Macrocyclic diterpenoid esters from Euphorbiaceae plants hold significant medicinal value owing to their structural diversity and for attributing structural uniqueness and biological efficacy. However, the responsible enzymes for the acylation of macrocyclic diterpenoids remain unknown. We identified two macrocyclic diterpenoid O-acyltransferases, ElBAHD16 and ElBAHD35, from the diterpene biosynthetic gene cluster of Euphorbia lathyris. ElBAHD16 and ElBAHD35 were characterized both in vitro (using Escherichia coli) and in vivo (using Nicotiana benthamiana and E. lathyris) and exhibited mono-acylation activities toward the hydroxy groups of their substrates, 7-hydroxylathyrol and lathyrol. ElBAHD16 showed not only regioselectivity toward the 7-OH group of 7-hydroxylathyrol but also donor promiscuity, thereby producing three different mono-acylation products. Conversely, ElBAHD35 demonstrated specific recognition for the 5-OH group of 7-hydroxylathyrol and lathyrol, thereby mediating mono-acetylation reactions with acetyl-CoA, showing donor specificity. Site-directed mutagenesis revealed that residues H154 and T363 in ElBAHD16 are critical for its catalytic activity. Notably, the Q35 residue enhanced the efficiency of ElBAHD16, while the M296, N292, and F394 residues were crucial for its donor promiscuity. These findings elucidate the last step in the biosynthesis of macrocyclic diterpenoid esters and highlight the contribution of acyltransferases to the structural diversity of diterpenoids.

ETHYLENE-INSENSITIVE 3/ETHYLENE-INSENSITIVE 3-LIKEs (EIN3/EILs) are important ethylene response factors during fruit ripening. Here, we discovered that EIL2 controls carotenoid metabolism and ascorbic acid (AsA) biosynthesis in tomato (Solanum lycopersicum). In contrast to the red fruits presented in the wild type (WT) 45 d after pollination, the fruits of CRISPR/Cas9 eil2 mutants and SlEIL2 RNA interference lines (ERIs) showed yellow or orange fruits. Correlation analysis of transcriptome and metabolome data for the ERI and WT ripe fruits revealed that SlEIL2 is involved in β-carotene and AsA accumulation. ETHYLENE RESPONSE FACTORs (ERFs) are the typical components downstream of EIN3 in the ethylene response pathway. Through a comprehensive screening of ERF family members, we determined that SlEIL2 directly regulates the expression of 4 SlERFs. Two of these, SlERF.H30 and SlERF.G6, encode proteins that participate in the regulation of LYCOPENE-β-CYCLASE 2 (SlLCYB2), encoding an enzyme that mediates the conversion of lycopene to carotene in fruits. In addition, SlEIL2 transcriptionally repressed L-GALACTOSE 1-PHOSPHATE PHOSPHATASE 3 (SlGPP3) and MYO-INOSITOL OXYGENASE 1 (SlMIOX1) expression, which resulted in a 1.62-fold increase of AsA via both the L-galactose and myoinositol pathways. Overall, we demonstrated that SlEIL2 functions in controlling β-carotene and AsA levels, providing a potential strategy for genetic engineering to improve the nutritional value and quality of tomato fruit.

Due to the increasing food safety issues, developing a rapid, efficient, and low-cost method for evaluating food quality has attracted worldwide attention. Herein, a novel “turn off-on” sensor based on fluorescein 5-isothiocyanate (5-FITC) was constructed for sensitive and visual detection of biogenic amines (BAs). The fluorescence of 5-FITC was found to be quenched in the presence of lignin-based porous carbon microspheres. And then, upon addition of BAs, 5-FITC was released from the surface of lignin-based porous carbon microspheres, which resulted in the fluorescence recovery of 5-FITC. The sensor exhibited outstanding performances for detecting BAs with a detection limit of µM level and a fast response time of less than 20 s. Furthermore, a test paper was fabricated for the visual detection of BAs in the spoilage process of shrimps and pork based on distinct fluorescence changes. It proved the capacity of the sensor for real-time and cost-effective detection of BAs.

The DREB transcription factors regulate multiple stress response genes, and are therefore useful for molecular plant breeding. AhDREB, a stress-inducible gene, was isolated from Atriplex hortensis L. and introduced into Populus tomentosa Carrière under the control of the CaMV35S promoter. Under salt stress, the chlorophyll content and net photosynthetic rate were higher in transgenic lines than in the wild type (WT). Moreover, the rate of electrolyte penetration (REC) was lower in the transgenic lines. Additional analyses revealed that the AhDREB transgenic plants generally displayed lower malondialdehyde (MDA) activity but higher superoxide dismutase (SOD) and peroxidase (POD) activities and proline content than the WT under salt stress. RNA sequencing indicated that AhDREB could enhance tolerance to salt by activating various downstream genes in the transgenic plants. Furthermore, no growth inhibition was detected in transgenic plants expressing AhDREB driven by the constitutive CaMV35S promoter. The transcriptome showed 165 and 52 differentially expressed genes in transgenic plants under stress and non-stress conditions, respectively, among which no significant metabolic pathway was enriched and no unintended effects have yet been identified. Together, these results suggest that AhDREB may be a good candidate gene for increasing salt tolerance in transgenic poplar breeding.

