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Amomum compactum Soland Ex Maton is one of the Zingiberaceae family plants which is the endemic plants from West Java, Indonesia. This study was aimed to determine the chemical structure of flavonoid compounds from n-hexane extract of A.compactum Sol. Ex Maton roots. Dried powder of the roots was extracted consecutively with n-hexane, ethyl acetate, and methanol solvents. Three flavonoids, 5-hydroxy-3,7,4`-trimethoxy kaempferol (1), 5-hydroxy-3,7,3',4'-tetra methoxy kaempferol (2) and 4'-hydroxy-3,5,7-trimethoxy kaempferol (3), have been isolated from the roots of A. compactum Sol. Ex Maton. The chemical structures of compounds 1-3 were identified by spectroscopy data including infrared 1D-NMR, 2D-NMR and HRTOF-MS as well as by comparison with previously reported spectral data. Compounds 1-3 were isolated from this plant for the first time and showed free radical DPPH scavenging activity.

In the course of our continuing search for anticancer compounds from Chisocheton species, three steroids, stigmast-5-en-3β-ol (1), stigmast-5-en-3β-ol-3-O-β-D-glucopyranoside (2) and stigmast-5,22-dien-3β-ol-3-O-β-D-glucopyranoside (3), were obtained from the stembark of Chisocheton celebicus. The structures of compound 1-3 were identified with spectroscopic data including IR, 1D-NMR, 2D-NMR and TOF-MS, as well as by comparing with those spectral data previously. Compounds 1-3, were evaluated for their cytotoxic effects against P-388 murine leukemia cells and displayed the cytotoxicity activity with IC50 values of 12.45 ± 0.050, 52.27 ± 0.031 and 62.52 ± 0.076 µg/mL, respectively.

Peptida antioksidan merupakan kelompok peptida yang berperan penting karena dapat menetralkan radikal bebas, sehingga dapat mencegah dan mengobati penyakit kronis. Salah satu senyawa peptida antioksidan alami yang telah ditemukan peneliti sebelumnya adalah senyawa tetrapeptida PAGY (Pro-Ala-Gly-Tyr) yang diisolasi dari gelatin kulit ikan amur sturgeon (Acipenser schrenckii) dan dilaporkan memiliki aktivitas antioksidannya dengan IC50 5.38 mg/mL dalam uji DPPH dan 0,008 mg/mL dalam uji ABTS berturut-turut. Kelompok kami telah berhasil mensintesis PAGY bersama dengan analognya yakni PSGY, PFFY, PAFY, dan PAIY dengan menggunakan metode sintesis peptida fase padat (SPPS). Pengujian aktivitas antioksidan pada senyawa hasil sintesis menunjukkan bahwa PSGY memiliki aktivitas antioksidan lebih baik dari PAGY. Pencarian analog tetrapeptida antioksidan yang lebih baik hingga saat ini masih terus dilakukan. Pada penelitian ini telah berhasil disintesis analog tetrapeptida lainnya PADY (Pro-Ala-Asp-Tyr) dengan metode sintesis peptida fase padat menggunakan strategi Fmoc/t-Bu pada resin 2-klorotritilklorida dilanjutkan dengan pengujian aktivitas antioksidannya. HATU/HOAT digunakan sebagai reagen pengkopling dalam sintesis PADY. Pemurnian krud PADY dilakukan menggunakan RP-HPLC preparatif sehingga diperoleh PADY murni seberat 14.7 mg (12.6%). Penentuan struktur peptida hasil sintesis dianalisis dengan menggunakan spektroskopi 1H-NMR dan TOF-MS. Pada pengujian aktivitas antioksidan dengan metode DPPH, PADY hasil sintesis memberikan nilai IC50 sebesar 1.850 mg/mL, yang mengindikasikan bahwa PADY menunjukkan aktivitas antioksidan yang lebih rendah daripada PAGY hasil sintesis peneliti sebelumnya. Kata kunci: Antioksidan, tetrapeptida, sintesis peptida fase padat. Antioxidant peptide is a class of peptides that play an important in neutralizing free radicals, therefore this compound can be used to prevent and treat chronic diseases. One of the natural antioxidant peptides reported by previous researcher is PAGY (Pro-Ala-Gly-Tyr), which is isolated from amur sturgeon fish (Acipenser schrenckii) gelatin that showed antioxidant activity with IC50 5.38 and 0.008 mg/mL using DPPH and ABTS assay, respectively. Our group has successfully synthesized PAGY, along with its analogues of PSGY, PFFY, PAFY, and PAIY using solid phase peptide synthesis method (SPPS). Antioxidant assay on synthesised compounds showed that PSGY has better antioxidant activity than PAGY. The search on the analogues of the antioxidant tetrapeptide was continued. From this study, a tetrapeptide analogue PADY (Pro-Ala-Asp-Tyr) has been successfully synthesised by solid phase peptide synthesis method with Fmoc/t-Bu strategy on 2-chlorotrityl chloride resin and tested for its antioxidant activity. HATU and HOAt reagents were used as the coupling reagent for the synthesis of PADY. The resulting PADY peptide solid was then purified using preparative RP-HPLC yielding PADY of 14.7 mg (12.6%). Characterisation of the synthesized compound was analysed by 1H-NMR and TOF-MS. On the antioxidant assay using DPPH method, PADY showed IC50 value of 1.850 mg/mLindicating a lower activity than the synthetic PAGY. Keywords: Antioxidant, tetrapeptide, solid phase peptide synthesis (SPPS).

