Smartphone-based paper strip assay for putrescine and spermidine detection using hybrid organic-inorganic perovskite with Eu3+ complex.

A new method utilizing fluorescent ratiometry is proposed for detecting putrescine and spermidine. The method involves the use of a fluorescent probe comprising a 2D halide perovskite synthesized from octadecylamine-iodine and PbI2via a grinding-sonicating technique, along with a Eu3+-complex. Upon excitation at 290 nm, the probe fluoresces at two distinguishable wavelengths. The addition of putrescine and spermidine significantly decreases the emission of the 2D halide perovskite at 496 nm, while the emission of the Eu3+-complex at 618 nm remains stable. The color changes of the probe depend on the concentration of putrescine and spermidine, and the assay offers linearity over a wide concentration range (30-4000 ng mL-1), a low detection limit (4 ng mL-1 for putrescine, and 7 ng mL-1 for spermidine), and a quick response time. Furthermore, a portable device based on a smartphone can be used to record the color change of the paper test strip using the prepared fluorescent materials. The fluorescence quenching mechanism of the probe is explained as dynamic quenching.

The DQQ is a Valid Tool to Collect Population-Level Food Group Consumption Data: A Study Among Women in Ethiopia, Vietnam, and Solomon Islands.

BACKGROUND: The Diet Quality Questionnaire (DQQ) is a rapid dietary assessment tool designed to enable feasible measuring and monitoring of diet quality at population level in the general public. OBJECTIVES: To evaluate validity of the DQQ for collecting population-level food group consumption data required for calculating diet quality indicators by comparing them with a multipass 24-h dietary recall (24hR) as the reference. METHODS: Cross-sectional data were collected among female participants aged 15-49 y in Ethiopia (n = 488), 18-49 y in Vietnam (n = 200), and 19-69 y in Solomon Islands (n = 65) to compare DQQ and 24hR data in proportional differences in food group consumption prevalence, percentage of participants achieving Minimum Dietary Diversity for Women (MDD-W), percent agreement, percentage misreporting food group consumption, and diet quality scores of Food Group Diversity Score (FGDS), noncommunicable disease (NCD)-Protect, NCD-Risk, and the Global Dietary Recommendation (GDR) score using a nonparametric analysis. RESULTS: The mean (standard deviation) percentage point difference between DQQ and 24hR in population prevalence of food group consumption was 0.6 (0.7), 2.4 (2.0), and 2.5 (2.7) in Ethiopia, Vietnam, and Solomon Islands, respectively. Percent agreement of food group consumption data ranged from 88.6% (10.1) in Solomon Islands to 96.3% (4.9) in Ethiopia. There was no significant difference between DQQ and 24hR in population prevalence of achieving MDD-W except for Ethiopia (DQQ 6.1 percentage points higher, P < 0.01). Median (25th-75th percentiles) scores of FGDS, NCD-Protect, NCD-Risk, and GDR score were comparable between the tools. CONCLUSIONS: The DQQ is a suitable tool for collecting population-level food group consumption data for estimating diet quality with food group-based indicators such as the MDD-W, FGDS, NCD-Protect, NCD-Risk, and GDR score.

A simple fruit and vegetable score is a valid tool to assess actual fruit and vegetable intake.

With the recent growing interest in improving fruit and vegetable intake for better health and limited research resources in many settings, simple-to-administer and low-priced indicators are essential tools for monitoring fruit and vegetable intake at the population level. A potential candidate indicator is the fruit and vegetable component of the Global Dietary Recommendation score (FV-GDR) based on data collected using the Diet Quality Questionnaire (DQQ). We investigated the relative validity of FV-GDR collected with the DQQ to measure fruit and vegetable intake by comparison with a 24-h recall (24hR) as a reference collected from 620 Vietnamese and 630 Nigerian adults in 2021. We found proportional differences in the prevalence of intake of vitamin A-rich vegetables, other vegetables and other fruits in Vietnam and all vegetable food groups in Nigeria. In both countries, we found a small difference in the total FV-GDR from DQQ compared with the 24hR, and the percentage of agreement between the two methods was quite high for the majority of the food groups. The FV-GDR calculated from the DQQ correlated with the actual intake, although less strongly than the FV-GDR from 24hR. The DQQ is a promising low-burden, low-cost and simple tool to calculate FV-GDR and to monitor fruit and vegetable consumption at the population level. This provides the possibility of evaluating an important aspect of diet quality in low-resource settings.

