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Three new ternary rare-earth zirconium chalcogenides, Ce 2 ZrSe 5 ( 1 ), Pr 2 ZrSe 5 ( 2 ) and Nd 2 ZrSe 5 ( 3 ), have been synthesized by a facile solid-state route with boron as the reducing reagent. They crystallize in the space group Pnma of the orthorhombic system, belonging to the U 3 Se 5 structure type. Their 3-D structures are constructed by parallel polyanionic {[ZrSe 5 ] 6– } n chains and LnSe 8 bicapped trigonal prisms. The magnetic susceptibilities' data indicate their antiferromagnetic-like behavior without magnetic order down to 2 K. The structural relationships among several similar structures are discussed, together with the lanthanide contraction in the Ln 2 ZrSe 5 system.

An unprecedented quaternary sulfide borate, Sm3S3BO3 (1), was obtained via a high-temperature solid-state synthesis method. It crystallizes in the triclinic space group P1, and its 3D structure features a 2D (Sm2S2)∞ wrinkled layer and a 1D (SmS)∞ ladderlike chain bridged by trigonal-planar (BO3)3– through Sm–O bonds, demonstrating the first sulfide borate without S–O and B–S bonds. Its optical energy gap is measured to be around 2.5 eV and verified by electronic structure calculation.

The asymmetric synthesis of ivorenolide B (I) is successfully achieved in six steps with an overall yield of 26%.

Six new mexicanolide-type limonoids, dysoxylumasins A–F (1–6), together with eight known compounds, namely litseagermacrane, 15-methoxyisodauc-3-ene-1β,5α-diol, isodauc-6-ene-10β,14-diol, 4-epi-isodauc-6-ene-10β,14-diol, 2α,3α,4β-trihydroxypregnan-16-one, 1,7-phenanthrenedimethanol, spicatin, and aurantiamide, were isolated from the leaves and twigs of Dysoxylum mollissimum Bl. Their structures were established by the analyses of spectroscopic data.

The title compounds are synthesized from mixtures of the elements in the ratio Ln:Cd:Ge = 1:25:1 (alumina crucible, 973 K, 2 d) and characterized by single crystal XRD and TB-LMTO electronic structure calculations.

The title compounds are prepared from stoichiometric mixtures of the elements (Nb tubes, 1223—1273 K, 5 h) and characterized by powder and single crystal XRD, magnetic measurements, and TB-LMTO-ASA calculations.

The title compounds are synthesized from stoichiometric mixtures of the elements (Nb tubes, 1253—1358 K, 5 h) and characterized by single crystal XRD, magnetic measurements, and TB-LMTO computations.

The new compounds Sr2Y2.67Sn3S12, Ca3La2Sn3S12, and Ca3Er2Sn3s12 are prepared from appropriate mixtures of CaS, SrS, La2S3, Er2S3, SnS2, Sn, S, La, or Y using KBr as fluxing agent (silica ampules, 950—1000 °C, 100—316 h).

The structures of the new title compounds (IV) (triclinic, space group P, Z = 2) and (VI) (P, Z = 2) are determined by single crystal XRD.

isolation, structure elucidation and antimicrobial activities of eleven new phragmalin-type limonoids, swietenitins N—X, such as (I) and (II)

Trigochinins E (Ib) and F (Ic) exhibit a strong inhibiting activity against the HL-60 tumor cell line.

Three highly oxygenated new diterpenes, trigochinins A−C (1−3) were isolated from Trigonostemon chinensis. Their structures with the absolute configuration were determined by a spectroscopic method, X-ray crystallography, and CD analysis. This study suggested the revision of the C-6 stereochemistry of trigonothyrins A−C reported quite recently. Compound 3 showed significant inhibition against MET tyrosine kinase activity with a IC50 value of 1.95 μM.

Two novel antimicrobial and cytotoxic triterpenoids, isopseudolarifuroic acids A (1) and B (2), were isolated from the bark of Pseudolarix kaempferi. The structural elucidation of two novel compounds was carried out mainly by spectroscopic methods, and also by computer modeling. Compounds 1 and 2 exhibited significant cytotoxic activities against several tumor cell lines. Compound 1 also showed most potent antimicrobial activities against both Gram-positive and Gram-negative bacteria.

Two novel sesquiterpenoid dimers, multistalides A and B ( 1 – 2 ), were isolated from the whole plant of Chloranthus multistachys . Their structures were established on the basis of spectroscopic analysis, and the absolute configuration of 1 – 2 was determined by CD exciton chirality method.

Six new apotirucallane-type triterpenoids, chisiamols A–F (1–6), along with two known compounds, were isolated from the twigs of Chisocheton siamensis. The structures of compounds 1–6 were established on the basis of spectroscopic and chemical methods.