Two dammarane-type triterpenoids, 20S,24S-epoxy-3α,25-dihydroxydammarane (1) and 3α-acetyl-20S,24S-epoxy-3α,25-dihydroxydammarane (2), have been isolated from the stembark of Aglaia argentea. The chemical structure of compounds (1 and 2) were identified by spectroscopic evidences including UV, IR, 1D-NMR, 2D-NMR and MS as well as by comparing with previously reported spectral data. Those compounds were isolated from this plant for first time. Compounds (1 and 2) showed cytotoxic activity against P-388 murine leukemia cells with IC50 values of 23.96 and 8.14 mM, respectively. DOI:http://dx.doi.org/10.15408/jkv.v4i1.7065

Tetrapeptide, OH-Pro-Ala-Gly-Tyr-NH2, was successfully synthesised on 2-chlorotrityl chloride resin by taking advantage of PyBOP (benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate) as coupling reagent. The selection of the peptide as the target of synthesis was due to its interesting bioactivity as antioxidant. The synthesis was undertaken with Fmoc strategy, where Fmoc-proline was added onto the resin at the first place. It is known from the literature that proline can resist from rasemisation when it was attached on the resin at the first time. Fmoc deprotection step was carried out by employing 20% piperidine in DMF and the reaction mixture was shaken for 30 minutes. Once the proline attached, the next step was to attach amino acids, alanine (Ala), glycine (Gly) and tyrosine(Tyr), subsequently onto the resin until tetrapeptidyl resin was constructed on the resin. Hydroxyl group of Tyr was protected with t-butyl, which is TFA-labiled. Coupling reaction was undertaken by mixing the amino acid and PyBOP in a mixture of dichloromethane and DMF (1:1) and in the presence of basic DIPEA. Resin cleavage step was carried out by using 95% TFA in water, where t-butyl protecting group on the side chain of Tyr was cleaved at the same time. The analytical RP-HPLC of the final product showed a single peak at 21.9 minutes (20-90% of acetonitrile in water with 0.1% of TFA during 30 minutes), indicating that each coupling has given a good coupling performance and resulting in a pure product. The desired product showed the correct molecular weight with m/z 407.2 [M+H]+ and 429.2 [M+Na]. DOI: http://dx.doi.org/10.15408/jkv.v0i0.4055