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Flavanones are one of the flavonoid group that has wide variety of applications such as a precursors in drug discovery. In the laboratory, flavanone is often synthesized from chalcone compounds. The conversion of chalcone to flavanone can be catalyzed by bronsted acid. The reaction mechanism for this process is proposed through the Michael addition reaction, however, the energetic details and the rate determining step for this reaction is not certainly known. This research aimed to investigate the reaction mechanism for chalcone-flavanone conversion with the present of bronsted acid as catalyst and also studied the effect of the solvent on the reaction energy profile with computational method. In this study, the modeling of the reaction mechanism for the said reaction was carried out using the DFT computational method with M06-2X functional. The computation was done both in the gas phase and in present of the solvent effect using the PCM models. The results showed that the mechanism of chalcone-flavanone conversion occurred in three steps which are protonation, cyclization, and then tautomerization. Based on these calculations, the rate determining step was the tautomerization reaction, which exhibited the same results with or without the solvent effects. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

The oxidation of quinine using hydrogen peroxide yielded quinine N-oxide as a major product. The reaction can be accelerated in the presence of palladium chloride (PdCl2) as catalyst. The trace products, however, were identified as the further oxidation products at quinoline moiety producing N-Oxide as a major product and the secondary alcohol at C-9 producing the ketone, furthermore the alkene translocation product. The trace products were successfully isolated and characterized by NMR protons and carbons. Purification of the product was performed by column chromatography.

An in vitro dimer-based screening system (DBSS) for selecting new HIV-1 protease dimerization inhibitor candidates from natural compounds had been established. This system utilizes a fusion between HIV-1 protease and dimer binding domain of AraC protein (proteaseHIV1-AraCDBD) where fluorescence signal will be emitted in the presence of HIV-1 protease inhibitor. However, this screening system had not been evaluated. Therefore, this study was aimed to evaluate it in recombinant Escherichia coli culture. The expression of proteaseHIV1-AraCDBD fusion gene was observed for 18 hours. Its crude lysate isolation was done once every 3 hours and analyzed using SDS PAGE. To test the DBSS, darunavir was used as positive control, and Nigella sativa extract (JH3) was used as the test compound. The results of SDS PAGE analysis on crude lysates presented a ~24.2 kDa band, which was the predicted size of the proteaseHIV1-AraCDBD fusion protein based on its amino acid sequence. The growth curve and protein expression profiles revealed that the 15 hours was the optimum culture age to be used in the screening system. Darunavir testing in DBSS showed an increase in fluorescence signal compared to the negative control. The same increase in fluorescence signal was also obtained from the JH3 compound test. In conclusion, DBSS could be used as an assay to screen for new HIV-1 protease inhibitors, and the JH3 compound demonstrated the ability to inhibit HIV-1 protease dimerization.

Tephrosia vogelii Hook.f. is a species of the family Fabaceae (Leguminoceae). These plants are termed ″Polong-polongan″ in Indonesia, and are known to contain active flavonoid groups. Previous studies have shown the isolation of one known flavanone: isolonchocarpin from methanol extract, and the structure obtained was established based on chemical evidence as well as spectroscopic methods, including NMR, and also by a comparison with published data. This research is aimed at evaluating the cytotoxic property of methanol extract against larvae of Arthemia salina Leach, using the Brine Shrimp Lethality Test (BSLT) method. The results show potent cytotoxicity at LC50 of 41.40 ppm.

Two new quinone derivatives, epoxyquinophomopsins A (1) and B (2), were purified from the EtOAc extract of endophytic fungus Phomopsis sp isolated from Morus cathayana. The structures of both compounds were determined based on 1D and 2D NMR and mass spectral data, as well as by x-ray diffraction analysis for 1. Compounds 1 and 2 were screened against eight receptor- (RTKs) and eight non-receptor tyrosine kinases (nRTKs). Both compounds showed strong inhibitory properties against Bruton's Tyrosine Kinase (nRTK) with their kinase activity were 19% and 20%, respectively. Only compound 1 that showed strong inhibitory properties against RTKs EGFR and HER-4 with its kinase activity were 16 and 15%, respectively. Thus, both compounds have potential as tyrosine kinase inhibitors.

