Nootkatone attenuates airway inflammation in asthmatic mice through repressing ROS-induced NLRP3 inflammasome activation.

Nootkatone (NKT) exhibits potential pharmacological activities including anti-oxidation and anti-inflammation. Nevertheless, little is known about the roles of NKT in asthmatic airway inflammation. In the study, mice were sensitized and challenged with ovalbumin (OVA) to establish experimental allergic asthma model. After treatment with NKT, lung tissues, peripheral blood, and bronchoalveolar lavage fluid (BALF) were collected to assess inflammatory cytokines, oxidative stress, and pathological alternations. The effects of NKT on regulating reactive oxygen species (ROS)-induced NLR family pyrin domain containing 3 (NLRP3) inflammasome activation was assessed in IL-13-treated BEAS-2B cell model. We found that NKT treatment decreased the production of Th2 inflammatory cytokines (IL-4, IL-5, and IL-13) in BALF and IgE levels in serum, and alleviated inflammatory cell penetration, goblet cell proliferation, collagen accumulation, and mucus hypersecretion in lung tissues. NKT treatment mitigated oxidative stress and NLRP3 inflammasome activation in asthmatic mice. IL-13 treatment induced oxidative stress and NLRP3-mediated pyroptosis in BEAS-2B bronchial epithelial cells, whereas these effects were blocked by NKT. NKT protected against airway remodeling, as indicated by decreased epithelial-mesenchymal transition. Taken together, these results demonstrate that NKT mitigates asthmatic airway inflammation by inhibiting ROS-triggered NLRP3 activation and may be a potential agent for treating asthma.

Microindolinone A, a Novel 4,5,6,7-Tetrahydroindole, from the Deep-Sea-Derived Actinomycete Microbacterium sp. MCCC 1A11207.

A novel indole, microindolinone A (1), was isolated from a deep-sea-derived actinomycete Microbacterium sp. MCCC 1A11207, together with 18 known compounds (2-19). By detailed analysis of the ¹H, 13C, HSQC, COSY, HMBC, high resolution electron spray ionization mass spectrum (HRESIMS), and circular dichroism (CD) data, the absolute configuration of 1 was elucidated as 5R-hydroxy-4,5,6,7-tetrahydroindole-4-one. It is noteworthy that 1 is the second example of a saturated indole isolated from nature.

Association of TCM body constitution with insulin resistance and risk of diabetes in impaired glucose regulation patients.

BACKGROUND: Impaired glucose regulation (IGR) patients have increased risk of type 2 diabetes mellitus (T2DM). Identifying relevant risk factors in IGR subjects could facilitate early detection and prevention of IGR progression to diabetes. This study investigated the association between Traditional Chinese Medicine (TCM) body constitution and serum cytokines, and whether body constitution could independently predict diabetes in IGR subjects. METHOD: Patients with IGR (n = 306) received a blood test and their body constitution type was assessed using a body constitution questionnaire (BCQ). Serum levels of cytokines were measured by ELISA. Patients were followed up for at least three years, and their status of diabetes were recorded. Multivariate logistic regression was used to estimate odds ratios (ORs) of diabetes for body constitution. RESULTS: Phlegm-damp, Damp-heat and Qi-deficiency were three most common unbanlenced constitutions among IGR subjects. Phlegm-damp and Damp-heat constitution subjects showed higher serum levels of interleukin 6 (IL-6), tumour necrosis factor-α (TNF-α), leptin and lower serum levels of adiponectin (P<0.05). Qi-deficiency constitution subjects showed higher serum levels of leptin and lower serum levels of adiponectin, glucagon-like peptide-1 (GLP-1) and gastric inhibitory polypeptide (GIP) (P<0.05). Subjects with Phlegm-damp or Damp-heat constitution demonstrated a significantly higher risk of diabetes (P<0.05). CONCLUSION: Phlegm-damp and Damp-heat TCM body constitution are strongly associated with abnormal serum cytokines, and could potentially serve as a predictor of diabetes in IGR subjects. Body constitution can help to identify IGR subjects who are at a high risk of progression to diabetes.

