singleCellBase: a high-quality manually curated database of cell markers for single cell annotation across multiple species.

Annotating cells in the analysis of single-cell RNA-seq (scRNA-seq) data is one of the most challenging tasks that researchers are actively addressing. Manual cell annotation is generally considered the gold standard method, although it is labor intensive and independent of prior knowledge. At present, the relationship between high-quality, known marker genes and cell types is very limited, especially for a variety of species other than humans and mice. The singleCellBase is a manually curated resource of high-quality cell types and gene markers associations across multiple species. In details, it offers 9,158 entries spanning a total of 1,221 cell types and linking with 8,740 genes (cell markers), covering 464 diseases/status, and 165 types of tissues across 31 species. The singleCellBase provides a user-friendly interface to the scientific community to browse, search, download and submit records of marker genes and cell types. The resource providing ineluctable prior knowledge required by manual cell annotation, which is valuable to interpret scRNA-seq data and elucidate what cell type or cell state that a cell population represents.

Aquilariperoxide A, a Sesquiterpene Dimer from Agarwood of Aquilaria sinensis with Dual Antitumor and Antimalarial Effects.

Aquilariperoxide A (1), an unprecedented sesquiterpene dimer characterized by a dioxepane ring connecting two sesquiterpene units via a C-C bond, was isolated from agarwood of Aquilaria sinensis-containing resins. The structure was elucidated by spectroscopic and computational methods. A bioassay revealed that 1 significantly inhibits cell proliferation and migration in human cancer cells. The mechanism of 1 against cancer cells was briefly discussed by analysis of RNA sequence data and epithelial-mesenchymal transition. Besides, the antimalarial activity of 1 was also evaluated.

Genetic Factors Causing Thyroid Dyshormonogenesis as the Major Etiologies for Primary Congenital Hypothyroidism: Clinical and Genetic Characterization of 33 Patients.

BACKGROUND AND AIMS: Although the significance of primary congenital hypothyroidism (CH) is supported by an increasing amount of evidence, the clinical and genetic characteristics of this condition are still poorly understood. This study aimed to explore the underlying genetic etiologies in a cohort of primary CH patients. SUBJECTS AND METHODS: The clinical data of 33 patients with primary CH were collected and analyzed via a cross-sectional study. Genetic analysis was performed by high-throughput sequencing and Sanger verification, and the pathogenicity of the novel missense variants was predicted using a variety of comprehensive bioinformatic tools. RESULTS: Among the 33 patients, 22 (22/33, 66.7%) harbored pathogenic variants in the causative genes of thyroid dysgenesis or dyshormonogenesis, with DUOX2 (15/33, 45.5%) topping the list, followed by TG, TPO, DUOXA2 and PAX8. Four novel genetic variants were detected, including a pathogenic frameshift and three likely pathogenic missense variants. Positive neonatal screening for TSH, neonatal jaundice and abnormal thyroid morphology were the main positive findings among all cases. Although 31 of the total 33 CH patients exhibited normal anthropometric and social performance, the other 2 had poor prognosis in this study. CONCLUSIONS: This study reported 33 new CH patients bearing four novel genetic variants, which enriched the variant spectrum of CH genes. In this cohort, genetic factors causing thyroid dyshormonogenesis were the main etiologies of CH development. Most patients exhibited a favorable prognosis; however, systematic management remains a challenge in achieving improved clinical outcomes for CH patients.

Sesquiterpenoid-Chromone Heterohybrids from Agarwood of Aquilaria sinensis as Potent Specific Smad3 Phosphorylation Inhibitors.

Aquilarines A (1) and B (2), two unprecedented sesquiterpenoid-chromone heterohybrids, were isolated from Aquilaria sinensis agarwood. 1 is an alkaloid featuring an unusual pyridine nucleus, and 2 possesses a rare sesquiterpenoid-chromone skeleton via a C-C bond. A plausible biosynthetic pathway for 1 and 2 was proposed. Both 1 and 2 could significantly inhibit the expression of extracellular matrix components, and α-SMA at low concentrations in TGF-ß1 induced two types of kidney cells (NRK 52E and NRK 49F) featuring selective inhibition of Smad3 instead of Smad2 phosphorylation, showing their potential in renal fibrosis.

Overexpression of Pennisetum purpureum CCoAOMT Contributes to Lignin Deposition and Drought Tolerance by Promoting the Accumulation of Flavonoids in Transgenic Tobacco.