The ytterbium ferrites nanocrystalline powders were prepared by sol–gel method, followed by the subsequent annealing, which exhibit considerable response to acetone gas. The ytterbium ferrite crystallizes as mixed phases of YbFeO3-Yb2Fe3O7 when annealed at 700°C and 800°C, but as single phase YbFeO3 annealed at 900°C, respectively. When exposed to acetone gas, the resistance increases for p-type YbFeO3 but decreases for mixed phases of YbFeO3-Yb2Fe3O7. The sensing properties for YbFeO3-Yb2Fe3O7 may be mainly associated with the charge order (CO) state of Yb2Fe3O7. The maximum sensitivities to 1 and 3ppm acetone gas in the background of air (with the room temperature humidity 33% RH) for sensor based on YbFeO3- Yb2Fe3O7 (withTA=800°C) are about 1.21 and 1.42 respectively at optimal operating temperature of 250°C. The appropriate replacement of Yb by Ca (about 20 at.%) in YbFeO3 annealed at 900°C not only decreases the resistance but also enhances the sensing response greatly. With increase of room temperature humidity, the sensing response of Yb0.8Ca0.2FeO3 sensor increases. The response for Yb0.8Ca0.2FeO3 in the background of air (with the room temperature humidity 90% RH) at its optimal temperature of 230°C is 2.1, 3.9, 4.3, 9.5 and 15.0–0.1, 0.3, 0.5, 1 and 3ppm acetone gas, respectively. Yb0.8Ca0.2FeO3 sensor may be a promising candidate for developing a breath analysis technique for monitoring diabetes. The sensing mechanisms of ytterbium ferrites to acetone are also discussed.

GRAS transcriptional factors have diverse functions in plant growth and development, and are named after the first three transcription factors, namely, GAI (GIBBERELLIC ACID INSENSITIVE), RGA (REPRESSOR OF GAI) and SCR (SCARECROW) identified in this family. Knowledge of the GRAS gene family in maize remains was largely unknown, and their characterization is necessary to understand their importance in the maize life cycle. This study identified 86 GRAS genes in maize, and further characterized with phylogenetics, gene structural analysis, genomic loci, and expression patterns. The 86 GRAS genes were divided into 8 groups (SCL3, HAM, LS, SCR, DELLA, SHR, PAT1 and LISCL) by phylogenetic analysis. Most of the maize GRAS genes contain one exon (80.23%) and closely related members in the phylogenetic tree had similar structure and motif composition. Different motifs especially in the N-terminus might be the sources of their functional divergence. Segmental- and tandem-duplication occurred in this family leading to expansion of maize GRAS genes and the expression patterns of the duplicated genes in the heat map according to the published microarray data were very similar. Quantitative RT-PCR (qRT-PCR) results demonstrated that the expression level of genes in different tissues were different, suggesting their differential roles in plant growth and development. The data set expands our knowledge to understanding the function of GRAS genes in maize, an important crop plant in the world.

With the view to creating novel sandwich-type phthalocyaninato rare earth complexes toward new applications in material science and catalysis, d- and l-enantiomers of a series of optically active homoleptic bis(phthalocyaninato) rare earth double-deckers with four chiral menthol moieties at the peripheral positions of the phthalocyanine ligand, M(Pc*)(2) [Pc* = 2(3),9(10),16(17),23(24)-tetrakis(2-isopropyl-5-methylcyclohexoxyl)phthalocyanine; M = Eu, Y, Lu] (1-3), have been designed and prepared by treating (d)- or (l)-4-(2-isopropyl-5-methylcyclohexoxyl)-1,2-dicyanobenzene with the corresponding M(acac)(3).nH(2)O (acac = acetylacetonate) in the presence of the organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in refluxing n-pentanol. For the purpose of comparative study, heteroleptic bis(phthalocyaninato) europium analogues (d)- and (l)-Eu(Pc)(Pc*) (4) as well as the unsubstituted homoleptic bis(phthalocyaninato) europium counterpart Eu(Pc)(2) (5) were also prepared. The novel synthesized bis(phthalocyaninato) rare earth double-deckers have been characterized by a wide range of spectroscopic methods including MS, (1)H NMR, IR, and electronic absorption spectroscopic measurements in addition to elemental analysis. In contrast to the CD silent monomeric metal-free 2(3),9(10),16(17),23(24)-tetrakis(2-isopropyl-5-methylcyclohexoxyl)phthalocyanine, observation of the CD signal in the N absorption region of 4 reveals the significant effect of intramolecular pi-pi interaction on intensifying the asymmetrical perturbation of the chiral menthol units onto the phthalocyanine chromophore, which results in successful chiral information transfer from menthol moieties to the phthalocyanine chromophore at a molecular level in the heteroleptic double-decker compound 4 despite the lack of CD signal in the Soret and Q absorption regions of the phthalocyanine ligand. This is further supported by the optical activity of homoleptic bis(phthalocyaninato) rare earth double-deckers M(Pc*)(2) (1-3), as revealed by the CD signals even in the Soret and Q absorption regions according to the CD spectroscopic result, indicating the intensified asymmetrical perturbation of the chiral menthol units onto the phthalocyanine chromophores along with the increase in the chiral menthol substituent number from 4 to 1-3. The present result at the molecular level is helpful for understanding the chiral information transfer mechanism at the supermolecular level. In addition, the electrochemical properties of bis(phthalocyaninato) rare earth complexes have also been comparatively investigated by cyclic voltammetry and differential pulse voltammetry.