Environmentally-Friendly Pesticidal Activities of Callicarpa and Karomia Essential Oils from Vietnam and Their Microemulsions.

There is an ongoing interest to identify alternative pesticidal agents to avoid the chronic problems associated with synthetic pesticides. Essential oils have shown promise as botanical pest control agents. In the present study, the essential oils of four members of the Lamiaceae (Callicarpa candicans, C. erioclona, C. macrophylla, and Karomia fragrans; Vietnamese names: Nàng nàng, Tu châu lông mem, Tu châu lá to and Cà dien, respectively), obtained from wild populations in Vietnam, have been obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The essential oils were formulated into microemulsions and the essential oils and their microemulsions were screened for mosquito larvicidal activity against Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and for molluscicidal activity against Pomacea canaliculata. Atractylone and (E)-caryophyllene dominated the volatiles of C. candicans (CCEO) and C. erioclona (CEEO), while the major component in C. macrophylla (CMEO) and K. fragrans (KFEO) was (E)-caryophyllene. The essential oils and microemulsions of both C. candicans and C. erioclona exhibited excellent larvicidal activity against all three mosquito species (Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus) with LC50 values <10 µg/mL. Additionally, the larvicidal activity of the microemulsions were significantly improved compared with their free essential oils, especially for C. candicans and C. erioclona. All four essential oils and their microemulsions showed excellent molluscicidal activity with LC50 <10 µg/mL. In most cases, the essential oils and microemulsions showed greater pesticidal activity against target organisms than the non-target freshwater fish, Oreochromis niloticus. The in silico studies on physicochemical and ADMET properties of the major components in the studied essential oils were also investigated and most of the compounds possessed a favorable ADMET profile. Computational modeling studies of the studied compounds demonstrated a favorable binding interaction with the mosquito odorant-binding protein target and support atractylone, ß-selinene, and caryophyllene oxide as potential inhibitors. Based on the observed pesticidal activities of the essential oils and their microemulsions, the Callicarpa species and K. fragrans should be considered for potential cultivation and further exploration as botanical pesticidal agents.

Essential Oils of Five Syzygium Species Growing Wild in Vietnam: Chemical Compositions and Antimicrobial and Mosquito Larvicidal Potentials.

The essential oils of five Vietnamese Syzygium species (Syzygium levinei, S. acuminatissimum, S. vestitum, S. cumini, and S. buxifolium) were first hydro-distilled and analyzed using GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry). Monoterpene hydrocarbons, sesquiterpene hydrocarbons, and oxygenated sesquiterpenoids were the main chemical classes in these oils. All these essential oils showed good-excellent antimicrobial activities against Gram-positive bacteria Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus, and the yeast Candida albicans. S. levinei leaf essential oil, rich in bicyclogermacrene (25.3%), (E)-ß-elemene (12.2%), (E)-caryophyllene (8.2%), and ß-selinene (7.4%), as well as S. acuminatissimum fruit essential oil containing (E)-caryophyllene (14.2%), α-pinene (12.1%), caryophyllene oxide (10.9%), ß-selinene (10.8%), α-selinene (8.0%), and α-humulene (5.7%), established the same MIC value of 8 µg/mL against E. faecalis and B. cereus, which were much better than the positive control streptomycin (MIC 128-256 µg/mL). The studied essential oils showed the potential to defend against mosquitoes since they caused the 24 and 48 h LC50 values of less than 50 µg/mL against the growth of Culex quinquefasciatus and Aedes aegypti larvae. Especially, S. buxifolium leaf essential oil strongly inhibited Ae. aegypti larvae with 24 and 48 h LC50 values of 6.73 and 6.73 µg/mL, respectively, and 24 and 48 h LC90 values of 13.37 and 10.83 µg/mL, respectively. These findings imply that Vietnamese Syzygium essential oils might have potential for use as supplemental antibacterial agents or as "green" alternatives for the control of mosquitoes.