Elephant grass (Pennisetum purpureum) is a fast-growing and low-nutrient demand plant that is widely used as a forage grass and potential energy crop in tropical and subtropical regions of Asia, Africa, and the United States. Transgenic tobacco with the PpCCoAOMT gene from Pennisetum purpureum produces high lignin content that is associated with drought tolerance in relation to lower accumulation of reactive oxygen species (ROS), along with higher antioxidant enzyme activities and osmotic adjustment. In this study, transgenic tobacco plants revealed no obvious cost to plant growth when expressing the PpCCoAOMT gene. Metabolomic studies demonstrated that tobacco plants tolerant to drought stress accumulated flavonoids under normal and drought conditions, which likely explains the observed tolerance phenotype in wild-type tobacco. Our results suggest that plants overexpressing PpCCoAOMT were better able to cope with water deficit than were wild-type controls; metabolic flux was redirected within primary and specialized metabolism to induce metabolites related to defense to drought stress. These results could help to develop drought-resistant plants for agriculture in the future.

Diterpenoids from Blumea balsamifera and Their Anti-Inflammatory Activities.

Six new diterpenoids, blusamiferoids A-F (1-6), including four pimarane-type diterpenoids, one rosane-type diterpenoid (3), and one rearranged abietane-type diterpenoid (6), were isolated from the dry aerial parts of Blumea balsamifera. Their structures were characterized by spectroscopic and computational methods. In particular, the structures of 1 and 4 were confirmed by X-ray crystallography. Compounds 5 and 6 were found to dose-dependently inhibit the production of TNF-α, IL-6, and nitrite oxide, and compound 5 also downregulated NF-κB phosphorylation in lipopolysaccharide (LPS)-induced RAW 264.7 cells.

Clinical characterization of NTCP deficiency in paediatric patients : A case-control study based on SLC10A1 genotyping analysis.

Na+ -taurocholate cotransporting polypeptide deficiency (NTCPD) is a newly described disorder arising from biallelic mutations of the SLC10A1 gene. As a result of a lack of compelling evidence from case-control studies, its genotypic and phenotypic features remain open for in-depth investigation. This study aimed to explore the genotypic and clinical phenotypic characteristics of paediatric patients with NTCPD. The SLC10A1 genotypes of all NTCPD patients were confirmed by screening for the prevalent variant c.800C>T and Sanger sequencing when necessary. The clinical presentations and laboratory changes were collected, reviewed and analysed, and then qualitatively and quantitatively compared with the relevant controls. A total of 113 paediatric NTCPD patients were diagnosed while c.374dupG and c.682_683delCT were detected as two novel pathogenic mutations. Hypercholanemia was observed in 99.12% of the patients. Indirect hyperbilirubinemia in affected neonates exhibited higher positive rates in comparison to controls. Moreover, transient cholestatic jaundice, elevated liver enzymes and 25-hydroxyvitamin D (Vit D) deficiency during early infancy were more commonly observed in patients than in controls. All NTCPD patients exhibited favourable clinical outcomes as a result of symptomatic and supportive treatment. The findings enriched the SLC10A1 mutation spectrum and provided comprehensive insights into the phenotypic characteristics of NTCPD. NTCPD should be considered and SLC10A1 gene should be analysed in patients with above age-dependent clinical features. Furthermore, over investigation and intervention should be avoided in the management of NTCPD patients.

[Effect of acupuncture on diaphragmatic function in patients with AECOPD typeâ ¡ respiratory failure evaluated by ultrasound detection].

