 min) and fraction 4 (65.25 ± 4.98 min). Chemical profiling using LC–QTOF–MS identified 17 secondary metabolites comprising triterpenoids, sterols, flavones, a glycoside, a non-flavone phenolid, a pyrrolizine, a fatty acid and a fatty amide. Thus, our study indicated that the D. suffruticosa fractions contained potent bioactive compounds with antiparasitic potential.

Abstract New bioactive 13-epi-neoverrucosane diterpenoid, 5β-acetoxy-13-epi-neoverrucosanic acid (1) along with three known secondary metabolites, 13-epi-neoverrucosan-5β-ol (2), chelodane (3) and (E)-β-farnesene (4) were isolated from the MeOH extract of east Malaysia’s liverwort Pleurozia subinflata. The chemical structure of new compound was elucidated by the analyses of its spectroscopic data (FTIR, NMR and HR-ESI-MS). These epi-neoverrucosane-type compounds seem to be notable chemosystematic markers for P. subinflata in Borneo. Compound 3 was widespread in marine sponges however this is the first record for 3 to be found in liverwort. These metabolites were tested for their antifungal potentials against selected fungi from the marine environment. Compound 1 exhibited effective antifungal activity against Lagenidium thermophilum. Graphic Abstract

HoploscopaMeyrick (Lepidoptera: Crambidae) is a fern-feeding genus found in montane areas of South-East Asia and Melanesia, eastwards up to the Samoan Islands. It includes sixteen described species, with at least 70 further undescribed species known from scientific collections. An iterative approach including morphological and molecular characters was used in order to explore the diversity ofHoploscopa. The hitherto described species are revised, and descriptions authored by T. Léger and M. Nuss are provided for an additional 26 new species:H. agtuuganonensissp. nov.,H. albipunctasp. nov.,H. albomaculatasp. nov.,H. anacanthasp. nov.,H. boletasp. nov.,H. cynodontasp. nov.,H. danaoensissp. nov.,H. gombongisp. nov.,H. gracilissp. nov.,H. ignitamaculaesp. nov.,H. isarogensissp. nov.,H. jubatasp. nov.,H. kelamasp. nov.,H. kinabaluensissp. nov.,H. mallyisp. nov.,H. marijoweissaesp. nov.,H. matheaesp. nov.,H. niveofasciasp. nov.,H. pangrangoensissp. nov.,H. parvimaculasp. nov.,H. pseudometacrossasp. nov.,H. sepanggisp. nov.,H. sumatrensissp. nov.,H. titikasp. nov.,H. tonsepisp. nov.,H. ypsilonsp. nov.Using a protocol specific for the amplification of DNA from old museum specimens, we recovered 101 COI barcodes for all but one of the newly described species, with 76 being barcode compliant (>487 bp). Species delimitation analyses suggest cryptic diversity, with six cases reflecting allopatric divergence, and two further cases found in sympatry.

Red algae of the genus Laurencia have been known to produce a wide array of bioactive secondary metabolites. Here, we report the isolation of two new halogenated chamigrenes, lauremantanones A (1) and B (2), along with seven known compounds, dendroidiol (3), (+)-elatol (4), cartilagineol (5), obtusol (6), (+)-laurencenone B (7), 2-chloro-3-hydroxy-α-chamigren-9-one (8), and puertitol A (9), from a population of Laurencia majuscula (Harvey) Lucas from Mantanani Island (North Borneo). The structures of the two new metabolites were determined based on spectroscopic data (IR, 1D and 2D NMR, and MS). Compounds isolated from this alga exhibited potent cytotoxic (HeLa, MCF-7, P-388) and antibacterial (against antibiotic-resistant clinical bacteria) activities. The major metabolite of this population has significant importance in the geographical distribution of this species globally.

Phyllopsora is a crustose to squamulose lichen genus inhabiting the bark of trees in moist tropical forests and rainforests. Species identification is generally challenging and is mainly based on ascospore morphology, thallus morphology and anatomy, vegetative dispersal units, and on secondary chemistry. While regional treatments of the genus have been conducted for Africa, South America and Australia, there exists no study focusing on the Asian and Melanesian species. Previously, 24 species of Phyllopsora s. str. have been reported from major national studies and checklists representing 13 countries. We have studied herbarium material of 625 Phyllopsora specimens from 18 countries using morphology, anatomy, secondary chemistry, and molecular data to investigate the diversity of Phyllopsora species in Asia and Melanesia. We report the occurrence of 28 species of Phyllopsora including the following three species described as new to science: P. sabahana from Malaysia, P. siamensis from Thailand and P. pseudocorallina from Asia and Africa. Eight species are reported as new to Asia. A key to the Asian and Melanesian species of Phyllopsora is provided. This Journal is a supporter of open science. Open access to content is clearly marked, with text and/or the open access logo, on all materials published under this model. Unless otherwise stated, open access content is published in accordance with the Creative Commons Attribution 4.0 licence (CC-BY). This particular licence allows the copying, displaying and distribution of the content at no charge, provided that the author and source are credited.

A new cembrane-type diterpenoid, sinulaflexiolide P (1), along with three known derivatives: sinulaflexiolide H (2), 11-epi-sinulariolide acetate (3), and (1S*,3S*,4S*,7E,11E)-3,4-epoxy-13-oxo-3,7,11,15-cembratriene (4), was isolated from a population of Bornean soft coral Sinularia flexibilis. The structures of these metabolites were elucidated based on spectroscopic data including NMR and HR-ESI-MS. In addition, these compounds were tested against six strains of marine fungi.

