Arabidopsis class A S-acyl transferases modify the pollen receptors LIP1 and PRK1 to regulate pollen tube guidance.

Protein S-acylation catalyzed by protein S-acyl transferases (PATs) is a reversible lipid modification regulating protein targeting, stability, and interaction profiles. PATs are encoded by large gene families in plants, and many proteins including receptor-like cytoplasmic kinases (RLCKs) and receptor-like kinases (RLKs) are subject to S-acylation. However, few PATs have been assigned substrates, and few S-acylated proteins have known upstream enzymes. We report that Arabidopsis (Arabidopsis thaliana) class A PATs redundantly mediate pollen tube guidance and participate in the S-acylation of POLLEN RECEPTOR KINASE1 (PRK1) and LOST IN POLLEN TUBE GUIDANCE1 (LIP1), a critical RLK or RLCK for pollen tube guidance, respectively. PAT1, PAT2, PAT3, PAT4, and PAT8, collectively named PENTAPAT for simplicity, are enriched in pollen and show similar subcellular distribution. Functional loss of PENTAPAT reduces seed set due to male gametophytic defects. Specifically, pentapat pollen tubes are compromised in directional growth. We determine that PRK1 and LIP1 interact with PENTAPAT, and their S-acylation is reduced in pentapat pollen. The plasma membrane (PM) association of LIP1 is reduced in pentapat pollen, whereas point mutations reducing PRK1 S-acylation affect its affinity with its interacting proteins. Our results suggest a key role of S-acylation in pollen tube guidance through modulating PM receptor complexes.

CBP60b clade proteins are prototypical transcription factors mediating immunity.

Transcriptional reprogramming is critical for plant immunity. Several calmodulin (CaM)-binding protein 60 (CBP60) family transcription factors (TFs) in Arabidopsis (Arabidopsis thaliana), including CBP60g, Systemic Acquired Resistance Deficient 1 (SARD1), CBP60a, and CBP60b, are critical for and show distinct roles in immunity. However, there are additional CBP60 members whose function is unclear. We report here that Arabidopsis CBP60c-f, four uncharacterized CBP60 members, play redundant roles with CBP60b in the transcriptional regulation of immunity responses, whose pCBP60b-driven expression compensates the loss of CBP60b. By contrast, neither CBP60g nor SARD1 is inter-changeable with CBP60b, suggesting clade-specific functionalization. We further show that function of CBP60b clade TFs relies on DNA-binding domains (DBDs) and CaM-binding domains, suggesting that they are downstream components of calcium signaling. Importantly, we demonstrate that CBP60s encoded in earliest land plant lineage Physcomitrium patens and Selaginella moellendorffii, are functionally homologous to Arabidopsis CBP60b, suggesting that the CBP60b clade contains the prototype TFs of the CBP60 family. Furthermore, tomato and cucumber CBP60b-like genes rescue the defects of Arabidopsis cbp60b and activate the expression of tomato and cucumber SALICYLIC ACID INDUCTION DEFICIIENT2 (SID2) and ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) genes, suggesting that immune response pathways centered on CBP60b are also evolutionarily conserved. Together, these findings suggest CBP60b clade transcription factors are functionally conserved in evolution and positively mediate immunity.

RHO OF PLANT proteins are essential for pollen germination in Arabidopsis.

Pollen germination is a process of polarity establishment, through which a single and unique growth axis is established. Although most of the intracellular activities associated with pollen germination are controlled by RHO OF PLANTs (ROPs) and increased ROP activation accompanies pollen germination, a critical role of ROPs in this process has not yet been demonstrated. Here, by genomic editing of all 4 Arabidopsis (Arabidopsis thaliana) ROPs that are preferentially expressed in pollen, we showed that ROPs are essential for polarity establishment during pollen germination. We further identified and characterized 2 ROP effectors in pollen germination (REGs) through genome-wide interactor screening, boundary of ROP domain (BDR) members BDR8 and BDR9, whose functional loss also resulted in no pollen germination. BDR8 and BDR9 were distributed in the cytosol and the vegetative nucleus of mature pollen grains but redistributed to the plasma membrane (PM) of the germination site and to the apical PM of growing pollen tubes. We demonstrated that the PM redistribution of BDR8 and BDR9 during pollen germination relies on ROPs but not vice versa. Furthermore, enhanced expression of BDR8 partially restored germination of rop1 pollen but had no effects on that of the quadruple rop pollen, supporting their genetic epistasis. Results presented here demonstrate an ROP signaling route essential for pollen germination, which supports evolutionarily conserved roles of Rho GTPases in polarity establishment.