OBJECTIVE: To observe the therapeutic effect of acupuncture combined with western conventional therapy on type Ⅱ respiratory failure of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and evaluate the effect of acupuncture on diaphragmatic function and prognosis by bedside ultrasound. METHODS: A total of 111 patients with AECOPD type Ⅱ respiratory failure were randomized into an acupuncture group, a conventional treatment group and a non-acupoint acupuncture group, 37 cases in each one. The routine AECOPD nursing care and treatment with western medicine were provided in the 3 groups. Additionally, in the acupuncture group, acupuncture was applied at Dingchuan (EX-B 1), Feishu (BL 13), Taiyuan (LU 9), Danzhong (CV 17) and Zhongwan (CV 12), etc. In the non-acupoint acupuncture group, acupuncture was given at the points 5 to 10 mm lateral to each of the acupoints selected in the acupuncture group. Acupuncture was given once every day, 30 min each time, consecutively for 10 days in the above two groups. Separately, before treatment, on day 3, 7 and 10 of treatment, arterial partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (PaCO2) and diaphragm thickening fraction (TFdi) were observed in each group. Before and after treatment, the inflammatory and immune indexes (levels of white blood cell [WBC], procalcitonin [PCT], hypersensitive C-reactive protein [hs-CRP] and T lymphocyte percentage [ %]), auxiliary respiratory muscle movement score, the score of chronic obstructive pulmonary disease (COPD) assessment test (CAT), the score of the modified British Medical Research Council dyspnea scale (mMRC) and the TCM syndrome score were compared in each group. The duration of mechanical ventilation, relative complications, 14-day clinical controlled discharge rate and the therapeutic effect were observed in each group. RESULTS: On day 3, 7 and 10 of treatment, PaO2 and TFdi were all increased as compared with those before treatment (P<0.01) and PaCO2 was reduced as compared with that before treatment in each group (P<0.01). After treatment, % was increased as compared with that before treatment in each group (P<0.01), WBC, PCT, hs-CRP, auxiliary respiratory muscle movement score, CAT score, mMRC score and TCM syndrome score were all reduced as compared with those before treatment in each group (P<0.01). After treatment, PaCO2, WBC, PCT, hs-CRP, auxiliary respiratory muscle movement score, CAT score and mMRC score in the acupuncture group were all lower than the other two groups (P<0.01), PaO2 and TFdi were higher than the other two groups (P<0.01); % was higher and TCM syndrome score was lower in the acupuncture group compared with those in the non-acupoint acupuncture group (P<0.01). The duration of mechanical ventilation and the total incidence of complications in the acupuncture group were all lower than the other two groups (P<0.01), and the 14-day clinical controlled discharge rate and total clinical effective rate were higher than the other two groups (P<0.01). CONCLUSION: Acupuncture as adjunctive therapy achieves significant therapeutic effect on AECOPD type Ⅱ respiratory failure. It improves diaphragmatic function, promotes oxygenation and relieves carbon dioxide retention of artery, alleviates clinical symptoms and reduces the time of mechanic ventilation and hospitalization. Besides, the bedside ultrasound detection can objectively reflect the effect of acupuncture on diaphragmatic function in the patients with AECOPD complicated with typeⅡrespiratory failure.

Potential Biomarkers Associated with Differential Manifestations of Ulcerative Colitis (UC) in Uyghur and Han Population in China.

BACKGROUND: Ulcerative colitis (UC) is one of the main subtypes of inflammatory bowel disease (IBD). The incidence of UC in the Xinjiang region is relatively high in China and the manifestations of UC in Uyghur and Han patients are usually differential. This study aimed to identify potential biomarkers of UC. METHODS: All miRNA and mRNA were extracted from the tissue samples obtained from participants in Xinjiang. Differential expression analysis was performed on all mRNAs and miRNAs. The target genes of miRNAs were predicted via three databases. The clusterProfiler package was used for GO and KEGG pathway enrichment analysis. RESULTS: Preliminarily, four miRNAs and 15 genes were associated with the differential manifestations of UC in Uyghur and Han patients. Through the co-expression network construction and further screening in more samples, two miRNAs (hsa-miR-141-5p and hsa-miR-378a-5p) and three genes (ARNTL2, CLDN1 and SLC6A14) were found to be more crucial. These 15 genes were enriched in tight junction, NF-κB, and several other pathways. CONCLUSION: Two miRNAs (hsa-miR-141-5p and hsa-miR-378a-5p) and three genes (ARNTL2, CLDN1, and SLC6A14) associated with the differential manifestations of UC in Uyghur and Han population were identified, which were potential biomarkers.

Imaging and therapeutic applications of Zn(ii)-cryptolepine-curcumin molecular probes in cell apoptosis detection and photodynamic therapy.

Novel red Zn(ii) complex-based fluorescent probes featuring cryptolepine-curcumin derivatives, namely, [Zn(BQ)Cl2] (BQ-Zn) and [Zn(BQ)(Cur)]Cl (BQCur-Zn), were developed for the simple and fluorescent label-free detection of apoptosis, an important biological process. The probes could synergistically promote mitochondrion-mediated apoptosis and enhance tumor therapeutic effects in vitro and vivo.

Strong in vitro and vivo cytotoxicity of novel organoplatinum(II) complexes with quinoline-coumarin derivatives.