Many lowland rainforests in Southeast Asia are severely altered by selective logging and there is a need for rapid assessment methods to identify characteristic communities of old growth forests and to monitor restoration success in regenerating forests. We have studied the effect of logging on the diversity and composition of lichen communities on trunks of trees in lowland rainforests of northeast Borneo dominated by Dipterocarpaceae. Using data from field observations and vouchers collected from plots in disturbed and undisturbed forests, we compared a taxonomy-based and a taxon-free method. Vouchers were identified to genus or genus group and assigned to functional groups based on sets of functional traits. Both datasets allowed the detection of significant differences in lichen communities between disturbed and undisturbed forest plots. Bark type diversity and the proportion of large trees, particularly those belonging to the family Dipterocarpaceae, were the main drivers of lichen community structure. Our results confirm the usefulness of a functional groups approach for the rapid assessment of tropical lowland rainforests in Southeast Asia. A high proportion of Dipterocarpaceae trees is revealed as an essential element for the restoration of near natural lichen communities in lowland rainforests of Southeast Asia.

Global fish demand could only be met with the intensification of aquaculture as fish consumption outpaces the population growth. But, intensification of production has also increased disease outbreak and higher mortality of fish fingerlings in hatcheries and grow-out facilities. Hatcheries are using antibiotics and other chemotherapeutic means in the disease management, but due to the side effects many fish culturists have started to use probiotics as direct application into the culture medium. However, detailed investigation has indicated the source of infection as the introduction of “Green-Water” that is a common source of microalgae for fish larvae and rotifer culture. Although application of probiotics in recent years has shown to reduce infection and increase immune resistance of fish but its application has to be targeted, gap still exists in the administration of microalgae- or alga-fed rotifers during first feeding of larvae at most hatcheries. High mortality in fish larvae and fish fingerlings could be attributed to the introduction of opportunistic microbes during first feeding. An innovative solution to address this issue is the production and utilization of probiotic fortified seaweed silage (SS) as feed for fish larvae and rotifers. Use of Rhodophyta, Eucheuma denticulatum Doty was found to be the best raw material as its inherently available fine chemicals were found to have no repelling effect on the larvae and rotifers during feeding. A consortium of lactic acid bacteria and yeast with the assistance of cellulase enzyme was sufficient for the conversion of seaweed powder into SS. The whole process could be performed by any aquaculturist with ease and this will lower the cost and increase the productivity at the hatchery. Application of 2% SS was sufficient to yield high growth rate in rotifers (r = 0.63) and produced high-quality rotifers with eggs. Combination of SS with the frozen microalgae, Nannochloropsis sp. in equal ratio further increased the growth rate of rotifers (r = 1.46). Probiotic-fortified SS was also formulated into a pellet feed and it gave better feed conversion and growth rates in Asian seabass when tested for a duration of 56 days. Here, we address the use of probiotic-fortified SS as a futuristic solution in fish hatcheries.

Cyanobacteria are reported as rich sources of secondary metabolites that provide biological activities such as enzyme inhibition and cytotoxicity. Ten depsipeptide derivatives (lyngbyabellins) were isolated from a Malaysian Moorea bouillonii and a Red Sea Okeania sp.: lyngbyabellins G (1), O (2), P (3), H (4), A (7), 27-deoxylyngbyabellin A (5), and homohydroxydolabellin (6). This study indicated that lyngbyabellins displayed cytotoxicity, antimalarial, and antifouling activities. The isolated compounds were tested for cytotoxic effect against human breast cancer cells (MCF7), for antifouling activity against Amphibalanus amphitrite barnacle larvae, and for antiplasmodial effect towards Plasmodium falciparum. Lyngbyabellins A and G displayed potent antiplasmodial effect against Plasmodium, whereas homohydroxydolabellin showed moderate effect. For antifouling activity, the side chain decreases the activity slightly, but the essential feature is the acyclic structure. As previously reported, the acyclic lyngbyabellins are less cytotoxic than the corresponding cyclic ones, and the side chain increases cytotoxicity. This study revealed that lyngbyabellins, despite being cytotoxic agents as previously reported, also exhibit antimalarial and antifouling activities. The unique chemical structures and functionalities of lyngbyabellin play an essential role in their biological activities.

Chemical investigation of the organic extract from Moorea bouillonii, collected in Sabah, Malaysia, led to the isolation of three new chlorinated fatty acid amides, columbamides F (1), G (2), and H (3). The planar structures of 1-3 were established by a combination of mass spectrometric and NMR spectroscopic analyses. The absolute configuration of 1 was determined by Marfey's analysis of its hydrolysate and chiral-phase HPLC analysis after conversion and esterification with Ohrui's acid, (1S,2S)-2-(anthracene-2,3-dicarboximido)cyclohexanecarboxylic acid. Compound 1 showed biosurfactant activity by an oil displacement assay. Related known fatty acid amides columbamide D and serinolamide C exhibited biosurfactant activity with critical micelle concentrations of about 0.34 and 0.78 mM, respectively.

The red alga Chondria armata is known to produce and contain a rich diversity of secondary metabolites, such as domoic acid-related alkaloids and triterpene polyethers. Our investigation on red alga C. armata from Kagoshima coast, Japan, resulted in the isolation of two new triterpene polyethers, bandokorols A (1) and B (2). The structures of these compounds were determined based on spectroscopic data such as infrared (FTIR), 1H-NMR, APT, 1H–1H-COSY, HSQC, HMBC, NOESY and FAB mass spectrometry (HRFABMS). The anticancer potentials of these compounds were tested against adult T-cell leukaemia (ATL), S1T cells and their IC50 values are reported here.