The self-assembly behavior of two sandwich-type mixed (phthalocyaninato)(porphyrinato) europium double-decker complexes, namely Eu(Pc)(TClPP) [Pc = phthalocyaninate; TClPP = meso-tetrakis(4-chlorophenyl)porphyrinate] (1) and optically active (R)- and (S)-EuH[Pc(OBNP)(2)](TClPP)] [Pc(OBNP)(2) = phthalocyaninate with two aromatic chiral binaphthayl units attached at the nonperipheral positions] (2), has been comparatively studied. In addition, a hydrophilic additive with intense adhesive ability, sodium carboxymethylcellulose (CMC), was also introduced onto the sandwich-type self-assembly systems to combine with double-decker molecules to induce additional hydrophilic/hydrophobic interaction. In the absence of the additive CMC, the double-decker molecules of 1 self-assemble into nanobelts in mixed solvent of chloroform and methanol. Introduction of two aromatic chiral binaphthayl units onto the nonperipheral positions of phthalocyanine ligand in the sandwich-type mixed double-decker complex 2 leads to the formation of tubal nanostructures. Observation of significant difference in the circular dichroism (CD) spectra of (R)- and (S)-2 in chloroform from their aggregates dispersed in methanol confirms the effective intermolecular interaction due to the interplay of pi-pi interaction between adjacent double-decker molecules with chiral discrimination among chiral side chains at supramolecular level. With addition of CMC, cooperation of intrinsic intermolecular pi-pi interaction with additionally introduced hydrophilic/hydrophobic interaction between adjacent double-decker molecules induces the formation of nanoscale hollow spheres at 45 degrees C during the self-assembly process of 1 and 2.

In the title compound, C(22)H(10)N(4)O(2), the dihedral angles between the mean planes of the central benzene ring and the pendant rings are 79.20 (6) and 80.29 (6)°. The dihedral angle between the pendant rings is 10.27 (7)°.

In the title compound, C22H10N4O2, the dihedral angles between the mean planes of the central benzene ring and the pendant rings are 79.20 (6) and 80.29 (6)°. The dihedral angle between the pendant rings is 10.27 (7)°.

Two novel sandwich-type mixed (phthalocyaninato)(porphyrinato) rare earth double-decker complexes with decreased molecular symmetry of Cs M(Pc)[D(NHC(8)H(17))(2)PP] [M = Eu, Lu; Pc = unsubstituted phthalocyaninate; D(NHC(8)H(17))(2)PP = 5,10-di(phenyl)-15,20-di(4-octylamino-phenyl)porphyrinate] (1, 2) have been designed, prepared, and characterized. The single crystal and molecular structure of the Eu analogue has been determined by X-ray diffraction analysis, revealing the head-to-tail supramolecular chains formed from closely bound double-decker molecules depending on the N-H-N hydrogen bonds between one octyl-substituted amidocyanogen group attached at the p-position of meso-attached phenyl group of the porphyrin ligand in the mixed ring double-decker molecule and one aza-nitrogen atom of the phthalocyanine ring in the neighboring double-decker molecule in a zigzag form. Their self-assembled nano-structures have been investigated by transmission electronic microscopy (TEM) and scanning electronic microscopy (SEM). Intermolecular H-N-H hydrogen bonding interaction leads to the formation of nano-structures with fusiform morphology with 220-250 nm average width and about 10 μm length for 1 and 300 nm width and 3-5 μm length for 2, respectively, revealing the effect of molecular size in the direction perpendicular to the tetrapyrrole ring on the dimensions of self-assembled nano-structures.

