Genetic variants of cell cycle pathway genes are associated with head and neck squamous cell carcinoma in the Chinese population.

Genetic alterations in the cell cycle pathway are common in head and neck squamous cell carcinoma (HNSCC). We identified four novel HNSCC susceptibility loci (CDKN1C rs452338, CDK4 rs2072052, E2F2 rs3820028 and E2F2 rs2075993) through a two-stage matched case-control study. There was a combined effect among the four single nucleotide polymorphisms (SNPs), as the number of risk genotypes increased, the risk of HNSCC displayed an increasing trend (Ptrend < 0.001). And there were multiplicative interactions between rs452338 and rs2072052, rs2072052 and rs3820028, rs2072052 and rs2075993. Functional bioinformatics analysis and dual-luciferase reporter assay revealed that E2F2 rs2075993 T>C reduced the stability of E2F2 3'-UTR secondary structure and affected the binding of E2F2 to miR-940, which was up-regulated in HNSCC tumor tissues (P = 2.9e-8) and was correlated with poor overall survival of HNSCC (HR = 1.39, 95% CI = 1.02-1.90). In vitro assays, we discovered that the expression of miR-940 was regulated by METTL3, and miR-940 promoted the proliferation, migration and invasion, and inhibited the senescence and autophagy of tumor cells. In terms of mechanism, compared with rs2075993 allele T, we found that the protective variant rs2075993 allele C interfered with the translational inhibition of E2F2 by miR-940, resulting in increased expression of E2F2 protein, which further reduced the proliferation, migration, invasion, and increased the senescence of tumor cells.

Discovery of Neuritogenic Securinega Alkaloids from Flueggea suffruticosa by a Building Blocks-Based Molecular Network Strategy.

A combined strategy of building blocks recognition and molecular network construction, termed the building blocks-based molecular network (BBMN), was first presented to facilitate the efficient discovery of novel natural products. By mapping the BBMN of the total alkaloid fraction of Flueggea suffruticosa, three Securinega alkaloids (SEAs) with unusual chemical architectures, suffranidines A-C (1-3), were discovered and isolated. Compound 1 characterizes an unprecedented 8/5/6/5/6/6/6/6-fused octacyclic scaffold with a unique cage-shaped 3-azatricyclo[6.4.0.03,11 ]dodecane core. Compounds 2 and 3 are highly modified SEA dimers that incorporate additional C6 motifs. A hypothetical biosynthetic pathway for 1-3 was proposed. In addition, 1 significantly induced neuronal differentiation and neurite extension by upregulating eukaryotic elongation factor 2 (eEF2)-mediated protein synthesis.

Feasibility and safety of single-incision laparoscopic cholecystectomy versus conventional laparoscopic cholecystectomy in an ambulatory setting.

BACKGROUND: Single-incision laparoscopic surgery has emerged as an alternative to conventional laparoscopic cholecystectomy (LC) in the clinical setting. Limited information is available on the possibility of performing single-incision laparoscopic surgery as an ambulatory procedure. This study aimed to determine the feasibility and safety of single-incision laparoscopic cholecystectomy (SILC) versus conventional LC in an ambulatory setting. METHODS: Ninety-one patients were randomized to SILC (n = 49) or LC (n = 42). The success rate, operative duration, blood loss, hospital stay, gallbladder perforation, drainage, delayed discharge, readmission, total cost, complications, pain score, vomiting, and cosmetic satisfaction of the two groups were then compared. RESULTS: There were significant differences in the operative time (46.89 ±â€¯10.03 min in SILC vs. 37.24 ±â€¯10.23 min in LC; P < 0.001). As compared with LC, SILC was associated with lower total costs (8012.28 ±â€¯752.67 RMB vs. 10258.91 ± 1087.63 RMB; P < 0.001) and better cosmetic satisfaction (4.94 ± 0.24 vs. 4.74 ± 0.54; P = 0.031). There were no significant differences between-group in terms of general data, success rate, blood loss, hospital stay, gallbladder perforation, drainage, delayed discharge, readmission, complications, pain score, and vomiting (P > 0.05). CONCLUSIONS: Ambulatory SILC is safe and feasible for selected patients. The advantages of SILC as compared with LC are improved cosmetic satisfaction and lower total costs.