In this report, the roasted Arabica coffees obtained from 4 Indonesian regions were analyzed with 1H NMR based-metabolomics. In total, 23 compounds were detected in the coffee 1H NMR spectra. Orthogonal projection to latent structure-discriminant analysis (OPLSDA) model successfully classified metabolites of the coffees based on their origins. S-plots of two-classes partial least square discriminant analysis (PLSDA) models successfully identified discriminant metabolites for every coffee. Chlorogenic acids, trigonelline, arabinoses were found as the discriminant compounds for Preanger-Java coffee. Lipids, acetic acid and lactic acid were discovered as the characteristic metabolites for Gayo-Sumatra coffee. γ-quinide was found as the most important marker for Bajawa-Flores coffee. Meanwhile, Toraja-Sulawesi coffee were characterized with a balance chemical composition indicating its well-balanced taste. The findings revealed the diversity of Indonesian Arabica coffees and shed more light on scientific information of Indonesian coffees.

Three new 5,6-dihydro-α-pyrones derivatives, named (S)-rugulactone (1) pulchrinervialactone A (2), and pulchrinervialactone B (4), along with one known pyrone, cryptobrachytone C (3), and three known amide derivatives (5-7) have been isolated from the leaves of Cryptocarya pulchrinervia. The structures of 1-7 were elucidated based on extensive spectroscopic data and comparison with literatures. The configurations of compounds 3 and 4 were established by single crystal X-ray diffraction analysis. This is also the first report in finding (S)-rugulactone (1) as a natural product. In addition, the preliminary cytotoxic activity of the isolated compounds was evaluated against P-388 cells using the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. All the pyrones, except compound 4, were active significantly inhibiting the growth of P-388 cells, while the amides derivatives (5-7) showed moderate to weak activities. Therefore, compounds 1-3 could be potentially examined further for anticancer agents.

Three new pyranoxanthones, calotetrapterins A-C (1-3) were isolated from the stem bark of Calophyllum tetrapterum Miq along with three known xanthones, α-mangostin (4), garciniafuran (5), and pyranojacareubin (6). All structures were elucidated based on their IR, UV, HRESIMS, 1 D (1H, 13C) and 2 D (HMBC, HMQC) NMR spectral data. Compounds 1-6 were tested to P-388 cells for cytotoxic activity, compound 2 exhibited high activity with IC50 value 1.0 μM.

Sektor kelautan dan perikanan merupakan salah satu sumber andalan dalam produksi pembangunan perikanan di Indonesia. Udang merupakan salah satu komoditas unggulan utama dalam menunjang produksi pendapatan devisa non migas. Untuk mencapai target produksi sesuai dengan yang diharapkan, berbagai permasalahan menghambat upaya peningkatan produksi tersebut, antara lain kegagalan produksi akibat penyakit oleh bakteri Vibrio, sehingga penyakit ini dikenal sebagai ‘vibriosis’. Salah satu pencarian senyawa yang bersifat antibakteri adalah dengan cara melakukan penapisan terhadap senyawa-senyawa alam. Salah satu sumber senyawa alam adalah dari tumbuhan Tephrosia vogelii . Penelitian ini bertujuan untuk mengidentifikasi dan mengisolasi senyawa dari tumbuhan T. vogelii sebagai sumber senyawa antibakteri terhadap dua bakteri Vibrio yaitu Vibrio alginolitycus dan Vibrio harveyi. Bahan ekstrak dibuat dengan metode maserasi menggunakan pelarut aseton, sementara uji antibakteri dilakukan dengan metode difusi agar secara in vitro . Deguelin dan tefrosin kemudian diisolasi dari ekstrak aseton daun T. vogelii. dengan metode difusi agar senyawa deguelin memberikan nilai inhibisi 6,3 mm terhadap V. harveyi dan 6,2 mm terhadap V alginolitycus . Sedangkan tefrosin memberikan nilai inhibisi 6,3 mm terhadap V. harveyi dan 6,6 mm terhadap V alginolitycus . Ini adalah evaluasi antibakteri pertama dari deguelin dan tefrosin terhadap dua bakteri yang diuji.

