Catalytic enantioselective bromoamination of allylic alcohols.

An enantioselective bromoamination of allylic alcohols has been developed for the first time using a newly designed cinchona-derived thiourea as the catalyst and N,N-dibromo-4-nitrobenzenesulfonamide as a bromine and amine source.

Bromoform reaction of tertiary amines with N,N-dibromosulfonamides or NBS/sulfonamides.

A new bromoform reaction of tertiary amines with N,N-dibromosulfonamides or NBS/sulfonamides has been developed. A series of amidines were prepared with moderate to good yields via a Csp(3)-Csp(3) bond cleavage.

A topology visualization early warning distribution algorithm for large-scale network security incidents.

It is of great significance to research the early warning system for large-scale network security incidents. It can improve the network system's emergency response capabilities, alleviate the cyber attacks' damage, and strengthen the system's counterattack ability. A comprehensive early warning system is presented in this paper, which combines active measurement and anomaly detection. The key visualization algorithm and technology of the system are mainly discussed. The large-scale network system's plane visualization is realized based on the divide and conquer thought. First, the topology of the large-scale network is divided into some small-scale networks by the MLkP/CR algorithm. Second, the sub graph plane visualization algorithm is applied to each small-scale network. Finally, the small-scale networks' topologies are combined into a topology based on the automatic distribution algorithm of force analysis. As the algorithm transforms the large-scale network topology plane visualization problem into a series of small-scale network topology plane visualization and distribution problems, it has higher parallelism and is able to handle the display of ultra-large-scale network topology.

Baculiferins A-O, O-sulfated pyrrole alkaloids with anti-HIV-1 activity, from the Chinese marine sponge Iotrochota baculifera.

Fifteen new DOPA-derived pyrrole alkaloids, named baculiferins A-O (2-16), were isolated from the Chinese marine sponge Iotrochota baculifera, together with the known alkaloids purpurone (1) and ningalin A (17). Most of the new compounds contain one to three O-sulfate units. Their structures were determined by extensive spectroscopic analysis including (1)H and (13)C NMR (COSY, HMQC, HMBC) and ESIMS data. A possible pathway for the biosynthetic origin of the isolated alkaloids is proposed, in which DOPA is assumed to be a joint biogenetic precursor. Baculiferins C, E-H, and K-N (4, 6-9, 12-15) were found to be potent inhibitors against the HIV-1 IIIB virus in both, MT4 and MAGI cells. Additional bioassay revealed that baculiferins could dramatically bind to the HIV-1 target proteins Vif, APOBEC3G, and gp41, for which structure-activity relationships are discussed.

10-Phenyl-[12]-cytochalasins Z7, Z8, and Z9 from the marine-derived fungus Spicaria elegans.

The three new 10-phenyl-[12]-cytochalasins Z7, Z8, and Z9 (1-3), together with two known analogues, cytochalasins E (4) and K (5), were isolated from the marine-derived fungus Spicaria elegans. This is only the second report to date that cytochalasins contain a 12-membered macrocyclic ring. The structures of the three new cytochalasins were elucidated by spectroscopic methods, and their absolute configurations were determined for the first time by the modified Mosher's method. All five cytochalasins were evaluated for their cytotoxic effects on P388 and A-549 cell lines by the MTT method.

Trichodermamide A and aspergillazine A, two cytotoxic modified dipeptides from a marine-derived fungus Spicaria elegans.

Two known modified dipeptides, trichodermamide A (1) and aspergillazine A (2), were isolated from an ethyl acetate extract of the metabolite of a marine-derived fungus Spicaria elegans, and were found to have a weak cytotoxic effect on three cancer cell lines P388, A-549, and HL-60 agreed. To our knowledge, this is the first report on the isolation of compounds 1 and 2 from the fungus Spicaria elegans and their cytotoxic effect.

Two new benzoquinone derivatives and two new bisorbicillinoids were isolated from a marine-derived fungus Penicillium terrestre.

Four new compounds were isolated from a marine-derived fungus Penicillium terrestre, namely 2-(2', 3'-dihydrosorbyl)-3,6-dimethyl-5-hydroxy-1,4-benzoquinone (1), 3-acetonyl-2,6-dimethyl-5-hydroxy-1,4-benzoquinone (2), dihydrobisvertinolone (3), tetrahydrobisvertinolone (4). Their structures were established on the basis of spectroscopic methods. The absolute configurations of 3 and 4 were determined by their CD spectra. Their cytotoxic effects on P388 and A-549 cell lines were preliminarily examined by the MTT method.

Dihydrotrichodimerol and tetrahydrotrichodimerol, two new bisorbicillinoids, from a marine-derived Penicillium terrestre.

Two new bisorbicillinoids possessing an open-ended cage structure, dihydrotrichodimerol (1) and tetrahydrotrichodimerol (2), were isolated from a marine-derived Penicillium terrestre. Their structures were established by spectroscopic methods. Their cytotoxic activities against P388 and A-549 cell lines were preliminarily evaluated by the MTT method.