A series of novel organoplatinum(II) complexes, [PtII(QC1)(H-QC1)Cl] (Pt1), [PtII(QC2)(H-QC2)Cl] (Pt2), [PtII(QC3)(H-QC3)Cl] (Pt3), [PtII(QC4)(H-QC4)Cl]⋅CH3OH (Pt4), [PtII(QC5)(H-QC5)Cl] (Pt5), [PtII(H-QC6)(DMSO)Cl2] (Pt6), [PtII(H-QC7)(DMSO)Cl2]⋅H2O (Pt7), [PtII(H-QC8)(DMSO)Cl2] (Pt8), [PtII(H-QC9)(DMSO)Cl2]⋅CH3OH (Pt9), [PtII(H-QC10)(DMSO)Cl2] (Pt10) and [PtII(H-QC11)(DMSO)Cl2] (Pt11), bearing quinoline-coumarin derivatives (H-QC1-H-QC11) have been first designed. Complexes Pt1-Pt11 selectively displayed obvious cytotoxicities in comparison to cisplatin for A549/DDP (cisplatin-resistant human lung adenocarcinoma) cells and HeLa cervical carcinoma cells, with IC50 values as low as 100 nM-10.33 µM. In addition, Pt4 and Pt5 display a green-colored luminescent properties, targeted mitochondrial membrane and, thereby induced mainly mitochondria-mediated cell apoptosis was in the following order: Pt4 > Pt5. The different anti-cancer activity of quinoline-coumarin complexes Pt4 (100 nM) and Pt5 (250 nM) were correlate with the presence of 3-(2'-quinolyl)-6-hydroxy-coumarin (H-QC4) ligand. The quinoline-coumarin complex Pt4 (2.0 mg/kg per 2 days) also displayed potent in vivo anti-tumor effect after 21 days-treated. In contrast, the H-QC4 ligand highly enhances the anti-tumor activity and selectivity of organoplatinum(II) complexes in comparison to other previously reported coumarin derivatives metal complexes.

Two telomerase-targeting Pt(ii) complexes of jatrorrhizine and berberine derivatives induce apoptosis in human bladder tumor cells.

Two novel Pt(ii) complexes, [Pt(B-TFA)Cl]Cl (Pt1) and [Pt(J-TFA)Cl]Cl (Pt2) with jatrorrhizine and berberine derivatives (B-TFA and J-TFA) were first prepared as desirable luminescent agents for cellular applications and potent telomerase inhibitors, which can induce bladder T-24 tumor cell apoptosis by targeting telomerase, together with induction of mitochondrial dysfunction, telomere DNA damage and cell-cycle arrest. Importantly, T-24 tumor inhibition rate (TIR) was 50.4% for Pt2, which was higher than that of Pt1 (26.4%) and cisplatin (37.1%). Taken together, all the results indicated that jatrorrhizine and berberine derivatives Pt1 and Pt2 show low toxicity and could be novel Pt-based anti-cancer drug candidates.

High in vitro and in vivo antitumor activities of luminecent platinum(II) complexes with jatrorrhizine derivatives.

Two highly active anticancer Pt(II) complexes, [Pt(Jat1)Cl]Cl (Pt1) and [Pt(Jat2)Cl]Cl (Pt2), containing jatrorrhizine derivative ligands (Jat1 and Jat2) are described. Cell intake study showed high accumulation in cell nuclear fraction. Pt1 and Pt2 exhibited high selectivity for HeLa cancer cells (IC50 = 15.01 ±â€¯1.05 nM and 1.00 ±â€¯0.17 nM) comparing with HL-7702 normal cells (IC50 > 150 µM), by targeting p53 and telomerase. Pt2 containing Jat2 ligand was more potent and showed high selectivity for telomerase. It also caused mitochondria and DNA damage, sub-G1 phase arrest, and a high rate of cell apoptosis at the low dose of 1.00 nM. The HeLa tumor inhibition rate (TIR) of Pt2 was 48.8%, which was even higher than cisplatin (35.2%). In addition, Pt2 displayed green luminescent property and potent telomerase inhibition. Our findings demonstrated the promising development of platinum(II) complexes containing jatrorrhizine derivatives as novel Pt-based anti-cancer agents.

High in Vitro and in Vivo Tumor-Selective Novel Ruthenium(II) Complexes with 3-(2'-Benzimidazolyl)-7-fluoro-coumarin.