Krogia borneensis Kistenich & Timdal, K. isidiata Kistenich & Timdal and K. macrophylla Kistenich & Timdal are described as new species, the first from Borneo and the two latter from New Caledonia. The new species are supported by morphology, secondary chemistry and DNA sequence data. Krogia borneensis and K. isidiata contain sekikaic and homosekikaic acid, both compounds reported here for the first time from the genus. Krogia macrophylla contains an unknown compound apparently related to boninic acid as the major compound. DNA sequences (mtSSU and nrITS) are provided for the first time for Krogia and a phylogeny of the genus based on 15 accessions of five of the six accepted species is presented. Krogia antillarum is reported as new to Brazil, Guatemala and Mexico. Krogia borneensis Kistenich & Timdal, K. isidiata Kistenich & Timdal and K. macrophylla Kistenich & Timdal are described as new species, the first from Borneo and the two latter from New Caledonia. The new species are supported by morphology, secondary chemistry and DNA sequence data. Krogia borneensis and K. isidiata contain sekikaic and homosekikaic acid, both compounds reported here for the first time from the genus. Krogia macrophylla contains an unknown compound apparently related to boninic acid as the major compound. DNA sequences (mtSSU and nrITS) are provided for the first time for Krogia and a phylogeny of the genus based on 15 accessions of five of the six accepted species is presented. Krogia antillarum is reported as new to Brazil, Guatemala and Mexico.

Rehabilitation of degraded forest is being intensified in Borneo, effort by the INIKEA Rehabilitation Project in Luasong (Sabah) has resulted in healthy growth of native timber species to Borneo. Slow growth rate of Dipterocarps has been attributed to presence of biofoulers on its leaves and herbivory. Therefore, an investigation was conducted to document the coverage and distribution of foliicolous lichens on the leaves of five common timber species Dipterocarpus conformis, Dryobalanops lanceolate, Dryobalanops keithii, Shorea ovalis, and Shorea fallax, planted during this project in 2008. Colonization of foliicolous lichen on timber species was seen to exist in two distinct pattern; leaves of genus Shorea showed surface colonization of 28–29%, while genus Dipterocarpus and Drybalanopsis exhibited a lesser coverage of 15–18%. A total of 32 species belonging to nine families were recorded during the course of this study. Lichen diversity was higher on leaves of Dipterocarpus conformis and Shorea ovalis as compared to the other three species. In addition, nine new records of foliicolous lichens were isolated, identified and their descriptions are presented here. Keywords: INIKEA, Borneo, Dipterocarps, Biofoulers, Foliicolous lichens

At the global scale, species diversity is known to strongly increase towards the equator for most taxa. According to theory, a higher resource specificity of consumers facilitates the coexistence of a larger number of species and has been suggested as an explanation for the latitudinal diversity gradient. However, only few studies support the predicted increase in specialisation or even showed opposite results. Surprisingly, analyses for detritivores are still missing. Therefore, we performed an analysis on the degree of trophic specialisation of dung beetles. We summarised 45 studies, covering the resource preferences of a total of 994503 individuals, to calculate the dung specificity in each study region. Our results highlighted a significant (4.3-fold) increase in the diversity of beetles attracted to vertebrate dung towards the equator. However, their resource specificity was low, unrelated to diversity and revealed a highly generalistic use of dung resources that remained similar along the latitudinal gradient.

The red algal genus Laurencia is a prolific producer of halogenated secondary metabolites. A new tricyclic dibrominated diterpenoid, neoiriepentaol (1) and chlorinated C15-acetogenin, nangenyne (2), along with two known terpenoids, neoirietetraol (3) and dactyloxene A (4), were isolated from methanol crude extract of red alga Laurencia nangii. The structures were established based on one- and two-dimensional nuclear magnetic resonance (NMR), Fourier-transform infrared (FTIR), and high-resolution electrospray ionization mass spectrometry (HRESIMS) data. These compounds were screened against seven species of marine fungi. Compounds 1–3 exhibited activity against Lagenidium thermophilum and Haliphthoros sabahensis. Potent activity was showed by 1 with L. thermophilum hyphal inhibition at MIC value of 12.5 μg mL−1 and hyphal motility was observed at 50 μg mL−1 within 24 h.

The red alga genus Laurencia (Rhodomelaceae, Ceramiales) is known to produce and contain a rich diversity of halogenated secondary metabolites. These compounds are dominated by two major biosynthetic groups: terpenes (sesquiterpenes, diterpenes, and triterpenes) and C15-acetogenins. In the course of our investigation on red algae genus Laurencia from North Borneo Island, three new halogenated chamigranes, 7-aldehydelaurencenone B (1), 2-chloro-3-methoxy-α-chamigren-9-one (2), and laureborneone (3) along with five known halogenated derivatives such as [1(15)Z,2Z,4R,8S,9R]-8,15-dibromochamigra-1(15),2,11(12)-trien-9-ol (4), [1(15)E,2Z,4R,8S,9R]-8,15-dibromochamigra-1(15),2,11(12)-trien-9-ol (5), ma’ilion (6), laurencenone B (7), and 2-chloro-3-hydroxy-α-chamigren-9-one (8) were isolated from Laurencia majuscula. The structures of these compounds were determined based on spectroscopic data which consisted of infrared (FT-IR), H1-NMR, C13-NMR, H1-H1-COSY, HSQC, HMBC, and NOESY. In addition, high-resolution electrospray ionization mass spectrometry (HRESIMS) was done to calculate their molecular formula and unsaturation index. The anticancer potentials of these compounds were tested against three cancer cell lines, and their IC50 values were determined.

The medicinal plant, Syzygium leucoxylon or commonly known as Obah found in North Borneo was considered as traditional medicine by local committee. Two new phenolics, leucoxenols A (1) and B (2) were isolated and identified as major secondary metabolites from the leaves of S. leucoxylon. Their chemical structures were elucidated based on spectroscopic data such as NMR and HRESIMS. Furthermore, these compounds were active against selected strains of fungi.