Readily available chiral thioureas derived from cyclohexane-1,2-diamine were prepared and found to be highly effective organocatalysts for the conjugate addition of aldehydes and ketones to nitroalkenes. Excellent enantioselectivities and yields were obtained for a variety of aryl and heteroaryl nitroalkenes. The base additives are essential for good yields and excellent enantioselectivities in this transformation. Based on new experimental evidence, a modified catalytic mechanism was proposed to rationalize the important role of the base additives.

Four new quaternary isostructural rare-earth thiosilicates, ZnY6Si2S14 (1), Al0.50Dy3(Si0.50Al0.50)S7 (2), Al0.38Dy3(Si0.85Al0.15)S7 (3), and Al0.33Sm3SiS7 (4), crystallized in the chiral and polar space group P63, have been prepared by a facile synthetic routine. Compounds 1−3 show strong second harmonic generation effects at 2.1 um with the intensities of 1, 2, and 3 being about 2, 2, and 1 times that of KTP (KTiOPO4), respectively. The calculated band structure of 1 implies that the optical absorptions of BLn6M2Q14 and ALn3MQ7 family compounds are mainly ascribed to the charge transitions from Q−p to Ln−4f (4d for Y) states. Compounds 2−4 exhibit antiferromagnetic-like interactions.

A novel chiral open-framework structural hexanary chalcogenoborate, (K3I)[SmB12(GaS4)3] (1), was obtained by a facile approach using boron as the reducing reagent; it shows weak SHG-activity and is transparent in the mid-IR region.

Asymmetric conjugate addition of 1-bromonitroalkanes to α,β-unsaturated ketones was studied using chiral primary amines as the catalysts. 9-Amino-9-deoxyepiquinine was found to be highly efficient catalyst for the transformation. 4-Bromo-4-nitroketones were obtained with excellent enantioselectivities (97–99% ee) and good yields (61–99%) for a variety of alkyl vinyl ketones. The product could be further debrominated with Bu3SnH/AIBN to provide chiral 4-nitroketones in good yield and without loss of the optical purity.

Chiral bifunctional sulfamides were found to be highly efficient organocatalysts for the conjugate addition of aldehydes to nitroolefins in the presence of base additives.

Five novel prenylated polyketides, harrisotones A–E (1–5) representing a rare spirocyclic skeleton, along with a new hydroperoxypolyketide harrisonol A (6), were isolated from the stems and leaves of Harrisonia perforata. The structures of harrisotones A–E (1–5) were extensively elucidated on the basis of spectroscopic analysis, especially 2D NMR and CD spectra. A plausible origin of compounds 1–5 was rationalized biogenetically, and traced back to harrisonol A (6). Harrisotones A–C (1–3) and harrisonol A (6) exhibited significant cytotoxicity against P-388 and/or A-549 tumor cell lines.

Two novel limonoids, chuktabrin A (1), featuring the unique motifs of a 1,3-dioxolan-2-one and a 3,4-dihydro-2H-pyran, and chuktabrin B (2), possessing an unprecedented polycyclic skeleton, were isolated from Chukrasia tabularis. The structures of 1 and 2 bearing a biosynthetically extended C3 and C2 unit at C-15, respectively, were elucidated on the basis of spectroscopic data, and that of 1 was confirmed by a single-crystal X-ray diffraction.

Four unusually fused polycyclic sesquiterpenoid dimers, chlorahololides C–F (1–4), were isolated from the whole plant of Chloranthus holostegius. Their structures and absolute configurations were established by spectroscopic methods, including 2D NMR and CD spectra. Chlorahololides C–F (1–4) exerted potent and selective inhibition on the delayed rectifier (IK) K+ current with the IC50 values of 3.6±10.1, 2.7±0.3, 27.5±5.1 and 57.5±6.1 μM, respectively.

The reaction of indole and its derivatives with aryldiazoacetates has been studied in the presence of copper and rhodium catalysts. The electronic property of N-1 substitutent showed significant effect on the reaction pathways. The electron-donating group favored the formation of the β-alkylation products, while the electron-withdrawing group favored the formation of the cyclopropane products. A reaction mechanism was proposed based on the experimental data and previous research results. The structure of aryl group in diazo compounds also affected the yield of the β-alkylation products or the cyclopropane products.

Walsucochins A (1) and B (2) with an unprecedented skeleton were isolated from Walsura cochinchinensis. Their structures including absolute configuration were elucidated by spectral methods. A biosynthetic pathway of 1 and 2 was postulated. Both 1 and 2 exhibited significant cell protecting activities against H2O2-induced PC12 cell damage.

