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A one-pot multicomponent approach was established for site selective synthesis of novel 1,3,6-trisubstituted 3,6-diunsaturated (3Z,6Z)-2,5-diketopiperazine derivatives with high stereoselectivity. The computational studies revealed that the steric hindrances between the 2-hydrogen atoms on the aromatic rings and the carbonyl, as well as the steric repulsions between the hydrogen atoms of the CH group in the benzylidene and the CH2 group in the N-alkylative part might be responsible for the Z/E selectivity. Compound (3Z,6Z)-3h (IC50=11 nM) has a close activity to the positive compound plinabulin (IC50=15 nM) against the cancer cell line HL60.

Aspernigrin C (Ia) and D (Ib) are isolated as new compounds together with six known compounds from the marine-derived fungus Aspergillus niger SCSIO Jcsw6F30.

Six new casbane diterpenoids, sinularcasbanes G-L (1-6, resp.) were isolated from the soft coral Sinularia sp. Their structures were established by extensive spectroscopic analyses, especially 2D-NMR and HR-ESI-MS. The configuration was confirmed by CD analyses and by comparison with data reported in the literature. The compounds were evaluated for cytotoxicity against ten human cancer cell lines (H1975, U937, K562, BGC823, MOLT-4, MCF-7, A549, HeLa, HL60, and Huh-7) and showed no activity.

This review, with 290 references, presents the fascinating area of iodinated natural products over the past hundred years for the first time. It covers literature published from 1896 to 2014 and refers to compounds isolated from both biogenic and abiotic sources. In total, 182 naturally-occurring organoiodine compounds are recorded. The emphasis is on the compounds together with the relevant biological activities, sources, collection places, countries of origin, biosynthetic studies, and first total syntheses.

Six new guignardins A-F (1-6) were isolated from the cultures of endophytic fungus Guignardia sp. KcF8 derived of a mangrove plant Kandelia candel, along with three known analogues, palmarumycins C-1 (7), BG1 (8), and JC1 (9). Compounds 2, 3, 7, and 8 showed antimicrobial activities. Compounds 5-7 exhibited significant cytotoxicities against 10 human tumor cell lines. Compound 3 also displayed significant inhibitory activity against human protein tyrosine phosphatase 1B and histone deacetylase silent information regulator T-1 enzymes, two key targets for the treatment of diabetes. This is the first report on the anti-PTP1B and anti-SIRT1 activities of spirodioxynaphthalenes. (C) 2014 Elsevier Ltd. All rights reserved.

The new indole alkaloids, mangrovamides A (I), B (II), and C (III) are isolated from the title fungus.

A facile and efficient synthesis of novel seven-membered heterocyclic derivatives containing 3-aminoazepan-2-one backbone is described using 1,4-protected piperazine-2,5-diones and alkynes as starting materials. The reaction may undergo Michael addition, unusual nucleophilic attack to an amide group, and keto-enol tautomerization. The reaction showed different reactivity when using substrates with different protecting groups: it had higher efficiency when using either alkanoyl-protecting group with cesium carbonate as the base, or benzoyl-protecting group with triethylamine as the base, but no reaction when using benzyl or allyl protecting groups with a variety of bases (Et3N, DBU, K2CO3, Cs2CO3, KHCO3, CsHCO3, and KOt-Bu).

by Jing Hua)b)c)d), Bin Yanga)b), Xiuping Lina)b), Xuefeng Zhoua)b), Xianwen Yanga)b)c), Lijuan Longa)b)c), and Yonghong Liu*a)b)c) a) Key Laboratory of Marine Bio-resources Sustainable Utilization, South China Sea Institute of Oceanology, Chinese Academy of Sciences, No. 164 West Xingang Road, Guangzhou 510-301, P. R. China (phone: þ86-20-89023244; fax: þ86-20-84451672; e-mail: yonghongliu@scscio.ac.cn) b) Guangdong Key Laboratory of Marine Materia Medica, SCSIO, CAS, Guangzhou 510-301, P. R. China c) Marine Microorganisms Centre, SCSIO, CAS, Guangzhou 510-301, P. R. China d) Graduate University of the Chinese Academy of Sciences, Beijing 100049, P. R. China

Starfish have been the research topic in many chemical and pharmacological laboratories due to their complex secondary metabolites and diverse bioactivities. The aim of this review is to provide an up-to-date review on the chemistry and bioactivity of compounds isolated from all kinds of starfish to illustrate the chemodiversity and biological significance of these constituents, along with their geographical distribution where it is discernible.

A highly oxygenated racemate with C8 skeleton, menellin A (I), and a polyhydroxylated steroid, menellsteroid C (II) are isolated as along with eight known natural products.

Contents1. Introduction2. Chemical Constituents2.1. Alkaloids2.2. Quinones2.3. Terpenoids2.4. Sterols2.5. Fatty Acids3. Biological Activities3.1. Cardiovascular Activity3.2. Cytotoxic and Antitumor Activities3.3. HIV Protease Inhibitory Activity3.4. Other Enzyme Inhibitory Activities3.5. Antimicrobial and Insecticidal Activities3.6. Other Activities4. Concluding Remarks1. Introduction. – Marine sponges (phylum Porifera) are sessile marine filterfeeders that have developed efficient defense mechanisms against foreign attackerssuch as viruses, bacteria, or eukaryotic organisms, by production of secondarymetabolitestorepelthem[1].Theyareamongtherichestsourcesofpharmacologicallyactive chemicals isolated from marine organisms. The Xestospongia species (classDesmospongia, order Haplosclerida, family Petrosiidae), known as barrel sponges, arelarge and common members of the coral reef communities at depths greater than 10 m,all over the Indo-Pacific Ocean and the Caribbean Sea. Since the 1970s, with thedevelopment of the investigations of marine natural products, the analysis of thechemical constituents of Xestospongia sponges has been carried out consecutively allover the world, particularly in the USA, Japan, and Australia. Xestospongia spongeshave been established as a rich source of diverse secondary metabolites, including

Ab initio calculations at the MP2 level with the 6-31G * and 6-311G * basis set satisfactorily reproduced the experimental structural and vibrational spectral features of the D 2h conformer of dinitrogen tetroxide. Calculations at the same level, however, indicate the D 2d conformation of this molecule is a transition state for the torsional motion around the N-N bond. Therefore, the previously observed matrix infrared spectral features should not be attributed to the D 2d structure of dinitrogen tetroxide

The recently developed unrestricted Hartree-Fock natural orbital-complete active space (UNO-CAS) method is applied to the determination of the geometry and force field of p-benzoquinone. With an active space consisting of eight electrons distributed in eight π orbitals (8×8) and the 6-31G* basis set, UNO-CAS predicts CC and CO distances in good agreement with gas electron diffraction results. The full quadratic force field is obtained by an empirical scaling of the 8×8 UNo-CAS/4-21G force constants evaluated at the 6-31G* UNO-CAS geometry

Ab initio calculations were carried out on the ground state cis- 1,3,5-hexatriene. The equilibrium structure was found to be planar with C 2υ symmetry at both the Hartree-Fock SCF and post-Hartree-Fock level of theory. The potential energy surface around the equilibrium geometry is however very flat for the torsional motions around both the C-C single bonds and the central C=C double bond. At room temperature, the average torsional angles estimated with the calculated torsional potential curves are close to that suggested by the electron diffraction study of Traetteberg