[The Use of FTIR Coupled with Partial Least Square for Quantitative Analysis of the Main Composition of Bamboo/Polypropylene Composites].

The biomass to plastic ratio in wood plastic composites (WPCs) greatly affects the physical and mechanical properties and price. Fast and accurate evaluation of the biomass to plastic ratio is important for the further development of WPCs. Quantitative analysis of the WPC main composition currently relies primarily on thermo-analytical methods. However, these methods have some inherent disadvantages, including time-consuming, high analytical errors and sophisticated, which severely limits the applications of these techniques. Therefore, in this study, Fourier Transform Infrared (FTIR) spectroscopy in combination with partial least square (PLS) has been used for rapid prediction of bamboo and polypropylene (PP) content in bamboo/PP composites. The bamboo powders were used as filler after being dried at 105 degrees C for 24 h. PP was used as matrix materials, and some chemical regents were used as additives. Then 42 WPC samples with different ratios of bamboo and PP were prepared by the methods of extrusion. FTIR spectral data of 42 WPC samples were collected by means of KBr pellets technique. The model for bamboo and PP content prediction was developed by PLS-2 and full cross validation. Results of internal cross validation showed that the first derivative spectra in the range of 1 800-800 cm(-1) corrected by standard normal variate (SNV) yielded the optimal model. For both bamboo and PP calibration, the coefficients of determination (R2) were 0.955. The standard errors of calibration (SEC) were 1.872 for bamboo content and 1.848 for PP content, respectively. For both bamboo and PP validation, the R2 values were 0.950. The standard errors of cross validation (SECV) were 1.927 for bamboo content and 1.950 for PP content, respectively. And the ratios of performance to deviation (RPD) were 4.45 for both biomass and PP examinations. The results of external validation showed that the relative prediction deviations for both biomass and PP contents were lower than ± 6%. FTIR combined with PLS can be used for rapid and accurate determination of bamboo and PP content in bamboo/PP composites.

[Quantification of Wood Flour and Polypropylene in Chinese Fir/Polypropylene Composites by FTIR].

The ratio of wood and plastic in Wood Plastic Composites (WPCss) influences quality and price, but traditional thermochemical methods cannot rapidly and accurately quantify the ratio of wood/PP in WPCss. This paper was addressed to investigate the feasibility of quantifying the wood flour content and plastic content in WPCss by Fourier Transform Infrared (FTIR) spectroscopy. With Chinese fir, polypropylene (PP) and other additives as raw materials, 13 WPCs samples with different wood flour contents, ranging from 9.8% to 61.5%, were prepared by modifying wood flour, mixing materials and extrusion pelletizing. The samples were analyzed by FTIR with the KBr pellets technique. The absorption peaks of WPCss at 1059, 1 033 and 1 740 cm(-1) are considered as characteristic of Chinese fir, and the absorption peaks at 1 377, 2 839 and 841 cm(-1) are typical of PP by comparing the spectra of WPCss with that of Chinese fir, PP and other additives. The relationship between the wood flour content, PP content in WPCss and their characteristic IR peaks height ratio was established. The results show that there is a strong linear correlation between the wood flour content in WPCss and I1 059/l 1 377/I1 033, /I1377, R2 are 0.992 and 0.993 respectively; there is a high linear correlation between the PP content in WPCss and I1 377/I1 740, I2 839 /I1 740 R2 are 0.985 and 0.981, respectively. Quantitative methods of the wood flour content and PP content in WPCss by FTIR were developed, the predictive equations of the wood flour content in WPCss are y = 53.297x-9. 107 and y = 55.922x-10.238, the predictive equations of the PP content in WPCss are y = 6.828 5x+5.403 6 and y = 8.719 7x+3.295 8. The results of the accuracy test and precision test show that the method has strong repeatability and high accuracy. The average prediction relative deviations of the wood flour content and PP content in WPCss are about 5%. The prediction accuracy has been improved remarkably, compared to thermochemical methods. More importantly, FTIR is more easy-handing. This experiment may provide a simple, rapid and accurate method for quantification of wood flour and PP in Chinese fir/PP composites.

[Secondary metabolites from a deep-sea-derived actinomycete Micrococcus sp. R21].

