Use of intensity quotients and differences in absolute structure refinement

N-(4-Eth-oxy-phen-yl)-3-oxobutanamide

The title compound, C12H15NO3, crystallizes with Z' = 2 in space group Pca21 with the two independent mol-ecules having almost the same conformation, differing mostly at the end of the butanamide chain. A local inversion center near 1/8, 3/4, z relates the two mol-ecules, as is common for structures in this space group with Z' = 2. The mol-ecule crystallizes as the keto tautomer, and the β-diketone moieties are twisted out of planarity, with O-C⋯C-O pseudo torsion angles of -74.4 (5) and -83.9 (5)°. The N-H group of each independent mol-ecule donates an inter-molecular hydrogen bond to an amide carbonyl oxygen atom by positive or negative translations along the b axis, thus forming anti-parallel chains propagating in the [010] direction.

Crystal structure and Hirshfeld surface analysis of (E)-1-(2,4-di-methyl-furan-3-yl)-3-phenyl-prop-2-en-1-one

The title compound, C15H14O2, adopts an E configuration about the C=C double bond. The furan ring is inclined to the phenyl ring by 12.03 (9)°. In the crystal, pairs of mol-ecules are linked by C-H⋯O hydrogen bonds, forming dimers with R 2 2(14) ring motifs. The mol-ecules are connected via C-H⋯π inter-actions, forming a three dimensional network. No π-π inter-actions are observed.

Synthesis and crystal structures of (E)-N'-(4-chloro-3-nitro-benzyl-idene)acetohydrazide and (E)-2-(4-chloro-benzyl-idene)-1-(quinolin-8-yl)hydrazine

The syntheses of two benzyl-idenehydrazine derivatives, namely, (E)-N'-(4-chloro-3-nitro-benzyl-idene)acetohydrazide, C9H8ClN3O3, and (E)-2-(4-chloro-benzyl-idene)-1-(quinolin-8-yl)hydrazine, C16H12ClN3, are reported. The mol-ecules have been characterized using IR, 1H NMR, 13C NMR and mass spectro-scopic and elemental analysis techniques, and their structures have been determined by single-crystal X-ray diffraction.

Bis(tetra-butyl-ammonium) tetra-chlorido-manganate(II) di-chloro-methane disolvate

The title compound, (C16H36N)2[MnCl4]·2CH2Cl2, is an ionic organic-inorganic hybride compound consisting of a tetra-butyl-ammonium cation and a tetra-chlorido-manganate(II) anion in a 2:1 stoichiometric ratio. The cation contains a central nitro-gen atom bonded to four n-butyl groups in a tetra-hedral arrangement, while the anion contains a central MnII atom tetra-hedrally coordinated by four chlorido ligands. It co-crystallized with two equivalents of di-chloro-methane solvent, CH2Cl2, to give the following empirical formula: [(C4H9)4N]2[MnCl4]·(CH2Cl2)2. The crystal structure is mainly stabilized by Coulombic inter-actions.

N-Cyclo-hexyl-tryptamine: freebase, bromide and fumarate

The solid-state structures of N-cyclo-hexyl-tryptamine (I) {systematic name: N-[2-(1H-indol-3-yl)eth-yl]cyclo-hexa-namine}, C16H22N2, and two of its salts, N-cyclo-hexyl-tryptammonium bromide (II) {systematic name: N-[2-(1H-indol-3-yl)eth-yl]cyclo-hexa-naminium bromide}, C16H23N2 +·Br-, and N-cyclo-hexyl-tryptammonium fumarate (III) (systematic name: bis-{N-[2-(1H-indol-3-yl)eth-yl]cyclo-hexa-naminium} (2E)-but-2-enedioate), 2C16H23N2 +·C4H2O4 2-, were determined by single-crystal X-ray diffraction. The freebase compound forms infinite chains along [010] through N-H⋯N hydrogen bonds. The bromide salt is held together by N-H⋯Br inter-actions in two-dimensional sheets along (001). The fumarate salt is held together in infinite three-dimensional frameworks by N-H⋯O hydrogen bonds.

The synthesis, crystal structure and spectroscopic analysis of (E)-3-(4-chloro-phen-yl)-1-(2,3-di-hydro-benzo[b][1,4]dioxin-6-yl)prop-2-en-1-one

The synthesis, crystal structure and spectroscopic analysis of (E)-1-(2,3-di-hydro-benzo[b][1,4]dioxin-6-yl)-3-(4-chloro-phen-yl)prop-2-en-1-one (C17H13ClO3), a substituted chalcone, are described. The overall geometry of the mol-ecule is largely planar (r.m.s. deviation = 0.1742 Å), but slightly kinked, leading to a dihedral angle between the planes of the benzene rings at either side of the mol-ecule of 8.31 (9)°. In the crystal, only weak inter-actions determine the packing motifs. These include C-H⋯O and C-H⋯Cl hydrogen bonds and π-π overlap of aromatic rings.

Crystal structure of 5-(β-d-gluco-pyran-osyl-thio)-N-(4-methyl-phen-yl)-1,3,4-thia-diazol-2-amine

In the structure of the title compound, C15H19N3O5S2, the bond lengths at the linking sulfur atom are significantly different [1.7473 (17) and 1.811 (2) Å], and the angle at the exocyclic nitro-gen atom is wide at 128.45 (18)°. The inter-planar angle between the tolyl and thia-diazole rings is 9.2 (1)°. The complex hydrogen-bonding pattern, involving five donors and five acceptors, can be broken down into a one-dimensional ribbon parallel to the b axis, involving hydrogen bonds of the sugar residues only, and a two-dimensional layer structure parallel to the ab plane, based on the N-H⋯O and O-H⋯N hydrogen bonds.

l-Me-thion-yl-l-tyrosine monohydrate

The study of the oxidation of various proteins necessitates scrutiny of the amino acid sequence. Since me-thio-nine (Met) and tyrosine (Tyr) are easily oxidized, peptides that contain these amino acids are frequently studied using a variety of oxidation methods, including, but not limited to, pulse radiolysis, electrochemical oxidation, and laser flash photolysis. To date, the oxidation of the Met-Tyr dipeptide is not fully understood. Several investigators have proposed a mechanism of intra-molecular electron transfer between the sulfide radical of Met and the Tyr residue. Our elucidation of the structure and absolute configuration of l-Met-l-Tyr monohydrate, C14H20N2O4S·H2O (systematic name: (2S)-2-{[(2S)-2-amino-4-methyl-sulfanyl-butano-yl]amino}-3-(4-hy-droxy-phen-yl)propanoic acid monohydrate) is presented herein and provides information about the zwitterionic nature of the dipeptide. We suspect that the zwitterionic state of the dipeptide and its inter-action within the solvent medium may play a major role in the oxidation of the dipeptide. In the crystal, all the potential donor atoms inter-act via strong N-H⋯O, C-H⋯O, O-H⋯S, and O-H⋯O hydrogen bonds.

