ABSTRACT
BACKGROUND: The prospective phase III multi-centre L-MOCA trial (NCT03534453) has demonstrated the encouraging efficacy and manageable safety profile of olaparib maintenance therapy in the Asian (mainly Chinese) patients with platinum-sensitive relapsed ovarian cancer (PSROC). In this study, we report the preplanned exploratory biomarker analysis of the L-MOCA trial, which investigated the effects of homologous recombination deficiency (HRD) and programmed cell death ligand 1 (PD-L1) expression on olaparib efficacy. METHODS: HRD status was determined using the ACTHRD assay, an enrichment-based targeted next-generation sequencing assay. PD-L1 expression was assessed by SP263 immunohistochemistry assay. PD-L1 expression positivity was defined by the PD-L1 expression on ≥ 1% of immune cells. Kaplan-Meier method was utilised to analyse progression-free survival (PFS). RESULTS: This exploratory biomarker analysis included 225 patients and tested HRD status [N = 190; positive, N = 125 (65.8%)], PD-L1 expression [N = 196; positive, N = 56 (28.6%)], and BRCA1/2 mutation status (N = 219). The HRD-positive patients displayed greater median PFS than the HRD-negative patients [17.9 months (95% CI: 14.5-22.1) versus 9.2 months (95% CI: 7.5-13.8)]. PD-L1 was predominantly expressed on immune cells. Positive PD-L1 expression on immune cells was associated with shortened median PFS in the patients with germline BRCA1/2 mutations [14.5 months (95% CI: 7.4-18.2) versus 22.2 months (95% CI: 18.3-NA)]. Conversely, positive PD-L1 expression on immune cells was associated with prolonged median PFS in the patients with wild-type BRCA1/2 [20.9 months (95% CI: 13.9-NA) versus 8.3 months (95% CI: 6.7-13.8)]. CONCLUSIONS: HRD remained an effective biomarker for enhanced olaparib efficacy in the Asian patients with PSROC. Positive PD-L1 expression was associated with decreased olaparib efficacy in the patients with germline BRCA1/2 mutations but associated with improved olaparib efficacy in the patients with wild-type BRCA1/2. TRIAL REGISTRATION: NCT03534453. Registered at May 23, 2018.
Subject(s)
B7-H1 Antigen , Biomarkers, Tumor , Maintenance Chemotherapy , Ovarian Neoplasms , Phthalazines , Piperazines , Humans , Female , Phthalazines/therapeutic use , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/genetics , Piperazines/therapeutic use , Biomarkers, Tumor/genetics , Middle Aged , Maintenance Chemotherapy/methods , Aged , Adult , Prospective Studies , Neoplasm Recurrence, Local/drug therapy , BRCA2 Protein/genetics , Antineoplastic Agents/therapeutic use , BRCA1 Protein/genetics , Homologous RecombinationABSTRACT
Aberrant cellular bioenergetics has detrimental consequences in host cells. For instance, pathogenic Zika virus strains can suppress mitochondria respiration and glycolytic functions, disrupting cellular bioenergetics that leads to apoptosis. Herein, we describe methods for flavivirus propagation, titering and infection, cell preparation, and procedures for mitochondrial and glycolytic stress tests. The protocol enables assessment of cellular respiration and glycolytic flux in flavivirus-infected cells. For complete details on the use and execution of this protocol, please refer to Yau et al. (2021).