The antifungal activity of two Bornean medicinal wild gingers Plagiostachys megacarpa and Zingiber phillippsiae were examined against Lagenidium thermophilum. The most active extract was P. megacarpa at concentration of 320 µg/mL inhibiting both hyphal growth and zoospore production of L. thermophilum in 24 h. Toxicity tests were conducted using mud crab (Scylla tranquebarica) larva. Bath treatment of P. megacarpa at concentrations of 320 and 640 µg/mL for 24 h were highly effective against hyphae and zoospores of the strain and it is non-toxic to mud crab larva. Therefore, crude extracts P. megacarpa may be used as alternative treatment for marine Oomycete infection of mud crab.

Decline in forest productivity due to forest conversion is defining the Bornean landscape. Responses of bacterial communities due to land-use changes are vital and could define our understanding of ecosystem functions. This study reports the changes in bacterial community structure in organic soil (0-5 cm; O-Horizon) and organic-mineral soil (5-15 cm; A-Horizon) across Maliau Basin Conservation Area old growth forest (MBOG), Fragment E logged forest (FELF) located in Kalabakan Forest Reserve to Benta Wawasan oil palm plantation (BWOP) using two-step PCR amplicon analysis of bacteria DNA on Illumina Miseq next generation sequencing. A total of 30 soil samples yielded 893,752-OTU reads at ≥97% similarity from 5,446,512 good quality sequences. Soil from BWOP plantation showed highest unshared OTUs for organic (49.2%) and organic-mineral (50.9%) soil. MBOG soil showed a drop in unshared OTUs between organic (48.6%) and organic-mineral (33.9%). At phylum level, Proteobacteria dominated MBOG but shifted to Actinobacteria in logged and plantation soil. Present findings also indicated that only FELF exhibited change in bacterial communities along the soil depth, moving from the organic to the organic-mineral layer. Both layers of BWOP plantation soils deviated from other forests' soil in β-diversity analysis. To our knowledge, this is the first report on transitions of bacterial community structures with different soil horizons in the tropical rainforest including Borneo, Sabah. Borneo tropical soils form a large reservoir for soil bacteria and future exploration is needed for fully understanding the diversity structure and their bacterial functional properties.

The antioxidant activity of Clarias gariepinus and Clarias sp.1 epidermal mucus were determined. Aqueous extracts of C.sp1 contained relatively higher levels of protein concentration [602.04mg g-1 fresh weight] than other extracts while the organic extracts (aqueous phase) of C.sp1 gave higher levels of protein concentration (43.50mg g-1 fresh weight) than dichloromethane phase for both species. The chemical composition analysis revealed the values of moisture, ash, crude protein, fat and carbohydrate contents present in both species. The DPPH scavenging effect of all extracts and standards on the DPPH radical decreased in order of: ascorbic acid > BHT > dichoromethane phase extract of C. gariepinus > aqueous phase of C. gariepinus > acidic extract of C.sp1 > acidic extract of C. gariepinus > dichloromethane phase extract of C.sp1 > aqueous phase extract of C.sp1 > aqueous extract of C. gariepinus > aqueous extract of C.sp1 at the concentration of 100ug/ml, respectively. Reducing power activities in all extracts increased with increasing concentration except for acidic extract of C. gariepinus which decreased at concentration of 100ug/ml. The Ferric Reducing Antioxidant Power (FRAP) also increased as the concentration increased for all extracts. However, all extracts showed lower scavenging activity, reducing power and FRAP activities than BHT and ascorbic acid at the same concentrations. This preliminary information suggest that mucus from these fish species may be a source of novel antioxidant agents for fish and human health related applicants.

A new sesquiterpene, capgermacrene H (1) was isolated together with 7 other compounds, capgermacrenes A-G (2-8), from a population of soft coral Capnella imbricata collected from Mantanani Island, Sabah, Malaysia. The structure of this metabolite was elucidated based on spectroscopic data such as nuclear magnetic resonance and high-resolution electrospray ionization mass spectrometry. Capgermacrene A (2) showed potent cytotoxicity against adult T-cell leukemia, S1T cells at half-maximal inhibitory concentration of 0.79 µg/mL., 論文

One new cembrane diterpene, 16-hydroxycembra-1,3,7,11-tetraene (1), along with three known compounds, 15-hydroxycembra-1,3,7,11-tetraene (2), sarcophine (3) and sarcophytoxide (4) were isolated from Sarcophyton sp. collected from Karah Island, Terengganu, West Malaysia. Their structures were elucidated based on spectroscopic data. Activities of these compounds against antibacterial resistant clinical bacteria are reported. Only 1 exhibited inhibition against Staphylococcus aureus.

Two new C15-acetogenins, 4-epi-isolaurallene (1) and 4-epi-itomanallene A (2) were isolated from a population of marine red alga Laurencia nangii Masuda from Carrington Reef. The structures of these compounds were determined intensively by NMR and HRESIMS data. Their configurations were elucidated by detailed comparison of chemical shifts, germinal protons splitting and NOE correlations with known and synthesized analogues. In addition, antibacterial activities of these compounds were evaluated. These compounds would serve as diastereomeric models for future reference. Since the isolaurallene, neolaurallene, 9-acetoxy-1,10,12-tribromo-4,7:6,13-bisepoxypentadeca-1,2-diene, itomanallene A and laurendecumallene A were isolated, compounds 1 and 2 were the sixth example of C15-acetogenin with dioxabicyclo[7.3.0]dodecene skeleton.