Rapid Characterization of the major chemical constituents from Polygoni Multiflori Caulis by liquid chromatography tandem mass spectrometry and comparative analysis with Polygoni Multiflori Radix.

Polygoni Multiflori Caulis is a traditional Chinese medicine that has been used for a long time to treat sleep disorders. However, the multiple chemical composition analysis has not been reported. In this study, a simple, rapid and effective ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method was established to characterize the components of Polygoni Multiflori Caulis. In addition, a chemical comparative analysis was performed with Polygoni Multiflori Radix, another traditional Chinese medicine from the same plant, through multivariate statistical analysis and semi-quantitative analysis to screen the difference in chemical ingredients between these two herbal medicines from same medicinal plant. A total of 33 peaks were detected within 25 min, and 28 of them were identified or tentatively characterized by comparing the retention time and mass spectrometry data. Based on the results, 12 characteristic components were screened out by multivariate statistical analysis, and their content change trends were compared by semi-quantitative analysis.

[HPLC Specific Fingerprint of Alcohol Extract of Andrographis paniculata].

OBJECTIVE: To establish the specific fingerprint of alcohol extract of Andrographis paniculata by HPLC. METHODS: The analysis was performed on Cosmosil 5C18 -MS-II (250 mm x 4. 6 mm, 5 µm) column, with gradient phase consisting of acetonitrile and water at the flow rate of 1. 0 mL/min. The UV detection wavelength was set at 225 nm, and column temperature was 30 °C. RESULTS: The specific fingerprint chromatogram was established and seven common peaks were identified by comparison with the reference standards and LC-MS. The relative retention times were 1. 00 (No. 1, andrographolide), 1. 04 (No. 2, deoxyandrographoside), 1. 07 (No. 3, isoandrographolide), 1. 10 (No. 4, 14-deoxy-11, 12-didehydroandrographoside), 1. 50 (No. 5, neoandrographolide), 1. 75 ( No. 6, deoxyandrographolide) and 1. 79 (No. 7, dehydroandrographolide). CONCLUSION: The method is simple and reproducible with high precision, which can provide the basis for the quality control and evaluation of alcohol extract of Andrographis paniculata and its preparations.

Psychological resilience and related factors among primary care workers in Wuhan, China: A cross-sectional study.

Purpose: Primary medical workers constitute a high-risk group for mental health problems, and psychological resilience might protect them from the negative psychological impacts of their work. Therefore, this study aimed to investigate the current situation of psychological resilience among primary care workers in Wuhan, China, as well as related factors. Methods: In this cross-sectional study, a total of 417 primary care workers (30.0 % men; 38.5 ± 8.5 years old) were randomly selected to complete a questionnaire. The brief version of the National Mental Health Literacy Questionnaire and the Psychological Resilience Scale were used to assess participants' mental health literacy and psychological resilience, respectively. Multiple linear regression was performed to identify factors associated with the psychological resilience of primary care workers. Results: More than four-fifths of the primary care workers included in this study exhibited appropriate levels of mental health knowledge. In terms of mental health skills, participants' attainment rates, ranging from high to low, were 60.9 % for distracting attention, 45.3 % for interpersonal support and 43.9 % for cognitive reappraisal. The average psychological resilience score obtained by primary care workers was 27.81 ± 5.71, and the factors associated with increased psychological resilience included being male, being older, and possessing higher mental health skills, including skills pertaining to interpersonal support and distracting attention. Conclusion: The psychological resilience of primary care workers in Wuhan is at a moderate level and thus requires further improvement. Although these medical staff exhibit appropriate levels of mental health knowledge, their mental health skills are relatively poor, despite the fact that interpersonal support and distracting attention are significantly associated with psychological resilience. Hence, interventions targeting mental health skills are recommended to promote psychological resilience among primary care workers.

Stigma toward mental disorders and associated factors among community mental health workers in Wuhan, China.