Cyclo-penta-dienone triisocyanide iron complexes: general synthesis and crystal structures of tris-(2,6-di-methyl-phenyl isocyanide)(η4-tetra-phenyl-cyclo-penta-dienone)iron and tris-(naphthalen-2-yl iso-cyanide)(η4-tetra-phenyl-cyclo-penta-dienone)iron acetone hemisolvate

Irradiation of a toluene solution containing cyclo-penta-dienone tricarbonyl iron complexes and isocyanides with blue LEDs afforded the formation and isolation of 12 triisocyanide complexes, two of which, namely tris-(2,6-di-methyl-phenyl isocyanide)(η4-tetra-phenyl-cyclo-penatedienone)iron, [Fe(C9H9N)3(C29H20O)], and tris-(naphthalen-2-yl isocyanide)(η4-tetra-phenyl-cyclo-penatedienone)iron acetone hemisolvate, [Fe(C11H7N)3(C29H20O)]2·C3H6O, could be characterized crystallographically. The air-stable compounds were purified by column chroma-tography and were characterized by 1H NMR, 13C NMR, elemental analysis and HRMS. NMR and XRD data indicate generally more electron-rich Fe0 centers compared to the corresponding tricarbonyl compounds.

Accurate structure models and absolute configuration determination using dynamical effects in continuous-rotation 3D electron diffraction data

Continuous-rotation 3D electron diffraction methods are increasingly popular for the structure analysis of very small organic molecular crystals and crystalline inorganic materials. Dynamical diffraction effects cause non-linear deviations from kinematical intensities that present issues in structure analysis. Here, a method for structure analysis of continuous-rotation 3D electron diffraction data is presented that takes multiple scattering effects into account. Dynamical and kinematical refinements of 12 compounds-ranging from small organic compounds to metal-organic frameworks to inorganic materials-are compared, for which the new approach yields significantly improved models in terms of accuracy and reliability with up to fourfold reduction of the noise level in difference Fourier maps. The intrinsic sensitivity of dynamical diffraction to the absolute structure is also used to assign the handedness of 58 crystals of 9 different chiral compounds, showing that 3D electron diffraction is a reliable tool for the routine determination of absolute structures.

Crystallographic and spectroscopic characterization of two 1-phenyl-1H-imidazoles: 4-(1H-imidazol-1-yl)benzaldehyde and 1-(4-meth-oxy-phen-yl)-1H-imidazole

The title compounds, C10H8N2O, (I), and C10H10N2O, (II), are two 1-phenyl-1H-imidazole derivatives, which differ in the substituent para to the imidazole group on the arene ring, i.e. a benzaldehyde, (I), and an anisole, (II). Both mol-ecules pack with different motifs via similar weak C-H⋯N/O inter-actions and differ with respect to the angles between the mean planes of the imidazole and arene rings [24.58 (7)° in (I) and 43.67 (4)° in (II)].

Diketopiperazine Alkaloids and Bisabolene Sesquiterpenoids from Aspergillus versicolor AS-212, an Endozoic Fungus Associated with Deep-Sea Coral of Magellan Seamounts

Two new quinazolinone diketopiperazine alkaloids, including versicomide E (2) and cottoquinazoline H (4), together with ten known compounds (1, 3, and 5-12) were isolated and identified from Aspergillus versicolor AS-212, an endozoic fungus associated with the deep-sea coral Hemicorallium cf. imperiale, which was collected from the Magellan Seamounts. Their chemical structures were determined by an extensive interpretation of the spectroscopic and X-ray crystallographic data as well as specific rotation calculation, ECD calculation, and comparison of their ECD spectra. The absolute configurations of (-)-isoversicomide A (1) and cottoquinazoline A (3) were not assigned in the literature reports and were solved in the present work by single-crystal X-ray diffraction analysis. In the antibacterial assays, compound 3 exhibited antibacterial activity against aquatic pathogenic bacteria Aeromonas hydrophilia with an MIC value of 18.6 μM, while compounds 4 and 8 exhibited inhibitory effects against Vibrio harveyi and V. parahaemolyticus with MIC values ranging from 9.0 to 18.1 μM.

Biological activity of mixed chelate copper(II) complexes, with substituted diimine and tridentate Schiff bases (NNO) and their hydrogenated derivatives as secondary ligands: Casiopeína's fourth generation

We synthesize and characterize nine copper(II) compounds. Four with general formula [Cu(NNO)(NO₃)] and five mixed chelates [Cu(NNO)(N-N)]⁺, where NNO corresponds to asymmetric salen ligands (E)-2-((2-(methylamino)ethylimino)methyl)phenolate (L1) and (E)-3-((2-(methylamino)ethylimino)methyl)naphthalenolate (LN1); and their hydrogenated derivatives 2-((2-(methylamino)ethylamino)methyl)phenolate (LH1) and 3-((2-(methylamino)ethylamino)methyl)naphthalenolate (LNH1); and N-N correspond to 4,4'-dimethyl-2,2'-bipiridyne(dmbpy) or 1,10-phenanthroline (phen). Using EPR, the geometries of the compounds in solution in DMSO were assigned, [Cu(LN1)(NO₃)] and [Cu(LNH1)(NO₃)] a square-planar, [Cu(L1)(NO₃)], [Cu(LH1)(NO₃)], [Cu(L1)(dmby)]⁺ and [Cu(LH1)(dmby)]⁺ a square-based pyramid; and [Cu(LN1)(dmby)]⁺, [Cu(LNH1)(dmby)]⁺ and [Cu(L1)(phen)]⁺ and elongated octahedral. By X-ray it was observed that [Cu(L1)(dmby)]⁺ and. [Cu(LN1)(dmby)]⁺ presented a square-based pyramidal, and [Cu(LN1)(NO₃)]⁺ a square-planar geometry. The electrochemical study showed that copper reduction process is a quasi-reversible system, where the complexes with hydrogenated ligands were less oxidizing. The cytotoxicity of the complexes was tested by MTT assay, all the compounds showed biological activity in HeLa cell line, the mixed compounds were the more active ones. Naphthalene moiety, imine hydrogenation and aromatic diimine coordination, increased biological activity. A structure-activity relationships were found: Log(IC₅₀) =  - 1.01(E_pc) - 0.35(Conjugated Rings) + 0.87, for Schiff base complexes and Log(IC₅₀) = 0.078(E_pc) - 0.32(Conjugated Rings) + 1.94, for hydrogenated complexes; the less oxidizing species with a great number of conjugated rings presented the best biological activity. Complexes-DNA binding constants were obtained by uv-vis studies using CT-DNA, the results suggested that the complexes can interact through the grooves, except the phenanthroline mixed complex that intercalate with DNA. Gel electrophoresis study with pBR 322 showed that compounds can produce changes in the form of DNA and some complexes can cleave DNA in the presence of H₂O₂.