To investigate cytotoxic secondary metabolites of Micrococcus sp. R21, an actinomycete isolated from a deep-sea sediment (-6 310 m; 142 degrees 19. 9' E, 10 degrees 54. 6' N) of the Western Pacific Ocean, column chromatography was introduced over silica gel, ODS, and Sephadex LH-20. As a result, eight compounds were obtained. By mainly detailed analysis of the NMR data, their structures were elucidated as cyclo(4-hydroxy-L-Pro-L-leu) (1), cyclo(L-Pro-L-Gly) (2), cyclo( L-Pro-L-Ala) (3), cyclo( D-Pro-L-Leu) (4), N-ß-acetyltryptamine (5), 2-hydroxybenzoic acid (6), and phenylacetic acid (7). Compound 1 exhibited weak cytotoxic activity against RAW264. 7 cells with IC50 value of 9.1 µmol x L(-1).

Strepsesquitriol, a rearranged zizaane-type sesquiterpenoid from the deep-sea-derived actinomycete Streptomyces sp. SCSIO 10355.

Strepsesquitriol, a new caged sesquiterpene, was isolated from Streptomyces sp. SCSIO 10355. Its absolute structure was established as (1R,2R,4S,5S,8S,10S)-4,9,9,10-tetramethyl-2,5,10-trihydroxytricyclo[6.2.1.0(1,5)]undecane by NMR analysis and a theoretical optical rotation derived from quantum-chemical calculations. It showed moderate inhibitory activity against lipopolysaccharide-induced TNFα production in RAW264.7 macrophages.

Elucidating the Mechanism of Agrimonolide in Treating Colon Cancer Based on Network Pharmacology.

Purpose: This study reported the efficacy and underlying mechanism of agrimonolide (AM) in treating colon cancer. Methods: Colon cancer-AM-related targets were screened from online database. AM targets for colon cancer were identified by Venn diagram. Main molecular function, biological process, cellular component and pathways associated with AM targets for colon cancer were analyzed by GO and KEGG enrichment analysis. Relationship of the 10 core targets of AM for colon cancer with the top 15 BP and KEGG pathways was analyzed by Cytoscape software. A "component-target-pathway" network was constructed to select the hub genes of AM for colon cancer. AM effects on colon cancer cell viability, proliferation, invasion, migration and apoptosis were researched by CCK-8, colony formation, Transwell invasion, wound healing and flow cytometry assays. Tumor-bearing nude mice models were constructed and given AM treatment. Hub gene expression in cells/tissues was detected by Western blot. Results: A total of 107 targets were selected as AM targets for colon cancer. The 10 core targets were related to the top 15 biological process terms and KEGG pathways. PI3K, AKT and mTOR were selected as the hub genes of AM for colon cancer. AM weakened colon cell proliferation, invasion, migration and apoptosis inhibition, and suppressed colon cell in vivo growth. AM up-regulated Caspase-3 and BAX proteins, down-regulated C-Myc, Cyclin D1 and BCL-2 proteins, and inactivated the PI3K/AKT/mTOR pathway both in vitro and in vivo. Conclusion: AM suppressed colon cancer progression through inactivating the PI3K/AKT/mTOR pathway. It may be useful for colon cancer treatment.

[Effect of gingival biotype on total crown repair and gingival crevicular fluid inflammatory factors].