Molecular regulation of DNA damage and repair in female infertility: a systematic review.

DNA damage is a key factor affecting gametogenesis and embryo development. The integrity and stability of DNA are fundamental to a woman's successful conception, embryonic development, pregnancy and the production of healthy offspring. Aging, reactive oxygen species, radiation therapy, and chemotherapy often induce oocyte DNA damage, diminished ovarian reserve, and infertility in women. With the increase of infertility population, there is an increasing need to study the relationship between infertility related diseases and DNA damage and repair. Researchers have tried various methods to reduce DNA damage in oocytes and enhance their DNA repair capabilities in an attempt to protect oocytes. In this review, we summarize recent advances in the DNA damage response mechanisms in infertility diseases such as PCOS, endometriosis, diminished ovarian reserve and hydrosalpinx, which has important implications for fertility preservation.

A new canthinone glycoside isolated from the root barks of Ailanthus altissima with NO inhibitory activity.

One new canthinone glycoside (1), together with six known compounds (2-7) including three lignans (2-4), two coumarins (5-6) and one phenol (7) was isolated from the root barks of Ailanthus altissima. The structure of new compound 1 was established by the interpretation of UV, IR, MS and NMR data, while its absolute configuration was determined by acid hydrolysis and GIAO NMR calculations with DP4+ probability analysis. The inhibitory effects of all compounds on Nitric oxide (NO) production were investigated in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Results showed that compounds 2 and 5 displayed NO production inhibitory activity with IC50 values of 30.1 and 15.3 µM, respectively.

Dissection of Metabolome and Transcriptome-Insights into Capsaicin and Flavonoid Accumulation in Two Typical Yunnan Xiaomila Fruits.

Pepper is an economically important vegetable worldwide, containing various specialized metabolites crucial for its development and flavor. Capsaicinoids, especially, are genus-specialized metabolites that confer a spicy flavor to Capsicum fruits. In this work, two pepper cultivars, YB (Capsicum frutescens L.) and JC (Capsicum baccatum L.) pepper, showed distinct differences in the accumulation of capsaicin and flavonoid. However, the molecular mechanism underlying them was still unclear. Metabolome analysis showed that the JC pepper induced a more abundant accumulation of metabolites associated with alkaloids, flavonoids, and capsaicinoids in the red ripening stages, leading to a spicier flavor in the JC pepper. Transcriptome analysis confirmed that the increased expression of transcripts associated with phenylpropanoid and flavonoid metabolic pathways occurred in the JC pepper. Integrative analysis of metabolome and transcriptome suggested that four structural genes, 4CL7, 4CL6, CHS, and COMT, were responsible for the higher accumulation of metabolites relevant to capsaicin and flavonoids. Through weighted gene co-expression network analyses, modules related to flavonoid biosynthesis and potential regulators for candidate genes were identified. The promoter analysis of four candidate genes showed they contained several cis-elements that were bonded to MYB, bZIP, and WRKY transcription factors. Further RT-qPCR examination verified three transcription factors, MYB, bZIP53, and WRKY25, that exhibited increased expression in the red ripening stage of the JC pepper compared to YB, which potentially regulated their expression. Altogether, our findings provide comprehensive understanding and valuable information for pepper breeding programs in the future.

DTRMWXHS-12, a novel Bruton tyrosine kinase inhibitor, in combination with everolimus and pomalidomide in patients with relapsed/refractory lymphomas: An open-label, multicenter, phase 1a/1b study.