N-Methyl-serotonin hydrogen oxalate

The solid-state structure of N-methyl-serotonin {systematic name: [2-(5-hy-droxy-1H-indol-3-yl)eth-yl](meth-yl)aza-nium hydrogen oxalate}, C₁₁H₁₅N₂O⁺·C₂HO₄ ^-, is reported. The structure possesses a singly protonated N-methylserotonin cation and one hydrogen oxalate anion in the asymmetric unit. In the crystal, the mol-ecules are linked by N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network.

Crystal structure of 4-[(4-methyl-benz-yl)-oxy]-N'-(4-nitro-benzyl-idene)benzohydrazide: a new hydrazone derivative

The mol-ecular structure of the title compound, C₂₂H₁₉N₃O₄, shows a non-coplanar conformation, with dihedral angles between the phenyl rings of 73.3 (1) and 80.9 (1)°. These deformations are induced by the crystal packing that is mainly governed by N-H⋯O and C-H⋯O hydrogen bonds, forming a mono-periodic arrangement parallel to the b axis.

Structure of racemic duloxetine hydro-chloride

Duloxetine hydro-chloride (trade name Cymbalta) is marketed as a single enanti-omer (S)-N-methyl-3-(naphthalen-1-yl-oxy)-3-(thio-phen-2-yl)propyl-am-in-ium chloride, C₁₈H₂₀NOS⁺·Cl^-, which is twice as effective as the (R)-enanti-omer in serotonin uptake. Here, we report the crystal structure of duloxetine hydro-chloride in its racemic form (space group Pna2₁), where it shows significant differences in the mol-ecular conformation and packing in its extended structure compared to the previously reported (S)-enanti-omer crystal structure. Mol-ecules of this type, comprising aromatic groups with a single side chain terminated in a protonated secondary amine, are commonly found in active anti-depressants. A Cambridge Structural Database survey of mol-ecules with these features reveals a strong correlation between side-chain conformation and the crystal packing: an extended side chain leads to mol-ecules packed into separated layers of hydro-phobic and ionic hydro-philic phases. By comparison, mol-ecules with bent side chains, such as racemic duloxetine hydro-chloride, lead to crystal-packing motifs where an ionic hydro-philic phase is encapsulated within a hydro-phobic shell.

Syntheses, crystal structures and Hirshfeld surface analyses of four mol-ecular salts of amitriptynol

The syntheses and crystal structures of four salts of amitriptynol (C20H25NO) with different carb-oxy-lic acids are described. The salts formed directly from solutions of amitriptyline (which first hydrolysed to amitriptynol) and the cor-responding acid in aceto-nitrile to form amitriptynolium [sys-tem-atic name: (3-{2-hy-droxy-tri-cy-clo[9.4.0.03,8]penta-deca-1(11),3,5,7,12,14-hexa-en-2-yl}pro-pyl)di-methyl-az-an-ium] 4-meth-oxy-benzoate monohydrate, C20H26NO+·C8H7O3 -·H2O, (I), ami-triptynolium 3,4-di-meth-oxy-benzoate trihydrate, C20H26NO+·C9H9O4 -·3H2O, (II), amitriptynolium 2-chloro-benzoate, C20H26NO+·C7H4ClO2 -, (III), and amitriptynolium thio-phene-2-carboxyl-ate monohydrate, C20H26NO+·C5H3O2S-·H2O, (IV). Compound (III) crystallizes with two cations, two anions and six water mol-ecules in the asymmetric unit. The different conformations of the amitriptynolium cations are determined by the torsion angles in the di-methyl-amino-propyl chains and the -CH2-CH2- bridge between the benzene rings in the tricyclic ring system, and are complicated by disorder of the bridging unit in II and III. The packing in all four salts is dominated by N-H⋯O and O-H⋯O hydrogen bonds. Hirshfeld surface analyses show that the amitriptynolium cations make similar inter-species contacts, despite the distinctly different packing in each salt.

Crystallographic evidence for the stereoselective substitution of equatorial pyridyl ligands in ruthenium(III) complexes

Mononuclear Ru complexes catalyze dioxygen formation via water splitting; therefore, a detailed investigation into their water-oxidation process is necessary. In this study, we synthesized a series of Ru(III) complexes containing a dianionic tridentate ligand with three pyridine groups (one coordinated to Ru while the other two are "free") and investigated their substitution reactions in a water/acetonitrile mixture. Among the monodentate pyridyl ligands, the one at the equatorial position was crystallographically proven to be selectively substituted. Therefore, our results experimentally demonstrate the proposed coordination geometry for an intermediate during water oxidation over Ru complexes.

Crystal structure and Hirshfeld surface analysis of (5aS,8aR)-3,5a-dimethyl-8-methyl-idene-2-oxododeca-hydro-oxireno[2',3':6,7]naphtho-[1,2-b]furan-6-yl (Z)-2-methyl-but-2-enoate extracted from Ferula persica

In the title compound, C20H26O5, the two cyclo-hexane rings adopt boat and half-chair conformations. In the crystal, adjacent mol-ecules are connected by inter-molecular C-H⋯O hydrogen bonds, forming a three-dimensional network. According to a Hirshfeld surface study, H⋯H inter-actions are the most significant contributors to the crystal packing (63.0%).