PURPOSE: To explore the effect of thick and thin sputum on the restoration of oral anterior teeth and the index of gingival crevicular fluid. METHODS: A study was conducted on 80 patients (130 teeth) who underwent full-ceramic crown treatment for anterior tooth restoration in Jiangnan University Affiliated Hospital 's oral clinic. The patients were divided into thick gingival type (42 cases, 67 teeth) and thin gingival type (38 cases, 63 teeth) according to their gingival biotype. The two groups were compared before and after the restoration with improved plaque index (mPI), modified bleeding index (mBI), probing depth (PD), clinical evaluation score of oral prosthesis, tumor necrosis factor-alpha (TNF-alpha) and IL-1 ß(interleukin-1ß) in gingival crevicular fluid. Statistical analysis was performed with SPSS 21.0 software package. RESULTS: Before treament, there were no significant differences in mPI, mBI and PD between the two groups (P＞0.05); 12 months after treament, mPI, mBI and PD of the thin gingiva group were significantly lower than those of the thick gingiva group(P＜0.05). Before treament, there were no significant differences in TNF-α and IL-1ß levels in gingival crevicular fluid between the two groups(P＞0.05); 12 months after treament, TNF-α and IL-1ß levels of the thin gingiva group were significantly lower than those of the thick gingiva group(P＜0.05). Six months after treament, there were no significant differences in prosthesis integrity, marginal adaptation, color matching, periodontal health status and secondary caries scores between the two groups (P＞0.05); 12 months after treament, the marginal adaptation, periodontal health status and secondary caries scores of the thick gingiva group were significantly higher than those of the thin gingiva group(P＜0.05); the marginal discoloration score of the thick gingiva group was significantly lower than that of the thin gingiva group at 6 months and 12 months after treament(P＜0.05). CONVLUSIONS: The thin sputum type is more conducive to repairing the oral cavity after treatment, and is beneficial to the maintenance of oral health condition after repair. The gingival index of the thick sputum type patient will be significantly increased after repair, and the risk of gingival inflammation is increased. The aesthetic effect is better than the thin sputum type.

Salidroside attenuates lipopolysaccharide-induced neuroinflammation and cognitive impairment in septic encephalopathy mice.

Salidroside (SAL) is a natural bioactive compound with anti-oxidative, anti-inflammatory, and neuroprotective properties. In the present study, we generate an experimental design to investigate SAL-mediated protective effect and underlying mechanism on lipopolysaccharide (LPS)-induced neuroinflammation and cognitive impairment in the septic encephalopathy mice model (SEMM). In SEMM, Open-Field Test (OFT) and Novel Object Recognition Test evaluated LPS-induced cognitive impairment, behavioural phenotypes, and memory impairment (NOR). Cytokines and protein expression were assessed using ELISA assay, RT-qPCR, and Western blotting. Our results showed cognitive dysfunction could be reversed when treated with SAL in SEMM. SAL treatment significantly reduced apoptotic TUNEL-positive cells and related gene expression (BAX and BCL-2) and considerably improved neuronal damage in SEMM. In addition, it markedly reduced the production of inflammatory cytokines (TNF-α, IL-1ß, and IL-6) and Iba-1-positive cells responsible for microglial activation in mice hippocampus (P < 0.05). The effects of SAL on ROS and oxidative stress markedly reduced malondialdehyde (MDA) content and increased superoxide dismutase (SOD) and catalase (CAT) in the hippocampal tissues of mice. Besides, SAL treatment enhanced LPS-induced autophagy in mice's hippocampus and increased autophagy-related protein expression (Beclin-1 and P62). In addition, the NLRP3 inflammasome pathway and its related proteins (NLRP3, ASC, and cleaved caspase-1) were suppressed by SAL treatment. However, SAL activated the SIRT1/Nrf2 pathway and exerts protection by enhanced expression of the proteins (SIRT1 and Nrf2) and downstream genes (HO-1 and NQO1). Our finding demonstrated that SAL employed neuroprotective effects in SEMM by promoting autophagy via activation of the SIRT1 pathway.

Isolation, characterization, and bioactivity evaluation of 3-((6-methylpyrazin-2-yl)methyl)-1H-indole, a new alkaloid from a deep-sea-derived actinomycete Serinicoccus profundi sp. nov.

One new alkaloid, 3-((6-methylpyrazin-2-yl)methyl)-1H-indole (1) was obtained from the deep-sea actinomycete Serinicoccus profundi sp. nov., along with five known compounds (2-6). Their structures were determined on the basis of detailed analysis of the 1D and 2D NMR as well as MS data. The new indole alkaloid displayed weak antimicrobial activity against Staphylococcus aureus ATCC 25923 with an MIC value of 96 µg/mL. It showed no cytotoxicity on a normal human liver cell line (BEL7402) and a human liver tumor cell line (HL-7702).