(D)- and (L)-enantiomers of a novel metal-free 2(3),9(10),16(17),23(24)-tetrakis(2-isopropyl-5-methylcyclohexoxyl)phthalocyanine (1) with four chiral menthol units attached at the peripheral positions of a phthalocyanine ligand have been synthesized, and characterized. Neither the (D)-1 nor the (L)-1 enantiomer display a circular dichroism (CD) signal in the Soret and Q absorption region of the phthalocyanine ligand, indicating the lack of effective chiral information transfer from the chiral menthol tails to the phthalocyanine chromophore at the molecular level. Their self-assembly properties were systematically studied by CD spectroscopy, transmission electron microscopy, scanning electron microscopy, and atom force microscopy technique. Although four constitutional stereoisomers of each enantiomer were synthesized, because the four chiral menthol substituents are randomly located at peripheral positions of the phthalocyanine ring, cooperation of intermolecular pi-pi interactions between the phthalocyanine rings with chiral discrimination of the chiral side chains of the (D)-1 and the (L)-1 enantiomer induces the formation of one-dimensional helices with left- and right-handed helical molecular arrangement, respectively, according to the CD spectroscopic results. This reveals the effective chiral information transfer from the chiral menthol tails to the phthalocyanine chromophore at the supermolecular level. The formed one-dimensional helices twist around each other to maximize the van der Waals interaction, leading to the formation of highly ordered fibrous nanostructures with both right- and left-handed helicity according to the staggering angles between the neighboring phthalocyanine molecules, indicating the hierarchical formation of these fibrous nanostructures. Careful inspection of these nanofibers indicates the majority of nanofibers with right- and left-handed helicity formed from (D)-1 and (L)-1 enantiomer, respectively, with the ratio of approximately 1.3-1.4:1 among all the fibrous nanostructures obtained. Electronic absorption spectroscopic and X-ray diffraction results reveal the H-aggregate nature of these nanofibers. The present results, showing part of our continuous effort towards preparation of self-assembled nanostructures with helical morphology through molecular design and synthesis, will be helpful on providing new insight into chiral information transfer and expression for synthetic conjugated systems at the supermolecular level.

Reaction between the optically active metal-free phthalocyanine with a pi system with noncentrosymmetrical C(2) [corrected] symmetry ((S)- and (R)-H(2){Pc(OBNP)(2)}; OBNP=binaphthylphthalocyanine) and half-sandwich complexes [M(III)(acac)(TClPP)] (M=Y, Eu; TClPP=meso-tetrakis(4-chlorophenyl)porphyrinate; acac=acetylacetonate), which were generated in situ from [M(acac)(3)].n H(2)O and H(2)(TClPP) in n-octanol at reflux, provided the first optically active protonated mixed phthalocyaninato-porphyrinato rare-earth double-decker complexes [M(III)H{Pc(OBNP)(2)}(TClPP)] (M=Y, Eu) in good yield. In addition to electronic absorption spectroscopy and magnetic circular dichroism results, circular dichroism shows different spectroscopic features of these mixed-ring rare-earth double-decker compounds in different solvents, such as DMF and CHCl(3), which was well-reproduced on the basis of time-dependent density functional theory calculation results for the yttrium species (S)-[Y(III){Pc(OBNP)(2)}(Por)](-) (Por=porphyrinate, which is obtained by removing the four chlorophenyl groups from the TClPP ligand) in terms of the change in the rotation angle between the two macrocyclic ligands in the double-decker molecules. These results revealed the solvent-dependent nature of the molecular conformation of mixed-ring rare-earth double-decker complexes, which suggests a new way of tuning the optical and the electrochemical properties of sandwich-type bis(tetrapyrrole)-metal double-decker complexes in solution by changing the solvent.

Optically active metal-free phthalocyanine (1) decorated with four octyl chains linked through binaphthyl units to the phthalocyanine ring was designed and prepared. This compound was characterized by a wide range of spectroscopic methods in addition to elemental analysis. By employing a solution injection method, both the (R) and (S) enantiomers self-assemble into nanoparticles. Surprisingly, with the addition of a small amount of cetyltrimethylammonium bromide (CTAB), nanostructures with hollow-sphere morphologies were formed. The hollow-spherical structure was determined by transmission electronic microscopy and scanning electronic microscopy. X-ray photoelectron spectroscopy together with FTIR spectra indicates the supramolecular structures formed from the metal-free phthalocyanine molecules. Low-angle X-ray diffraction reveals the stacked phthalocyanine molecules with a face-to-face configuration in the nanoscale hollow spheres formed with the help of CTAB surfactant. The formation of H-aggregates in the nanoscale hollow spheres is further confirmed by electronic absorption spectroscopic result. This work, representing the first example of controllable organic nanostructures with a hollow sphere morphology fabricated from phthalocyanine provides an effective method towards phthalocyanine hollow nanospheres. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)