Acetylcholinesterase Inhibitory Activities of Essential Oils from Vietnamese Traditional Medicinal Plants.

Essential oils are promising as environmentally friendly and safe sources of pesticides for human use. Furthermore, they are also of interest as aromatherapeutic agents in the treatment of Alzheimer's disease, and inhibition of the enzyme acetylcholinesterase (AChE) has been evaluated as an important mechanism. The essential oils of some species in the genera Callicarpa, Premna, Vitex and Karomia of the family Lamiaceae were evaluated for inhibition of electric eel AChE using the Ellman method. The essential oils of Callicarpa candicans showed promising activity, with IC50 values between 45.67 and 58.38 µg/mL. The essential oils of Callicarpa sinuata, Callicarpa petelotii, Callicarpa nudiflora, Callicarpa erioclona and Vitex ajugifolia showed good activity with IC50 values between 28.71 and 54.69 µg/mL. The essential oils Vitex trifolia subsp. trifolia and Callicarpa rubella showed modest activity, with IC50 values of 81.34 and 89.38, respectively. trans-Carveol showed an IC50 value of 102.88 µg/mL. Molecular docking and molecular dynamics simulation were performed on the major components of the studied essential oils to investigate the possible mechanisms of action of potential inhibitors. The results obtained suggest that these essential oils may be used to control mosquito vectors that transmit pathogenic viruses or to support the treatment of Alzheimer's disease.

Essential Oils from Vietnamese Asteraceae for Environmentally Friendly Control of Aedes Mosquitoes.

Mosquitoes, in addition to being a biting nuisance, are vectors of several pathogenic viruses and parasites. As a continuation of our work identifying abundant and/or invasive plant species in Vietnam for use as ecologically friendly pesticidal agents, we obtained the essential oils of Blumea lacera, Blumea sinuata, Emilia sonchifolia, Parthenium hysterophorus, and Sphaeranthus africanus; analyzed the essential oils using gas chromatographic techniques; and screened the essential oils for mosquito larvicidal activity against Aedes aegypti and Aedes albopictus. The most active larvicidal essential oils were B. sinuata, which was rich in thymohydroquinone dimethyl ether (29.4%), (E)-ß-caryophyllene (19.7%), α-pinene (8.8%), germacrene D (7.8%), and α-humulene (4.3%), (24-h LC50 23.4 and 29.1 µg/mL) on Ae. aegypti and Ae. albopictus, respectively, and Emilia sonchifolia, dominated by 1-undecene (41.9%) and germacrene D (11.0%), (24-h LC50 30.1 and 29.6 µg/mL) on the two mosquito species. The essential oils of P. hysterophorus and S. africanus were also active against mosquito larvae. Notably, B. sinuata, P. hysterophorus, and S. africanus essential oils were not toxic to the non-target water bug, Diplonychus rusticus. However, E. sonchifolia essential oil showed insecticidal activity (24-h LC50 48.1 µg/mL) on D. rusticus. Based on these results, B. sinuata, P. hysterophorus, and S. africanus essential oils appear promising for further investigations.

Design, synthesis and evaluation of novel indirubin-based N-hydroxybenzamides, N-hydroxypropenamides and N-hydroxyheptanamides as histone deacetylase inhibitors and antitumor agents.

