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Volatile chemical constituents of four species of local bamboo (Schizostachyum blumei Nees., Schizostachyum brachycladum Nees., Schizostachyum lima (Blanco) Merrill and Schizostachyum pilosum S.Dransf.) were investigated. The oils were obtained from bamboo culm through steam distillation and profiled using Gas Chromatography-Mass Spectrometry (GCMS). A total of 59 volatile constituents were identified, and these contained oxygenated sesquiterpene, α-elemol (8.2~21.1 %), coumaran (6.7~32.3 %), guaiacol-4-vinyl (0.6~0.9 %), palmitic acid (1.5~25.6 %), pentacosane (0.1~0.2 %), phytol (1.0~12.6 %), phytol acetate (0.5~1.7 %) and trans-squalene (0.2~1.6 %) consistently in the specimens studied. Based on the observation, S. pilosum exhibited wider diameter of inhibition against Escherchia coli and Staphylococcus aureus compared to the other species of Schizostachyum essential oil.

Two cembrane diterpenoids; (+)-11,12-epoxysarcophytol A (1) and sarcophytol W (2) were isolated from Sarcophyton sp. collected from Mantanani Island, Sabah. Secondary metabolites structures were elucidated based on spectroscopic data. This is the first record of cembranoid diterpenes isolated from the Bornean soft coral genus Sarcophyton. The isopropyl(ene)-type cembrane derivatives could be suggested as chemotaxonomical markers for soft coral genus Sarcophyton.

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 Innoprise-IKEA (INIKEA) Forest Rehabilitation Project in Kalabakan Forest Reserve, Sabah, was established to rehabilitate degraded forest affected by conventional logging and forest fires that occurred during an El-Nino event (1982–1983). The present study aimed to investigate the responses of ground-dwelling mammals and birds to the different rehabilitation practices in INIKEA: gap-cluster planting, line planting and liberation, where enrichment planting applied in both gap-cluster and line planting. A total of 74 camera traps were deployed at random locations across reforested INIKEA plots, including plots in control areas comprising naturally regenerated forest. A total of 6534 independent photographs of medium-to-large vertebrates from 7266 camera-trap nights representing 33 species from 14 families and 7 orders were obtained. Among the detected vertebrate species, 2 are listed as Critically endangered, 5 as Endangered, 8 as Vulnerable and 6 as Near threatened on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Mousedeer was the most frequently photocaptured species, followed by muntjac, bearded pig, sambar deer, pig-tailed macaque and crested fireback. The present study demonstrates that the rehabilitation methods applied in INIKEA have aided forest recovery, providing habitat for the ground-dwelling mammals and birds in Sabah. General forest structure, species richness and species composition did not significantly differ between the areas subjected to rehabilitation treatment and the control area. The results suggest that the liberation method should be abandoned to ensure a variety of food resources for animal species. Provided major forest components remain after disturbance, disturbed forest areas should be left to undergo natural recovery.

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.

Forest termites mitigate the effects of drought In many tropical regions, where drought is predicted to become more frequent in the coming years, termites are key components of ecosystem function. Ashton et al. experimentally manipulated termite communities to quantify their role during the 2015–2016 “super El Niño” drought in a Malaysian tropical rainforest. Termite relative abundance more than doubled in control plots during drought, maintaining three major ecosystem processes: decomposition, nutrient heterogeneity, and moisture retention. Seedling mortality increased where termites were suppressed. Science , this issue p. 174

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.

Marine aquaculture development is recently impeded by parasitic leech Zeylanicobdellaarugamensis (Hirudinea, Piscicolidae) in Sabah, Malaysia. The parasitic leech infests a variety of cultured fishes in aquaculture facilities. In this study, we evaluated the antiparasitic activity of the chromatographic fractions of the medicinal plant Nephrolepis biserrata methanol extract against Z.arugamensis and highlighted the potential metabolites responsible for the antiparasitic properties through liquid chromatography (LC)&ndash, quadrupole time-of-flight (QTOF)&ndash, mass spectrometry (MS) analysis. Out of seven fractions obtained through flash column chromatography techniques, three fractions demonstrated antiparasitic properties. Significant parasitic mortality was indicated by fraction 3 at a concentration of 2.50 mg/mL, all the leeches were killed in a time limit of 1.92 &plusmn, 0.59 min. followed by fraction 4 (14 mg/mL) in 34.57 &plusmn, 3.39 and fraction 5 (15.3 mg/mL) in 36.82 &plusmn, 4.53 min. LC-QTOF-MS analysis indicated the presence of secondary metabolites including phytosphingosine (6), pyrethrosin (1), haplophytine (9), ivalin (2), warburganal (3), isodomedin (4) and pheophorbide a (16), representing sphingoid, alkaloid, terpenoid, phenolic and flavonoid groups. Thus, our study indicated that the chromatographic fractions of N. biserrata demonstrated significant antiparasitic activity against the marine parasitic leeches due to the presence of potent antiparasitic bioactive compounds.

