A study on isolation and characterisation of cellulose nanofibre (CNF) and lignin was conducted to expand the application of CNF and lignin from oil palm biomass. CNF was extracted by steam explosion and the by-product was precipitated to obtain lignin by using the soda-pulping method. The concentrations of NaOH used for CNF by-product precipitation were 2%, 4%, and 6%. The morphology of CNF and lignin was characterised using scanning electron microscopy (SEM). The nanofibre of CNF with dimension between 50 nm and 100 nm was investigated using transmission electron microscopy (TEM). The functional group was observed using Fourier-transform infrared (FTIR) spectroscopy, showing that CNF had the structure of cellulose-I. In addition, the chemical structures of isolated and commercial lignin were analysed using 1H-NMR spectrometry. CNF had a 72% crystallinity index characterised by X-ray diffraction (XRD), while lignin showed an amorphous form. The characterisation of isolated lignin was compared with commercial lignin. The two lignins had similar particle size distribution from 1 to 100 μm. From UV-visible analysis, the lignin had aromatic rings/non-conjugated phenolic groups. The morphology of isolated lignin was rough and flaky. Commercial lignin was in powder form with near-spherical morphology. Thermogravimetric analysis (TGA) of CNF showed 30% of residue at 600 °C. The results showed a simple method to isolate CNF and lignin from oil palm empty fruit bunches.

Abstract. Batubara R, Wirjosentono B, Siregar AH, Harahap U, Tamrin. 2021. Bioactive compounds of ethanol extract from agarwood leaves (Aquilaria malaccensis) and antimicrobial activity against bacteria and fungi growing on the skin. Biodiversitas 22: 2884-2890. Agarwood plants (Aquilaria malaccensis Lamk.) provide numerous benefits and have been cultivated by the people. The leaves containing various compounds, such as flavonoids, glycosides, triterpenoids and tannins with antibacterial and antifungal activities, were reported to be potential for flesh wound healing. Therefore, research on these activities against microorganisms that cause infection in wounds was carried out in vitro. This research aims to determine the antibacterial and antifungal activities of agarwood leaves ethanol extract against three bacteria species (Staphylococcus epidermidis, Staphylococcus aureus, and Propionibacterium acnes) and two fungi species (Candida albicans and Trichophyton sp.) that commonly cause skin infection. The results of this research show that the concentration of ethanol extract of agarwood leaves affected the bacterial and fungal growth inhibition zone’s diameter. The best inhibitory potential occurred at 5% concentration in activity against bacteria and fungi. The extract’s active compounds contributing to the antimicrobial activity were the flavonoids and tannins. Furthermore, GC-MS identification shows that the ethanol extract from agarwood leaves contained Disulfide, dioctyl; 6,7-Dimethylquinoxaline; (E)-1,3-Di-m-tolylallyl ethyl Carbonate; 5-(2-Methoxyphenyl)-1,2-dihydropyrazol-3-one; 9-[(tert-Butyldimethylsilyl)oxy]benzo[3,4]cyclod ec-3-ene-1,5-diyne; Neophytadiene, 2-Hexadecen-1-ol, 3,7,11,15-tetramethyl-, [R-[R*,R*-(E)]]-; Hexadecanoic acid, methyl ester and a-(3-chloro-4-hydroxyphenyl)-aphenoxy-a-phenyl acetonitrile

Agarwood (Aquilaria malaccensis Lamk) leaves has potential as a source of antioxidants because in the hot water extract contains secondary metabolite compounds. This research aims to observe the chemical compounds and antioxidant potential in hot water extract of cultivated agarwood leaves. Agarwood leaves are processed into simplicia, and extracted with hot water. Several tests conducted in this research, including phytochemical screening in order to observe the chemical compounds in hot water extract of agarwood leaves; GC-MS test to observe the chemical constituents, and DPPH method to observe the antioxidant activity. Agarwood leaves hot water extract positively contained of flavonoid, triterpenoid, tannin and glycoside compounds. The identification result of agarwood leaves hot water extract using GC-MS test showed 9 compounds, they are Undecane, Benzene 1.3-dichloro-2-methoxy-, 1.alpha.- (Angeloxy)-6.beta-(isobutyroxy)-9-oxo-10.alpha.Hfuranoeremophilane, Methyl (6-Methyl-3-pyridazinyl) Ketone, 1-Heptyl-1H-(1,2,3)-triazole-N-{[2′-(hydroxyethoxy)ethylamino] ethyl}-4-carboxamide, 1-Heptyl-1H-(1,2,3)-triazole-N-{[2′-(hydroxyethoxy)ethylamino]ethyl}-4-carboxamide, Borane. [2-(dimethylphenylsilyl)-1-, ethyl-1-propenyl]diethyl-, (E)-, Hexadecanoic acid, methyl ester, and 1-Phenyl-5,5-dimethyl-4,6-dioxa-5-sila-8-nitrooct-1-ene. The antioxidant activity of agarwood leaves hot water extract is categorized as the very strong antioxidant activity.

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