Several novel indirubin-based N-hydroxybenzamides, N-hydropropenamides and N-hydroxyheptanamides (4a-h, 7a-h, 10a-h) were designed using a fragment-based approach with structural features extracted from several previously reported HDAC inhibitors, such as SAHA (vorinostat), MGCD0103 (mocetinostat), nexturastat A and PXD-101 (belinostat). The biological results reveal that our compounds showed excellent cytotoxicity toward three common human cancer cell lines (SW620, PC-3 and NCI-H23) with IC50 values ranging from 0.09 to 0.007 µM. The cytotoxicity of the compounds was equipotent or even up to 10-times more potent than adriamycin and up to 205-times more potent than SAHA. Among the series of N-hydroxypropenamides, compounds 10a-d were the most potent HDAC inhibitors as well as cytotoxicity toward the cell lines tested. In addition, the strong inhibitory activites toward HDAC of our compounds were observed with IC50 values of below-micromolar range. Especially, compound 4a inhibited HDAC6 with an IC50 value of 29-fold lower than that against HDAC2 isoform. Representative compounds 4a and 7a were found to significantly arrest SW620 cells at G0/G1 phase. Compounds 7a and 10a were found to strongly induce apoptosis in SW620 cells. Docking studies revealed some important features affecting the selectivity against HDAC6 isoform. The results clearly demonstrate the potential of the indirubin-hydroxamic acid hybrids and these compounds should be very promising for further development.

Factors associated with the duration of hospitalisation among COVID-19 patients in Vietnam: A survival analysis.

BACKGROUND: The median duration of hospital stays due to COVID-19 has been reported in several studies on China as 10-13 days. Global studies have indicated that the length of hospitalisation depends on different factors, such as the time elapsed from exposure to symptom onset, and from symptom onset to hospital admission, as well as specificities of the country under study. The goal of this paper is to identify factors associated with the median duration of hospital stays of COVID-19 patients during the second COVID-19 wave that hit Vietnam from 5 March to 8 April 2020. METHOD: We used retrospective data on 133 hospitalised patients with COVID-19 recorded over at least two weeks during the study period. The Cox proportional-hazards regression model was applied to determine the potential risk factors associated with length of hospital stay. RESULTS: There were 65 (48.9%) females, 98 (73.7%) patients 48 years old or younger, 15 (11.3%) persons with comorbidities, 21 (16.0%) severely ill patients and 5 (3.8%) individuals with life-threatening conditions. Eighty-two (61.7%) patients were discharged after testing negative for the SARS-CoV-2 virus, 51 were still in the hospital at the end of the study period and none died. The median duration of stay in a hospital was 21 (IQR: 16-34) days. The multivariable Cox regression model showed that age, residence and sources of contamination were significantly associated with longer duration of hospitalisation. CONCLUSION: A close look at how long COVID-19 patients stayed in the hospital could provide an overview of their treatment process in Vietnam, and support the country's National Steering Committee on COVID-19 Prevention and Control in the efficient allocation of resources over the next stages of the COVID-19 prevention period.

Exploration of certain 1,3-oxazole- and 1,3-thiazole-based hydroxamic acids as histone deacetylase inhibitors and antitumor agents.

Several novel series of hydroxamic acids bearing 2-benzamidooxazole/thiazole (5a-g, 6a-g) or 2-phenylsulfonamidothiazole (8a-c) were designed and synthesized. The compounds were obtained straightforwards via a two step pathway, starting from commercially available ethyl 2-aminooxazole-4-carboxylate or ethyl 2-aminothiazole-4-carboxylate. Biological evaluation showed that these hydroxamic acids generally exhibited good cytotoxicity against three human cancer cell lines (SW620, colon; PC-3, prostate; NCI-H23, lung cancer), with IC50 values in low micromolar range and comparable to that of SAHA. These compounds also comparably inhibited HDACs with IC50 values in sub-micromolar range (0.010-0.131 µM) and some compounds (e.g 5f, IC50, 0.010 µM) were even more potent than SAHA (IC50, 0.025 µM) in HDAC inhibition. Representative compounds 6a and 8a appeared to arrest the SW620 cell cycle at G2 phase and significantly induced both early and late apoptosis of SW620 colon cancer cells. Docking experiments on HDAC2 and HDAC6 isozymes revealed favorable interactions at the tunnel of the HDAC active site which positively contributed to the inhibitory activity of synthesized compound. The binding affinity predicted by docking program showed good correlation with the experimental IC50 values. This study demonstrates that simple 1,3-oxazole- and 1,3-thiazole-based hydroxamic acids are also promising as antitumor agents and HDAC inhibitors and these results should provide valuable information for further design of more potent HDAC inhibitors and antitumor agents.

New Acetohydrazides Incorporating 2-Oxoindoline and 4-Oxoquinazoline: Synthesis and Evaluation of Cytotoxicity and Caspase Activation Activity.