Four new bicyclogermacrenes, capgermacrenes D (1) E (2) F (3) and G (4) were isolated from a population of Bornean soft coral Capnella imbricata. The structures of these metabolites were elucidated based on their nuclear magnetic resonance and high-resolution electrospray ionisation mass spectrometry spectral data. These compounds showed bacteriastatic and bacteriacidal activities against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.

Three new cembranoid diterpenes, 10-hydroxy-nephthenol acetate (1), 7,8-epoxy-10-hydroxy-nephthenol acetate (2), and 6-acetoxy-7,8-epoxy-10-hydroxy-nephthenol acetate (3), along with a known compound, 6-acetoxy-7,8-epoxy-nephthenol acetate (4), were isolated from the Bornean soft coral Nephthea sp. Antibacterial and anticancer activities were exhibited by compounds 1 and 2 against Staphylococcus aureus (ATCC 6538)/Escherichia coli (ATCC 13311) and Hela/MCF-7, respectively.

We examined the constitution of Laurencia mariannensis collected from the east coast of Tean Island, Thailand. The structure of a new brominated rearranged cyclolaurane-type sesquiterpene, named teanol (1), is reported. This is the first report on biology and chemistry of the Thailand red algal genus Laurencia (Rhodomelaceae, Ceramiales).

The Bornean liverwort Gottschelia schizopleura was investigated phytochemically for the first time. Two new and four previously known clerodane-type diterpenoids were isolated from the MeOH extract of G. schizopleura through a series of chromatographic techniques. The structures of the new metabolites were established by analyses of their spectroscopic data (1D NMR, 2D NMR, HRESIMS and IR). All the isolated compounds 1–6 were tested against human promyelocytic leukaemia (HL-60), human colon adenocarcinoma (HT-29) and Mus musculus skin melanoma (B16-F10). Compound 1 and 2 showed active inhibition against HL-60 and B16-F10 cells.

Six new compounds, omaezol, intricatriol, hachijojimallenes A and B, debromoaplysinal, and 11,12-dihydro-3-hydroxyretinol have been isolated from four collections of Laurencia sp. These structures were determined by MS and NMR analyses. Their antifouling activities were evaluated together with eight previously known compounds isolated from the same samples. In particular, omaezol and hachijojimallene A showed potent activities (EC50 = 0.15-0.23 mu g/mL) against larvae of the barnacle Amphibalanus amphitrite.

Two new halogenated nonterpenoids C15-acetogenins, nangallenes A-B (1–2), together with two known halogenated compounds itomanallene A (3) and 2,10-dibromo-3-chloro-α-chamigrene (4), were isolated and identified from the organic extract of the marine red alga Laurencia nangii Masuda collected from the coastal waters in Semporna, Borneo. Their structures were established by means of spectroscopic analysis including IR, high-resolution electrospray ionization mass spectrometry (HRESI-MS), and 1D and 2D NMR techniques. All these metabolites were submitted for the antifungal assay against four species of selected marine fungi. Compounds 1–4 showed potent activity against Haliphthoros sabahensis and Lagenidium thermophilum.

Three new halogenated tricyclic sesquiterpenes, omphalaurediol (1), rhodolaurenones B (2) and C (3) were isolated together with nine known haloganated sesquiterpenes such as rhodolaurenone A (4), rhodolaureol (5), isorhodolaureol (6), (−)-laurencenone D (7), elatol (8), (+)-deschloroelatol (9), cartilagineol (10), (+)-laurencenone B (11) and 2-chloro-3-hydroxy-α-chamigren-9-one (12) from a population of Bornean red algae Laurencia majuscula. The structures of three new metabolites were determined based on their spectroscopic data (IR, 1D and 2D NMR, and MS). These compounds showed antibacterial activity against three human pathogenic bacteria (Escherichia coli, Salmonella typhi and Vibrio cholera).

A new aaptamine-related alkaloid, 1,3-dioxolo [4,5- d] benzo [ de]-1,6-naphthyridine (methylenedioxyaaptamine, 1), was isolated from the organic extracts of the Bornean marine sponge Aaptos aaptos, together with a known aaptamine derivative, 8,9,9-trimethoxy-9 H-benzo [ de]-1,6-naphthyridine (2). The structure of compound 1 was elucidated by interpretation of its spectroscopic data. Two compounds were tested for their cytotoxic potentials against adult T-cell leukemia (ATL) cells, and compound 1 showed moderate cytotoxic potential.

A new cembranolide diterpene, sarcophytonolide V (1), along with 6 known compounds, isosarcophytonolide D (2), (4 Z,8 S*,9 R*,12 E,14 E)-9-hydroxy-1-(prop-1-en-2-yl)-8,12-dimethyl-oxabicyclo[9.3.2]-hexadeca-4,12,14-trien-18-one (3), (7 E,11 E)-3,4-epoxy-7,11,15-cembratriene (4), (1 S*,3 S*,4 S*,7 E,11 E)-3,4-epoxy-13-oxo-7,11,15-cembratriene (5), (-)-eunicenone (6), and 2-[( E, E, E)-7′,8′-epoxy-4′,8′,12′-trimethylcyclotetradeca-1′,3′,11′-trienyl]propan-2-ol (7) were isolated from the Bornean soft coral Sarcophyton sp. Their structures were elucidated based on spectroscopic data, such as nuclear magnetic resonance (NMR) and high resolution electron spray ionization mass spectroscopy (HRESIMS). These compounds were evaluated for their biological activity against marine pathogenic fungi.