Half-Sandwich Type Platinum-Group Metal Complexes of C-Glucosaminyl Azines: Synthesis and Antineoplastic and Antimicrobial Activities

While platinum-based compounds such as cisplatin form the backbone of chemotherapy, the use of these compounds is limited by resistance and toxicity, driving the development of novel complexes with cytostatic properties. In this study, we synthesized a set of half-sandwich complexes of platinum-group metal ions (Ru(II), Os(II), Ir(III) and Rh(III)) with an N,N-bidentate ligand comprising a C-glucosaminyl group and a heterocycle, such as pyridine, pyridazine, pyrimidine, pyrazine or quinoline. The sugar-containing ligands themselves are unknown compounds and were obtained by nucleophilic additions of lithiated heterocycles to O-perbenzylated 2-nitro-glucal. Reduction of the adducts and, where necessary, subsequent protecting group manipulations furnished the above C-glucosaminyl heterocycles in their O-perbenzylated, O-perbenzoylated and O-unprotected forms. The derived complexes were tested on A2780 ovarian cancer cells. Pyridine, pyrazine and pyridazine-containing complexes proved to be cytostatic and cytotoxic on A2780 cells, while pyrimidine and quinoline derivatives were inactive. The best complexes contained pyridine as the heterocycle. The metal ion with polyhapto arene/arenyl moiety also impacted on the biological activity of the complexes. Ruthenium complexes with p-cymene and iridium complexes with Cp* had the best performance in ovarian cancer cells, followed by osmium complexes with p-cymene and rhodium complexes with Cp*. Finally, the chemical nature of the protective groups on the hydroxyl groups of the carbohydrate moiety were also key determinants of bioactivity; in particular, O-benzyl groups were superior to O-benzoyl groups. The IC50 values of the complexes were in the low micromolar range, and, importantly, the complexes were less active against primary, untransformed human dermal fibroblasts; however, the anticipated therapeutic window is narrow. The bioactive complexes exerted cytostasis on a set of carcinomas such as cell models of glioblastoma, as well as breast and pancreatic cancers. Furthermore, the same complexes exhibited bacteriostatic properties against multiresistant Gram-positive Staphylococcus aureus and Enterococcus clinical isolates in the low micromolar range.

Pyranonaphthoquinones and Naphthoquinones from the Stem Bark of Ventilago harmandiana and Their Anti-HIV-1 Activity

Seven previously undescribed compounds, including five pyranonaphthoquinones (ventilanones L-P) and two naphthoquinones (ventilanones Q and R), along with 15 known compounds were isolated from the stem bark of Ventilago harmandiana (Rhamnaceae). The structures were established by extensive analysis of their spectroscopic data. The absolute configuration of ventilanone L was established from single crystal X-ray crystallographic analysis using Cu Kα radiation and from its electronic circular dichroism data. Anti-HIV-1 activity using a syncytium inhibition assay and the cytotoxic activities of some isolated compounds were evaluated. Compounds 12, 13, 15, and 16 showed activity against syncytium formation with half maximal effective concentration (EC₅₀) values ranging from 9.9 to 47 μM (selectivity index (SI) 2.4-4.5).

Clarifying the Configuration of Pandamine by an Extensive Spectroscopic Reinvestigation of the Authentic 1964 Sample

Since its partial configurational assignment in 1964, pandamine has not been isolated or obtained by total synthesis. For decades, different works representing the structure of pandamine for illustrative purposes have lent different configurations to this molecule, causing tenacious confusion about the structure of this ansapeptide. A comprehensive spectroscopic analysis of the authentic pandamine sample led to the complete and unambiguous assignment of its configuration, 59 years after its isolation. In addition to ascertaining and completing the initial structural deductions by a state-of-the-art set of analytical techniques, the purpose of this study is also to clarify the literature in a context in which various erroneous structures have been attributed to pandamine for half a century. While fully in agreement with Goutarel's conclusions, the specific example of pandamine should serve as a cautionary tale to any chemist interested in natural products, encouraging access to initial structural assignments rather than relying solely on subsequent, possibly erroneous, structure depictions of a natural product.

Dipeptide-Derived Alkynes as Potent and Selective Irreversible Inhibitors of Cysteine Cathepsins

The potential of designing irreversible alkyne-based inhibitors of cysteine cathepsins by isoelectronic replacement in reversibly acting potent peptide nitriles was explored. The synthesis of the dipeptide alkynes was developed with special emphasis on stereochemically homogeneous products obtained in the Gilbert-Seyferth homologation for C≡C bond formation. Twenty-three dipeptide alkynes and 12 analogous nitriles were synthesized and investigated for their inhibition of cathepsins B, L, S, and K. Numerous combinations of residues at positions P1 and P2 as well as terminal acyl groups allowed for the derivation of extensive structure-activity relationships, which were rationalized by computational covalent docking for selected examples. The determined inactivation constants of the alkynes at the target enzymes span a range of >3 orders of magnitude (3-10 133 M^-1 s^-1). Notably, the selectivity profiles of alkynes do not necessarily reflect those of the nitriles. Inhibitory activity at the cellular level was demonstrated for selected compounds.

Antimicrobial polyketides and sesquiterpene lactones from the deep-sea cold-seep-derived fungus Talaromyces minioluteus CS-113 triggered by the histone deacetylase inhibitor SAHA

Seven new highly oxygenated natural products with diverse chemical structural types, including three new glucosidic polyketides, talaminiosides A-C (1-3), a pair of racemic aromatic polyketides, (±)-talaminone A (4a and 4b), two new azaphilone polyketides, (+)-5-chloromitorubrinic acid (5) and 7-epi-purpurquinone C (7), and one new drimane sesquiterpene lactone, 11-hydroxyminioluteumide B (8), together with a pinazaphilone B sodium salt (6) and 10 known compounds (9-18), were isolated and identified from the culture extract of Talaromyces minioluteus CS-113, a fungus obtained from deep-sea cold-seep sediments collected from the South China Sea. LCMS results indicated that compounds 3 and 4 might be produced by the real activation of silent BGCs triggered by the histone deacetylase inhibitor SAHA, and some of the other compounds were enhanced minor components. Their structures were elucidated by the detailed interpretation of NMR spectroscopic and mass spectrometric data, X-ray crystallographic analysis, ECD and specific rotation (SR) calculations, and DP4+ probability analysis. Compound 7, an azaphilone derivative, exhibited potent activities against several agricultural pathogenic fungi with MIC values equivalent or comparable to amphotericin B. The structure-activity relationship of the isolated azaphilones is briefly discussed. This is the first report of the chemical diversity study of deep-sea cold-seep-derived fungi triggered by SAHA, providing a useful strategy for the activation of cryptic fungal metabolites from deep-sea-derived fungi.