In our search for new small molecules activating procaspase-3, we have designed and synthesized a series of new acetohydrazides incorporating both 2-oxoindoline and 4-oxoquinazoline scaffolds. Biological evaluation showed that a number of these acetohydrazides were comparably or even more cytotoxic against three human cancer cell lines (SW620, colon cancer; PC-3, prostate cancer; NCI-H23, lung cancer) in comparison to PAC-1, a first procaspase-3 activating compound, which was used as a positive control. One of those new compounds, 2-(6-chloro-4-oxoquinazolin-3(4H)-yl)-N'-[(3Z)-5-methyl-2-oxo-1,2-dihydro-3H-indol-3-ylidene]acetohydrazide activated the caspase-3 activity in U937 human lymphoma cells by 5-fold higher than the untreated control. Three of the new compounds significantly induced necrosis and apoptosis in U937 cells.

Essential Oil Compositions of Three Invasive Conyza Species Collected in Vietnam and Their Larvicidal Activities against Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus.

Mosquito-borne infectious diseases are a persistent problem in tropical regions of the world, including Southeast Asia. Vector control has relied principally on synthetic insecticides, but these have detrimental environmental effects and there is an increasing demand for plant-based agents to control insect pests. Invasive weedy plant species may be able to serve as readily available sources of essential oils, some of which may be useful as larvicidal agents for control of mosquito populations. We hypothesize that members of the genus Conyza (Asteraceae) may produce essential oils that may have mosquito larvicidal properties. The essential oils from the aerial parts of Conyza bonariensis, C. canadensis, and C. sumatrensis were obtained by hydrodistillation, analyzed by gas chromatography-mass spectrometry, and screened for mosquito larvicidal activity against Aedes aegypti, Ae. albopictus and Culex quinquefasciatus. The essential oils of C. canadensis and C. sumatrensis, both rich in limonene (41.5% and 25.5%, respectively), showed notable larvicidal activities against Ae. aegypti (24-h LC50 = 9.80 and 21.7 µg/mL, respectively) and Ae. albopictus (24-h LC50 = 18.0 and 19.1 µg/mL, respectively). These two Conyza species may, therefore, serve as sources for alternative, environmentally-benign larvicidal control agents.

Definitions for warning signs and signs of severe dengue according to the WHO 2009 classification: Systematic review of literature.

Since warning signs and signs of severe dengue are defined differently between studies, we conducted a systematic review on how researchers defined these signs. We conducted an electronic search in Scopus to identify relevant articles, using key words including dengue, "warning signs," "severe dengue," and "classification." A total of 491 articles were identified through this search strategy and were subsequently screened by 2 independent reviewers for definitions of any of the warning or severe signs in the 2009 WHO dengue classification. We included all original articles published in English after 2009, classifying dengue by the 2009 WHO classification or providing the additional definition or criterion of warning signs and severity (besides the information of 2009 WHO). Analysis of the extracted data from 44 articles showed wide variations among definitions and cutoff values used by physicians to classify patients diagnosed with dengue infection. The establishment of clear definitions for warning signs and severity is essential to prevent unnecessary hospitalization and harmonizing the interpretation and comparability of epidemiological studies dedicated to dengue infection.

Novel 3,4-dihydro-4-oxoquinazoline-based acetohydrazides: Design, synthesis and evaluation of antitumor cytotoxicity and caspase activation activity.

In search for novel small molecules with antitumor cytotoxicity via activating procaspase-3, we have designed and synthesized three series of novel (E)-N'-benzylidene-4-oxoquinazolin-3(4H)-yl)acetohydrazides (5a-j, 6a-h, and 7a-h). On the phenyl ring ò the benzylidene part, three different substituents, including 2-OH-4-OCH3, 4-OCH3, and 4-N(CH3)2, were introduced, respectively. Biological evaluation showed that the acetohydrazides in series 5a-j, in which the phenyl ring of the benzylidene part was substituted by 2-OH-4-OCH3 substituent, exhibited potent cytotoxicity against three human cancer cell lines (SW620, colon; PC-3, prostate; NCI-H23, lung). Most of the compounds, in this series, especially compounds 5c, 5b and 5h, also significantly activated caspase-3 activity. Among these, compound 5c displayed 1.61-fold more potent than PAC-1 as caspase-3 activator. Cell cycle analysis showed that compounds 5b, 5c, and 5h significantly arrested the cell cycle in G1 phase. Further apoptotic studies also demonstrated compounds 5b, 5c, and 5h as strong apoptotic cell death inducers. The docking simulation studies showed that these compounds could activate procaspase via chelating Zn2+ ion bound to the allosteric site of the zymogen.