The red algae genus Laurencia (Rhodomelaceae, Ceramiales) is known as a prolific producer of halogenated secondary metabolites with a high level of species diversity and geographical distribution. In North Borneo Island, Malaysia, there are four main Laurencia species: Laurencia snackeyi, Laurencia majuscula, Laurencia similis and L. nangii. Although the chemistry of Laurencia is well studied, the diversity of compounds in L. nangii has not been thoroughly investigated. Therefore, we studied the chemical constituents of seven populations of L. nangii from Tunku Abdul Rahman Marine Park (two populations), Dinawan Island (one population), Tun Mustapha Marine Park (two populations) and Tun Sakaran Marine Park (two populations). Halogenated compounds were isolated and the structures determined via spectroscopic methods. A total of 20 metabolites belonging to the classes of sesquiterpenes, acetylenes, bromoallenes, diterpenes and triterpenes were identified. Populations from Tunku Abdul Rahman Marine Park and Dinawan Island contained non-chamigrane-type sesquiterpenes, acetylenes and diterpenes. Populations from Tun Mustapha Marine Park contained chamigrane-type sesquiterpenes, acetylenes and diterpenes. However, the chemical compositions of populations from Tun Sakaran Marine Park were found to differ significantly, containing chamigrane-type and non-chamigrane-type sesquiterpenes, bromoallenes and triterpenes. This investigation has revealed the presence of interesting chemotaxonomical markers in populations of L. nangii and the existence of chemical races in this species.

Epiphytism of filamentous red algae is a serious problem in Kappaphycus farms in the Philippines, Indonesia, Malaysia, and Tanzania. The causative organism of epiphyte outbreak has been identified as Neosiphonia apiculata (Hollenberg) Masuda and Kogame, but its actual effect on carrageenan quality has not yet been established. Therefore, yield and quality of carrageenan from healthy and infected specimens were examined. Infected specimens showed 20.5 ± 2.5 % DW lower carrageenan yield compared with the healthy seaweed (65.5 ± 4.2 % DW). Infected specimens also had a higher phenolic and fatty acid content, compared with healthy specimens. The carrageenan from the infected seaweed showed 74.5 ± 2.8 % lower viscosity, 52.6 ± 3.6 % lower gel strength, 22.9 ± 1.5 % higher syneresis, and 5 °C higher melting temperature as compared with carrageenan from healthy specimens. FTIR and 13C-NMR analysis of carrageenan from infected seaweed did not show any differences in their functionality or carbon atom chemical shift as compared with healthy and standard k-carrageenan. However, size exclusion chromatography showed the infected carrageenan molecular size to be 80 kDa as compared with 800 kDa for the healthy and standard k-carrageenan. These findings prove that infection of Kappaphycus by the filamentous red algae epiphyte, N. apiculata, reduces carrageenan molecular size and affects the physical properties of the carrageenan.

Red algae genus Laurencia is an interesting alga with the ability to produce halogenated secondary metabolites that exhibits ecological and pharmaceutical potential. In nature, Laurencia is selectively grazed by sea hares (Aplysia dactylomela). In this study, Laurencia populations in three islands (Mantanani, Sulug, and Dinawan Islands) in the coastal waters of North Borneo were investigated and their chemical relationship with sea hare determined. Four species of Laurencia were found to grow abundantly in these waters, Laurencia snackeyi, Laurencia majuscula, Laurencia nangii, and Laurencia similis. Sea hares, Aplysia dactylomela, found grazing on Laurencia were collected and their chemical composition determined. A total of 20 halogenated metabolites were isolated and identified via spectroscopic data. Isolated compounds could be grouped into syndrean (5), chamigrane (6), non-chamigrane sesquiterpene (3), cuparane (1), bromoindole (2), and C15 acetogenin (acetylene type) (3). Sea hares from Mantanani, Sulug, and Dinawan Islands contained a total of 9, 10, and 10 compounds, respectively. In addition, 12-acetoxypalisadin B (1), which was isolated from sea hares of Sulug Island is a first record of its existence in nature.

The green algae genus Caulerpa is coenocytic, and the thallus consists of only one cell with many nuclei. It is widely distributed in the tropical seas. In the Southeast Asian waters, there are at least ten known species. Three species, particularly Caulerpa racemosa var. clavifera f. macrophysa (Kutzing) Weber-van Bosse, C. racemosa var. laetevirens (Montagne) Weber-van Bosse, and Caulerpa lentillifera J. Agardh are widely consumed. The proximate analysis and secondary metabolite composition of these three species were determined to describe their lipid and nutritional values. Glycolipids and phospholipids were the major lipid classes, with significant levels of triacylglycerol. Polyunsaturated fatty acids (PUFA) were the major fatty acids of all the three species. Typical n-3 and n-6 PUFA such as 18:3n-3, 18:4n-3, 20:5n-3, 18;2n-6, and 20:4n-6 were found in significant amount in all these three species. All three species contained a red-pigmented secondary metabolite determined as caulerpin. All three extracts exhibited potent antimicrobial activity against human food pathogenic bacteria and anti-inflammatory activity against the murine macrophage cell line, RAW 264.7.

Red alga Kappaphycus alvarezii Doty is an important commercial species widely cultivated in southeast Asian countries for its polysaccharide, kappa-carrageenan. Common post-harvest handling technique involves sun-drying of harvested seaweed on platforms at the farms. Quantity and quality of carrageenan varies depending on the duration and care taken during the post-harvest handling of the raw seaweed. In this study, dynamics of moisture content, water activity index (aw), carrageenan yield, and carrageenan quality were investigated by subjecting the seaweed to three post-harvest methods: (1) freeze-drying (FD), (2) shade-drying (SD), and (3) direct sun-drying (DSD). Seaweed dried under FD and SD produced high yield (56–58 %), superior gel strength (1,454–1,424 g cm−2), high viscosity (57–58 cPs), and low syneresis (15–17 %). But, carrageenan extracted from DSD seaweed gave 28 % lower yield, 38 % lower gel strength, 27 % lower viscosity, and 8–9 % higher syneresis. In addition, gelling temperature and melting temperature of the DSD carrageenan were lower by 4 and 9 °C, respectively. Molecular size analyses of carrageenan extracted from seaweed dried under FD and SD contained carrageenan of 700 KDa (80 %) and 200 KDa (4–10 %). However, carrageenan extracted from DSD seaweed contained smaller carrageenan molecules, 460 KDa (55 %), 210 KDa (25 %), and