Macaranga merupakan salah satu genus terbesar dari famili Euphorbiaceae yang terdiri dari 300 spesies dengan nama lokal mahang-mahangan. Tumbuhan Macaranga tersebar luas di wilayah Afrika dan Madagaskar di bagian barat hingga ke wilayah tropis Asia, Australia utara dan kepulauan Pasifik. Di Indonesia tumbuhan Macaranga tersebar di beberapa daerah yaitu daerah Papua, Maluku, Sulawesi, Kalimantan, Sumatera, Bangka, dan Jawa. Kajian fitokimia beberapa spesies Macaranga menunjukan adanya kelompok senyawa fenolik yaitu turunan flavonoid dan stilben, serta turunan terpenoid. Senyawa turunan fenolik tersebut memiliki keunikan dari struktur molekulnya, yaitu adanya subtituen tambahan dari metabolit terpenoid yaitu prenil (C 5 ), geranil (C 10 ), farnesil (C 15 ), dan geranilgeranil (C 20 ). Pada penelitian ini telah dilakukan isolasi metabolit sekunder dari daun M. involucrata (Roxb.) Baill dengan metode maserasi menggunakan pelarut aseton, kemudian dilanjutkan pemisahan dan pemurnian dengan menggunakan kromatografi cair vakum dan kromatografi radial untuk mendapatkan senyawa murni. Penentuan struktur dilakukan berdasarkan analisis data spektrum NMR 1D ( 1 H-NMR dan 13 C-NMR), NMR 2D (NOESY, TOCSY, HSQC, dan HMBC), dan spektrum massa (MS). Berdasarkan metodologi tersebut, dua senyawa turunan flavon yaitu 5,7,4’-trihidroksi-3’(3-metilbut-2-enil)-3-metoksiflavon ( 1 ) dan makarangin ( 2 ), telah berhasil diisolasi dari tumbuhan ini. Berdasarkan hasil penelitian tersebut menunjukan daun M. involucrata (Roxb.) Baill yang berasal dari Kabupaten Buton Tengah, Sulawesi Tenggara menghasilkan senyawa fenolik turunan flavonoid. Kata kunci: Euphorbiaceae, Macaranga involucrata (Roxb.) Baill, flavon. Macaranga is one of the largest genera of the family Euphorbiaceae comprising 300 species with local name “mahang-mahangan ” . Macaranga is widespread in the region of Africa and the west of Madagascar to the tropical regions of Asia, northern Australia, and the Pacific islands. In Indonesia Macaranga spread in several areas: Papua, Maluku, Sulawesi, Kalimantan, Sumatra, Bangka, and Java. Phytochemical studies showed the presence of several phenolic compounds such as flavonoids and stilbene derivatives. The phenolic compounds have a unique molecular structure with the addition of some substituents such as prenyl (C 5 ), geranyl (C 10 ), farnesyl (C 15 ), and geranylgeranyl (C 20 ). This research has been conducted on the isolation of secondary metabolites from the leaves of M. involucrata (Roxb.) Baill by maceration method using acetone, followed by separation and purification by using liquid vacuum chromatography and radial chromatography to obtain pure compounds. Determination of the structure is based on data analysis of 1D NMR spectrum (1H-NMR and 13C-NMR), 2D NMR ( 1 H- 1 HCOSY, NOESY, TOCSY, HSQC, and HMBC), and mass spectra (MS). Based on this methodology, two flavone derivatives 5,7,4'-trihydroxy-3'(3-methylbut-2-enyl)-3-methoxy flavone ( 1 ) and macarangin ( 2 ), have been isolated from this plant. Based on these results showed that leaf of M. involucrata (Roxb.) Baill from Central Buton, Southeast Sulawesi produces phenolic compounds from flavonoid derivatives. Keywords: Euphorbiaceae, Macaranga involucrata (Roxb.) Baill, flavone.

The purpose of study to determine the content of secondary metabolites, toxicity and antioxidant activity of bark extract from Artocarpus lanceifolius Roxb. The extracts were obtained by maceration method using hexane, chloroform, ethyl acetate and methanol solvents, respectively. The extract obtained was tested for phytochemicals, toxicity test using the shrimp Brine Lethality Test (BSLT), antioxidant test using the DPPH (2,2-diphenyl-1- picrylhydrazyl) method. Phytochemical test results showed that n-hexane extract contained terpenoids and steroids while flavonoid and phenol compounds contained in extracts of chloroform, ethyl acetate, and methanol. The dominant alkaloid compounds were found in ethyl acetate and methanol extracts. Toxicity values (LC50) for n-hexane, chloroform, ethyl acetate extract were 1.0853 μg/mL, 0.1635 μg/mL, 0.3615 μg/mL and 0.2609 μg/mL respectively. The IC50 value of free radical scevange activity of chloroform extract, ethyl acetate were 19.66 μg/mL, 15.85 μg/mL, and 19.01 μg/mL respectively.