(E)-N'-Arylidene-2-(4-oxoquinazolin-4(3H)-yl) acetohydrazides: Synthesis and evaluation of antitumor cytotoxicity and caspase activation activity.

In our search for novel small molecules activating procaspase-3, we have designed and synthesised a series of novel acetohydrazides incorporating quinazolin-4(3H)-ones (5, 6, 7). Biological evaluation revealed eight compounds with significant cytotoxicity against three human cancer cell lines (SW620, colon cancer; PC-3, prostate cancer; NCI-H23, lung cancer). The most potent compound 5t displayed cytotoxicity up to 5-fold more potent than 5-FU. Analysis of structure-activity relationships showed that the introduction of different substituents at C-6 position on the quinazolin-4(3H)-4-one moiety, such as 6-chloro or 6-methoxy potentially increased the cytotoxicity of the compounds. In term of caspase activation activity, several compounds were found to exhibit potent effects, (e.g. compounds 7 b, 5n, and 5l). Especially, compound 7 b activated caspases activity by almost 200% in comparison to that of PAC-1. Further docking simulation also revealed that this compound potentially is a potent allosteric inhibitor of procaspase-3.

Quinazolin-4(3H)-one-Based Hydroxamic Acids: Design, Synthesis and Evaluation of Histone Deacetylase Inhibitory Effects and Cytotoxicity.

The present article describes the synthesis and biological activity of various series of novel hydroxamic acids incorporating quinazolin-4(3H)-ones as novel small molecules targeting histone deacetylases. Biological evaluation showed that these hydroxamic acids were potently cytotoxic against three human cancer cell lines (SW620, colon; PC-3, prostate; NCI-H23, lung). Most compounds displayed superior cytotoxicity than SAHA (suberoylanilide hydroxamic acid, Vorinostat) in term of cytotoxicity. Especially, N-hydroxy-7-(7-methyl-4-oxoquinazolin-3(4H)-yl)heptanamide (5b) and N-hydroxy-7-(6-methyl-4-oxoquinazolin-3(4H)-yl)heptanamide (5c) (IC50 values, 0.10-0.16 µm) were found to be approximately 30-fold more cytotoxic than SAHA (IC50 values of 3.29-3.67 µm). N-Hydroxy-7-(4-oxoquinazolin-3(4H)-yl)heptanamide (5a; IC50 values of 0.21-0.38 µm) was approximately 10- to 15-fold more potent than SAHA in cytotoxicity assay. These compounds also showed comparable HDAC inhibition potency with IC50 values in sub-micromolar ranges. Molecular docking experiments indicated that most compounds, as represented by 5b and 5c, strictly bound to HDAC2 at the active binding site with binding affinities much higher than that of SAHA.

The higher prevalence of developmental defects of enamel in the dioxin-affected region than non-dioxin-affected region: result from a cross-sectional study in Vietnam.

