Judul: Uji Aktivitas Antibakteri Fraksi Daun Lidah Mertua (Sansevieria trifasciata)
Abstrak: Sansevieria trifasciata is an indigenous plant of South Africa used in herbal medicine for the treatment of various infectious diseases. The purpose of this study is to evaluate potency of S. trifasciata extracts through in vitro antibacterial test against Grampositive (Staphylococcus aureus) bacteria and Gram-negative (Escherichia coli) bacteria on Mueller-Hinton medium. The plant sample were obtained from research garden at Lodaya Campus, Bogor Agricultural University. The result indicated that methanol crude extract at concentration 10000, 5000, 2500, and 1250 ppm showed no activity against the tested bacteria. Methanol crude extract was fractionated using coloumn chromatography with gradient method. Methanol and chloroform were used as eluent with the best ratio of 9:1. The fractionation yielded 10 fractions. The fractions were tested at concentration 40000, 20000, and 10000 ppm. The antibacterial assay showed there were 2 active fractions for both of the tested bacteria, 5 active fractions against only Gram-positive (S. aureus) and 3 non-active fractions.
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Judul: Fraksi aktif ekstrak daun Sansevieria trifasciata Prain sebagai penghambat pertumbuhan sel lestari HeLa
Abstrak: Sansevieria trifasciata Prain is an ornamental plant which is also useful as a source of antibacterial and antioxidant agent. Studies of S. trifasciata Prain as anticancer have not been reported. Therefore, the objective of this study is to isolate bioactive compounds of S. trifasciata Prain leaves that shows in vitro proliferation inhibition of HeLa cell lines. The sample was macerated in 96% methanol and concentrated using a rotary evaporator. The crude extract was fractionated using chromatography column with silica gel as the stationary phase and gradient chloroform-ethyl acetate as the mobile phase. Qualitative phytochemical and inhibition activity using MTT assay (3- (4,5-dimethylthiazol- 2-yl)-diphenyltetrazolium-2,5-bromide) were performed on the crude extract and its fractions at concentrations between 200 and 1000 ppm. The crude extract contained flavonoids, alkaloids, and steroids, but the crude extract could not inhibit proliferation of HeLa cell lines. The chromatography resulted 10 fractions, however, there was only one fraction with the highest proliferation inhibition was 87.52% at concentration of 10000 ppm that. This fraction contained flavonoids and alkaloids.
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Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular