Abstract. Suryanti V, Kusumaningsih T, Marliyana SD, Setyono HA, Trisnawati EW. 2020. Identification of active compounds and antioxidant activity of teak (Tectona grandis) leaves. Biodiversitas 21: 941-947. Teak (Tectona grandis) grows in tropical area and the teak wood is widely used for building construction and furniture. Young teak leaf contains red pigment and often are used for natural food coloring. The research objectives were to isolate the young teak leaf chemical compounds and to investigate their antioxidant activities. The compounds identification was carried out by UV-Vis Spectroscopy, GC-MS and LC-MS. The antioxidant activity determination was carried out by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) method. The total phenolics content was determined using Folin-Ciocalteu method and total anthocyanins content was examined using the H-differential method. Two fractions were observed further by UV-Vis Spectroscopy, GC-MS and LC-MS. The UV-Vis spectrum of FA confirmed the presence of anthocyanins which has maximum absorbance at 208 and 492 nm. The GC-MS spectrum of fraction A (FA) revealed 4-hydroxy-4-methyl-2-pentanone, glycerin monoacetate, glycerin diacetate and 1-eicosanol. The UV-Vis spectrum of FC also confirms the presence of anthocyanins which has maximum absorbance at 489 nm. The LC-MS spectrum of fraction C (FC) shows anthocyanins, namely malvidin-3-o- (6-o-acetyl)-5-o-diglucoside. The FA and FC teak leaf fractions have strong antioxidant activities as their IC50 values are less than 50 ppm. Total phenolic of teak leaf extract was 6.17 mg GAE/g and total anthocyanins of teak leaf extract were 67.5 mg/L.

Biosurfactant with efficient emulsification properties could be produced by Pseudomonas flourescens using cassava flour wastewater (manipueira) as media.

Abstract. Purwoko T, Suranto, Setyaningsih R, Marliyana SD. 2021. Chlorogenic acid and caffeine content of fermented robusta bean. Biodiversitas 23: 902-906. Robusta beans contain caffeine and chlorogenic acid higher than arabica beans, however, it has a lower economic value than arabica beans. Therefore, microorganisms in the robusta bean for the fermentation process are expected to reduce caffeine and chlorogenic acid contents. The objective of this research was to investigate the ability of fungus Rhizopus oryzae, yeast Saccharomyces cerevisiae, and bacteria Lactobacillus casei and Leuconostoc mesenteroides in degrading caffeine and chlorogenic acid content of robusta beans. Analysis of caffeine and chlorogenic acid content was carried out by spectrophotometer at OD275 and OD324, respectively. The caffeine and chlorogenic acid content of unfermented robusta beans were 18.64 mg/g and 62.18 mg/g. Saccharomyces cerevisiae, L. mesenteroides, L. casei, and R. oryzae were able to degrade caffeine, and reduce the caffeine content of fermented robusta beans to 16.92, 16.71, 16.67, and 13.57 mg/g, respectively. The decrease of caffeine by S. cerevisiae, L. mesenteroides and L. casei were not significantly different (p>0.05) from control, however, the decrease of caffeine by R. oryzae was significant (p<0.05). Saccharomyces cerevisiae, R. oryzae, L. mesenteroide, and L. casei were able to degrade chlorogenic acid and reduce the chlorogenic acid content of fermented robusta beans to 44.54, 45.21, 45.79, and 47.31 mg/g. Chlorogenic acid was reduced significantly by S. cerevisiae, R. oryzae, L. mesenteroides, and L. casei (p<0.05). It can be concluded that R. oryzae was a potential microorganism to reduce caffeine and chlorogenic acid contents in robusta beans.

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Curcuma soloensis Val. is a family plant Zingiberaceae and is known as “temu glenyeh”. This plant has potential as a medicinal plant but has not been widely reported about its bioactivities. One of them was antibacterial activity. Therefore, the aim of this study was to evaluate the antibacterial activity of ar-turmerone, a sesquiterpenoid which was successfully isolated from Curcuma soloensis Val. rizhomes. Antibacterial test was carried out by using disc diffusion method and evaluated against four bacteria namely Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Klebsiella pneumonia ATCC 13883, and Pseudomonas aeruginosa ATCC 27853. The result showed that ar-turmerone was not active against all of these bacteria.