Abstract. Faramayuda F, Mariani TS, Elfahmi, Sukrasno. 2020. Short Communication: Callus induction in purple and white-purple varieties of Orthosiphon aristatus (Blume) Miq. Biodiversitas 21: 4967-4972. Orthosiphon aristatus (Blume) Miq. are known to have many benefits, including stimulating urine expenditure (diuretics) and dissolving kidney stones. O. aristatus widely planted in Indonesia are purple and white-purple. The main secondary metabolite components of O. aristatus are sinensetin, rosmarinic acid, and eupatorin. One of the initial steps to increase secondary metabolites in O. aristatus is by induction of callus using plant tissue, which later can be developed into a culture suspension for secondary metabolites. The materials used are the leaf of two varieties of O. aristatus that have been sterilized and grown on Murashige and Skoog media with growth regulatory 2,4-dichlorophenoxyacetic acid at a concentration of 0.4;1.0; 2.0 mg/L. The identification of secondary metabolites of callus was carried out by thin-layer chromatography. The best growth regulating agent for callus induction on the leaves of purple and white-purple varieties of O. aristatus is 2,4-D 0.4 mg/L on Murashige and Skoog media. These media can grow callus at a faster time, friable, and slightly white-yellow color. The identification of secondary metabolites in callus acetone extract showed the presence of sinensetin and rosmarinic acid.

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Objective: Antioxidants are compounds that can inhibit free radical reactivity. They become very interesting to be observed because they can prevent some diseases such as goat arthritis, cancer, cardiovascular disease, Alzheimer's disease, and macular degeneration. Since Indonesia is rich for its biodiversity, there are a lot of plants that have potential to be developed as new alternative antioxidants. The aim of this research was to evaluate antioxidant activity from 10 species of Myrtaceae (Syzygium cumini, Syzygium samarangense, Syzygium aqueum, Syzygium aromaticum, Syzygium polyanthum, Syzygium jambos, Syzygium malaccense, Psidium guajava, Eucalyptus deglupta, and Melaleuca leucadendra). Methods:Continuous extraction with Soxhlet apparatus was selected as extraction method. Three solvents (n-hexane, ethyl acetate, and methanol) with different polarity were used in this process. 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity was used to evaluate antioxidant activity with ascorbic acid as a standard drug.Results: Based on the experiments, methanol extracts showed higher activity than other extracts with their inhibitory concentration 50% (IC 50 ) was below than 25 µg/ml. The lowest IC 50 was exhibited by methanol extract of S. jambos, which was 7.8 µg/ml. Conclusion:It can be concluded that S. jambos is potential to be developed as a new alternative antioxidant.

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Angelica keiskei sap is used as a blood-sugar reducer in Indonesia, however its molecular mechanism has not yet been explored. 4-hydroxyderricin (4-HD) is one of the major components extracted from A. keiskei sap. The aim of this work was to isolate 4-HD from the sap of A. keiskei planted in Lombok, Indonesia, and to study in silico and in vitro mechanisms against dipeptidyl peptidase-IV (DPP-IV). The dried sap was submitted to liquid–liquid extraction using solvents with different polarity. Further purification processing was conducted using gradient elution column chromatography. The isolated compound was a yellowish powder, m/z 339.2215 [M + H]+, which was confirmed as 4-HD. Sitagliptin, a DPP-IV inhibitor, was employed as the positive control for both the in silico and in vitro studies. It was indicated that 4-HD interacts with Glu206 and Phe357, important amino acid residues in the DPP-IV binding pocket. These interactions are similar to that of sitagliptin. The affinity of 4-HD (inhibition constant (Ki) = 3.99 μM) to DPP-IV is lower than that of sitagliptin (inhibition constant (Ki) = 0.17 μM). Furthermore, in vitro study showed that 4-HD inhibits DPP-IV (IC50 = 81.44 μM) weaker than for sitagliptin (IC50 = 0.87 μM). We concluded that 4- HD might have potential in inhibiting DPP-IV. However, by considering the polar interaction of sitagliptin with DPP-IV, a further structure modification of 4-HD, e.g., by introducing a polar moiety such as a hydroxyl group, might be needed to obtain stronger activity as a DPP-IV inhibitor.

The aim of this study was to identify the antifungal activity of coumarin isolated from Ageratum conyzoides L. leaves and to observe its influence on Candida albicans cells by scanning electron microscope (SEM) and transmission electron microscope (TEM). Antifungal activity testing with the disk diffusion method showed coumarin was active toward pathogenic fungus Candida albicans with an MIC value of coumarin of 125 g mL -1 . The results show that this compound damaged the cell by pores formation on the cell wall. Death of cells occurred due to leakage and necrosis of cytoplasmic content.

Background: Ganoderma fungus is rich in terpenoids. These compounds are known for their anti-hyperglycemic activities. However, the study of terpenoids as the secondary metabolite from Ganoderma as a dipeptidyl peptidase-4 (DPP-4) inhibitor remains unexplored. In addition, we examined the α-glucosidase inhibition activity. Objective: This study aimed to isolate the major terpenoid from non-laccate Ganoderma and examined its inhibitor activity on DPP-4 and α-glucosidase enzymes, and its interaction. Methods: The compound was isolated using column chromatography from Ganoderma australe. The structure of the isolated compound was confirmed by 1H and 13C nuclear magnetic resonance spectroscopy, while the inhibitory activity was evaluated using an enzymatic assay. The interaction of the isolated compound with DPP-4 and α-glucosidase enzymes was investigated using an in silico study. Results: The isolated compound was identified as stellasterol; IC50 values for DPP-4 and α-glucosidase inhibitor were 427.39 µM and 314.54 µM, respectively. This study revealed that the inhibitory effect of stellasterol on DPP-4 enzyme is through hydrophobic interaction, while the α-glucosidase enzyme is due to the interaction with six amino acids of the enzyme. Conclusion: Stellasterol is the major component of the steroid from G. australe. Enzyme inhibitory assay and in silico study suggest that stellasterol may contribute antidiabetic activity with a mechanism closer to acarbose rather than to sitagliptin.

Objectives:The objectives of this research were to evaluate antioxidant activity from different polarities rice bran extract of three varieties of rice using two methods of antioxidant testing which were ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), and correlation of total phenolic, flavonoid and carotenoid content with their exhibitory concentration 50 (EC 50 ) of FRAP and inhibitory concentration 50 (IC 50 ) of DPPH antioxidant activities.Methods: Extraction was conducted by reflux using different polarity solvents. The extracts were evaporated using rotary evaporator. Determination of total phenolic, flavonoid and carotenoid content, antioxidant activities using FRAP and DPPH assays was performed by ultraviolet-visible spectrophotometry and its correlation with EC 50 of FRAP capacities and IC 50 of DPPH scavenging activities was analyzed by Pearson's method. Results:Ethanolic rice bran extract of black rice showed the lowest EC 50 of FRAP capacity 64.35 µg/ml and IC 50 of DPPH scavenging activity 23.92 µg/ml. The highest phenolic content, flavonoid content, and carotenoid content were also given by ethanolic rice bran extract of black rice. There was significantly negative correlation between total phenolic content and carotenoid content in rice bran extract of red rice and black rice with their IC 50 of DPPH. Conclusions:All of the rice bran extracts (except n-hexane rice bran extract of black rice and ethanolic rice bran extract of white rice) were very strong antioxidant by DPPH assay. Phenolic and carotenoid compounds in rice bran extracts of red rice and black rice were the major contributor in antioxidant activity by DPPH assay. Rice bran extracts of black rice had linear results by FRAP and DPPH assays.