BACKGROUND: Stigma toward mental disorders (STMD) is a significant barrier to mental health service delivery. To improve the provision of mental health services for community-dwelling residents in China, this study investigated STMD and its associated factors in community mental health workers (CMHWs) in Wuhan, China. METHODS: In this cross-sectional study, a total of 3869 CMHWs (22.9% men and 37.1 ± 8.4 years old) were randomly selected through multistage sampling and invited to participate in this survey. The perceived devaluation-discrimination scale (PDD) and the National Mental Health Literacy Questionnaire (NMHLQ) were used to assess STMD and mental health knowledge, respectively. The presence of STMD was indicated by a mean item score of 3.0 or higher on the PDD. Multiple logistic regression was used to identify factors associated with STMD. RESULTS: Of the CMHWs, 41.9% had poor mental health knowledge (NMHLQ score < 80), and 18.5% exhibited STMD. In multiple regression analysis, factors significantly associated with STMD were social workers (vs. primary care physicians, OR = 1.44, p < .001), poor self-rated capacity to handle common mental health problems (vs. good, OR = 1.57, p < .001), and poor mental health knowledge (vs. NMHLQ score ≥ 80, OR = 1.46, p < .001). CONCLUSION: STMD is common among Chinese CMHWs. To reduce STMD among CMHWs, training programs in mental health care skills and mental health education may be necessary.

Nitrogen fertilization coupled with foliar application of iron and molybdenum improves shade tolerance of soybean under maize-soybean intercropping.

Maize-soybean intercropping is practiced worldwide because of some of the anticipated advantages such as high crop yield and better utilization of resources (i.e., water, light, nutrients and land). However, the shade of the maize crop has a detrimental effect on the growth and yield of soybean under the maize-soybean intercropping system. Hence, this experiment was conducted to improve the shade tolerance of such soybean crops with optimal nitrogen (N) fertilization combined with foliar application of iron (Fe) and molybdenum (Mo). The treatments comprised five (5) maize-soybean intercropping practices: without fertilizer application (F0), with N fertilizer application (F1), with N fertilizer combined with foliar application of Fe (F2), with N fertilizer coupled with foliar application of Mo (F3) and with N fertilizer combined with foliar application of Fe and Mo (F4). The findings of this study showed that maize-soybean intercropping under F4 treatment had significantly (p< 0.05) increased growth indices such as leaf area (cm2), plant height (cm), stem diameter (mm), stem strength (g pot-1), and internode length (cm) and yield indices (i.e., No of pods plant-1, grain yield (g plant-1), 100-grain weight (g), and biomass dry matter (g plant-1)) of the soybean crop. Moreover, intercropping under F4 treatment enhanced the chlorophyll SPAD values by 26% and photosynthetic activities such as Pn by 30%, gs by 28%, and Tr by 28% of the soybean crops, but reduced its CO2 by 11%. Furthermore, maize-soybean intercropping under F4 treatment showed improved efficiency of leaf chlorophyll florescence parameters of soybean crops such as Fv/Fm (26%), qp (17%), ϕPSII (20%), and ETR (17%), but reduced NPQ (12%). In addition, the rubisco activity and soluble protein content of the soybean crop increased by 18% in maize-soybean intercropping under F4 treatment. Thus, this suggested that intercropping under optimal N fertilization combined with foliar application of Fe and Mo can improve the shade tolerance of soybean crops by regulating their chlorophyll content, photosynthetic activities, and the associated enzymes, thereby enhancing their yield and yield traits.

Nitrogen fertilization coupled with iron foliar application improves the photosynthetic characteristics, photosynthetic nitrogen use efficiency, and the related enzymes of maize crops under different planting patterns.

Photosynthetic rate (Pn) and photosynthetic nitrogen use efficiency (PNUE) are the two important factors affecting the photosynthesis and nutrient utilization of plant leaves. However, the effect of N fertilization combined with foliar application of Fe on the Pn and PNUE of the maize crops under different planting patterns (i.e., monocropping and intercropping) is elusive. Therefore, this experiment was conducted to determine the effect of N fertilization combined with foliar application of Fe on the photosynthetic characteristics, PNUE, and the associated enzymes of the maize crops under different planting patterns. The results of this study showed that under intercropping, maize treated with N fertilizer combined with foliar application of Fe had not only significantly (p < 0.05) improved physio-agronomic indices but also higher chlorophyll content, better photosynthetic characteristics, and related leaf traits. In addition, the same crops under such treatments had increased photosynthetic enzyme activity (i.e., rubisco activity) and nitrogen metabolism enzymes activities, such as nitrate reductase (NR activity), nitrite reductase (NiR activity), and glutamate synthase (GOGAT activity). Consequently, intercropping enhanced the PNUE and soluble sugar content of the maize crops, thus increasing its yield compared with monocropping. Thus, these findings suggest that intercropping under optimal N fertilizer application combined with Fe foliation can improve the chlorophyll content and photosynthetic characteristics of maize crops by regulating the associated enzymatic activities. Consequently, this results in enhanced PNUE, which eventually leads to better growth and higher yield in the intercropping system. Thus, practicing intercropping under optimal nutrient management (i.e., N and Fe) could be crucial for better growth and yield, and efficient nitrogen use efficiency of maize crops.