Consistent zincophosphite 4-ring 'ladder' chain structural motif with isomeric ligands

The syntheses and crystal structures of four hydro-thermally prepared organo-zinc phosphites, viz. poly[[(2-amino-3-methyl-pyridine)-μ3-phospho-nato-zinc] hemihydrate], {[Zn(HPO3)(C6H8N2)]·0.5H2O} n , (I), poly[(2-amino-4-methyl-pyridine)-μ3-phospho-nato-zinc], [Zn(HPO3)(C6H8N2)] n , (II), poly[(2-amino-5-methyl-pyridine)-μ3-phospho-nato-zinc], [Zn(HPO3)(C6H8N2)] n , (III), and poly[bis-(2-amino-4-methyl-pyridinium) [tetra-μ3-phospho-nato-trizinc] monohydrate], {(C6H9N2)2[Zn3(HPO3)4]·H2O} n , (IV), are described. Compounds (I)-(III) are constructed from vertex-sharing ZnO3N tetra-hedra (the organic mol-ecule acting as a ligand) and HPO3 pseudo pyramids in a 1:1 ratio to generate the same motif of infinite 4-ring 'ladder' chains propagating in the [010], [101] and [100] directions, respectively, whereas (IV) consists of (010) layers of vertex-sharing ZnO4 and HPO3 units in a 3:4 ratio with the protonated organic mol-ecule acting as a template. When an excess of HCl is used in the synthesis, the simple hydrated mol-ecular salt, bis-(2-amino-3-methyl-pyridinium) tetra-chloro-zincate monohydrate, (C6H8N2)2[ZnCl4]·H2O, (V), arises. Com-pounds (I)-(V) feature extensive networks of hydrogen bonds, both classical (N-H⋯O, N-H⋯Cl, O-H⋯O) and non-classical (C-H⋯O, C-H⋯Cl) in nature, which help to consolidate the extended structures.

(E,E)-1,1'-[1,2-Bis(4-chlorophenyl)ethane-1,2-diyl]bis(phenyldiazene) revisited: threefold configurational disorder of (S,S), (R,R) and (S,R) isomers, a detailed critique

Crystal structures described as concomitant triclinic (I) and monoclinic (II) polymorphs of meso-(E,E)-1,1'-[1,2-bis(4-chlorophenyl)ethane-1,2-diyl]bis(phenyldiazene) [Mohamed et al. (2016). Acta Cryst. C72, 57-62] have been re-investigated. The published model for II was distorted due to forcing the symmetry of space group C2/c on an incomplete structure model. It is shown here to be a likely three-component superposition of S,S and R,R enantiomers with a lesser amount of the meso form. A detailed analysis of how the improbable distortion in the published model aroused suspicion and the subsequent construction of undistorted chemically and crystallographically plausible alternatives having the symmetry of Cc and C2/c is presented. For the sake of completeness, an improved model for the triclinic P-1 structure of the meso isomer I, revised to include a minor disorder component, is also given.

Enantioselectivity of chiral dihydromyricetin in multicomponent solid solutions regulated by subtle structural mutation

Multicomponent crystals of a chiral drug with non-chiral components have attracted increasing attention in the application of enantiomer purification and regulation of the physicochemical properties of crystalline materials. Crystalline solid solutions provide opportunities for fine-tuning material properties because of continuously adjustable component stoichiometry ratios. The synthesis, crystal structure, thermodynamics and solid-state enantioselectivity of a series of multicomponent crystals of chiral dihydromyricetin (DMY) with caffeine (CAF) or theophylline (THE) were investigated and the results reveal how the subtle change of molecular structure of the coformer dictates the enantiomer selectivity in multicomponent cocrystals. A series of multicomponent cocrystal solvates of chiral DMY with CAF and THE were synthesized by the slurry cocrystallization method in acetonitrile. Although most racemic mixtures crystallize as racemic compounds or conglomerates, both DMY-CAF and DMY-THE crystallize as chiral solid solutions, unveiled by pseudo-binary melt phase diagrams and pseudo-ternary solution phase diagrams. Crystal structures of Rac-DMY-CAF, R,R-DMY-CAF, Rac-DMY-THE and R,R-DMY-THE are reported for the first time via single-crystal X-ray diffraction, displaying two distinct types of solid solution differing in mixing scale of enantiomers spanning several orders of magnitude. Surprisingly, this remarkable impact on enantiomer discrimination was simply achieved by the reduction of a methyl group of CAF to the THE coformer, which was further rationalized from their crystal structures and intermolecular interactions. Collectively, this work has demonstrated that a subtle change in the molecular structure of a coformer can regulate enantioselectivity in crystalline materials, guiding the purification of chiral racemic compounds via the cocrystallization method and the design of solid-solution crystalline materials.

A mixed phosphine sulfide/selenide structure as an instructional example for how to evaluate the quality of a model

This paper compares variations on a structure model derived from an X-ray diffraction data set from a solid solution of chalcogenide derivatives of cis-1,2-bis-(di-phenyl-phosphan-yl)ethyl-ene, namely, 1,2-(ethene-1,2-di-yl)bis-(di-phenyl-phoshpine sulfide/selenide), C26H22P2S1.13Se0.87. A sequence of processes are presented to ascertain the composition of the crystal, along with strategies for which aspects of the model to inspect to ensure a chemically and crystallographically realistic structure. Criteria include mis-matches between F obs 2 and F calc 2, plots of |F obs| vs |F calc|, residual electron density, checkCIF alerts, pitfalls of the OMIT command used to suppress ill-fitting data, comparative size of displacement ellipsoids, and critical inspection of inter-atomic distances. Since the structure is quite small, solves easily, and presents a number of readily expressible refinement concepts, we feel that it would make a straightforward and concise instructional piece for students learning how to determine if their model provides the best fit for the data and show students how to critically assess their structures.