Preclinical studies have shown augmented activity when combining Bruton tyrosine kinase inhibitors (BTKi) with inhibitors of mammalian target of rapamycin (mTOR) and immunomodulatory agents (IMiD). We conducted a phase 1, open-label study at five centers in USA to evaluate the safety of triplet BTKi/mTOR/IMiD therapy. Eligible patients were adults aged 18 years or older with relapsed/refractory CLL, B cell NHL, or Hodgkin lymphoma. Our dose escalation study used an accelerated titration design and moved sequentially from single agent BTKi (DTRMWXHS-12), doublet (DTRMWXHS-12 + everolimus), and then to triplet therapy (DTRMWXHS-12 + everolimus + pomalidomide). All drugs were dosed once daily on days 1-21 of each 28-day cycle. The primary goal was to establish the recommended phase 2 dose of the triplet combination. Between September 27, 2016, and July 24, 2019, a total of 32 patients with a median age of 70 years (range 46 to 94 years) were enrolled. No MTD was identified for monotherapy and the doublet combination. The MTD for the triplet combination was determined to be DTRMWXHS-12 200 mg + everolimus 5 mg + pomalidomide 2 mg. Responses across all studied cohorts were seen in 13 of 32 (41.9%). Combining DTRMWXHS-12 with everolimus and pomalidomide is tolerable and shows clinical activity. Additional trials could confirm benefit of this all-oral combination therapy for relapsed/refractory lymphomas.

Machine Learning-Assisted Design of Thin-Film Composite Membranes for Solvent Recovery.

Organic solvents are extensively utilized in industries as raw materials, reaction media, and cleaning agents. It is crucial to efficiently recover solvents for environmental protection and sustainable manufacturing. Recently, organic solvent nanofiltration (OSN) has emerged as an energy-efficient membrane technology for solvent recovery; however, current OSN membranes are largely fabricated by trial-and-error methods. In this study, for the first time, we develop a machine learning (ML) approach to design new thin-film composite membranes for solvent recovery. The monomers used in interfacial polymerization, along with membrane, solvent and solute properties, are featurized to train ML models via gradient boosting regression. The ML models demonstrate high accuracy in predicting OSN performance including solvent permeance and solute rejection. Subsequently, 167 new membranes are designed from 40 monomers and their OSN performance is predicted by the ML models for common solvents (methanol, acetone, dimethylformamide, and n-hexane). New top-performing membranes are identified with methanol permeance superior to that of existing membranes. Particularly, nitrogen-containing heterocyclic monomers are found to enhance microporosity and contribute to higher permeance. Finally, one new membrane is experimentally synthesized and tested to validate the ML predictions. Based on the chemical structures of monomers, the ML approach developed here provides a bottom-up strategy toward the rational design of new membranes for high-performance solvent recovery and many other technologically important applications.

Two new guaianolide-type sesquiterpenoids with NO inhibitory activity from Chrysanthemum indicum.

Two new guaianolide-type sesquiterpenoids chrysanthemulides K and L (1 and 2), together with six known analogues (3-8), were isolated from an CH2Cl2 extract of the aerial parts of Chrysanthemum indicum. The structures of new compounds 1 and 2 were established by extensive spectroscopic analysis, including UV, IR, MS, NMR and computational electronic circular dichroism (ECD) methods. Inhibitory effects of all compounds on nitric oxide production were investigated in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Results showed that compounds 1-8 displayed NO production inhibitory activity with IC50 values ranged from 3.5 to 34.3 µM.

LSD1 inhibitors from the roots of Pueraria lobata.

One new 6a,11a-dehydropterocarpan derivative, 6-O-methyl-anhydrotuberosin (1), one new 6a-hydroxypterocarpan, (6aR,11aR,11bR)-hydroxytuberosone (7), and seven known compounds including two 6a,11a-dehydropterocarpans (2 and 4), two coumestans (3 and 5), one isoflavonoid (6) and two other phenolic compounds (8 and 9) were isolated from the roots of Pueraria lobata. The structures of the isolated compounds were elucidated with spectroscopic and spectrometric methods (1 D and 2DNMR, HRESIMS). Compounds 1, 2, 4-5 showed potent LSD1 inhibitory activities with IC50 values ranging from 1.73 to 4.99 µM. Furthermore, compound 2 showed potent cytotoxicity against gastric cancer cell lines MGC-803 and BGC-823, and lung cancer cell lines H1299 and H460.

Using UPLC-LTQ-Orbitrap-MS and HPLC-CAD to Identify Impurities in Cycloastragenol, Which Is a Pre-Clinical Candidate for COPD.