Three novel Ru(II) complexes, namely, (RuCl2[La][DMSO]2)·H2O (Ru1), (RuCl2[Lb][DMSO]2) (Ru2), and (RuCl2[Lc][DMSO]2) (Ru3), which respectively contain 3-(2'-benzimidazolyl)coumarin (La), 3-(2'-benzimidazolyl)-7-fluoro-coumarin (Lb), and 3-(2'-benzimidazolyl)-7-methoxyl-coumarin (Lc), were first designed and characterized. Ru2 showed potent antitumor activity against NCI-H460 cells (IC50 = 0.30 ± 0.02 µM) and high selectivity between NCI-H460 cancer cells and normal HL-7702 cells. Ru2 induced NCI-H460 apoptosis via telomerase inhibition, which involved DNA damage, cell-cycle distribution, and S phase-protein down-regulation. However, Ru1 did not demonstrate such effects in NCI-H460 cells, which is undoubtedly associated with the key regulatory role of the 7-fluoro substituted group in the Lb ligand of Ru2. Ru2 exhibited considerably higher anticancer efficacy (inhibition rate [IR] = 61.3%) compared with cisplatin (IR= 25.5%) in a NCI-H460 xenograft mouse model. Thus, this coumarin Ru(II) compound is a promising Ru2-targeting telomerase anticancer agent.

Complexes of lanthanides(iii) with mixed 2,2'-bipyridyl and 5,7-dibromo-8-quinolinoline chelating ligands as a new class of promising anti-cancer agents.

Five novel lanthanides(iii) complexes, [Lu(Me)(MBrQ)2NO3] (MeMBrQ-Lu), [Ho(MeO)(MBrQ)2NO3] (MeOMBrQ-Ho), [Ho(Me)(MBrQ)2NO3] (MeMBrQ-Ho), [La(Me)2(BrQ)2NO3] (MeBrQ-La) and [Sm(Me)(BrQ)2(CH3OH)NO3] (MeBrQ-Sm), have been synthesized, in which 2,2'-bipyridyl (4,4'-dimethyl-2,2'-bipyridyl (Me) and 4,4'-dimethoxy-2,2'-bipyridine (MeO)) and 5,7-dibromo-8-quinolinoline derivatives (5,7-dibromo-2-methyl-8-quinolinol (MBrQ-H) and 5,7-dibromo-8-quinolinol (BrQ-H)) act as the chelating ligands. The in vitro cytotoxic activities of the five Ln(iii) complexes have been studied with the SK-OV-3/DDP, NCI-H460 and HeLa cancer cells. MeMBrQ-Lu, MeOMBrQ-Ho, MeMBrQ-Ho, MeBrQ-La and MeBrQ-Sm show higher cytotoxicity against the HeLa cells (IC50 values of 1.00 nM-3.45 µM) than cisplatin (13.11 ± 0.53 µM). In particular, the MeOMBrQ-Ho and MeMBrQ-Ho complexes exhibit superior cytotoxic activity, with IC50 values at 1.00 ± 0.34 nM and 125.00 ± 1.08 nM. We further demonstrate that MeOMBrQ-Ho and MeMBrQ-Ho inhibit the proliferation of HeLa cells by inhibiting telomerase and targeting mitochondria to induce DNA damage-mediated apoptosis. In addition, MeOMBrQ-Ho significantly inhibits tumor growth with a tumor growth inhibition rate (IR) of 50.8% in a HeLa mouse xenograft model. Taken together, MeOMBrQ-Ho is a novel lanthanide(iii) complex with promising antitumor activity.

Synthesis and anti-phytopathogenic activity of 8-hydroxyquinoline derivatives.

Phytopathogenic fungi have become a serious threat to the quality of agricultural products, food security and human health globally, necessitating the need to discover new antifungal agents with de novo chemical scaffolds and high efficiency. A series of 8-hydroxyquinoline derivatives were designed and synthesized, and their antifungal activity was evaluated against five phytopathogenic fungi. In vitro assays revealed that most of the tested compounds remarkably impacted the five target fungi and their inhibitory activities were better than that of the positive control azoxystrobin. Compound 2, in particular, exhibited the highest potency among all the tested compounds, with an EC50 of 0.0021, 0.0016, 0.0124, 0.0059 and 0.0120 mM respectively against B. cinerea, S. sclerotiorum, F. graminearum, F. oxysporum and M. oryzae, followed by compound 5c. The morphological observations of optical microscopy and scanning electron microscopy revealed that compounds 2 and 5c caused mycelial abnormalities of S. sclerotiorum. Futhermore, the results of in vivo antifungal activity of compounds 2 and 5c against S. sclerotiorum showed that 5c possessed stronger protective and curative activity than that of 2, and the curative effects of 5c at 40 and 80 µg mL-1 (84.18% and 95.44%) were better than those of azoxystrobin (77.32% and 83.59%). Therefore, compounds 2 and 5c are expected to be novel lead structures for the development of new fungicides.