Effect of electroacupuncture combined with rehabilitation training on hypertension: A systematic review and meta-analysis.

To evaluate the clinical effects of electroacupuncture combined with rehabilitation training (EART) versus conventional rehabilitation training (CRT) on hypertension. Multiple databases like PubMed, Embase, Web of Science and Wanfang database, China National Knowledge Internet database, and Chinese Biological Medical database were used to search for the relevant studies and full-text articles involved in evaluating EART versus CRT with hypertension. Review Manager 5.4 was used to estimate the effects of the results among included articles. Forest plots, sensitivity analysis, and funnel plots were also conducted on the included articles. In this meta-analysis study, there were 9 relevant studies were eventually satisfied the included criteria. There were significant differences between EART group and CRT group in systolic blood pressure after treatment (MD -16.62, 95 %CI = -21.84 to -11.39; P < 0.00001), diastolic blood pressure after treatment (MD = -16.03, 95 % CI = -21.55 to -10.50; P < 0.00001), and effective rate (MD = 1.22, 95 % CI = 1.13 to 1.32; P < 0.00001). Sensitivity analysis and funnel chart demonstrated that the study was robust and limited publication bias was observed. Our data showed that EART was clinically more significant than CRT in hypertension. Further studies need to be performed using large relevance references to verify the effectiveness of EART in the treatment of hypertension.

N6-Methyladenosine Reader YTHDF2 Enhances Non-Small-Cell Lung Cancer Cell Proliferation and Metastasis through Mediating circ_SFMBT2 Degradation.

Objective: circ_SFMBT2 was reported to facilitate malignant progression in various cancers, but its function in non-small-cell lung cancer (NSCLC) has not been fully uncovered. This study aimed to investigate the effects of N6-methyladenosine (m6A) methylation of circ_SFMBT2 (circ_0017628) on non-small-cell lung cancer (NSCLC) and its underlying mechanisms. Methods: Paired tumor and noncancerous tissues from NSCLC patients were surgically collected from January 2020 to March 2021 in our hospital. The levels of circ_SFMBT2 and LATS2 in NSCLC and human bronchial epithelial cells were assayed with qRT-PCR. Overexpression or silencing of circ_SFMBT2, LATS2, or YTHDF2 was performed in the NSCLC cells. CCK-8, colony-forming, and transwell assays were performed to analyze cell proliferation, viability, and migration, respectively. Meanwhile, the expression of MMP-9, E-cadherin, vimentin, and the Hippo/YAP pathway components was examined by western blotting. The m6A enrichment in circ_SFMBT2 was verified using methylated RNA immunoprecipitation, and interaction between circ_SFMBT2 and YTHDF2 was assessed by RNA pull-down and immunoprecipitation assays. Results: Both circ_SFMBT2 and LATS2 were lowly expressed in NSCLC cells and tissues. A positive correlation of circ_SFMBT2 with LATS2 was identified, and circ_SFMBT2 was localized predominantly in the cytoplasm. circ_SFMBT2 overexpression negatively regulated cell proliferation, viability, migration, and epithelial-mesenchymal transition while promoting the Hippo/YAP pathway activation. Notably, knockdown of LATS2 effectively abrogated the inhibitory effects of circ_SFMBT2 overexpression on NSCLC cell malignancies. Besides, m6A was specifically enriched in circ_SFMBT2, and circ_SFMBT2 could bind to YTHDF2. Silencing of YTHDF2 led to an increase in circ_SFMBT2 expression while inhibiting the malignancy of cancer cells. Conclusion: Our results showed that YTHDF2 could facilitate NSCLC cell proliferation and metastasis via the Hippo/YAP pathway activation by mediating circ_SFMBT2 degradation.

Expression and prognostic values of Id-1 and Id-3 in gastric adenocarcinoma.

