Besides traditional problems such as potential bugs, (smartphone) application clones on Android markets bring new threats. That is, attackers clone the code from legitimate Android applications, assemble it with malicious code or advertisements, and publish these "purpose-added" app clones on the same or other markets for benefits. Three inherent and unique characteristics make app clones difficult to detect by existing techniques: a billion opcode problem caused by cross-market publishing, gap between code clones and app clones, and prevalent Type 2 and Type 3 clones.Existing techniques achieve either accuracy or scalability, but not both. To achieve both goals, we use a geometry characteristic, called centroid, of dependency graphs to measure the similarity between methods (code fragments) in two apps. Then we synthesize the method-level similarities and draw a Y/N conclusion on app (core functionality) cloning. The observed "centroid effect " and the inherent "monotonicity" property enable our approach to achieve both high accuracy and scalability. We implemented the app clone detection system and evaluated it on five whole Android markets (including 150,145 apps, 203 million methods and 26 billion opcodes). It takes less than one hour to perform cross-market app clone detection on the five markets after generating centroids only once.

As part of our search for new antifungal agents from natural resources, 22 C-27 steroidal saponins and 6 steroidal sapogenins isolated from several monocotyledonous plants were tested for their antifungal activity against the opportunistic pathogens Candida albicans, Candida glabrata, Candida krusei, Cryptococcus neoformans, and Aspergillus fumigatus. The results showed that the antifungal activity of the steroidal saponins was associated with their aglycone moieties and the number and structure of monosaccharide units in their sugar chains. Within the 10 active saponins, four tigogenin saponins (compounds 1 to 4) with a sugar moiety of four or five monosaccharide units exhibited significant activity against C. neoformans and A. fumigatus, comparable to the positive control amphotericin B. The antifungal potency of these compounds was not associated with cytotoxicity to mammalian cells. This suggests that the C-27 steroidal saponins may be considered potential antifungal leads for further preclinical study.

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Six new ellagitannins, phyllanemblinins A-F (1-6), were isolated from Phyllanthus emblica, along with 30 known tannins and related compounds. Their structures were determined by spectral and chemical methods. Phyllanemblinins A (1) and B (2) were confirmed to be ellagitannins having a tetrahydroxybenzofuran dicarboxyl group and a hexahydroxydiphenoyl group, respectively, by chemical synthesis from furosin (8). Phyllanemblinin C (3) has a new acyl group at the glucose 2,4-positions and is structurally related to chebulagic acid. Phyllanemblinins D (4), E (5), and F (6) were found to be positional isomers of neochebuloyl 1(beta)-O-galloylglucose.

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Phyllanthus emblica L. (Euphorbiaceae) is a shrub or tree growing in subtropical and tropical areas of the People's Republic of China, India, Indonesia, and the Malay Peninsula. The whole plant, especially the fruit has been used as an antiinflammatory and antipyretic drug in many local traditional medicines: Chinese herbal medicine, Tibetan medicine, and Ayurvedic medicine.1) Several reports about this plant have shown that the fruits are rich in vitamin C, mucic acid, and tannins.2-6) In our previous work, 7,8) a novel highly oxygenated norbisabolane together with its methyl ester and three ester glycosides were isolated from the roots of the plant along with 15 tannins and related compounds. As part of our continuing studies on the plant, we report herein the isolation and structural elucidation of new phenolic constituents, L-malic acid 2-O-(1), mucic acid 2-O-(5), mucic acid 1,4-lactone 2-O-(6), 5-O-(8), 3-O-(10), 3,5-di-O-(11) gallates, and their methyl esters (2-4, 7, 9) from the fruit juice of P. emblica. Results and DiscussionA 60% aqueous acetone extract of the powdered form of fruit juice of P. emblica was subjected to MCI gel CHP 20P column chromatography to afford five fractions. Fraction 1 obtained by elution with H 2 O was further chromatographed successively over Sephadex LH-20, MCI gel CHP20P, Toyopearl HW-40F, and Cosmosil 75C 18 OPN to afford compounds 1-11 and three known compounds. By comparison of the physical and spectral data with those of authentic samples, the known compounds were identified as gallic acid, chebulic acid, 9) and 1-O-galloyl-b-D-glucose, 10) respectively. Compound 1 was obtained as a white amorphous powder and showed a dark blue coloration with ferric chloride reagent. Its molecular formula was assigned as C 11 H 10 O 9 on the basis of the 13 C-NMR spectral data, the negative-ion 2-O-(1), mucic acid 2-O-(5), mucic acid 1,4-lactone 2-O-(6), 5-O-(8), 3-O-(10), and 3,5-di-O-(11) gallates, were isolated from the fruit juice of Phyllanthus emblica together with their methyl esters (2-4, 7, 9), and their structures were determined by spectral and chemical methods. Compounds 5, 6, and 8, the major phenolic constituents of the juice, were present as an equilibrium mixture in aqueous solution.

GLS4 is a new and unique potential anti-HBV agent that possesses a different mechanism of action than existing therapeutic drugs.