Syntheses, crystal structures and Hirshfeld surface analyses of N-aryl-sulfonyl derivatives of cytisine

By aryl-sulfonyl-ation of cytisine in the presence of tri-ethyl-amine, three new compounds have been obtained in good yields: (7R,9R)-N-[(4-ethyl-phen-yl)sulfon-yl]cytisine, C19H22N2O3S (I) {systematic name: (1R,5R)-3-[(4-ethyl-phen-yl)sulfon-yl]-1,2,3,4,5,6-hexa-hydro-8H-1,5-methano-pyrido[1,2-a][1,5]diazo-cin-8-one}, (7R,9R)-N-[(4-chloro-phen-yl)sulfon-yl]cytisine, C17H17ClN2O3S (II) {systematic name: (1R,5R)-3-[(4-chloro-phen-yl)sulfon-yl]-1,2,3,4,5,6-hexa-hydro-8H-1,5-methano-pyrido[1,2-a][1,5]diazo-cin-8-one} and (7R,9R)-N-[(3-nitro-phen-yl)sulfon-yl]cytisine, C17H17N3O5S (III) {systematic name: (1R,5R)-3-[(3-nitro-phen-yl)sulfon-yl]-1,2,3,4,5,6-hexa-hydro-8H-1,5-methano-pyrido[1,2-a][1,5]diazo-cin-8-one}. The crystal structures of the compounds were determined on the basis of single-crystal X-ray diffraction data. The crystal structures of (I)-(III) are distinguished by the arrangement of two fragments of the mol-ecule around the sulfonyl site. For all structures, weak C-H⋯O hydrogen bonds are developed. Hirshfeld surface analysis shows that H⋯H (for I and II) and H⋯O/O⋯H (for III) inter-actions make the most important contribution to the crystal packing.

The crystal structure of catena–poly[aqua(1-naphthoato-κ 2 O,O′)-(μ-1-naphthoato-κ 4 O:O,O′:O′)lead(II)], C22H16O5Pb

C22H16O5Pb, orthorhombic, P212121 (no. 19), a = 7.3395(8) Å, b = 10.7768(11) Å, c = 23.034(3) Å, V = 1821.9(3) Å3, Z = 4, R gt(F) = 0.0327, wR ref(F 2) = 0.0735, T = 296(2) K.

Screening a small hydrazide-hydrazone combinatorial library for targeting the STAT3 in monocyte-macrophages with insulated reporter transposons

The Signal Transducer and Activator of Transcription 3 (STAT3) pharmacological targeting is regarded as a prospective approach to treat cancer, autoimmune disorders, or inflammatory diseases. We have developed a series of reporters of the STAT3, NF-κB, Nrf2, metal-responsive transcription factor-1 (MTF-1), and hypoxia-inducible factor 1α (HIF-1α) transcriptional activation in human monocyte-macrophage line THP-1. The reporter lines were employed to test a set of hydrazide-hydrazones as potential STAT3 inhibitors. A hydrazide-hydrazone library composed of 70 binary combinations of 7 carbonyl and 10 hydrazide components, including a STAT3 inhibitor clinical drug nifuroxazide, has been assembled and screened by the reporters. For the library as a whole, significant correlations between responses of the STAT3 and NF-κB or the STAT3 and HIF-1α reporters in THP-1 monocytes were found. For selected inhibitory combinations, respective hydrazide-hydrazones have been prepared and tested individually. The most potent 2-acetylpyridine 4-chlorobenzoylhydrazone exhibited the STAT3 inhibitory potential significantly exceeding that of nifuroxazide (ED50 2 vs 50 μM respectively) in THP-1 cells. We conclude that insulated reporter transposons could be a useful tool for drug discovery applications.

Graphical Abstract

Benzyl-hexa-decyl-dimethyl-ammonium chloride dihydrate

The title compound, C25H46N+·Cl-·2H2O, crystallizes in the space group P21 with one organic mol-ecule in the asymmetric unit. The compound belongs to a class of benzalkonium chlorides (BACs) with an alkyl chain length of 16 carbon atoms in an all-trans conformation.

Crystal structure of dimethyl 4,4′-((4R, 5R)-4,5-diphenylimidazolidine-1,3-diyl)dibenzoate, C31H28N2O4

C31H28N2O4, monoclinic, P21 (no. 4), a = 10.2166(2) Å, b = 11.5327(2) Å, c = 11.6484(2) Å, β = 109.637(2)°, V = 1292.65(5) Å3, Z = 2, R gt (F) = 0.0502, wR ref (F 2) = 0.1312, T = 149.9(5) K.

Structures of S-(pyridin-2-yl) 4-nitro-benzo-thio-ate, S-(pyridin-2-yl) 4-methyl-benzo-thio-ate and S-(pyridin-2-yl) 4-meth-oxy-benzo-thio-ate: building blocks for low-symmetry multifunctional tetra-pyrroles

The crystal structures of three S-(pyridin-2-yl) benzo-thio-esters with varying para-phenyl substituents are presented, namely, S-(pyridin-2-yl) 4-nitro-benzo-thio-ate (1, C12H8N2O3S), S-(pyridin-2-yl) 4-methyl-benzo-thio-ate (2, C13H11NO2S) and S-(pyridin-2-yl) 4-meth-oxy-benzo-thio-ate (3, C13H11NO2S). This class of compounds are used in the mono-acyl-ation of pyrrolic species to yield multifunctional tetra-pyrroles. The structures presented herein are the first of their compound class. The dominant inter-actions present in this series are π-π stacking and C-H⋯O inter-actions, and as the para-phenyl motif changes from electron withdrawing (NO2, 1) to electron donating (OCH3, 3), changes are observed in the inter-actions present in the crystal packing, from predominant π-π stacking in 1 to exclusively C-H⋯O/N inter-actions (Car-yl-H⋯Ocarbon-yl, C-H⋯Ometh-oxy and Car-yl-H⋯Npyridine) in 3.

Diisopropyl 2-[(4-nitro-benzo-yl)amino]-propane-dioate

The title compound, C16H20N2O7, crystallizes in the space group C2 with two mol-ecules in the asymmetric unit. The crystal packing shows O⋯π inter-actions between the two mol-ecules.

Crystal structures of two 1,2,3,4-tetra-hydro-naphthalenes obtained during efforts towards the total synthesis of elisabethin A

The two substituted 1,2,3,4-tetra-hydro-naphthalenes, methyl (R)-3-{(1R,4S)-6-meth-oxy-4,7-dimethyl-5,8-bis-[(triiso-propyl-sil-yl)-oxy]-1,2,3,4-tetra-hydro-naph-th-al-en-1-yl}butano-ate, C36H66O5Si2, (2), and methyl (E)-3-{(1R,4S)-8-hy-droxy-6-meth-oxy-4,7-dimethyl-5-[(triiso-propyl-sil-yl)-oxy]-1,2,3,4-tetra-hydro-naphthalen-1-yl}acrylate, C26H42O5Si, (8), crystallize in the Sohncke space groups P212121 and P21, respectively, with the absolute structure determined on the basis of anomalous dispersion effects. The configurations of the stereo centres in the 1,2,3,4-tetra-hydro-naphthalene moiety of (2) and (8) are the same, and the conformation of the non-aromatic part of the ring system is nearly identical. In the crystal of (2), weak non-classical C-H⋯O inter-actions consolidate the packing, whereas in (8), inter-molecular O-H⋯O hydrogen-bonding inter-actions of medium-to-weak strength direct the mol-ecules into Z-shaped strands extending parallel to [010].