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease that has become the third leading cause of death worldwide. Cycloastragenol (CAG), which is the genuine sapogenin of the main active triterpene saponins in Astragali radix, is a bioavailable pre-clinical candidate for chronic obstructive pulmonary disease (COPD), and it was investigated in our previous study. In order to progress medical research, it was first efficiently produced on a 2.5-kg scale via Smith degradation from astragaloside IV (AS-IV). Simultaneously, since the impurity profiling of a drug is critical for performing CMC documentation in pre-clinical development, a study on impurities was carried out. As these structures do not contain chromophores and possess weak UV absorption characteristics, HPLC-CAD and UPLC-LTQ-Orbitrap-MS were employed to carry out the quality control of the impurities. Then, column chromatography (CC), preparative thin-layer chromatography (PTLC), and crystallization led to the identification of 15 impurities from CAG API. Among these impurities, compounds 1, 4, 9, 10, 14, and 15 were elucidated via spectroscopic analysis, and 2-3, 5-8, and 11-13 were putatively identified. Interestingly, the new compounds 9 and 14 were rare 10, 19-secocycloartane triterpenoids that displayed certain anti-inflammatory activities against LPS-induced lymphocyte cells and CSE-induced MLE-12 cells. Additionally, a plausible structural transformation pathway of the degradation compounds from CAG or AS IV was proposed. The information obtained will provide a material basis to carry out the quality control and clinical safety assurance of API and related prescriptions. Reasonable guidance will also be provided regarding the compounds with weak UV absorption characteristics.

[Anti-infectious pneumonia target discovery and molecular mechanism study of Jingfang Granules].

This study aimed to identify the direct pharmacological targets of Jingfang Granules in treating infectious pneumonia via "target fishing" strategy. Moreover, the molecular mechanism of Jingfang Granules in treating infectious pneumonia was also investigated based on target-related pharmacological signaling pathways. First, the Jingfang Granules extract-bound magnetic nanoparticles were prepared, which were incubated with lipopolysaccharide(LPS)-induced mouse pneumonia tissue lysates. The captured proteins were analyzed by high-resolution mass spectrometry(HRMS), and the target groups with specific binding to the Jingfang Granules extract were screened out. Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis was used to identify the target protein-associated signaling pathways. On this basis, the LPS-induced mouse model of infectious pneumonia was established. The possible biological functions of target proteins were verified by hematoxylin-eosin(HE) staining and immunohistochemical assay. A total of 186 Jingfang Granules-specific binding proteins were identified from lung tissues. KEGG pathway enrichment analysis showed that the target protein-associated signaling pathways mainly included Salmonella infection, vascular and pulmonary epithelial adherens junction, ribosomal viral replication, viral endocytosis, and fatty acid degradation. The target functions of Jingfang Granules were related to pulmonary inflammation and immunity, pulmonary energy metabolism, pulmonary microcirculation, and viral infection. Based on the in vivo inflammation model, Jingfang Granules significantly improved the alveolar structure of the LPS-induced mouse model of infectious pneumonia and down-regulated the expressions of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6). Meanwhile, Jingfang Gra-nules significantly up-regulated the expressions of key proteins of mitochondrial function COX Ⅳ and ATP, microcirculation-related proteins CD31 and Occludin, and proteins associated with viral infection DDX21 and DDX3. These results suggest that Jingfang Gra-nules can inhibit lung inflammation, improve lung energy metabolism and pulmonary microcirculation, resist virus infection, thus playing a protective role in the lung. This study systematically explains the molecular mechanism of Jingfang Granules in the treatment of respiratory inflammation from the perspective of target-signaling pathway-pharmacological efficacy, thereby providing key information for clinical rational use of Jingfang Granules and expanding potential pharmacological application.

[Anti-depression targets and mechanism study of Kaixin San].

This study identified the anti-depression targets of Kaixin San(KXS) in the brain tissue with "target fishing" strategy, and explored the target-associated pharmacological signaling pathways to reveal the anti-depression molecular mechanism of KXS. The Balb/c mouse model of depression was established by chronic unpredictable mild stress(CUMS) and the anti-depression effect of KXS was evaluated by forced swimming test and sucrose preference test. KXS active components were bonded to the benzophenone-modified magnetic nanoparticles by photocrosslinking reaction for capturing target proteins from cortex, thalamus and hippocampus of depressive mice. The target proteins were identified by liquid chromatography-mass spectrometry/mass spectrometry(LC-MS/MS). The enrichment analysis on signaling pathways was performed by Cytoscape. The potential biological functions of targets were verified by immunohistochemistry and Western blot assay. The results showed that KXS significantly improved the behavioral indexes. There were 64, 91, and 44 potential targets of KXS identified in cortex, thalamus, and hippocampus, respectively, according to the target identification experiment. The functions of these targets were mainly associated with vasopressin-regulated water reabsorption, salmonella infection, thyroid hormone synthesis, and other signaling pathways. Besides, the results of immunohistochemistry and Western blot showed that KXS up-regulated the expressions of argipressine(AVP) in the cortex, heat shock protein 60(HSP60), cytochrome C oxidase 4(COX4), and thyrotropin-releasing hormone(TRH) in the thalamus, and down-regulated the expressions of tumor necrosis factor-α(TNF-α) and nuclear factor kappa B(NF-κB) p65 in the thalamus. Therefore, KXS may exert anti-depression effect through regulating vasopressin signaling pathway in the cortex and inflammation, energy metabolism, and thyroid hormone signaling pathways in the thalamus, and the effect of KXS on hippocampus is not significant.