Complete chloroplast genome of Rhododendron pulchrum, an ornamental medicinal and food tree.

The semi-evergreen azalea, Rhododendron pulchrum, a valuable horticultural and medicinal plant species. Using next-generation sequencing, applying a combination of de novo and reference-guided assembly, we sequenced its complete chloroplast genome. Our study reveals that R. pulchrum have a typical cp genome of 136,249 bp in length, without inverted repeat regions. A total of 73 genes, 42 of which are protein coding genes, 29 tRNA genes, two rRNA genes were identified. The GC content of the whole genome is 35.98%. Phylogenetic analysis indicates that R. pulchrum is closely related to the species of Vaccinium oldhamii and Vaccinium macrocarpon.

Hypolipidemic effect of SIPI-7623, a derivative of an extract from oriental wormwood, through farnesoid X receptor antagonism.

Farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily of ligand-activated transcription factors. As a metabolic regulator, FXR plays key roles in bile acid and cholesterol metabolism and lipid and glucose homeostasis. Therefore, FXR is a potential drug target for several metabolic syndromes, especially those related to lipidemia disorders. In the present study, we identified small molecule SIPI-7623, a derivative of an extract from Oriental wormwood (Artemisia capillaris), and found that it specifically upregulated the expression of cholesterol-7-alpha-hydroxylase (CYP7A1), downregulated the expression of sterol-regulatory element-binding protein 1c (SREBP-1c) in the liver, and inhibited the expression of ileal bile acid binding-protein (IBABP) in the ileum of rats. We found that inhibition of FXR by SIPI-7623 decreased the level of cholesterol and triglyceride. SIPI-7623 reduced the levels of cholesterol and triglyceride in in vitro HepG2 cell models, ameliorated diet-induced atherosclerosis, and decreased the serum lipid content on rats and rabbits model of atherosclerosis in vivo. Furthermore, SIPI-7623 decreased the extent of atherosclerotic lesions. Our resutls demonstrated that antagonism of the FXR pathway can be employed as a therapeutic strategy to treat metabolic diseases such as hyperlipidemia and atherosclerosis. In conclusion, SIPI-7623 could be a promising lead compound for development of drugs to treat hyperlipidemia and atherosclerosis.

Synthesis and antitumor mechanisms of two novel platinum(ii) complexes with 3-(2'-benzimidazolyl)-7-methoxycoumarin.

Two novel platinum(ii) complexes, [PtCl2(H-MeOBC)(DMSO)] (Pt1) and [Pt2Cl3(MeOBC)(DMSO)2] (Pt2), with 3-(2'-benzimidazolyl)-8-methoxycoumarin (H-MeOBC) as the ligand were synthesized and evaluated for their antiproliferative activity. Among all the tumor cells, dual-Pt(ii) complex Pt2 exhibited the most potent activity, with an IC50 value of 0.5 ± 0.2 µM against cisplatin-resistant SK-OV-3/DDP cancer cells. In the case of SK-OV-3/DDP cells, Pt2 displayed a 20.1-196.0-fold increased activity when compared with cisplatin, H-MeOBC and Pt1. Importantly, Pt1 and Pt2 displayed low inhibitory rates against normal HL-7702 cells. Further investigation revealed that Pt2 is a novel telomerase inhibitor binding to c-myc promoter elements. Mechanistic studies demonstrated that dual-Pt(ii) complex Pt2 arrests the cell cycle at the G2/M phase and induces apoptosis and causes mitochondrial dysfunction.

Norcrassin A, a novel C16 tetranorditerpenoid, and bicrotonol A, an unusual dimeric labdane-type diterpenoid, from the roots of Croton crassifolius.

A novel C16 tetranorditerpenoid, norcrassin A (1), and an unusual dimeric labdane-type diterpenoid, bicrotonol A (2), were isolated from the roots of Croton crassifolius. Norcrassin A (1) featured a new carbon skeleton with an unprecedented 5/5/5/6 tetracyclic system. Bicrotonol A (2) possessed an unusual tetrahydroxypyran ring linkage connecting two labdane diterpenoid monomers. The structures of all compounds, including the absolute configuration, were elucidated by the interpretation of their NMR spectroscopic data, high resolution mass spectrometry, and single-crystal X-ray diffraction. A plausible biosynthetic pathway of 1 is proposed. The anti-Alzheimer's Disease (AD) activities of 1 and 2 are also evaluated using the AD pathological model.