A new farnesylated flavonol (4′- O -methylmacagigantin) and a new geranylated stilbene (macatrichocarpin H), together with eight known phenolic compounds, have been isolated from the leaves of Macaranga trichocarpa . Structures of these compounds were determined based on NMR and mass spectrroscopic data. Cytotoxic properties of the isolated compounds were tested against P-388 cells showing that mactrichocarpin G was the most active compound with IC 50 was 3.5 μM.

Metabolite profiles of green beans (the caged and the wild) Luwak (civet) coffees were evaluated by NMR techniques combined with chemometrics. The bioactivities of the green coffee beans were examined with antioxidant tests and an alpha-glucosidase inhibitory assay. Both are invitro tests related to the antidiabetic properties. Our results showed the civet coffees possessed unique metabolomes and were different from the regular arabica coffee. Both civet coffees were characterized by higher concentrations of alanine, citrate, lactate, malate, and trigonelline. Lactate and lipids were found as the most important compounds discriminating the caged civet coffee from the wild civet coffee. Bioactivity assays exhibited the antidiabetic activities of the civet coffees were better than the activity of the regular coffee. These results suggested that the civet coffees are promising functional foods reducing the diabetes risk. It is the first report evaluating metabolite profiles of both civet coffees using 1H NMR-based metabolomics.

Phytochemical isolation of the methanol extract of Macaranga rubiginosa leaves afforded five prenylated dihydrostilbenes. Two of them were known dihydrostilbenes laevifolins A (1) and B (2), while the other three were new compounds, trivially named macarubiginosins A–C (3–5). The structures of the new compounds were elucidated based on their UV, 1D and 2D NMR, and HR-ESI-MS spectral data. Compounds 1–5 were tested for their cytotoxicity against P-388 cells, showing that compound 1 was the most active with IC50 4.3 μM.

A new phenolic sesquiterpene, dysoxyphenol (1), and the known sesquiterpene, 7R,10S-2-hydroxycalamenene (2), were isolated from the acetone extract of Dysoxylum densiflorum seeds. The structures of these compounds were determined based on physical, Nuclear Magnetic Resonance, and mass spectral data. Both compounds were evaluated for their antibacterial and antifungal properties against seven pathogenic bacteria and two wood-rotting fungi, respectively. The results showed that both compounds have significant antibacterial properties only against Bacillus subtilis (Minimum Inhibitory Concentration 28 μM), while in the antifungal evaluation compound 1 was found to be more active than compound 2. Therefore, compound 1 has promising antifungal properties that can be developed further for finding new antifungal agents.

Three andirobin- and one trijugin-class limonoids, named koetjapins A-D (1–4), have been isolated from the seed extracts of Sandoricum koetjape. The structures of these compounds were determined by extensive NMR and mass spectral data, and the chemotaxonomic significance of these limonoids in the family Meliaceae is highlighted. Preliminary biological activity showed that only compound 4 has significant inhibitory activity against P-388 cells, while antibacterial tests showed that none of these compounds were active.

Determination of total phenol content and antioxidant activity of brown algae (Padina sp) from Kayoa Island and determining the relationship between total phenol content and its antioxidant activity have been carried out. Crude extract of methanol was obtained by maceration of dried algae Padina sp. Determination of the extract secondary metabolites was carried out by phytochemical screening which showed the presence of alkaloid, phenolic, steroid, and flavonoid content. The total phenol extract was determined by the Folin-Ciocalteu method and the total phenol content was 4,43 mgGAE/g. Antioxidant activity was analyzed using the DPPH method and the IC50 value was 564,99 µg/mL. The total phenol content of the extract and its IC50 value shows a linear relationship y = 1218x - 4830.7 with a determination value R2 = 0.9981

Mutations in katG gene are often associated with isoniazid (INH) resistance in Mycobacterium tuberculosis strain. This research was perfomed to identify the katG mutation in clinical isolate (L8) that is resistant to INH at 1 μg/ml. In addition to characterize the catalase-peroxidase of KatG L8 and perform the ab initio structural study of the protein to get a more complete understanding in drug activation and the resistan­ce mechanism. The katG gene was cloned and expressed in Escherichia coli, then followed by characterization of catalase-peroxidase of KatG. The structure modelling was performed to know a basis of alterations in enzyme activity. A substitution of A713G that correspond to Asn238Ser replacement was found in the L8 katG. The Asn238Ser modification leads to a decline in the activity of catalase-peroxidase and INH oxidation of the L8 KatG protein. The catalytic efficiency (Kcat/KM) of mutant KatGAsn238Ser respectively decreases to 41 and 52% for catalase and peroxidase. The mutant KatGAsn238Ser also shows a decrease of 62% in INH oxidation if compared to a wild type KatG (KatGwt). The mutant Asn238Ser might cause instability in the substrate binding­ site of KatG, because of removal of a salt bridge connecting the amine group of Asn238 to the carbo­xyl group of Glu233, which presents in KatGwt. The lost of the salt bridge in the substrate binding site in mutant KatGAsn238Ser created changes unfavorable for enzyme activities, which in turn emerge as INH resistan­ce in the L8 isolate of M. tuberculosis.