Developmental defects of enamel (DDE) are induced and regulated by several factors including genetics and the environment. There is evidence showing that dioxin in polluted areas has a strong effect on the health and development of teeth. However, there has been no study on DDE in the dioxin-affected regions in Vietnam. To identify the effect of dioxin on the prevalence of DDE in studied areas in Vietnam, a cross-sectional study was conducted in 2200 adults in the A Luoi district in the Thua Thien Hue province (the dioxin-affected region) and in the Kim Bang district in the Ha Nam province (dioxin-unaffected region) in 2015. All subjects were interviewed using a structured questionnaire and their teeth were examined and scored for enamel defects based on the 1992 FDI criteria. The defected teeth were then photographed. Our results showed that the DDE rate in A Luoi was 20.5% when measured as mouth prevalence and 5.8% when measured as tooth prevalence, while the rates in Kim Bang were 10.4 and 2.32% for mouth and tooth prevalence, respectively. Demarcated opacities were predominated in both districts (45.5% in A Luoi and 52.2% in Kim Bang). The DDE rate of the anterior teeth group was higher than that of the posterior teeth group. Most lesions presented on the buccal surface of the tooth. Overall, the DDE prevalence in the dioxin-affected region was 2.2 times higher than that in non-dioxin-affected region in the studied regions in Vietnam.

Chemical Compositions and Mosquito Larvicidal Activities of Essential Oils from Piper Species Growing Wild in Central Vietnam.

Mosquitoes are the deadliest animals on earth and are the vectors of several neglected tropical diseases. Recently, essential oils have emerged as potential renewable, cost-effective, and environmentally benign alternatives to synthetic pesticides for control of mosquitoes. In this work, thirteen species of Piper were collected from different areas of central Vietnam. The essential oils were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The essential oils were screened for mosquito larvicidal activity against Aedes aegypti. Four of the Piper essential oils showed outstanding larvicidal activity against Ae. aegypti, namely P. caninum, P. longum, P. montium, and P. mutabile, with LC50 and LC90 values less than 10 µg/mL. Multivariate analysis has correlated concentrations of ß-caryophyllene, ß-bisabolene, α-pinene, and ß-pinene with mosquito larvicidal activity.

Design, synthesis and evaluation of novel N-hydroxybenzamides/N-hydroxypropenamides incorporating quinazolin-4(3H)-ones as histone deacetylase inhibitors and antitumor agents.

In our search for novel small molecules targeting histone deacetylases, we have designed and synthesized several series of novel N-hydroxybenzamides/N-hydroxypropenamides incorporating quinazolin-4(3H)-ones (4a-h, 8a-d, 10a-d). Biological evaluation showed that these hydroxamic acids were generally cytotoxic against three human cancer cell lines (SW620, colon; PC-3, prostate; NCI-H23, lung cancer). It was found that the N-hydroxypropenamides (10a-d) were the most potent, both in term of HDAC inhibition and cytotoxicity. Several compounds, e.g. 4e, 8b-c, and 10a-c, displayed up to 4-fold more potent than SAHA (suberoylanilide hydroxamic acid, vorinostat) in term of cytotoxicity. These compounds also comparably inhibited HDACs with IC50 values in sub-micromolar range. Docking experiments on HDAC2 isozyme revealed some important features contributing to the inhibitory activity of synthesized compounds, especially for propenamide analogues. Importantly, the free binding energy computed was found to have high quantitative correlation (R2 ∼ 95%) with experimental results.

N'-[(E)-Arylidene]-2-(2,3-dihydro-3-oxo-4H-1,4-benzoxazin-4-yl)-acetohydrazides: Synthesis and Evaluation of Caspase Activation Activity and Cytotoxicity.

In our search for novel small cytotoxic molecules potentially activating procaspase-3, we have designed and synthesized a series of novel N'-[(E)-arylidene]-2-(2,3-dihydro-3-oxo-4H-1,4-benzoxazin-4-yl)acetohydrazides (5, 6). Biological evaluation revealed that seven compounds, including 5h, 5j, 5k, 5l, 5n, 6a, and 6b, exhibited moderate to strong cytotoxicity against three human cancer cell lines (SW620, colon cancer; PC-3, prostate cancer; NCI-H23, lung cancer). Among these compounds, two most cytotoxic compounds (5h and 5j) displayed from 3- up to 10-fold higher potency than PAC-1 and 5-FU in three cancer cell lines tested. Three compounds 5j, 5k, and 5n were also found to display better caspases activation activity in comparison to PAC-1. Especially, compound 5k activated the level of caspases activity by 200% higher than that of PAC-1. From this study, three compounds 5j, 5k, and 5n could be considered as potential leads for further design and development of caspase activators and anticancer agents.