Hem-o-lok Clips Migration: An Easily Neglected Complication after Laparoscopic Biliary Surgery.

Clip migration into the common bile duct (CBD) is a rare but well-established phenomenon of laparoscopic biliary surgery. The mechanism and exact incidence of clip migration are both poorly understood. Clip migration into the common bile duct can cause recurrent cholangitis and serve as a nidus for stone formation. We present a case, a 54-year-old woman, of clip-induced cholangitis resulting from surgical clip migration 12 months after laparoscopic cholecystectomy and laparoscopic common bile duct exploration (LC+LCBDE) with primary closure.

Gelsekoumidines A and B: Two Pairs of Atropisomeric Bisindole Alkaloids from the Roots of Gelsemium elegans.

Two pairs of atropisomeric bisindole alkaloids, gelsekoumidines A (1) and B (2), with a new carbon skeleton, were isolated from the roots of Gelsemium elegans. Compounds 1 and 2 represent the first examples of seco-koumine-gelsedine type alkaloids, which feature an unprecedented 20,21-seco-koumine scaffold fused with a gelsedine framework via a double bond. Their structures including absolute stereochemistry were elucidated by spectroscopic data, single-crystal X-ray diffraction, and electronic circular dichroism (ECD) calculation. A plausible biogenetic pathway for the new compounds is also proposed. Compound 2 exhibited a moderate inhibitory effect against nitric oxide (NO) production.

Two new diterpenoid lactones isolated from Andrographis paniculata.

In the present study, two new diterpenoid lactones, 3-deoxy-andrographoside (1) and 14-deoxy-15-methoxy-andrographolide (2), were isolated from the aerial parts of Andrographis paniculata. Their structures were elucidated by combination of NMR, MS, and chemical methods. The configurations of 1 and 2 were established based on the analysis of ROESY data and single crystal X-ray diffraction experiment.

Five new koumine-type alkaloids from the roots of Gelsemium elegans.

Five new koumine-type alkaloids (1-5) along with six known ones were isolated from the roots of Gelsemium elegans. Their structures with absolute configurations were elucidated on the basis of NMR spectroscopy and electronic circular dichroism spectral analyses. The inhibitory effects of compounds 1-11 on the viability of three tumor cell lines (A-649, HepG2, and HuH7) were evaluated by the MTT assay.

Inhibitory effect of silymarin on CCl4-induced liver fibrosis by reducing Ly6Chi monocytes infiltration.

It has been well established that silymarin has hepatoprotective and anti-fibrotic effects. But the mechanisms are poorly understood. In recent years, the role of Ly6Chi monocytes in liver fibrosis has been well demonstrated. Thus, in present study we aimed to investigate whether silymarin can relieve liver fibrosis by reducing Ly6Chi monocytes infiltration. The mouse model of liver fibrosis was established by injected with carbon tetrachloride (CCl4) via intraperitoneal repeatedly. Mice in silymarin group received silymarin treatment by gavage. Silymarin significantly reduced liver inflammation and fibrosis of the mice induced by CCl4 injection, as revealed by liver histological and pathological analysis. Mice administrated by silymarin exhibited less infiltration of Ly6Chi monocytes. But there was no difference on other tested leukocyte subsets between CCl4 group and silymarin group. Meanwhile, further study found that silymarin significantly reduced CCl4-induced increased expression of tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-ß1 and monocyte chemoattractant protein 1 (MCP-1), which was in line with the decreased numbers of intrahepatic Ly6Chi monocytes. In conclusion, our study showed that the anti-inflammatory and anti-fibrotic effects of silymarin could be contributed to the prevention of Ly6Chi monocytes infiltration into the injured livers, which will give us a better understanding on the cellular mechanism of hepatoprotective and anti-fibrotic effect for silymarin.

Association of serum gamma-glutamyl transferase with treatment outcome in chronic hepatitis B patients.