Subject(s)
Flavivirus , Zika Virus Infection , Zika Virus , Energy Metabolism , Glycolysis , Humans , Mitochondria/metabolism , Zika Virus Infection/metabolismABSTRACT
PURPOSE: In patients with platinum-sensitive relapsed (PSR) ovarian cancer, olaparib maintenance monotherapy significantly improves progression-free survival (PFS) versus placebo. However, evidence in the Asian population is lacking. This is the first study to evaluate olaparib efficacy and tolerability exclusively in Asian patients with PSR ovarian cancer. PATIENTS AND METHODS: Considering the limited placebo effect and significant clinical benefit of olaparib in previous trials, and the rapid approval of olaparib in China, this phase III study was designed as an open-label, single-arm trial. Patients with high-grade epithelial PSR ovarian cancer were enrolled from country-wide clinical centers across China and Malaysia. Patients received oral olaparib (300 mg) twice daily until disease progression or unacceptable toxicity. Primary endpoint was median PFS (mPFS). Primary analysis of PFS using the Kaplan-Meier method was performed when data reached 60% maturity (clinicaltrials.gov NCT03534453). RESULTS: Between 2018 and 2020, 225 patients were enrolled, and 224 received olaparib; 35.7% had received ≥3 lines of chemotherapy, 35.3% had achieved complete response to their last line of platinum-based chemotherapy, and 41.1% had a platinum-free interval ≤12 months. At primary data cut-off (December 25, 2020), overall mPFS was 16.1 months; mPFS was 21.2 and 11.0 months in BRCA-mutated and wild-type BRCA subgroups, respectively. Adverse events (AE) occurred in 99.1% of patients (grade ≥3, 48.7%); 9.4% discontinued therapy due to treatment-related AEs. CONCLUSIONS: Olaparib maintenance therapy was highly effective and well tolerated in Asian patients with PSR ovarian cancer, regardless of BRCA status. This study highlights the promising efficacy of olaparib in this Asian population. See related commentary by Nicum and Blagden, p. 2201.
Subject(s)
Ovarian Neoplasms , Carcinoma, Ovarian Epithelial/drug therapy , Female , Humans , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/mortality , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/genetics , Phthalazines/administration & dosage , Phthalazines/adverse effects , Piperazines/administration & dosage , Piperazines/adverse effectsABSTRACT
AIM: A large proportion of cancer patients are at high risk for chemotherapy-induced nausea and vomiting (CINV), but the choice of anti-emetics for CINV in Malaysia is limited. METHODS: This was a real-world study of a fixed-dose combination of netupitant and palonosetron (NEPA) to inhibit CINV in adult patients receiving moderately (MEC) or highly emetogenic chemotherapy (HEC) for solid/hematological malignancies at eight Malaysian centers. Each HEC/MEC cycle received one dose of NEPA + dexamethasone for CINV prevention. Complete response (no emesis, no rescue medication) (CR), no more than mild nausea (severity score ≤ 2.5), and complete control (CR) (no more than mild nausea) during the acute (0-24 h), delayed (25-120 h), and overall (0-120 h) phases post-chemotherapy were measured. Treatment-related adverse events (AEs) were recorded. RESULTS: During March 2016-April 2018 (NMRR-17-3286-38282), NEPA + dexamethasone was administered to 54 patients (77.8% solid, 22.2% hematological malignancies). Note that 59.3% received HEC, while 40.7% received MEC regimen. During the overall phase of the first cycle, the majority had CR (77.8%), no more than mild nausea (74.1%), and complete control (61.1%). Seventeen patients received two consecutive cycles at any point of chemotherapy cycles. During the overall phases across two consecutive cycles, all patients achieved CR, and the majority reported no more than mild nausea and complete control. No grades 3-4 AEs were reported. CONCLUSIONS: NEPA had sustained efficacy and tolerability at first administration and across two cycles of MEC/HEC for CINV prevention.
Subject(s)
Antiemetics , Antineoplastic Agents , Hematologic Neoplasms , Adult , Antiemetics/therapeutic use , Antineoplastic Agents/adverse effects , Benzeneacetamides , Dexamethasone , Hematologic Neoplasms/drug therapy , Humans , Nausea/chemically induced , Nausea/prevention & control , Palonosetron/adverse effects , Piperazines , Pyridines , Quinuclidines/adverse effects , Vomiting/chemically induced , Vomiting/prevention & controlABSTRACT
BACKGROUND: Identifying patients with BRCA mutations is clinically important to inform on the potential response to treatment and for risk management of patients and their relatives. However, traditional referral routes may not meet clinical needs, and therefore, mainstreaming cancer genetics has been shown to be effective in some high-income and high health-literacy settings. To date, no study has reported on the feasibility of mainstreaming in low-income and middle-income settings, where the service considerations and health literacy could detrimentally affect the feasibility of mainstreaming. METHODS: The Mainstreaming Genetic Counselling for Ovarian Cancer Patients (MaGiC) study is a prospective, two-arm observational study comparing oncologist-led and genetics-led counselling. This study included 790 multiethnic patients with ovarian cancer from 23 sites in Malaysia. We compared the impact of different method of delivery of genetic counselling on the uptake of genetic testing and assessed the feasibility, knowledge and satisfaction of patients with ovarian cancer. RESULTS: Oncologists were satisfied with the mainstreaming experience, with 95% indicating a desire to incorporate testing into their clinical practice. The uptake of genetic testing was similar in the mainstreaming and genetics arm (80% and 79%, respectively). Patient satisfaction was high, whereas decision conflict and psychological impact were low in both arms of the study. Notably, decisional conflict, although lower than threshold, was higher for the mainstreaming group compared with the genetics arm. Overall, 13.5% of patients had a pathogenic variant in BRCA1 or BRCA2, and there was no difference between psychosocial measures for carriers in both arms. CONCLUSION: The MaGiC study demonstrates that mainstreaming cancer genetics is feasible in low-resource and middle-resource Asian setting and increased coverage for genetic testing.
Subject(s)
Oncologists , Ovarian Neoplasms , BRCA1 Protein/genetics , BRCA2 Protein/genetics , Counseling , Female , Genetic Counseling , Genetic Testing/methods , Humans , Ovarian Neoplasms/diagnosis , Ovarian Neoplasms/epidemiology , Ovarian Neoplasms/genetics , Prospective StudiesABSTRACT
Zika virus (ZIKV) is an Aedes-mosquito-borne flavivirus that causes debilitating congenital and developmental disorders. Improved understanding of ZIKV pathogenesis could assist efforts to fill the therapeutic and vaccine gap. We use several ZIKV strains, including a pair differing by a single phenylalanine-to-leucine substitution (M-F37L) in the membrane (M) protein, coupled with unbiased genomics to demarcate the border between attenuated and pathogenic infection. We identify infection-induced metabolic dysregulation as a minimal set of host alterations that differentiates attenuated from pathogenic ZIKV strains. Glycolytic rewiring results in impaired oxidative phosphorylation and mitochondrial dysfunction that trigger inflammation and apoptosis in pathogenic but not attenuated ZIKV strains. Critically, pyruvate supplementation prevents cell death, in vitro, and rescues fetal development in ZIKV-infected dams. Our findings thus demonstrate dysregulated metabolism as an underpinning of ZIKV pathogenicity and raise the potential of pyruvate supplementation in expectant women as a prophylaxis against congenital Zika syndrome.
Subject(s)
Fetal Development , Glycolysis , Mitochondria/pathology , Virus Replication , Zika Virus Infection/complications , Zika Virus/physiology , Animals , Chlorocebus aethiops , Dietary Supplements , Female , Humans , Male , Mitochondria/drug effects , Mitochondria/metabolism , Oxidative Phosphorylation , Pentose Phosphate Pathway , Pyruvic Acid/administration & dosage , Vero Cells , Zika Virus Infection/pathology , Zika Virus Infection/virologyABSTRACT
BACKGROUND: Near to 5-7 million people are infected with T. cruzi in the world, and about 10,000 people per year die of problems associated with this disease. METHODS: Herein, the synthesis, antitrypanosomal and antimycobacterial activities of seventeen coumarinic N-acylhydrazonic derivatives have been reported. RESULTS: These compounds were synthesized using methodology with reactions global yields ranging from 46%-70%. T. cruzi in vitro effects were evaluated against trypomastigote and amastigote, forming M. tuberculosis activity towards H37Rv sensitive strain and resistant strains. DISCUSSION: Against T. cruzi, the more active compounds revealed only moderate activity IC50/96h~20 µM for both trypomastigotes and amastigotes intracellular forms. (E)-2-oxo-N'- (3,4,5-trimethoxybenzylidene)-2H-chromene-3-carbohydrazide showed meaningful activity in INH resistant/RIP resistant strain. CONCLUSION: These compound acting as multitarget could be good leads for the development of new trypanocidal and bactericidal agents.
Subject(s)
Coumarins/chemistry , Hydrazones/chemical synthesis , Hydrazones/pharmacology , Nitrogen/chemistry , Trypanosoma/drug effects , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Antiprotozoal Agents/chemical synthesis , Antiprotozoal Agents/chemistry , Antiprotozoal Agents/pharmacology , Chemistry Techniques, Synthetic , Drug Resistance, Bacterial/drug effects , Hydrazones/chemistry , Mycobacterium tuberculosis/drug effectsABSTRACT
Members of the China-ASEAN Joint Laboratory for International Cooperation in Traditional Medicine Research used the video conference platform to exchange and discuss the advantages of traditional medicine through the form of score exchange and report, and research and develop the amount and issues of the therapeutic COVID-19 products of concern. This paper mainly reviews the achievements of the implementation of the epidemic prevention and control plan, advances of scientific basic studies on SARS-CoV-2, analysis and screening of potential targets and pathways of antiviral compounds based on network pharmacology and development of antiviral food dual-use products. The authors believe that the declaration of the (10 + 3) special meeting of national leaders on epidemic prevention and control should raise the medical and pharmaceutical issues of common concern. It is the responsibility of our joint laboratory members to accelerate the development of traditional medicine research and industry. Also the authors believe that this exchange will certainly promote the development of the cause of cooperation.
ABSTRACT
Epstein-Barr virus (EBV) is associated with a variety of tumors and nonmalignant conditions. Latent EBV genomes in cells, including tumor cells, are often CpG methylated, whereas virion DNA is not CpG methylated. We demonstrate that methyl CpG binding magnetic beads can be used to fractionate among sources of EBV DNA (DNA extracted from laboratory-purified virions vs DNA extracted from latently infected cell lines). We then applied the technique to plasma specimens and showed that this technique can distinguish EBV DNA from patients with EBV-associated tumors (nasopharyngeal carcinoma, Hodgkin lymphoma) and viral DNA from patients without EBV-associated tumors, including immunocompromised patients and patients with EBV(-) Hodgkin lymphoma.
Subject(s)
Epstein-Barr Virus Infections , Hodgkin Disease , DNA, Viral/metabolism , Herpesvirus 4, Human/genetics , Herpesvirus 4, Human/metabolism , Humans , MethylationABSTRACT
The structure of the title quinoline carboxamide derivative, C26H25N3O, is described. The quinoline moiety is not planar as a result of a slight puckering of the pyridine ring. The secondary amine has a slightly pyramidal geometry, certainly not planar. Both intra- and inter-molecular hydrogen bonds are present. Hirshfeld surface analysis and lattice energies were used to investigate the inter-molecular inter-actions.
ABSTRACT
Colorectal cancer (CRC) continues to be one of the most common cancers globally. The incidence has increased in developing countries in the past few decades, this could be partly attributed to aging populations and unhealthy lifestyles. While the treatment of CRC has seen significant improvement since the advent of target-specific therapies and personalized medicine, CRC is oftentimes detected at late or advanced stages, thereby reducing the efficacy of treatment. Hence, screening for early detection is still the key to combat CRC and to increase overall survival (OS). Considering that the field of medical diagnostics is moving towards molecular diagnostics, CRC can now be effectively screened and diagnosed with high accuracy and sensitivity. Depending on the tumor genotype and genetic profile of the individual, personalized treatments including tyrosine kinase inhibitor therapy and immunotherapy can be administered. Notably, there can be no one single treatment that is effective for all CRC patients due to the variation in tumor genetics, which highlights the importance of molecular diagnostics. This review provides insights on therapeutic modalities, molecular biomarkers, advancement of diagnostic technologies, and current challenges in managing CRC.
ABSTRACT
[This corrects the article DOI: 10.1107/S2056989019012015.].
ABSTRACT
A 1:1 epimeric mixture of 3-[(4-nitro-benzyl-idene)amino]-2(R,S)-(4-nitro-phen-yl)-5(S)-(propan-2-yl)imidazolidin-4-one, C19H19N5O5, was isolated from a reaction mixture of 2(S)-amino-3-methyl-1-oxo-butane-hydrazine and 4-nitro-benz-alde-hyde in ethanol. The product was derived from an initial reaction of 2(S)-amino-3-methyl-1-oxo-butane-hydrazine at its hydrazine group to provide a 4-nitro-benzyl-idene derivative, followed by a cyclization reaction with another mol-ecule of 4-nitro-benzaldehyde to form the chiral five-membered imidazolidin-4-one ring. The formation of the five-membered imidazolidin-4-one ring occurred with retention of the configuration at the 5-position, but with racemization at the 2-position. In the crystal, N-Hâ¯O(nitro) hydrogen bonds, weak C-Hâ¯O(carbon-yl) and C-Hâ¯O(nitro) hydrogen bonds, as well as C-Hâ¯π, N-Hâ¯π and π-π inter-actions, are present. These combine to generate a three-dimensional array. Hirshfeld surface analysis and PIXEL calculations are also reported.
ABSTRACT
The crystal structures of the disordered hemi-DMSO solvate of (E)-2-oxo-N'-(3,4,5-tri-meth-oxy-benzyl-idene)-2H-chromene-3-carbohydrazide, C20H18N2O6·0.5C2H6OS, and (E)-N'-benzyl-idene-2-oxo-2H-chromene-3-carbohydrazide, C17H12N2O3 (4: R = C6H5), are discussed. The non-hydrogen atoms in compound [4: R = (3,4,5-MeO)3C6H2)] exhibit a distinct curvature, while those in compound, (4: R = C6H5), are essential coplanar. In (4: R = C6H5), C-Hâ¯O and π-π intra-molecular inter-actions combine to form a three-dimensional array. A three-dimensional array is also found for the hemi-DMSO solvate of [4: R = (3,4,5-MeO)3C6H2], in which the mol-ecules of coumarin are linked by C-Hâ¯O and C-Hâ¯π inter-actions, and form tubes into which the DMSO mol-ecules are cocooned. Hirshfeld surface analyses of both compounds are reported, as are the lattice energy and inter-molecular inter-action energy calculations of compound (4: R = C6H5).
ABSTRACT
BACKGROUND: This study aimed to evaluate the efficacy, side-effects and resistance mechanisms of first-line afatinib in a real-world setting. METHODS: This is a multicenter observational study of first-line afatinib in Malaysian patients with epidermal growth factor receptor (EGFR)-mutant advanced non-small cell lung cancer (NSCLC). Patients' demographic, clinical and treatment data, as well as resistance mechanisms to afatinib were retrospectively captured. The statistical methods included Chi-squared test and independent t-test for variables, Kaplan-Meier curve and log-rank test for survival, and Cox regression model for multivariate analysis. RESULTS: Eighty-five patients on first-line afatinib from 1st October 2014 to 30th April 2018 were eligible for the study. EGFR mutations detected in tumors included exon 19 deletion in 80.0%, exon 21 L858R point mutation in 12.9%, and rare or complex EGFR mutations in 7.1% of patients. Among these patients, 18.8% had Eastern Cooperative Oncology Group performance status of 2-4, 29.4% had symptomatic brain metastases and 17.6% had abnormal organ function. Afatinib 40 mg or 30 mg once daily were the most common starting and maintenance doses. Only one-tenth of patients experienced severe side-effects with none having grade 4 toxicities. The objective response rate was 76.5% while the disease control rate was 95.3%. At the time of analysis, 56 (65.9%) patients had progression of disease (PD) with a median progression-free survival (mPFS) of 14.2 months (95% CI, 11.85-16.55 months). Only 12.5% of the progressed patients developed new symptomatic brain metastases. The overall survival (OS) data was not mature. Thirty-three (38.8%) patients had died with a median OS of 28.9 months (95% CI, 19.82-37.99 months). The median follow-up period for the survivors was 20.0 months (95% CI, 17.49-22.51 months). Of patients with PD while on afatinib, 55.3% were investigated for resistance mechanisms with exon 20 T790 M mutation detected in 42.0% of them. CONCLUSIONS: Afatinib is an effective first-line treatment for patients with EGFR-mutant advanced NSCLC with a good response rate and long survival, even in patients with unfavorable clinical characteristics. The side-effects of afatinib were manageable and T790 M mutation was the most common resistance mechanism causing treatment failure.