In this work, 1H NMR analysis, along with a chemometrics approach, had been applied for investigating metabolite profiles of Indonesian roasted Robusta coffees obtained from Lampung and Aceh. In total, 24 compounds had been successfully detected in the 1H NMR spectra of the Robusta coffee extracts. Concentrations of some identified metabolites present in the coffees were determined by the quantitative 1H NMR technique. Orthogonal projection to latent structure-discriminant analysis (OPLSDA) was used as a primary method for the chemometric approach. OPLSDA had classified clearly the Robusta coffee samples corresponding to their origin. Loading plot and S-plot of the OPLSDA revealed characteristic metabolites for each Robusta coffee. The results indicated that quinic acid, mannose, arabinoses, and acetic acid were an important discriminant compound for Lampung Robusta coffees. Meanwhile, lipids, lactic acid, and 5-caffeoylquinic acid were found as characteristic metabolites for Aceh Robusta coffee. This report provided knowledge about the chemical composition of Lampung and Aceh Robusta coffees and shed more light on the diversity of Indonesian Robusta coffees. Furthermore, it confirmed that 1H NMR analysis coupled with chemometrics was a powerful method for evaluating and classifying metabolite profiles of the roasted Robusta coffees.

This paper discusses laboratory activities that can improve the meaningfulness of natural product chemistry course. These laboratory activities can be useful for students from many different disciplines including chemistry, pharmacy, and medicine. Students at the third-year undergraduate level of chemistry education undertake the project to isolate secondary metabolites from medicinal plants. This project provides opportunities for students to design their own activities to isolate secondary metabolites from medicinal plants. Students were exposed to skills as extraction, fractionation, purification, and structural elucidation of secondary metabolites. In this project, two secondary metabolites were successfully isolated from medicinal plants. The implementation of this project improved students’ understanding of natural product chemistry.

A new flavanone, epoxynymphaeol C ( 1 ), was isolated from the acetone extract of the leaves of Macaranga tanarius , together with two known compounds, nymphaeols B ( 2 ) and C ( 3 ). The structure of the new compound was determined by NMR and mass spectral data. Chemotaxonomic significance for the presence of the flavanone derivatives in M. tanarius is discussed.

Carbonic Anhydrase II (CAII) has role in pH regulation, water transport and hydration of CO 2 . In addition, CAII is also related to many diseases, including glaucoma, tumours, epilepsy, diabetes and osteopetrosis. Various inhibitors for CAII have been developed and commercialized as a drug. Recent development of CAII inhibitors drive the invention of novel inhibitors based on natural product structures and their derivatives. This research aim to screen potential inhibitors from phenolic and flavonoid groups by in silico approach. The screening of natural products compounds was performed by a molecular docking method. The best ligand derived from the molecular docking selection was further refined with a molecular dynamics simulation and the resulted structure was used to evaluate the stability of CAII-ligand complex. By using the upper mentioned procedures, fisetin (Fic) and 6-(3,4-dihydroxyphenyl)-5,6,7,8-tetrahydronaphthalene-1,3,7-triol (Afr3) were strongly suggested to be a potent inhibitor for CAII.

Two new isoprenylated benzofuran 3-ones, airlanggin A (1) and B (2) along with two known xanthones, ananixanthone (3) and trapezifolixanthone (4) were isolated from the stem bark of Calophyllum soulattri. Structures of all the compounds were elucidated using extensive spectroscopic methods, including UV, IR, HRESIMS, 1D and 2D NMR. Compounds 1–4 were evaluated for their cytotoxicity against P-388 cells, showing that compound 3 was the most active with IC50 0.68 μg/mL and compound 1 showed moderate activity with IC50 5.80 μg/mL.

