Berna Elya

Screening of α-Glucosidase Inhibitory Activity from Some Plants of Apocynaceae, Clusiaceae, Euphorbiaceae, and Rubiaceae

Diabetes mellitus (DM) is recognized as a serious global health problem that is characterized by high blood sugar levels. Type 2 DM is more common in diabetic populations. In this type of DM, inhibition of α-glucosidase is a useful treatment to delay the absorption of glucose after meals. As a megabiodiversity country, Indonesia still has a lot of potential unexploited forests to be developed as a medicine source, including as the α-glucosidase inhibitor. In this study, we determine the α-glucosidase inhibitory activity of 80% ethanol extracts of leaves and twigs of some plants from the Apocynaceae, Clusiaceae, Euphorbiaceae, and Rubiaceae. Inhibitory activity test of the α-glucosidase was performed in vitro using spectrophotometric methods. Compared with the control acarbose (IC50 117.20 μg/mL), thirty-seven samples of forty-five were shown to be more potent α-glucosidase inhibitors with IC50 values in the range 2.33–112.02 μg/mL.

A new cytotoxic xanthone from Garcinia rigida.

A new xanthone, yahyaxanthone (1), was isolated from Garcinia rigida leaves. Cytotoxicity evaluation showed that 1 was inhibitory to L1210 cell, with an IC50 value 4.08 microg/ml.

A new benzophenone from the stem bark of Garcinia benthami

From the stem bark of Garcinia benthami a new benzophenone, named Salimbenzophenone, was isolated. The structure was determined by means of spectroscopic analysis.

Two new xanthons from Garcinia rigida leaves

Two new xanthons, musaxanthone (1) and asmaxanthone (2) were isolated from the leaves of Garcinia rigida. The structures were determined by means of spectroscopic analysis.

Arginase Inhibitory, Antioxidant Activity and Pharmacognosy Study of Sterculia macrophylla Vent. Leaves

Objective: The purpose of this study was to investigate the arginase inhibitory activity, antioxidant activity, and also pharmacognostical study of Sterculia macrophylla leaves. The main component of genus Sterculia was flavonoid that was well known to demonstrate arginase inhibitory activity. Methods: Sample was extracted gradually using n-hexane, ethyl acetate, and methanol solvents, subsequently. The n-hexane, ethyl acetate, and methanol extract were determined for their arginase inhibitory activity. The most active extract was methanol extract. This extract was determined for its antioxidant activity, arginase inhibitory activity, identification of chemical compound, chromatogram profile and determined the content of total flavonoid. The leaves and powder of Sterculia macrophylla were identified with microscopic and macroscopic evaluation. Results: The most active extract was methanol extract with IC50 114,659 μg/mL for arginase inhibitory activity and IC50 78.47 μg/mL for DPPH scavenging activity. The secondary metabolite of methanol extract presence compound of alkaloid, flavonoid, tannin, terpene, and glycoside. The total flavonoid content was 141.10 mg/gram extract. The star-shape trichoma was identified as a specific fragment. Conclusion: The methanol extract of Sterculia macrophylla showed activity as arginase inhibitor and antioxidant.

SENYAWA TRITERPENOID DARI EKSTRAK N-HEKSANA KULIT BATANG TANAMAN Garcinia benthami

Triterpenoids compounds from N-hexane extract of the stem bark of Garcinia benthami. Two triperpenoids compounds, i.e. friedelin (1) and 3β-hydroxy-lanosta-9(11),24-dien-26-oic acid (2) were isolated from the n-hexane extract of the stem bark of Garcinia benthami. The structures of these compounds were elucidated by IR, MS, 1 H-NMR and 13 C-NMR spectroscopy and by comparison of their spectroscopic data with those reported data from the literature.