Crystal structures of 4-(2/3-meth-oxy-phen-oxy)phthalo-nitrile

The syntheses and crystal structures are reported of 4-phen-oxy-substituted phthalo-nitriles with meth-oxy groups in the ortho- and meta-positions of the terminal benzene rings, respectively, namely, 4-(2-meth-oxy-phen-oxy)phthalo-nitrile and 4-(3-meth-oxy-phen-oxy)phthalo-nitrile, both C15H10N2O2. The https://journals.iucr.org/e/issues/2023/03/00/mol-ecular structure was determined using the single-crystal X-ray diffraction method. It is shown that short contacts play a more decisive role in the mol-ecular packing compared to van der Waals inter-actions.

Solid-state versatility in tranexamic acid drug: structural and thermal behavior of new salts and cocrystals

Tranexamic acid (TNA) is an anti-fibrinolytic hemostatic drug widely used in various medical treatments. Six new salts and five cocrystals of TNA are reported here and the crystal structures of the obtained multicomponent compounds were determined using single-crystal X-ray diffraction (SC-XRD) techniques. TNA formed salts with coformers maleic acid (MEA), nicotinic acid, DL-mandelic acid and saccharin. Salt formation with MEA resulted in three different solid forms, namely TNA-MEA (1:1), TNA-MEA (2:1) and TNA-MEA-H₂O (1:1:1). All synthesized TNA salt structures were crystallized as anhydrous except for TNA-MEA-H₂O (1:1:1). TNA formed cocrystals with phenolic coformers such as catechol (CAT), resorcinol, hydroquinone, pyrogallol (PRG) and phloroglucinol. All cocrystal structures crystallized as hydrates except for TNA-PRG (1:1). The detailed structural investigation using SC-XRD revealed the presence of robust N-H...O and O-H...O hydrogen bonds in TNA salts and cocrystals. In TNA cocrystals, except for TNA-CAT-H₂O (1:1:1), the coformer molecules interact with TNA molecules via bridged water molecules. In all the salt structures, TNA exists as cations, in which both carboxylic and amino groups are protonated (-COOH and -NH₃⁺), while in cocrystals TNA exists as zwitterions with total charge zero. All synthesized multicomponent compounds were further characterized by differential scanning calorimetric, thermogravimetric and Fourier transform infrared analyses, and the formation of new multicomponent compounds were assessed based on the melting temperatures, percentage weight loss and stretching frequencies, respectively, corresponding to TNA/coformer molecules. A powder X-ray diffraction study confirmed the bulk purity of the synthesized crystalline multicomponent compounds.

Crystal structure of dimethyl 4,4′-(((1R, 2R)-cyclohexane-1,2-diyl)bis(azanediyl))dibenzoate, C22H26N2O4

C22H26N2O4, trigonal, P32 (no. 145), a = 8.0196(2) Å, c = 26.2366(5) Å, V = 1461.31(8) Å3, Z = 3, R gt(F) = 0.0290, wR ref(F 2) = 0.0829, T = 149.99(10) K.

Syntheses and crystal structures of bis-(4-methyl-pyridine-κN)bis-(seleno-cyanato-κN)zinc(II) and catena-poly[[bis-(4-methyl-pyridine-κN)cadmium(II)]-di-μ-seleno-cyanato-κ2 N:Se;κ2 Se:N]

The reactions of Zn(NO3)2 .6H2O and Cd(NO3)2 .4H2O with KSeCN and 4-meth-yl-pyridine (C6H7N; 4-picoline) lead to the formation of crystals of bis-(4-methyl-pyridine-κN)bis-(seleno-cyanato-κN)zinc(II), [Cd(NCSe)2(C6H7N)2] (1), and catena-poly[[bis-(4-methyl-pyridine-κN)cadmium(II)]-di-μ-seleno-cyanato-κ2 N:Se;κ2 Se:N], [Cd(NCSe)2(C6H7N)2] n (2), suitable for single-crystal X-ray diffraction. The asymmetric unit of compound 1 consists of one Zn cation that is located on a twofold rotation axis as well as one seleno-cyanate anion and one 4-methyl-pyridine ligand in general positions. The Zn cations are tetra-hedrally coordinated by two terminal N-bonding thio-cyanate anions and two 4-methyl-pyridine ligands, forming discrete complexes. The asymmetric unit of compound 2 consists of two crystallographically independent Cd cations, of which one is located on a twofold rotation axis and the second on a center of inversion, as well as two crystallographically independent seleno-cyanate anions and two crystallographically independent 4-methyl-pyridine ligands in general positions. The Cd cations are octa-hedrally coordinated by two N- and two S-bonding seleno-cyanate anions and two 4-methyl-pyridine ligands and are linked into chains by pairs of seleno-cyanate anions. Within the chains, the Cd cations show an alternating cis-cis-trans and all-trans coordination and therefore, the chains are corrugated. PXRD investigations prove that the Zn compound was obtained as a pure phase and that the Cd compound contains a very small amount of an additional and unknown phase. In the IR spectrum of 1, the CN stretching vibration of the seleno-cyanate anion is observed at 2072 cm-1, whereas in the 2 it is shifted to 2094 cm-1, in agreement with the crystal structures.

2-Bromo-6-hydrazinyl-pyridine

The title compound, C5H6BrN3, crystallizes in the ortho-rhom-bic space group P212121 with two mol-ecules with different conformations in the asymmetric unit. In the crystal, N-H⋯N and bifurcated N-H⋯(N,N) hydrogen bonds link the mol-ecules into [100] chains; a short Br⋯Br halogen bond and π-π stacking inter-actions are also observed.

The crystal structure of 3-hydroxy-2-nitroestra-1,3,5(10)-trien-17-one, C18H21NO4

C18H21NO4, orthorhombic, C2221 (no. 20), a = 10.6891(2) Å, b = 11.8375(2) Å, c = 25.4410(4) Å, V = 3219.11(10) Å3, Z = 8, R gt(F) = 0.0483, wR ref(F 2) = 0.1449, T = 295 K.