[Neuroprotective effect of ginsenoside Re on drosophila model of Parkinson's disease].

This study aims to explore the neuroprotective mechanism of ginsenoside Re(GS-Re) on drosophila model of Parkinson's disease(PD) induced by rotenone(Rot). To be specific, Rot was used to induce PD in drosophilas. Then the drosophilas were grouped and respectively treated(GS-Re: 0.1, 0.4, 1.6 mmol·L~(-1); L-dopa: 80 µmol·L~(-1)). Life span and crawling ability of drosophilas were determined. The brain antioxidant activity [content of catalase(CAT), malondialdehyde(MDA), reactive oxygen species(ROS), superoxide dismutase(SOD)], dopamine(DA) content, and mitochondrial function [content of adenosine triphosphate(ATP), NADH:ubiquinone oxidoreductase subunit B8(NDUFB8) Ⅰ activity, succinate dehydrogenase complex, subunit B(SDHB) Ⅱ activity] were detected by enzyme-linked immunosorbent assay(ELISA). The number of DA neurons in the brains of drosophilas was measured with the immunofluorescence method. The levels of NDUFB8 Ⅰ, SDHB Ⅱ, cytochrome C(Cyt C), nuclear factor-E2-related factor 2(Nrf2), heme oxygenase-1(HO-1), B-cell lymphoma/leukemia 2(Bcl-2)/Bcl-2-assaciated X protein(Bax), and cleaved caspase-3/caspase-3 in the brain were detected by Western blot. The results showed that model group [475 µmol·L~(-1) Rot(IC_(50))] demonstrated significantly low survival rate, obvious dyskinesia, small number of neurons and low DA content in the brain, high ROS level and MDA content, low content of SOD and CAT, significantly low ATP content, NDUFB8 Ⅰ activity, and SDHB Ⅱ activity, significantly low expression of NDUFB8 Ⅰ, SDHB Ⅱ, and Bcl-2/Bax, large amount of Cyt C released from mitochondria to cytoplasm, low nuclear transfer of Nrf2, and significantly high expression of cleaved caspase-3/caspase-3 compared with the control group. GS-Re(0.1, 0.4, and 1.6 mmol·L~(-1)) significantly improved the survival rate of PD drosophilas, alleviated the dyskinesia, increased DA content, reduced the loss of DA neurons, ROS level, and MDA content in brain, improved content of SOD and CAT and antioxidant activity in brain, maintained mitochondrial homeostasis(significantly increased ATP content and activity of NDUFB8 Ⅰ and SDHB Ⅱ, significantly up-regulated expression of NDUFB8 Ⅰ, SDHB Ⅱ, and Bcl-2/Bax), significantly reduced the expression of Cyt C, increased the nuclear transfer of Nrf2, and down-regulated the expression of cleaved caspase-3/caspase-3. In conclusion, GS-Re can significantly relieve the Rot-induced cerebral neurotoxicity in drosophilas. The mechanism may be that GS-Re activates Keap1-Nrf2-ARE signaling pathway by maintaining mitochondrial homeostasis, improves antioxidant capacity of brain neurons, then inhibits mitochondria-mediated caspase-3 signaling pathway, and the apoptosis of neuronal cells, thereby exerting the neuroprotective effect.

Light-Driven Ammonia Production by Azotobacter vinelandii Cultured in Medium Containing Colloidal Quantum Dots.