Malignant tumors are one of the main causes of death in the world. Until now the search for cytotoxic (antitumor) compounds from nature, particularly from plants, is being a continuation activities. One group of plants that produce potential cytotoxic compounds is the Cryptocarya, one of the large genera of the Lauraceae family. As a part of our chemical and cytotoxic evaluation of the Cryptocarya species, we examined three species of Indonesian Cryptocarya. The sample of the wood of C. konishii hayata was collected from Cibodas Botanical Garden, West Java while the stem bark of C. phoebeopsis and C. cagayanensis were obtained from Sorong, Papua. Our investigation of flavonoid constituents on these species afforded three chalcone compounds i.e. desmethylinfectocaryone (1), infectocaryone (2) and cryptocaryone (3). The molecular structures of the isolated compounds were determined based on spectroscopic data, including UV, IR, 1D and 2D NMR. Cytotoxic effects of the compounds were evaluated using MTT [3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide] assay. Compound 1, 2 and 3 displayed strong cytotoxic properties (IC50 < 2 μg/mL) against Murine Leukemia P388 and HL 60 (blood premyelocytic leukemia) cells whereas 2 and 3 exhibited strong cytotoxicity properties against HCT116 (colon cancer). Cryptocaryone (3) also showed moderate cytotoxic properties (IC50 < 10 μg/mL) towards A549 (human lung adenocarcinoma epithelial) cells.

Normal 0 false false false MicrosoftInternetExplorer4 The isolation of terpenoids from C. heyneana rhizomes and their antibacterial activity have been conducted. The terpenoids were isolated by using vacuum liquid chromatography and radial chromatography. The structures of the compounds were determined based on spectroscopic data ( 1 H-NMR, 13 C-NMR (1D and 2D)). The antibacterial activity was carried out by using microdilution method and evaluated against eight bacteria. Three germacrane type sesquiterpenes have been isolated from C. heyneana rhizhomes and were identified as germacrone, dehydrocurdione, and 1(10),4(5)-diepoxygermacrone. Germacrone showed highest antibacterial activity against P. aeruginosa with MIC values of 15.6 µg/mL and MBC values 31.2 µg/mL. Dehydrocurdione showed highest antibacterial activity against B. subtilis with MIC values of 31.2 µg/mL and MBC values of 31.2 µg/m L . However, 1(10),4(5)-diepoxygermacrone showed a weak antibacterial activity. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

An acetone extract of Curcuma xanthorrhiza rhizomes and the n-hexane and chloroform fractions obtained from it were tested on eight pathogenic bacteria. The results showed that the acetone extract and the nhexane fraction exhibited significant activities against Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus, and weak activities against Shigella dysenteriae and Vibrio cholerae. They were inactive against Escherichia coli, Enterobacter aerogenes and Salmonella thypi, while the chloroform fraction was devoid of activities. NMR analysis disclosed the presence of α-curcumene, xanthorrhizol and an unknown monoterpene in the nhexane fraction. In the chloroform fraction, curcumin was found to be the main compound, together with xanthorrhizol as a minor compound. These results suggest that the antibacterial potency of acetone extract of C. xanthorrhiza is contained in the n-hexane fraction, in which the active constituents are terpenoid compounds. This is the first report of the use of NMR analysis for compound identification contained in an extract or fractions of C. xanthorrhiza.

Prenylated flavone compounds, 14-hydroxyartonin E have been isolated from CHCl3 extract of Artocarpus lanceifolius Roxb bark. The molecular structure compound was determined based on the UV-Vis, IR, 1H-NMR and 13C-NMR HSQC, HMBC spectra and compared to the previous data reported.14-hydroxyartonin E compound provides antibacterial activity with a moderate category against Streptococcus pneumonia and Staphylococcus aureus but the category is weak against Escherichiacoli and Salmonella thyposa

Two flavanone derivatives, norartocarpanone (1) and euchrenone a7 (2) had been isolated for the first time from the methanol extract of the wood of Morus nigra. The structures of these compounds were determined base on spectral evidence, including UV, IR, and NMR. The first compound also confirmed by comparison with the reported data. Cytotoxic properties of these compounds were evaluated against murine leukemia P-388 cells. Euchrenone a7 (2) was found more cytotoxic than norartocarpanone (1) with their IC50 7.8 and 12.7 mg/mL respectively.