Subject(s)
Afatinib/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Mutation , Aged , Antineoplastic Agents/therapeutic use , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/genetics , Female , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Male , Middle Aged , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use , Retrospective Studies , Treatment OutcomeABSTRACT
Dengue is caused by infection with any one of four dengue viruses (DENV); the risk of severe disease appears to be enhanced by the cross-reactive or subneutralizing levels of antibody from a prior DENV infection. These antibodies opsonize DENV entry through the activating Fc gamma receptors (FcγR), instead of infection through canonical receptor-mediated endocytosis, to result in higher levels of DENV replication. However, whether the enhanced replication is solely due to more efficient FcγR-mediated DENV entry or is also through FcγR-mediated alteration of the host transcriptome response to favor DENV infection remains unclear. Indeed, more efficient viral entry through activation of the FcγR can result in an increased viral antigenic load within target cells and confound direct comparisons of the host transcriptome response under antibody-dependent and antibody-independent conditions. Herein, we show that, despite controlling for the viral antigenic load in primary monocytes, the antibody-dependent and non-antibody-dependent routes of DENV entry induce transcriptome responses that are remarkably different. Notably, antibody-dependent DENV entry upregulated DENV host dependency factors associated with RNA splicing, mitochondrial respiratory chain complexes, and vesicle trafficking. Additionally, supporting findings from other studies, antibody-dependent DENV entry impeded the downregulation of ribosomal genes caused by canonical receptor-mediated endocytosis to increase viral translation. Collectively, our findings support the notion that antibody-dependent DENV entry alters host responses that support the viral life cycle and that host responses to DENV need to be defined in the context of its entry pathway.IMPORTANCE Dengue virus is the most prevalent mosquito-borne viral infection globally, resulting in variable manifestations ranging from asymptomatic viremia to life-threatening shock and multiorgan failure. Previous studies have indicated that the risk of severe dengue in humans can be increased by a specific range of preexisting anti-dengue virus antibody titers, a phenomenon termed antibody-dependent enhancement. There is hence a need to understand how antibodies augment dengue virus infection compared to the alternative canonical receptor-mediated viral entry route. Herein, we show that, besides facilitating viral uptake, antibody-mediated entry increases the expression of early host dependency factors to promote viral infection; these factors include RNA splicing, mitochondrial respiratory chain complexes, vesicle trafficking, and ribosomal genes. These findings will enhance our understanding of how differences in entry pathways can affect host responses and offer opportunities to design therapeutics that can specifically inhibit antibody-dependent enhancement of dengue virus infection.
Subject(s)
Antibodies, Viral/immunology , Dengue Virus/physiology , Host Microbial Interactions , Receptors, IgG/immunology , Virus Internalization , Antibody-Dependent Enhancement , Antigens, Viral/immunology , Cell Line , Cells, Cultured , Dengue/virology , Humans , Monocytes/immunology , Monocytes/virology , Sequence Analysis, RNA , Transcriptome , Virus ReplicationABSTRACT
Flaviviral infections result in a wide spectrum of clinical outcomes, ranging from asymptomatic infection to severe disease. Although the correlates of severe disease have been explored1-4, the pathophysiology that differentiates symptomatic from asymptomatic infection remains undefined. To understand the molecular underpinnings of symptomatic infection, the blood transcriptomic and metabolomic profiles of individuals were examined before and after inoculation with the live yellow fever viral vaccine (YF17D). It was found that individuals with adaptive endoplasmic reticulum (ER) stress and reduced tricarboxylic acid cycle activity at baseline showed increased susceptibility to symptomatic outcome. YF17D infection in these individuals induced maladaptive ER stress, triggering downstream proinflammatory responses that correlated with symptomatic outcome. The findings of the present study thus suggest that the ER stress response and immunometabolism underpin symptomatic yellow fever and possibly even other flaviviral infections. Modulating either ER stress or metabolism could be exploited for prophylaxis against symptomatic flaviviral infection outcome.
Subject(s)
Endoplasmic Reticulum Stress , Yellow Fever Vaccine/immunology , Yellow Fever/metabolism , Adult , Citric Acid Cycle , Disease Susceptibility , Humans , Middle Aged , Reactive Oxygen Species/metabolism , Vaccines, Attenuated/immunology , Yellow Fever/etiologyABSTRACT
The crystal structures of four (E)-meth-oxy-benzaldehyde oxime derivatives, namely (2-meth-oxy-benzaldehyde oxime, 1, 2,3-di-meth-oxy-benzaldehyde oxime, 2, 4-di-meth-oxy-benzaldehyde oxime, 3, and 2,5-di-meth-oxy-benzaldehyde oxime, 4, are discussed. The arrangements of the 2-meth-oxy group and the H atom of the oxime unit are s-cis in compounds 1-3, but in both independent mol-ecules of compound 4, the arrangements are s-trans. There is also a difference in the conformation of the two mol-ecules in 4, involving the orientations of the 2- and 5-meth-oxy groups. The primary inter-molecular O-H(oxime)â¯O(hy-droxy) hydrogen bonds generate C(3) chains in 1 and 2. In contrast, in compound 3, the O-H(oxime)â¯O(hy-droxy) hydrogen bonds generate symmetric R 2 2(6) dimers. A more complex dimer is generated in 4 from the O-H(oxime)â¯O(hy-droxy) and C-H(2-meth-oxy)â¯O(hy-droxy) hydrogen bonds. In all cases, further inter-actions, C-Hâ¯O and C-Hâ¯π or π-π, generate three-dimensional arrays. Hirshfeld surface and fingerprint analyses are discussed.