There is an evergrowing demand for environment-friendly processes to synthesize ammonia (NH3) from atmospheric nitrogen (N2). Although diazotrophic N2 fixation represents an undeniably "green" process of NH3 synthesis, the slow reaction rate makes it less suitable for industrially meaningful large-scale production. Here, we report the photoinduced N2 fixation using a hybrid system composed of colloidal quantum dots (QDs) and aerobic N2-fixing bacteria, Azotobacter vinelandii. Compared to the case where A. vinelandii cells are simply mixed with QDs, NH3 production increases significantly when A. vinelandii cells are cultured in the presence of core/shell InP/ZnSe QDs. During the cell culture of A. vinelandii, the cellular uptake of QDs is facilitated in the exponential growth phase. Experimental results as well as theoretical calculations indicate that the photoexcited electrons in QDs within A. vinelandii cells are directly transferred to MoFe protein, the catalytic component of nitrogenase. We also observe that the excess amount of QDs left on the outer surface of A. vinelandii disrupts the cellular membrane, leading to the decrease in NH3 production due to the deactivation of nitrogenase. The successful uptake of QDs in QD-A. vinelandii hybrid with minimal amount of QDs on the outer surface of the bacteria is key to efficient photosensitized NH3 production. The comprehensive understanding of the QD-bacteria interface paves an avenue to novel and efficient nanobiohybrid systems for chemical production.

Streptomyces blattellae, a novel actinomycete isolated from the in vivo of a Blattella germanica.

During a screening for novel and useful actinobacteria in desert animal, a new actinomycete was isolated and designated strain TRM63209T. The strain was isolated from in vivo of a Blattella germanica in Tarim University in Alar City, Xinjiang, north-west China. The strain was found to exhibit an inhibitory effect on biofilm formation by Candida albicans ATCC 18,804. The strain was observed to form abundant aerial mycelium, occasionally twisted and which differentiated into spiral spore chains. Spores of TRM63209T were observed to be oval-shaped, with a smooth surface. Strain TRM63209T was found to grow optimally at 28 °C, pH 8 and in the presence of 1% (w/v) NaCl. The whole-cell sugars of strain TRM63209T were rhamnose ribose, xylose, mannose, galactose and glucose, and the principal polarlipids were found to be diphosphatidylglycerol, phos-phatidylethanolamine, phosphatidylcholine, phosphatidylinositol mannoside, phosphatidylinositol and an unknown phospholipid(L). The diagnostic cell wall amino acid was identified as LL-diaminopimelic acid. The predominant menaquinone was found to be MK-9(H6) (14.64%), MK-9(H2) (19.65%), MK-9(H8) (22.34%), MK-10(H2) (25.37%). The major cellular fatty acids were identified as iso-C16:0, 16:0, anteiso-C15:0, anteiso-C17:0, iso-C15:0 and Sum in Feature 3. Analysis of the 16S rRNA sequence showed that strain TRM63209T exhibits high sequence similarity to Streptomyces bungoensis strain DSM 41781T 98.20%. A multi-locus sequence analysis of five house-keeping genes (atpD, gyrB, rpoB, recA and trpB) and phylogenomic analysis also illustrated that strain TRM63209T should be assigned to the genus Streptomyces. The DNA G + C content of the strain was determined to be 70.2 mol%. Average nucleotide identity (ANI) between strain TRM63209T and S. bungoensis DSM 41781T, Streptomyces phyllanthi PA1-07T, Streptomyces longwoodensis DSM 41677T and Streptomyces caeruleatus NRRL B-24802T were 82.76%, 82.54%, 82.65%, 84.02%, respectively. Digtal DNA-DNA (dDDH) hybridization were 26.30%, 25.10%, 26.20%, 29.50%, respectively. Therefore, it is concluded that strain TRM63209T represents a novel species of the genus Streptomyces, for which the name Streptomyces blattelae is proposed. The type strain is TRM63209T (CCTCC AA 2018093T = LMG 31,403 = TRM63209T).

Can CD147 work as a therapeutic target for tumors through COVID-19 infection?