BACKGROUND: Id (inhibitor of differentiation/DNA binding)-1 and -3 are involved in neoangiogenesis; they antagonize basic helix-loop-helix proteins, inhibit differentiation, and enhance cell proliferation. The aim of this study was to investigate Id-1 and -3 expression in gastric tumors and their clinical relevance in gastric cancer. MATERIALS AND METHODS: We investigated Id-1 and Id-3 expression in gastric cancer samples by immunohistochemistry and Western blotting, and further analyzed the relationship between expression of Id-1 and Id-3 and clinicopathologic characteristics. RESULTS: Expression of Id-1 and -3 was found significantly more often in gastric cancers than in matched adjacent nonmalignant tissues. Cancer samples with poor or moderate histologic differentiation showed significantly stronger Id-1 and -3 expression than cancer samples with high differentiation. In cancer samples, strong or moderate expression of Id-3, but not Id-1, was a strong independent predictor for shorter overall survival in multivariate analysis. CONCLUSIONS: The level of Id-1 and -3 protein expression was associated with the malignant potential of gastric tumors. In cancer samples, stronger Id-1 and -3 expression is associated with poor differentiation and more aggressive behavior of tumor cells, resulting in poor clinical outcome. Consequently, Id-3 might be used to independently predict survival of patients with gastric cancer.

[Study of tyrosine online fluorescence spectrum under high pressure].

The effect of pressure on fluorescence of tyrosine (Tyr) and Tyr in different concentration of Cu2+ was investigated. The results showed that Tyr fluorescence intensity was enhanced with increasing pressure in the absence of Cu2+, with the fluorescence intensity increasing by about 9% when the pressure reached 60 MPa. Furthermore, Tyr fluorescence quenched by Cu2+ and the quenching became stronger when the concentration of Cu2+ was higher. The effect of pressure on the fluorescence of Tyr was different under various Cu2+ concentrations. When Cu2+ concentration was lower, the fluorescence intensity increased relatively weakly (under 60 MPa and [Copper ion]/[Tyr] = 1, fluorescence intensity increased by 14.4%) and vice versa, the fluorescence intensity increased relatively strongly (under 60 MPa and [Copper ion]/[Tyr] = 40, fluorescence intensity increased by 38.4%).

[Application of chemometric methods in three-dimensional fluorescence spectral analysis].

With the increasing complexity of analytical data, traditional data processing methods for spectral analysis can not meet the analysis needs. The chemometrics uses methods of mathematics, statistics and computer sciences to design optimum chemical measurement procedures and to provide maximum information about fluorescence spectrum by analyzing data. In the present paper, the main kinds of three-dimensional fluorescence spectrum, which are widely analyzed by chemometric methods, were illustrated at first. Secondly, an overview of the chemometric methods such as statistical methods, pattern recognition, neural network and the second-order calibration methods is presented. And the applications of these methods are followed by. Finally,the prospect of chemometric methods applied in multidimensional spectral analysis is discussed.

Feiyanning Formula Induces Apoptosis of Lung Adenocarcinoma Cells by Activating the Mitochondrial Pathway.

Feiyanning formula (FYN) is a traditional Chinese medicine (TCM) prescription used for more than 20 years in the treatment of lung cancer. FYN is composed of Astragalus membranaceus, Polygonatum sibiricum, Atractylodes macrocephala, Cornus officinalis, Paris polyphylla, and Polistes olivaceous, etc. All of them have been proved to have anti-tumor effect. In this study, we used the TCM network pharmacological analysis to perform the collection of compound and disease target, the prediction of compound target and biological signal and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. It was found that the activation of mitochondrial pathway might be the molecular mechanism of the anti-lung cancer effect of FYN. The experimental results showed that FYN had an inhibitory effect on the growth of lung cancer cells in a dose-dependent and time-dependent manner. Moreover, FYN induced G2/M cell cycle arrest and apoptotic cell death as early as 6 h after treatment. In addition, FYN significantly induced mitochondrial membrane depolarization and increased calreticulin expression. Metabolomics analysis showed the increase of ATP utilization (assessed by a significant increase of the AMP/ATP and ADP/ATP ratio, necessary for apoptosis induction) and decrease of polyamines (that reflects growth potential). Taken together, our study suggested that FYN induced apoptosis of lung adenocarcinoma cells by promoting metabolism and changing the mitochondrial membrane potential, further supporting the validity of network pharmacological prediction.

[Effect of reduction by sodium borohydride on the structural characteristics of brown-rotted lignin].