Cinchona alkaloids are one of abundant natural chiral pool for organocatalysts. The application of an N-oxide group containing molecule in asymmetric reaction is currently wide developed. The structure of quinine consist two amine groups that could be oxidized to the N-oxide groups at N-1’ of quinoline and at N-1 of quinuclidine moieties. The oxidation reaction took place selectively at quinuclidine moiety by controlling the concentration of oxidizing agents. In this study we showed that N-1-oxide quinine could be occurred chemo­selectively by using a low concentration of ozone thana palladium catalyzed oxidation. The structure of products N1-oxide quinine was elucidated by spectroscopy data including 1H-NMR, 13C-NMR, 2D-NMR, infra-red and mass spectrometry. The developed method is a chemoselectively and eco-friendly method for synthesis N1-oxide quinine.

Three new prenylated 9,10-dihydrophenanthrenes, macajavanicins A (Ia), macajavanicins B (Ib), and macajavanicins C (II) are isolated from the acetone extract of Macaranga javanica leaves along with two known prenylated dihydrostilenes, laevifolins A and B.

Most of isoniazid-resistant Mycobacterium tuberculosis evolved due to mutation in the katG gene encoding catalase-peroxidase. A set of new mutations, namely T1310C, G1388T, G1481A, T1553C, and A1660G, which correspond to amino acid substitutions of L437P, R463L, G494D, I518T, and K554E, in the katG gene of the L10 clinical isolate M. tuberculosis was identified. The wild-type and mutant KatG proteins were expressed in Escherichia coli BL21(DE3) as a protein of 80 kDa based on sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis. The mutant KatG protein exhibited catalase and peroxidase activities of 4.6% and 24.8% toward its wild type, respectively, and retained 19.4% isoniazid oxidation activity. The structure modelling study revealed that these C-terminal mutations might have induced formation of a new turn, perturbing the active site environment and also generated new intramolecular interactions, which could be unfavourable for the enzyme activities.

A new isoprenylated dihydroflavonol derivative, macalowiinin ( 1 ), together with two known flavonoids 4’- O -methyl-8-isoprenylnaringenin ( 2 ) and 4’- O -methyl-5,7,4’-trihydroxyflavone ( 3 ) (= acasetin), have been isolated from the methanol extract of the leaves of Macaranga lowii . The structures of these compounds were determined based on UV, NMR, and mass spectral data, and optical rotation. Preliminary cytotoxic evaluation of compounds 1 – 3 against P-388 cells showed that compound 3 is the most active with IC 50 was 58.7 mM.

Six resveratrol dimers have been isolated from the stem bark of H. gregaria, ampelopsin A (1), balanocarpol (2), ε-viniferin (3), hopeafuran (4), heimiol A (5), and parviflorol (6). The structures of these compounds were determined based on spectroscopic evidence such as UV, IR, 1-D, 2-D NMR and comparison with the reported data. These compound inventions are strengthen conclusion that Hopea tends to produce resveratrol dimers. Biological activity of those compounds against murine leukemia P-388 cells showed that ε-viniferin (3) is the most active compound with IC50 value 5.1 ± 0.3 μg/mL. Keywords: H. gregaria, resveratrol dimers, murine leukemia P-388 cells

Kaempferia pandurata (syn. Boesenbergia rotunda, B. pandurata (Roxb.)Schltr), locally known as "TemuKunci"in Indonesia, is one of the medicinal plants of the family Zingiberaceae. Phytochemical studies on the rhizome of K. pandurata showed the presence of flavonoid derivative, namely flavanones, which constitute as the main components of this plant. Bioactivity studies on this species exhibited various biological activities, such as antibacteria, anti-inflammatory, antitumor, antidiarrhea, antidisentri, anti-HIV, antioxidant, antipyretic, analgesic and insecticides. Among the biological activities, the antibacterial activity results are important as an attempt to answer the emergence of resistance of some bacteria against existing drugs, as well as the emergence of a number of outbreaks of disease caused by bacteria. Therefore, a search to find new compounds that are potential as an antibacterial is an urgent matter. The present study was aimed at the chemical transformation of pinostrobin (1) from K. pandurata rhizome and an antibacterial activity.The chemical transformation was performed through a prenylation reaction of pinostrobin (1) which is the main component of K. pandurata rhizome. The prenylation reaction was carried out by reacting pinostrobin (1) with prenyl bromide and potassium carbonat (K2CO3). The purification of product was done using the radial chromatography with mix solvent n-hexane and ethyl acetate (97.5:2.5; 9.5:0.5; 9.0:1.0.; 8.0:2.0). The purity test of isolated compound was analysedby TLC using different types of eluent. The identification of compounds was determined based on NMR data and mass spectra analysis. Five compounds were obtained from the prenylation reaction, i.e. monooxyprenylated pinostrobin (2), monooxyprenylated chalcone (3), diprenylated chalcone (4), triprenylated chalcone (5), and triprenylated cyclohexene chalcone (6). These compounds were tested for antibacterial activities against four clinical bacteria, namely Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The antibacterial test was conducted using microdilution method. The five compounds showed moderate antibacterial activity against clinical bacteria with MIC values in the range of 25 to 50 µg/mL.

