Abstract. Amirta R, Yuliansyah, Angi EM, Ananto BR, Setiyono B, Haqiqi MT, Septiana HA, Lodong M, Oktavianto RN. 2016. Plant diversity and energy potency of community forest in East Kalimantan, Indonesia: Searching for fast growing wood species for energy production. Nusantara Bioscience 8: 22-30. Nowadays, there is an increasing interest in intensifying the production and use of biomass to replace fossil fuels for the production of heat and electricity, especially for a remote area that generally abundance with the wood biomass resources including in East Kalimantan, Indonesia. In this work, diversity of plant species that commonly growth in community forest area of East Kutai District, East Kalimantan, Indonesia had been studied to point out their energy potency to be used as biomass feedstock for the electricity generated. Diversity of plant species in the community forest was evaluated by making 13 sampling plots with 20mx20m size approximately. Concurrently, the energy properties of plant biomass such as proximate and ultimate compositions were also analyzed using ASTM methods. Results showed that more than 30 species of tropical trees and wood shrubs were grown in the community forest. The presence of them was classified into two different growths of origins: natural and artificial plantation, and also three different categories of plant resources: tree species from logged over forest, commercial fast growing plant tree species for the fiber production and woody shrubs. The highest dominancy and productivity was found in Paraserianthes falcataria (L.) Nielsen since the wood biomass was artificially planted for the commercial purposes. Among the 31 plant species analyzed we found the highest energy potency was obtained from Cratoxylum cochinchinense (Lour.) Blume that produced 3.17 MWh/ton, and the lowest was from Trema orientalis (L.) Blume 0.97 MWh/ton. The woody shrubs species such as Vernonia amygdalina Delile., Piper aduncum L., Gliricidia sepium (Jacq.) Kunth ex Walp., Calliandra calothyrsus Meissner., Bridelia tomentosa Blume, Vitex pinnata L., Vernonia arborea Buch.-Ham. and Bauhinia purpurea var. corneri de Wit. were suitable to be used as sustainable feedstocks for the electricity generated and promising to be developed as energy plant species in the future using Short Rotation Coppice system (SRC).

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Abstract. Herawati E, Ramadhan R, Ariyani F, Marjenah, Kusuma IW, Suwinarti W, Mardji D, Amirta R, Arung ET. 2021. Phytochemical screening and antioxidant activity of wild mushrooms growing in tropical regions. Biodiversitas 22: 4716-4721. This study aims to determine the presence of secondary metabolites which generally have bioactivity that is antioxidant with phytochemical tests and antioxidant tests in Auricularia auricula, Schyzophyllum commune, Microporus xanthopus, and Trametes versicolor fungi that grow in the wild. Phytochemical analysis was carried out by testing color changes and modifications, while antioxidant tests were carried out by using a UV-Vis spectrophotometer and a DPPH solution (1,1-diphenyl-2-picrylhydrazyl). This research found that edible wood fungus that grows, wild such as A. auricula, contains secondary metabolites, namely flavonoids, triterpenoids, saponins, and tannins, but does not contain steroids, alkaloids, carotenoids, or coumarin, while S. commune contains secondary metabolites, namely flavonoids, steroids, tannins, and coumarin, but does not contain triterpenoids, alkaloids, carotenoids, or saponins and non-edible wood fungus, such as M. xanthopus, contains secondary metabolites, namely, flavonoids, saponins, tannins, coumarin, and steroids, but does not contain triterpenoids, alkaloids, or carotenoids, while T. versicolor contains compounds, secondary metabolites, flavonoids, saponin, tannins, coumarin, and triterpenoids, but does not contain steroids, alkaloids, or carotenoids. The antioxidant test results are based on IC50 calculations; it is known that the IC50 value of A. auricula is 499.25 g/mL, while S. commune is 121.37 g/mL, M. xanthopus is 251.20 g/mL, and T. versicolor is 493.04 g/mL. Based on the research results, edible and inedible wood mushroom extracts contain several phytochemicals and show potential for antioxidant activity.