The FTIR, UV-Visible, 1H NMR and GPC were used to study structural changes of brown-rotted lignin after sodium borohydride reduction. FTIR spectra showed that, after reduction, the band at 1,677 cm(-1) attributed to the conjugated carbonyl groups disappeared, and the band intensity at 1,715 cm(-1) attributed to the nonconjugated carbonyl groups decreased. On the other hand, the band at 1,509 and 1,603 cm(-1) attributed to aromatic skeletal vibration remained almost unchanged. UV spectra showed the decreased absorptions at 288 nm and 300-400 nm after reduction. 1H NMR spectra showed that, after reduction, the number of aromatic methoxyl and aromatic hydroxyls decreased, the number of aliphatic hydroxyls and the proton number attributed to many linkage structures connecting the phenylpropane units increased. GPC results showed that the molecular weight of reduced brown-rotted lignin increased and the molecular distribution got wider, as a consequence of the large molecular weight molecules generated during the reduction reaction. Our results suggest that the conjugated carbonyl groups can be totally reduced to the hydroxyl groups, but only some nonconjugated carbonyl groups can be reduced to the hydroxyl groups. The chemical structure of the brown-rotted lignin changed, but the benzyl ring kept stable. The condensation reaction took place during the sodium borohydride reduction process.

[FTIR studies of masson pine wood decayed by brown-rot fungi].

Fourier transform infrared (FTIR) spectroscopy was used to study the chemical changes of masson pine (pinus massoniana lamb.) decayed by the brown-rot fungus Wolfiporia cocos (Schwein.) Ryvarden & Gilbn. for different durations up to 23 weeks. The ratios of height of the lignin/holocellulose and holocellulose/lignin IR peaks were measured, and the klason lignin content and holocellulose content of the sound wood and brown-rotted wood with different level of decay were analyzed by wet chemical methods. The relationship between the two chemical components and the ratios of IR peak height was also established. FTIR spectra showed that, during the first 15 weeks of decay, the intensity of absorption bands at 1 736 and 1 372 cm(-1) ascribed to holocellulose decreased gradually, accompanied by a successive increase in the intensity of band at 1 510 and 1 225 cm(-1) ascribed to lignin. However, the intensities of holocellulose bands at 1736 and 1372 cm(-1) had a little increase, and the intensities of lignin bands at 1 510 and 1 225 cm(-1) had a very slight decrease after 15 weeks of decay. There was a very good correlation between the ratios of height of the lignin/holocellulose (I1510/1736, I1510/I1372, I1225/I736 and I1225/I1372) and the klason lignin content or holocellulose content. The coefficients of determination for the klason lignin content and the holocellulose content were 0.97-0.99 and 0.96-0.97, respectively. High coeffieients of determination were also obtained between the holocellulose/ lignin peak height ratios and the holocellulose content (R2 = 0.96). The above results suggest that, in the system studied, the klason lignin content and holocellulose content of wood decayed to differnent levels could be determined with reasonable accuracy by the FTIR technology.

Isolation and characteristics of the CN gene, a tobacco mosaic virus resistance N gene homolog, from tobacco.

Nicotiana rustica L. HZNH, a native Chinese tobacco germplasm, displays a hypersensitive response (HR) and systemic acquired resistance following infection with tobacco mosaic virus (TMV). A resistance gene, CN, cloned from HZNH plants, was homologous to the N and NH genes identified in other Nicotiana species. The CN coding region (3423 bp) shares 93.63% and 86.50% nucleotide identity with N and NH, respectively. Whereas the five CN exon sequences are highly homologous with those of N and NH, the four introns differ significantly in length and sequence. Sequence analysis revealed that CN belongs to the TIR/NBS/LRR gene class. Expression of CN was up-regulated after TMV infection and was temperature sensitive. Organ-specific expression analysis suggested that CN transcripts accumulated at high levels in leaves, low levels in stems, and minimal levels in roots. When CN was inserted into TMV-susceptible N. tabacum cv. K326 plants by Agrobacterium-mediated transformation, the transgenic plants displayed HR and systemic HR due to uninhibited movement of the virus.