AIM: To investigate the association of serum gamma-glutamyl transferase (GGT) levels with chronic hepatitis B infection and hepatitis B e antigen (HBeAg) seroconversion. METHODS: A retrospective study was performed on clinical data collected from patients who had been positive for hepatitis B surface antigen for > 6 mo and who were antiviral-treatment naïve (n = 215) attending the Hepatitis Clinic at Nanjing Drum Tower Hospital between August 2010 and December 2013. Healthy individuals without liver disease (n = 83) were included as controls. Patients were categorized into four groups based on disease status as recommended by the European Association for the Study of the Liver: immune tolerance (IT; n = 47), HBeAg-positive hepatitis (EPH; n = 93), HBeAg-negative hepatitis (ENH; n = 20), and inactive carrier (IC; n = 55). Prediction of complete response (CR) based on serum GGT was also examined in EPH patients (n = 33) treated for 48 wk with nucleos(t)ide analogue (NA) therapy, including lamivudine plus adefovir combination therapy (n = 20) or entecavir monotherapy (n = 13). CR was defined as a serum hepatitis B virus DNA level < 500 copies/mL and HBeAg seroconversion by 48 wk of treatment. RESULTS: Serum GGT levels were significantly increased in EPH and ENH patients relative to the IT, IC, and healthy control groups (P < 0.01 for all). However, no significant difference in serum GGT levels was found between the EPH and ENH groups. Baseline serum GGT levels were significantly higher in patients who achieved CR (7/33; 21.2%) compared to patients in the non-CR group (26/33; 78.8%; P = 0.011). In addition, the decline in serum GGT was greater in CR patients compared to non-CR patients after 24 wk and 48 wk of treatment (P = 0.012 and P = 0.008, respectively). The receiver operating characteristic curve yielded a sensitivity of 85.71% and a specificity of 61.54% at a threshold value of 0.89 times the upper limit of normal for baseline serum GGT in the prediction of CR following NA therapy. CONCLUSION: Serum GGT is significantly elevated in EPH and ENH patients and is a potential biomarker for the prediction of HBeAg seroconversion following NA therapy.

Crude triterpenoid saponins from Anemone flaccida (Di Wu) exert anti-arthritic effects on type II collagen-induced arthritis in rats.

BACKGROUND: Anemone flaccida Fr . Schmidt (Ranunculaceae) (Di Wu in Chinese) is used to treat punch injury and rheumatoid arthritis (RA). However, the active compounds and underlying mechanism of action mediating the anti-arthritic effects of A. flaccida remain unclear. This study aims to evaluate the underlying action mechanism of A. flaccida crude triterpenoid saponins (AFS) on RA using a type II collagen (CII)-induced arthritis (CIA) rat model, and to assess the anti-inflammatory effects of the main active compounds of AFS, namely flaccidoside II, anhuienoside E, glycoside St-I4a, hemsgiganoside B, hederasaponin B, and 3-O-α-l-rhamnopyranosyl (1 â†’ 2)-ß-d-glucopyranosyl oleanolic acid 28-O-ß-d-glucopyranosyl (1 â†’ 6)-ß-d-glucopyranosyl ester. METHODS: Male Wistar rats (n = 50) were randomly separated into five groups (n = 10) and immunized by CII injection. AFS (200 or 400 mg/kg) and dexamethasone were orally administered for 30 days after establishing the model. The arthritis severity was assessed by paw volume using a plethysmometer. After 30 days of treatment, the right hind paws of the rats were obtained. Paw histology was analyzed by hematoxylin and eosin staining, and radiologic imaging was performed by micro-computed tomography. MTT assays were used to evaluate the cytotoxicity of AFS and its main compounds in RAW264.7 cells. Enzyme-linked immunosorbent assay kits were used to measure interleukin (IL)-6 and tumor necrosis factor (TNF)-α in serum and supernatants from AFS- and main AFS compound-treated RAW264.7 cells stimulated by lipopolysaccharide (LPS). RESULTS: Anemone flaccida crude triterpenoid saponins inhibited redness and swelling of the right hind paw in the CIA model. Radiological and histological examinations indicated that inflammatory responses were reduced by AFS treatment. Moreover, comparing with untreated rats, serum TNF-α (P = 0.0035 and P < 0.001) and IL-6 (P = 0.0058 and P = 0.0087) were lower in AFS-treated CIA rats at the dose of 200 and 400 mg/kg/day. AFS and its main compounds, including hederasaponin B, flaccidoside II, and hemsgiganoside B, significantly inhibited TNF-α (P = 0.0022, P = 0.013, P = 0.0015, and P = 0.016) and IL-6 (P = 0.0175, P < 0.001, P < 0.001, and P < 0.001) production in LPS-treated RAW264.7 cells, respectively. CONCLUSIONS: Anemone flaccida crude triterpenoid saponins and its main bioactive components, including hederasaponin B, flaccidoside II, and hemsgiganoside B, decreased pro-inflammatory cytokine levels in a CIA rat model and LPS-induced RAW264.7 cells.