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Macaranga species collected from secondary forests in East Kalimantan for biorefinery of unutilized fast growing wood. Biodiversitas 17: 116-123. Wood species for industrial forest plantation has been selected to produce construction wood materials, boards and papers, and unutilized fast growing wood as a source for biofuel production has been out of the scope for selection. Macaranga Thouars (Euphorbiaceae) is widely distributed in the tropics and importance of the genus has been recognized due to its high level of growth rate and adaptability to constitute forest ecosystem. However, potency of the genus as a source for bioethanol production has not been systematically studied. We herein first report differential properties of six Macaranga wood species collected in East Kalimantan, Indonesia, as a raw feedstock for enzymatic saccharification for bioethanol production. Among the wood species examined, the highest sugar yield 48.6% (weight of original wood basis), which corresponds to 315 mL ethanol/kg biomass, was obtained with 5.0% NaOH at 160ºC for M. hypoleuca. Significant differences in the sensitivity to alkaline concentration and temperature have been found among the species. A high sugar yield, 40.4% was obtained for M. winkleri with a low alkaline concentration, 3.5% NaOH at 150ºC, while M. motleyana gave the sugar yield 12.8% under the same condition. M. motleyana required a set of the conditions with higher NaOH concentration 5.0% and temperatures over 160ºC. The harsh condition with 5.0% NaOH at 170ºC promoted delignification of all the species but M. hypoleuca decreased the saccharification yield by raising the temperature from 160ºC to 170ºC, probably due to decomposition of carbohydrate cores. This temperature-dependent negative effect was not observed with 3.5% NaOH for M. hypoleuca. These results indicate that differences in the balance between disintegration effects and excess degradation of carbohydrates are different among the species and the variation should be taken into account on screening. Thus, we found a wide range of diversity in the susceptibility to alkaline pretreatment in the genus Macaranga and selected the wood species giving high productivity of fermentable sugars.

In search for effective antidiabetic agents that simultaneously inhibit α-glucosidase and scavenge free radicals, Horsfieldia motleyi showed promising bioactivity according to the proposed criteria. Bioassay-guided isolation of pericarp extract yielded a new 4-arylflavan named myristinin G (6), whose gross structure and absolute configuration were verified by 2D NMR and electronic circular dichorism (ECD). Myristinin G (6) concomitantly inhibited α-glucosidases (IC 107.0 and 126.9 μM) and free radicals (SC 54.3 and 279.9 μM). Of interest, 6 inhibited sucrase through an uncompetitive manner, which is rare in nature.

The stages of flower and fruit development of Macaranga gigantea, its seed germination behavior in nature and from fruit harvesting, as well as the process of raising its seedlings in the laboratory were studied to determine the potential for production of M. gigantea seedlings. Five reproductive trees of M. gigantea were chosen as sources of seed. To estimate natural germination rates, four sample plots of 1 x 1 m 2 in four cardinal directions below the crown of every tree were set up. In addition, dry and wet extraction processes were carried out to determine, which the more effective method for germination of M. gigantea seeds. The results showed that the time required from flower development to fruit ripening in M. gigantea flowers was 5-6 months. The flower buds initiated in the dry season (August 2011) and the fruits ripened in the rainy season (December 2011-January 2012). The seeds that fell under the parent tree germinated in approximately 24 days with an average seedling density of 75-267 per m 2. The germination in laboratory showed that the percentage and the rate of germination of the seeds extracted through the wet extraction process were higher than those extracted through the dry extraction process. The highest rate of germination (65%) is by the combination of seeds extracted through wet extraction process and grown on compost media. The relative growth rate of seedlings planted on mushroom spawn waste media was the highest rate (0.36 0.42%), followed by those planted on compost media (0.150.09%), top soil media (0.100.04%) and sand media (0.100.07%).