Two new sesquiterpenoids, namely 1β,4β-dihydroxy-5α,8β(H)-eudesm-7(11)Z-en-8,12-olide (1) and 1β,4α-dihydroxy-5α,8β(H)-eudesm-7(11)Z-en-8,12-olide (2), along with six known ones, homalomenol A (3), oplodiol (4), 5α,7α(H)-6,8-cycloeudesma-1(,4β-diol (5), oplopanone (6), 4β,10α-dihydroxyaromadendrane (7) and spathulenol (8), were isolated from the aerial part of Chloranthus spicatus (Thunb.) Makino, and their structures were established by spectroscopic methods.

Chuktabularins A−D (1−4), four novel 16-norphragmalin-type limonoids that feature unprecedented skeletons with a biosynthetically extended C2 or C3 unit at C-15 forming a unique 2,7-dioxabicyclo[2.2.1]heptane moiety, were isolated from the stem bark of Chukrasia tabularis. Their structures were elucidated by spectroscopic analysis and computer modeling. The biosynthetic pathway of 1−4 was postulated.

Four new Daphniphyllum alkaloids, daphnilongeranins A−D (1−4), along with four known ones, daphniphylline, longistylumphylline A, deoxyisocalyciphylline B, and daphnicyclidin D, were isolated from the leaves and stems of Daphniphyllum longeracemosum. Daphnilongeranin A (1) is the first seco-10,17-longistylumphylline A type Daphniphyllum alkaloid, and daphnilongeranin B (2) is a new C-22 nor-Daphniphyllum alkaloid based on a new C21 skeleton. Their structures and stereochemistry were determined using spectroscopic data and chemical methods.

Seven new sesquiterpenoids, namely eupatochinilides I–VII (1–7), together with eight known compounds, euponin (8), mollisorin A (9), niveusin B (10), 8β-(4′,-acetoxy-tiglyloxy)-3β -hydroxy-6Hβ,7Hα-germacra-1(10)E,4E,11(13)-trien-6,12-olide (11), eupalinilide B (12), 8β-(4′-hydroxytigloyloxy)-5-desoxy-8-desacyleuparotin (13), 3-deacetyeupalinin A (14), and 15-hydroxyleptocarpin (15), were isolated from the ethanolic extract of the whole plant of Eupatorium chinense L. Their structures and stereochemistry were established by spectroscopic methods and GIAO based 13C NMR chemical shift calculations.

DPP8 is a prolyl dipeptidase homologous to DPP-IV, which is a drug target for Type II diabetes. The biological function of DPP8 is not known. To identify potent and selective chemical compounds against DPP8, we have synthesized a series of isoquinoline and isoindoline derivatives and have tested their inhibitory activity against DPP8, DPP-IV and DPP-II. Isoindoline derivatives were found to be more potent DPP8 inhibitors than isoquinoline derivatives. Isoindoline with a 1-(4,4′-difluor-benzhydryl)-piperazine group at the P2 site was observed to be a very potent DPP8 inhibitor, having an IC50 value of 14 nM with at least a 2500-fold selectivity over either DPP-IV or DPP-II. From SAR results, we speculate that the S1 site of DPP8 may be larger than that of DPP-IV, which would allow the accommodation of larger C-terminal residues, such as isoquinoline or isoindoline.

[structure: see text] The first diamino Daphniphyllum alkaloid, daphnipaxinin (1), with an unprecedented hexacyclic fused skeleton, along with a known alkaloid, daphnicyclidin A (2), was isolated from the stem of Daphniphyllum paxianum Rosenth. The structure and absolute stereochemistry of 1 were established by spectral methods, especially two-dimensional NMR techniques and CD analysis.

Two novel major alkaloids, deoxycalyciphylline B (1) and deoxyisocalyciphylline B (2) with a unique fused hexacyclic skeleton, together with a quite recently reported alkaloid calyciphylline B (3), were isolated from the stem of Daphniphyllum subverticillatum. Their structures were established by spectral methods and chemical evidence, especially 2D NMR techniques. The structure of 1 was further confirmed by a single-crystal X-ray diffraction determination.

Four novel sesquiterpenes, namely 7alpha,8beta,13-trihydroxy-5,13-marasmanolide (2), isoplorantinone (5), 4,8,14-trihydroxyilludala-2,6,8-triene (6), and 8-hydroxy-8,9-secolactara-1,6-dien-5,13-olide (10), together with six known ones, 7alpha,8beta-dihydroxy-5,13-marasmanolide (1), 7alpha,8alpha-dihydroxy-5,13-marasmanolide (3), isolactarorufin (4), blennin A (7), blennin D (8), and lactarorufin (9), were isolated from the ethanolic extract of Lactarius piperatus. The structures of these sesquiterpenes, representing diversified structural types, were determined mainly by spectroscopic methods, especially 2D-NMR techniques. The structure of 6 was further confirmed by a single-crystal X-ray-diffraction determination.