Logging and conversion of tropical forests in Southeast Asia have resulted in the expansion of landscapes containing a mosaic of habitats that may vary in their ability to sustain local biodiversity. However, the complexity of these landscapes makes it difficult to assess abundance and distribution of some species using ground-based surveys alone. Here, we deployed a combination of ground-transects and aerial surveys to determine drivers of the critically endangered Bornean Orangutan (Pongo pygmaeus morio) distribution across a large multiple-use landscape in Sabah, Malaysian Borneo. Ground-transects and aerial surveys using drones were conducted for orangutan nests and hemi-epiphytic strangler fig trees (Ficus spp.) (an important food resource) in 48 survey areas across 76 km², within a study landscape of 261 km². Orangutan nest count data were fitted to models accounting for variation in land use, above-ground carbon density (ACD, a surrogate for forest quality), strangler fig density, and elevation (between 117 and 675 m). Orangutan nest counts were significantly higher in all land uses possessing natural forest cover, regardless of degradation status, than in monoculture plantations. Within these natural forests, nest counts increased with higher ACD and strangler fig density, but not with elevation. In logged forest (ACD 14–150 Mg ha⁻¹), strangler fig density had a significant, positive relationship with orangutan nest counts, but this relationship disappeared in a forest with higher carbon content (ACD 150–209 Mg ha⁻¹). Based on an area-to-area comparison, orangutan nest counts from ground transects were higher than from counts derived from aerial surveys, but this did not constitute a statistically significant difference. Although the difference in nest counts was not significantly different, this analysis indicates that both methods under-sample the total number of nests present within a given area. Aerial surveys are, therefore, a useful method for assessing the orangutan habitat use over large areas. However, the under-estimation of nest counts by both methods suggests that a small number of ground surveys should be retained in future surveys using this technique, particularly in areas with dense understory vegetation. This study shows that even highly degraded forests may be a suitable orangutan habitat as long as strangler fig trees remain intact after areas of forest are logged. Enrichment planting of strangler figs may, therefore, be a valuable tool for orangutan conservation in these landscapes. Published version This research was funded by the Government of Malaysia-UNDP-GEF project on biodiversity conservation in multiple-use forest landscapes in Sabah, Sub-Contract SC-6B.

There is growing interest in the ecological value of set-aside habitats around rivers in tropical agriculture. These riparian buffers typically comprise forest or other non-production habitat, and are established to maintain water quality and hydrological processes, while also supporting biodiversity, ecosystem function and landscape connectivity. We investigated the capacity for riparian buffers to act as microclimatic refugia by combining field-based measurements of temperature, humidity and dung beetle communities with remotely sensed data from LiDAR across an oil palm dominated landscape in Borneo. Riparian buffers offer a cool and humid habitat relative to surrounding oil palm plantations, with wider buffers characterised by conditions comparable to riparian sites in continuous logged forest. High vegetation quality and topographic sheltering were strongly associated with cooler and more humid microclimates in riparian habitats across the landscape. Variance in beetle diversity was also predicted by both proximity-to-edge and microclimatic conditions within the buffer, suggesting that narrow buffers amplify the negative impacts that high temperatures have on biodiversity. Synthesis and applications. Widely legislated riparian buffer widths of 20–30 m each side of a river may provide drier and less humid microclimatic conditions than continuous forest. Adopting wider buffers and maintaining high vegetation quality will ensure set-asides established for hydrological reasons bring co-benefits for terrestrial biodiversity, both now, and in the face of anthropogenic climate change. Published version This work was funded by the Natural Environmental Research Council (NERC) through the Human Modified Tropical Forests programme (NE/K016261/1; NE/K016377/1), as well as the Newton-Ungku Omar Fund via the British Council and Malaysian Industry Government Group for High Technology (216433953). NERC also funded the PhD studentship for J.W. (NE/L002485/1) and research fellowship of T.J. (NE/S01537X/1). We are grateful to the Sabah Biodiversity Council for permission to conduct the fieldwork (S.H.L.: JKM/MBS.1000-2/2JLD.5(13); J.W.: JKM/MBS. 1000-2/2JLD.7(83); E.M.S.: JKM/MBS.1000-2/2(381)), Jonathan Parrett for help with dung beetle identification, Sui Peng Heon for translating the abstract into Malay, Matilda Brindle for proof-reading the manuscript and the South East Asian Rainforest Research Programme staff, who made this work possible: Unding Jami, Johnny Larenus, Amir, Anis, David, Didy, Dino, Joanni, Kiki, Loly, Mudin, Noy and Zul.

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.

The red alga

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.

Two new nardosinane-type sesquiterpenoids, paralemnolin V (1) and paralemnolin W (2), along with five known sesquiterpenoids (3–7), were isolated from a population of Bornean soft coral Lemnalia sp. The structures of these metabolites were elucidated based on their NMR and HR-ESI-MS spectral data. These compounds were subjected to antibacterial and antifungal tests against eight bacterial and seven fungal strains.

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.

Two new chlorinated fatty acid amides, columbamides D (1) and E (2), along with apratoxins A and C and wewakazole, were isolated from the organic extract of a Moorea bouillonii sample from Sabah, Malaysia. Structure elucidation was accomplished by a combination of MS and NMR analyses. The total synthesis of all four stereoisomers of 1 was completed, and the absolute configuration was determined by chiral-phase HPLC and Marfey's analysis.

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.