In this work, the oligomer of 4-vinylpyridine designated as O(4-VP) was synthesized by hydrogen peroxide initiated chain growth polymerization and characterized in terms of molecular weight and structure by matrix assisted laser desorption ionization time of flight mass spectroscopy (MALDI-TOF MS). The oligomer was tested as corrosion inhibitor of mild steel in brine solution saturated with carbon dioxide, with the main purpose to investigate the effect of inhibitor concentrations and temperatures on the inhibition activity defined in terms of corrosion rate and percent of protection. The inhibition tests were carried out using the methods of weight loss (WL) and linear polarization (LP). Characterization using MALDI-TOF MS revealed that the oligomer has the mass (m/z) in the range 200-2400, which corresponds to chain length of 2-22 repeating units. The results of corrosion rate measurements show that the corrosion rate with the use of oligomer is significantly lower than that without inhibitor, demonstrating that the oligomer functioned as effective corrosion inhibitor, while the 4-vinyl pyridine monomer was found to promote the corrosion. It was also found that the protection by the oligomer increased with increasing temperature and it was predicted the oligomer was chemically adsorbed by the surface of the metal.

This research aims to investigate effect of learning using natural product mini project laboratory on students’ critical thinking skills. The research was conducted on sixth semester of 59 students of chemistry and chemistry education program from one of the state universities in West Nusa Tenggara, Indonesia in 2012/2013. This research revealed class where the student learn using natural product mini project laboratory had more critical thinking skills than those using verification laboratory. The average n-gain of critical thinking skills for experiment class was 0.58 while for the control class was 0.37. The highest n-gain in the experiment class was 0.70 for “deciding on an action (selecting criteria to judge possible solutions) indicators”, while the smallest n-gain was 0.47 for “the making and judging value of judgments (balancing, weighing, and deciding) indicators. We concluded that the natural product mini project laboratory was better than verification laboratory in improving the students’ critical thinking skills.

The benzene derivatives from the Spermonde Archipelago sponges Cinachyrella was isolated. 4-hydroxy-benzenepropanoic acid (1) from Cinachyrella australiensis, 4-methyl- benzoic acid (2) and 4-hydroxy-benzonitrile (3) from Cinachyrella sp. The structues of 1, 2, and 3 have been determined by 1H-NMR, 13C-NMR, and HR-MS.

A new oligostilbenoid, diptoindonesin C, has been isolated from the tree bark of Shorea pinanga Scheff., along with the two known oligostilbenoids gnetin H and hopeaphenol, and a known coumarin scopoletin. The new oligostilbenoid was moderately active against brine shrimps Artemia salina.

Phytochemical studies on the woods of Vatica pauciflora and Vatica lowii have been conducted. The woods of V. pauciflora were extracted with methanol by using Soxhlet apparatus while the woods of V. lowii were extracted with acetone at room temperature. The methanolic extract of V. pauciflora was semi-purified by using vacuum liquid chromatography (VLC) and further purified by high performance liquid chromatography (HPLC) to obtain a pure compound (1) . The same technique of semi-purification has been employed on V. lowii acetone extract which was further purified by radial chromatography to give a pure compound (2) . Based on the UV, IR, NMR and mass spectral data, the isolated compounds were characterized as (-)- cis -resveratrol-10- C -b-D-glucopyranoside and (-)-piceid respectively.

Previously we had isolated two prenylated flavanones and two prenylated dihydrochalcones, macatrichocarpins A-D (1 - 4), from the acetone extract of the leaves of Macaranga trichocarpa. Reexamination of the fractions containing minor components resulted in the isolation of four more flavonoid derivatives, including two new prenylated dihydrochalcones, oxymacatrichocarpin C (5) and isomacatrichocarpin C (6). The structures of these compounds were determined by the analysis of UV, NMR, and mass spectral data. The eight isolated flavonoids were tested on eight pathogenic bacteria and found to be mostly moderate antibacterial agents, with the lowest MIC value of 26.5 μM achieved by the flavanone macatrichocarpin A (1) against Bacillus subtilis.