Novel Camphor Sulfonohydrazide and Sulfonamide Derivatives as Potential Succinate Dehydrogenase Inhibitors against Phytopathogenic Fungi/Oomycetes

To discover novel fungicidal agrochemicals for treating wheat scab, 39 novel camphor sulfonohydrazide/sulfonamide derivatives 4a-4t and 6a-6s were designed and synthesized. In the in vitro antifungal/antioomycete assay, compounds 4g, 4n, and 4o displayed significant inhibitory activities against Fusarium graminearum, Botryosphaeria dothidea, and Phytophthora capsici. Among them, 4n exhibited the best antifungal activity against F. graminearum with an EC₅₀ value of 0.41 mg/L, which was at the same level as that of pydiflumetofen. The in vivo experiment revealed that 4n presented excellent protective and curative efficacy toward F. graminearum. In the antifungal mechanism study, 4n could increase the cell membrane permeability and reduce the exopolysaccharide and ergosterol content of F. graminearum. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses revealed that 4n could significantly damage the surface morphology and the cell ultrastructure of mycelia to interfere with the growth of F. graminearum. Furthermore, 4n exhibited potent succinate dehydrogenase (SDH) inhibitory activity in vitro with an IC₅₀ value of 3.94 μM, which was equipotent to pydiflumetofen (IC₅₀ = 4.07 μM). The molecular dynamics simulation and docking study suggested that compound 4n could well occupy the active site and form strong interactions with the key residues of SDH. The above-mentioned results demonstrated that the title camphor sulfonohydrazide/sulfonamide derivatives could be promising lead compounds for further succinate dehydrogenase inhibitor (SDHI) fungicide development.

N-Heterocyclic Carbene-Iridium Complexes as Photosensitizers for In Vitro Photodynamic Therapy to Trigger Non-Apoptotic Cell Death in Cancer Cells

A series of seven novel iridium complexes were synthetized and characterized as potential photosensitizers for photodynamic therapy (PDT) applications. Among them, four complexes were evaluated in vitro for their anti-proliferative activity with and without irradiation on a panel of five cancer cell lines, namely PC-3 (prostate cancer), T24 (bladder cancer), MCF7 (breast cancer), A549 (lung cancer) and HeLa (cervix cancer), and two non-cancerous cell models (NIH-3T3 fibroblasts and MC3T3 osteoblasts). After irradiation at 458 nm, all tested complexes showed a strong selectivity against cancer cells, with a selectivity index (SI) ranging from 8 to 34 compared with non-cancerous cells. The cytotoxic effect of all these complexes was found to be independent of the anti-apoptotic protein Bcl-xL. The compound exhibiting the best selectivity, complex 4a, was selected for further investigations. Complex 4a was mainly localized in the mitochondria. We found that the loss of cell viability and the decrease in ATP and GSH content induced by complex 4a were independent of both Bcl-xL and caspase activation, leading to a non-apoptotic cell death. By counteracting the intrinsic or acquired resistance to apoptosis associated with cancer, complex 4a could be an interesting therapeutic alternative to be studied in preclinical models.

Crystal structures of rac-2,3-diphenyl-2,3,5,6-tetra-hydro-4H-1,3-thia-zine-1,1,4-trione and N-[(2S,5R)-1,1,4-trioxo-2,3-diphenyl-1,3-thia-zinan-5-yl]acet-amide

The syntheses and crystal structures of two thia-zinone compounds, namely, rac-2,3-diphenyl-2,3,5,6-tetra-hydro-4H-1,3-thia-zine-1,1,4-trione, C16H15NO3S, in its racemic form, and N-[(2S,5R)-1,1,4-trioxo-2,3-diphenyl-1,3-thia-zinan-5-yl]acet-amide, C18H18N2O4S, in an enanti-opure form, are reported. The thia-zine rings in the two structures differ in their puckering, as a half-chair in the first and a boat pucker in the second. The extended structures for both compounds have only C-H⋯O-type inter-actions between symmetry-related mol-ecules, and exhibit no π-π stacking inter-actions in spite of each having two phenyl rings.

Crystal structure of a new europium(III) compound based on thio-phene-acrylic acid

A europium(III) coordination compound based on thio-phene-acrylic acid (Htpa), tri-aqua-tris-[3-(thio-phen-2-yl)prop-2-enoato-κ2 O,O']europium(III)-3-(thio-phen-2-yl)prop-2-enoic acid (1/3), [Eu(C7H5O2S)3(H2O)3]·3C7H6O2S or [Eu(tpa)3(H2O)3]·3(Htpa) (1), where tpa is the conjugate base of Htpa, has been synthesized and structurally characterized. Compound 1 crystallizes in the trigonal space group R3. The structure of 1 consists of a discrete mol-ecular complex [Eu(tpa)3(H2O)3] species and the Htpa mol-ecule. In the crystal, the two components are involved in O-H⋯O [ring motif R 2 2(8)] and C-H⋯π hydrogen-bonding inter-actions. These inter-actions were further investigated by Hirshfeld surface analysis, which showed high contributions of H⋯H, H⋯C/C⋯H and H⋯O/O⋯H contacts to the total Hirshfeld surfaces.

Bioactive icetexane and abietane diterpenes from Isodon phyllopodus

A new icetexane diterpenoid, 11, 12, 20α-trihydroxyl-7β-methoxyicetexa-8, 11, 13-triene-19, 10-lactone [Phyllane A (1)], and a new abietane diterpenoid, 7β, 20-epoxy-3β, 17-acetoxy-abieta-8, 11, 13-teriene-11, 12-diol [phyllane B (2)], along with two known compounds (3 and 4) were isolated from the methanol (MeOH) extract of twigs and leaves of the folk medicinal Isodon phyllopodus. Their structures were determined by spectroscopic analyses including 2 D NMR spectral data, and further confirmed by X-ray single crystal diffraction. Moreover, the compounds were evaluated for their cytotoxicity and anti-HIV activities, and phyllane A showed anti-HIV activity with an IC₅₀ value of 15.7 μM, but phyllane B was found to be cytotoxic to the A549 host cells with a CC₅₀ value of 108.5 μM.

(S)-2-[(S)-2,2,2-Tri-fluoro-1-hy-droxy-eth-yl]-1-tetra-lone

The crystal structure of the title compound, C12H11F3O2, was elucidated by low-temperature single-crystal X-ray diffraction. The enanti-opure compound crystallizes in the Sohncke space group P21 and features one mol-ecule in the asymmetric unit. The structure displays inter-molecular O-H⋯O hydrogen bonding, which links the mol-ecules into infinite chains propagating parallel to [010]. The absolute configuration was established from anomalous dispersion.