Secondary metabolites of tropical seaweed are proven to exhibit variety of biological activities. Six species of seaweed (Caulerpa racemosa var. laete-virens, Caulerpa sertularioides f. longipes, Halymenia dilatata, Laurencia snackeyi, Padina boryana, and Sargassum swartzii) were tested for anti-inflammatory activity in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Crude L. snackeyi extract exhibit potent activity, and upon bioassay-guided isolation, it contained four halogenated compounds that exert profound inhibitory effects against nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. These compounds were subjected to spectroscopic measurements and were identified as palisadin A (1), aplysistatin (2), 5-acetoxypalisadin B (3), and palisol (4). Further experiments showed aplysistatin (2) to significantly inhibit NO production and prostaglandin-E2 (PGE2) production, and suppress inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression in LPS-stimulated RAW 264.7 cells. Therefore, aplysistatin (2) is suggested to inhibit NO and PGE2 production via the inhibition of iNOS and COX-2, indicating that its activity may be attributed to the modulation of anti-inflammatory agents.

Two new non-halogenated sesquiterpenes, snakeol (1) and snakediol (2) were isolated together with 9 known sesquiterpenes such as (R,Z)-33-dimethyl-5-methylene-4-(3-methylpenta-24-dien-1-yl)cyclohex-1-ene (3), palisol (4), pacifigorgiol (5), palisadin D (6), palisadin A (7), palisadin B (8), 5-acetoxypalisadin B (9), debromolaurinterol (10) and α-bromocuparane (11) from the red algae Laurencia snackeyi. The structures of two new metabolites were determined from their spectroscopic data (IR, 1D and 2D NMR and MS). Compounds 1, 2, 10 and 11 showed strong antibacterial activity against selected human clinical bacterial pathogens.

A fanged frog Limnonectes kuhlii was once thought to be wide-ranging in Southeast Asia, but is now confined to its type locality Java through recent phylogenetic studies, which clarified heterospecific status of non-Javanese populations, and monophyly of Bornean populations. However, large genetic differences among Bornean populations suggest occurrence of cryptic species, which we test using dense geographic sampling. We estimated the phylogenetic relationships among samples of Bornean populations together with their putative relatives from the continental Southeast Asia, using 2517bp sequences of the 12S rRNA, tRNA(val), and 16S rRNA of mitochondrial DNA, and 2367bp sequences of the NCX1, POMC, and RAG1 of nuclear genes. In the mtDNA trees, Bornean L. kuhlii-like frogs formed a monophyletic group split into 18 species lineages including L. hikidai, with the deepest phylogenetic split separating L. cintalubang from the remaining species. Almost all of these lineages co-occur geographically, and two to three lineages were found syntopically in each locality. Co-occurrence of more than one lineage may be maintained by differential morphology and microhabitat selection. These syntopic lineages should be regarded as distinct species. Our results clearly indicate that taxonomic revision is urgent to clarify many evolutionary problems of Bornean L. kuhlii-like frogs.

Vibrio alginolyticus infection is common in aquatic species. The species has been isolated from infected green mussels (Perna viridis) cultivated at Marudu Bay, Sabah. The infection of V. alginolyticus was prevalent since 2009 and caused more than 60% mortality of the mollusc. This study was conducted on V. alginolyticus isolated from clinically infected P. viridis at cultivation area in Marudu Bay from 2013. Twenty isolates were randomly selected and subjected to RAPD-PCR analysis using 20 sets of RAPD primers. Results showed that the most suitable primers were OPA 3, OPA 5, OPA 9, OPA 10 and OPA 12 where the significant bands ranging from 100-2500 bp. Genetic variability among the isolates as revealed by these primers indicated that RAPD-PCR method has good discriminative ability and can be used as a rapid typing method of differentiating V. alginolyticus strains isolated from infected green mussels for epidemiological investigation.

A total of three carbazole alkaloids and essential oil from the leaves of Murraya koenigii (Rutaceae) were obtained and examined for their effects on the growth of five antibiotic resistant pathogenic bacteria and three tumor cell lines (MCF-7, P 388 and Hela). The structures of these carbazoles were elucidated based on spectroscopy data and compared with literature data, hence, were identified as mahanine (1), mahanimbicine (2) and mahanimbine (3). The chemical constituents of the essential oil were identified using Gas Chromatography-Mass Spectroscopy (GCMS). These compounds exhibited potent inhibition against antibiotic resistant bacteria such as Staphylococcus aureus (210P JTU), Psedomonas aeruginosa (ATCC 25619), Klebsiella pneumonia (SR1-TU), Escherchia coli (NI23 JTU) and Streptococcus pneumoniae (SR16677-PRSP) with significant minimum inhibition concentration (MIC) values (25.0–175.0 mg/mL) and minimum bacteriacidal concentrations (MBC) (100.0–500.0 mg/mL). The isolated compounds showed significant antitumor activity against MCF-7, Hela and P388 cell lines. Mahanimbine (3) and essential oil in particular showed potent antibacteria and cytotoxic effect with dose dependent trends (≤5.0 μg/mL). The findings from this investigation are the first report of carbazole alkaloids’ potential against antibiotic resistant clinical bacteria, MCF-7 and P388 cell lines.