In this review, we discussed an interesting case infected with "COVID-19" (Corona Virus Disease 2019). The patients with Hodgkin's lymphoma recovered after infection with COVID-19. It may be that COVID-19 activates the patient's immune system, or it may be a coincidence. COVID-19 spike protein can interact with CD147 and use it as an entry to invade host cells. CD147 is a partner of SLC3A2, which is the chaperone subunit of cystine/glutamate reverse transporter (system XC). The catalytic subunit of system XC is SLC7A11. SLC7A11 mediated cysteine uptake plays a key role in ferroptosis. Through literature review and data analysis, we suggest that CD147, as a new potential COVID-19 infection entry, may also lead to ferroptosis of host cells. Our hypothesis is that spike protein of COVID-19 induced ferroptosis in host cells via CD147/SLC3A2/SLC7A11 complex. This is another explanation for the cancer patient recovered after COVID-19 infection.

Approaches to Configuration Determinations of Flexible Marine Natural Products: Advances and Prospects.

Flexible marine natural products (MNPs), such as eribulin and bryostatin, play an important role in the development of modern marine drugs. However, due to the multiple chiral centers and geometrical uncertainty of flexible systems, configuration determinations of flexible MNPs face great challenges, which, in turn, have led to obstacles in druggability research. To resolve this issue, the comprehensive use of multiple methods is necessary. Additionally, configuration assignment methods, such as X-ray single-crystal diffraction (crystalline derivatives, crystallization chaperones, and crystalline sponges), NMR-based methods (JBCA and Mosher's method), circular dichroism-based methods (ECCD and ICD), quantum computational chemistry-based methods (NMR calculations, ECD calculations, and VCD calculations), and chemical transformation-based methods should be summarized. This paper reviews the basic principles, characteristics, and applicability of the methods mentioned above as well as application examples to broaden the research and applications of these methods and to provide a reference for the configuration determinations of flexible MNPs.

The Derived Components of Gnaphalium hypoleucum DC. Reduce Quorum Sensing of Chromobacterium violaceum.

Gnaphalium hypoleucum DC. was first recorded in the Chinese National Pharmacopoeia "Yi Plant Medicine". There is no detailed report on its main components' activity in suppressing the quorum sensing activity (QS) of bacteria. Our study aimed to screen the main components in extracts of G. hypoleucum DC. in order to measure their effects on bacterial QS activity and to explore specific quorum sensing mechanisms that are affected by G. hypoleucum DC. extracts. Crude extracts of G. hypoleucum DC. contained significant amounts of two compounds shown to inhibit bacterial QS activity, namely apigenin and luteolin. Apigenin and luteolin in crude extracts of G. hypoleucum DC. showed substantial inhibition of pigment formation, biofilm production, and motility in Chromobacterium violaceum ATCC 12472 compared to the effects of other phytochemicals from G. hypoleucum DC. Apigenin and luteolin exhibited a strong QS inhibitory effect on C. violaceum, interfering with the violacein pigment biosynthesis by downregulating the vioB, vioC, and vioD genes. In the presence of signal molecules, the QS effect is prevented, and the selected compounds can still inhibit the production of the characteristic purple pigment in C. violaceum. Based on qualitative and quantitative research using genomics and bioinformatics, we concluded that apigenin and luteolin in crude extracts of G. hypoleucum DC can interfere with the generation of QS in C. violaceum by downregulating the vioB, vioC, and vioD genes. Indeed, G. hypoleucum DC. is used for the treatment of bacterial infections, and this research provides new ideas and potential alternative uses for medicinal plants.

MS/MS-Based Molecular Networking: An Efficient Approach for Natural Products Dereplication.

Natural products (NPs) have historically played a primary role in the discovery of small-molecule drugs. However, due to the advent of other methodologies and the drawbacks of NPs, the pharmaceutical industry has largely declined in interest regarding the screening of new drugs from NPs since 2000. There are many technical bottlenecks to quickly obtaining new bioactive NPs on a large scale, which has made NP-based drug discovery very time-consuming, and the first thorny problem faced by researchers is how to dereplicate NPs from crude extracts. Remarkably, with the rapid development of omics, analytical instrumentation, and artificial intelligence technology, in 2012, an efficient approach, known as tandem mass spectrometry (MS/MS)-based molecular networking (MN) analysis, was developed to avoid the rediscovery of known compounds from the complex natural mixtures. Then, in the past decade, based on the classical MN (CLMN), feature-based MN (FBMN), ion identity MN (IIMN), building blocks-based molecular network (BBMN), substructure-based MN (MS2LDA), and bioactivity-based MN (BMN) methods have been presented. In this paper, we review the basic principles, general workflow, and application examples of the methods mentioned above, to further the research and applications of these methods.