Effects of cholecystectomy on the changes of motility of Beagle dogs' sphincter of Oddi.

PURPOSE: To observe the effect of cholecystectomy on the changes of motion pattern of Beagle dogs' sphincter of Oddi (SO), and investigate the modulatory role of nitric oxide (NO) and cholecystokinin (CCK) in the regulation of SO. METHODS: Pressure of common bile duct, SO motility, response to bolus injections of cholecystokinin (CCK, 20 ng/kg and 100 ng/kg), basal pressure (BP) and phasic contraction amplitude (PCA) were measured respectively by manometry in six Beagle dogs before and after cholecystectomy. RESULTS: After cholecystectomy, the pressure and diameter of common bile ducts (CBD) was significantly increased (p<0.01); BP and phasic contraction frequency (PCF) were also increased, however, no significant differences were found between the two groups; the SO motilities was not significantly changed. The relaxation responded to physiological dose of CCK (20ng/kg) was decreased, while bolus-dose of CCK (100ng/kg) induced rapid contractions and decreased PCA after cholecystectomy. The regulation pattern of SO pressure modulated by NO and its inhibitor had changed after cholecystectomy. CONCLUSION: After cholecystectomy in Beagle dogs, no obviously change of motion pattern of SO was observed through self-compensation, but these compensations may lead to some changes of regulation pattern of CCK and NO on SO.

Effects of cholecystectomy on the changes of motility of Beagle dogs' sphincter of Oddi

To observe the effect of cholecystectomy on the changes of motion pattern of Beagle dogs' sphincter of Oddi (SO), and investigate the modulatory role of nitric oxide (NO) and cholecystokinin (CCK) in the regulation of SO. Pressure of common bile duct, SO motility, response to bolus injections of cholecystokinin (CCK, 20 ng/kg and 100 ng/kg), basal pressure (BP) and phasic contraction amplitude (PCA) were measured respectively by manometry in six Beagle dogs before and after cholecystectomy. After cholecystectomy, the pressure and diameter of common bile ducts (CBD) was significantly increased (p<0.01); BP and phasic contraction frequency (PCF) were also increased, however, no significant differences were found between the two groups; the SO motilities was not significantly changed. The relaxation responded to physiological dose of CCK (20ng/kg) was decreased, while bolus-dose of CCK (100ng/kg) induced rapid contractions and decreased PCA after cholecystectomy. The regulation pattern of SO pressure modulated by NO and its inhibitor had changed after cholecystectomy. CONCLUSION: After cholecystectomy in Beagle dogs, no obviously change of motion pattern of SO was observed through self-compensation, but these compensations may lead to some changes of regulation pattern of CCK and NO on SO.

Psammaplins from the sponge Pseudoceratina purpurea: inhibition of both histone deacetylase and DNA methyltransferase.

Four novel bisulfide bromotyrosine derivatives, psammaplins E (9), F (10), G (11), and H (12), and two new bromotyrosine derivatives, psammaplins I (13) and J (14), were isolated from the sponge Pseudoceratina purpurea, along with known psammaplins A (4), B (6), C (7), and D (8) and bisaprasin (5). The structures of psammaplins E (9) and F (10), which each contain an oxalyl group rarely found in marine organisms, were determined by spectroscopic analysis. Compounds 4, 5, and 10 are potent histone deacetylase inhibitors and also show mild cytotoxicity. Furthermore, compounds 4, 5, and 11 are potent DNA methyltransferase inhibitors. The biogenetic pathway previously proposed for the psammaplins class is also revisited.