Biochemical Systematics and Ecology, Volume x, Issue x, Pages x–x (dd mm yyyy). A new bisabolane-type sesquiterpenoid from Curcuma domestica. Takahiro Ishii, Hiroshi Matsuura, Kunimitsu Kaya, Charles Santhanaraju Vairappan.► Chemical constituents of lowland and highland Curcuma domestica of Borneo are reported. ► Three sesquiterpenes and three curcuminoids secondary metabolites were found in common. ► Highland populations contained two additional bisabolane-type sesquiterpenoid metabolites. ► Curcuma domestica is reported as a new source for novel compound, bisacurol B.

One new phenylbutenoid, (3 Z)-2′,4′,5′-trimethoxyphenylbutadiene (1) along with five known metabolites were isolated from aquatic galangal ( Alpinia aquatica Rosc.) and their chemotaxonomy importance in five populations of A. aquatica collected from Kota Kinabalu, Ranau and Kota Belut in Sabah, Malaysia. The antibacterial potential as well as the chemosystematics importance of this discovery is discussed.

In our continuous interest to study the diversity of halogenated metabolites of Malaysian species of the red algal genus Laurencia, we examined the chemical composition of five populations of unrecorded Laurencia sp. A new brominated diterpene, 10-acetoxyangasiol (1), and four other known metabolites, aplysidiol (2), cupalaurenol (3), 1-methyl-2,3,5-tribromoindole (4), and chamigrane epoxide (5), were isolated and identified. Isolated metabolites exhibited potent antibacterial activities against clinical bacteria, Staphylococcus aureus, Staphylococcus sp., Streptococcus pyogenes, Salmonella sp. and Vibrio cholerae.

Soft corals are known to be prolific producers of a wide spectrum of biologically active cembranoids. One new cembranoid, sinularolide F (2), along with three known compounds, cembranolide (1), (E,E,E)-6,10,14-trimethyl-3-methylene-cis-3α,4,5,8,9,12,13,15α-octahydrocyclo tetradeca[β]furan-2(3H)-one (3), and denticulatolide (4), were isolated from the Bornean soft coral Sinularia sp. Compounds 2 and 4 showed potential anti-inflammatory activities against lipopolysaccharide-stimulated RAW 264.7 with IC50 values less than 6.25 µg/mL and anticancer activity against HL60 cell lines. The compounds’ mechanisms of action were investigated via the Western blot evaluation of their protein markers. These activities could be attributed to the presence of tertiary methyl at C-8 and the compounds’ 3D configurations.

One new cembrane diterpene, (1 S, 2 E, 4 R, 6 E, 8 S, 11 S, 12 S)-11,12-epoxy-8-hydroperoxy-4-hydroxy-2,6-cembradiene (1) was isolated from a population of Bornean soft coral genus Sarcophyton collected from the coastal waters Bohey Dulang, Sabah, Malaysia. Its structure was elucidated based on extensive spectroscopic analysis including NMR and HRESIMS spectra. Cytotoxic, anti-inflammatory and antibacterial activities were tested.

As part of our continuous interest in the diversity of halogenated metabolites in the red algae genus Laurencia and their grazers, the sea hare genus Aplysia in Sabah coastal waters, we report the chemical composition of Aplysia parvula collected from Sepanggar Island, Kota Kinabalu. Chemical analysis resulted in the isolation and identification of three sesquiterpenes; palisadin A (1), iso-obtusol (2) and elatol (3). Compounds were present as 13.9%, 6.7%, and 8.5% of crude extract, respectively. A similar analysis of its diet from the same location, Laurencia snackeyi (Weber-van Bosse) Masuda and Laurencia majuscula (Harvey) Lucas, showed the existence of palisadin A, palisadin B, aplysistatin and 5-acetoxypalisadin B in Laurencia snackeyi, while Laurencia majuscula contained elatol and isoobtusol. Hence, it is suggestive that A. parvula is capable of selective sequestering of compounds derived from its diet. Based on the chemicals sequestered, it is confirmed that A. parvula is an oligophagous feeder. Its ability to selectively sequester palisadin A and not the other syndreans, reflects on the complexity of its digestive glands. All three compounds also showed potent antimicrobial, antifeedant and cytotoxic activities.Sehubungan dengan minat kami dalam penyelidikan sebatian berhalogen ‘seahare’ dari perairan Sabah, kami ingin melaporkan komposisi kimia sebatian berhalogen dari Aplysia parvula dari Pulau Sepanggar, Kota Kinabalu. Hasil kajian telah membawa kepada pemencilan dan identifikasi tiga sesquiterpene; Palisadin A (1), iso-obtusol (2) and elatol (3). Sebatian-sebatian ini wujud dalam kuantiti yang signifikan 13.9%, 6.7%, and 8.5% dalam esktrak kasarnya ‘sea hare’ yang dikaji. Analisis kimia sedemikian keatas dietnya, Laurencia snackeyi (Weber-van Bosse) Masuda and Laurencia majuscula (Harvey) Lucas, telah menunjukkan kehadiran palisadin A, palisadin B, aplysistatin and 5-acetoxypalisadin B dalam Laurencia snackeyi, manakala Laurencia majuscula mengandungi elatol and isoobtusol. Maka, dapat disyorkan bahawa A. parvula dapat melakukan menepuan sebatian kimia daripada dietnya secara selektif. Berdasarkan bahan kimia yang ditepukan, dapat dikenalpasti bahawa A. parvula merupakan pemakan oligofagus. Kebolehannya untuk melakukan penemuan selektif terhadap palisadin A dan bukan ‘syndrean’ yang lain dapat membayangkan betapa kompleksnya kelenjar penghadamannya. Semua ketiga-tiga sebatian ini telah menunjukkan aktiviti antimikrob, ‘antifeedant’ dan sititoksik.