ABSTRACT
The crystal structures, Hirshfeld surface analyses and electrostatic potential surfaces of the di- and tri-hydrates of (5α,17E)-17-hydrazonoandrostan-3-ol, 3, namely [3·(H2O)2] and [3·(H2O)3], are reported. The trihydrate, isolated from a solution of 3 in moist methanol, recrystallizes in the orthorhombic space group, P212121, while that of the dihydrate, isolated from a 1:1 aqueous methanol solution, recrystallizes in the monoclinic space group, P21. The asymmetric unit of the trihydrate involves one steroid and three water molecules, while that of the dihydrate has two similar but independent steroid molecules and four hydrate molecules. Very similar conformations are found for the steroid molecules in both hydrates. As expected, the different mole ratios of water: steroid have major influences on the structures. In both cases, complex crystal structures are constructed from various classical hydrogen bonds, involving the hydrate molecules and the hydroxy and hydrazonyl moieties of the steroid. In the trihydrate, there are no direct connections between the steroid molecules, instead the water molecules link the steroid molecules, with only weak van der Waals forces between the steroid molecules. There are some direct links between the steroid molecules in the dihydrate, involving OH(steroid hydroxyl)â¯O(steroid oxo) hydrogen bonds, in a head to head fashion, and OHâ¯N(hydrazonyl) hydrogen bonds, in a head to tail fashion. However, the major occurrence throughout the structure is of steroid molecules linked by water molecules.
Subject(s)
Androstanols/chemistry , Crystallography, X-Ray , Hydrogen Bonding , Methanol/chemistry , Models, Molecular , Molecular Conformation , Static Electricity , Surface Properties , Water/chemistryABSTRACT
The crystal structures of three salicyaldoxime compounds, namely 2-hy-droxy-4-methyl-benzaldehyde oxime, C8H9NO2, 1, 2,4-di-hydroxy-benzaldehyde oxime, C7H7NO3, 2, and 2-hy-droxy-4-meth-oxy-benzaldehyde oxime, C8H9NO3, 3, are discussed. In each compound, the hydroxyl groups are essentially coplanar with their attached phenyl group. The inter-planar angles between the C=N-O moieties of the oxime unit and their attached phenyl rings are 0.08â (9), 1.08â (15) and 6.65â (15)° in 1, 2 and 3, respectively. In all three mol-ecules, the 2-hy-droxy group forms an intra-molecular O-Hâ¯N(oxime) hydrogen bond. In compound (1), inter-molecular O-H(oxime)â¯O(hydrox-yl) hydrogen bonds generate R 2 2(14) dimers, related by inversion centres. In compound 2, inter-molecular O-H(oxime)â¯O(4-hy-droxy) hydrogen bonds generate C9 chains along the b-axis direction, while O-H(4-hydrox-yl)â¯O(2-hydrox-yl) inter-actions form zigzag C6 spiral chains along the c-axis direction, generated by a screw axis at 1, y, 1/4: the combination of the two chains provides a bimolecular sheet running parallel to the b axis, which lies between 0-1/2 c and 1/2-1 c. In compound 3, similar C9 chains, along the b-axis direction are generated by O-H(oxime)â¯O(4-meth-oxy) hydrogen bonds. Further weaker, C-Hâ¯π (in 1), π-π (in 2) and both C-Hâ¯π and π-π inter-actions (in 3) further cement the three-dimensional structures. Hirshfeld surface and fingerprint analyses are discussed.