Endophytic Fungi: Cellular factories of novel medicinal chemistries.

Inflammation and associated disorders have been a major contributing factor to mortality worldwide. The augmented mortality rate and emerging resistance against the approved therapeutics necessitate the discovery of novel chemistries destined for multiple clinical settings. Cellular factories including endophytic fungi have been tapped for chemical diversity with therapeutic potential. The emerging evidence has suggested the potential of bioactive compounds isolated from the endophytic fungi as putative agents to combat inflammation-associated disorders. The review summarizesand assists the readers in comprehending the structural and functional aspects of the medicinal chemistries identified from endophytic fungi as anticancer, antiobesity, antigout, and immunomodulatory agents.

Caregivers' experiences of accessing HIV Early Infant Diagnosis (EID) services and its barriers and facilitators, India.

BACKGROUND: India has rolled out Early Infant Diagnosis (EID) program for HIV infection in all states. EID program consists of testing of Infants exposed to HIV periodically over 18 months of age which is a multi-step complex testing cascade. Caregivers represent the primary beneficiary of EID program i.e., infants exposed to HIV and face multiple challenges to access EID services. As part of national EID program outcome assessment study, this study narrates caregivers' perspectives on barriers and facilitators to access and utilize EID services. METHODS: The study was conducted in 31 integrated counselling and testing centres (ICTCs) located in 11 high burden HIV states. A total of 66 in-depth interviews were conducted with caregivers' of infants enrolled in EID program. Thematic analysis was carried out to help identify themes underlying barriers and facilitators to access EID services and utilization from caregivers' perspectives. RESULTS: The stigma and discrimination prevalent in society about HIV remains a key demand side (caregiver-level) barrier. Non-disclosure or selective disclosure of HIV status led to missed or delayed EID tests and delayed HIV diagnosis and initiation of Anti-Retroviral Therapy (ART) for infants exposed to HIV. On supply side (health system-level), accessibility of healthcare facility with EID services was reported as a key barrier. The distance, time and cost were key concerns. Many caregivers faced difficulties to remember the details of complex EID test schedule and relied on a phone call from ICTC counsellor for next due EID test. Delayed EID test results and lack of communication of test results to caregiver were reported as primary barriers for completing the EID test cascade. DISCUSSION: The study reports caregiver-level and health system-level barriers and facilitators for access to EID services from the caregivers' perspectives. While, decentralisation and single window approaches can improve the access, timely communication of test results to the caregiver also need to be built in with appropriate use of technology. A holistic intervention including PLHIV support networks and the peer-led support mechanisms would be useful to address societal factors. CONCLUSION: The study findings have high significance for developing program implementation strategies to improve access and to build right-based and patient-centred EID services.

A systematic review on antimicrobial activities of green synthesised Selaginella silver nanoparticles.

BACKGROUND: Metallic nanoparticles from different natural sources exhibit superior therapeutic options as compared to the conventional methods. Selaginella species have attracted special attention of researchers worldwide due to the presence of bioactive molecules such as flavonoids, biflavonoids, triterpenes, steroids, saponins, tannins and other secondary metabolites that exhibit antimicrobial, antiplasmodial, anticancer and anti-inflammatory activities. Environment friendly green synthesised silver nanoparticles from Selaginella species provide viable, safe and efficient treatment against different fungal pathogens. OBJECTIVE: This systematic review aims to summarise the literature pertaining to superior antifungal ability of green synthesised silver nanoparticles using plant extracts of Selaginella spp. in comparison to both aqueous and ethanolic raw plant extracts by electronically collecting articles from databases. METHODS: The recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis were taken into consideration while preparing this review. The titles and abstracts of the collected data were stored in Endnote20 based on the inclusion and exclusion criteria. The search strategy included literature from established sources like PubMed, Google Scholar and Retrieval System Online using subject descriptors. RESULTS: The search yielded 60 articles with unique hits. After removal of duplications, 46 articles were identified, 40 were assessed and only seven articles were chosen and included in this review based on our eligibility criteria. CONCLUSION: The physicochemical and preliminary phytochemical investigations of Selaginella suggest higher drug potency of nanoparticles synthesised from plant extract against different diseases as compared to aqueous and ethanolic plant extracts. The study holds great promise as the synthesis of nanoparticles involves low energy consumption, minimal technology and least toxic effects.

Impact of COVID-19 Pandemic on HIV Testing Uptake Among Key Populations Enrolled in Targeted Intervention Program in Maharashtra, India.

The COVID-19 pandemic posed unprecedented challenges to HIV services globally. We evaluated the impact of the COVID-19 pandemic on the uptake of HIV testing in the Targeted Intervention (TI) program in Maharashtra-a high HIV burden state in India. Annual HIV testing was sustained during the pandemic year (2020-2021), at levels similar to the pre-pandemic year (2019-2020), among Female Sex Workers (FSW), Men having Sex with Men (MSM), Transgender (TG), and Truckers; but not among Migrants and Intravenous Drug Users (IDU). There was an acute decline during the lockdown across all typologies. Sharp recovery was seen among FSW, MSM, and TG during the early months of the un-lockdown. The community-based screening (CBS) approach primarily contributed to this recovery. Among migrants and truckers, recovery was delayed. There was an overall reduction of 58% in annual HIV-positive registrations. The community-based networks, participatory structures, and processes of HIV programs played an essential role in reaching the community during the pandemic.

Identification of Sesamin from Sesamum indicum as a Potent Antifungal Agent Using an Integrated in Silico and Biological Screening Platform.

Due to the limited availability of antifungal drugs, their relevant side effects and considering the insurgence of drug-resistant strains, novel antifungal agents are urgently needed. To identify such agents, we have developed an integrated computational and biological screening platform. We have considered a promising drug target in antifungal drug discovery (exo-1,3-ß-glucanase) and a phytochemical library composed of bioactive natural products was used. These products were computationally screened against the selected target using molecular docking and molecular dynamics techniques along with the evaluation of drug-like profile. We selected sesamin as the most promising phytochemical endowed with a potential antifungal profile and satisfactory drug-like properties. Sesamin was submitted to a preliminary biological evaluation to test its capability to inhibit the growth of several Candida species by calculating the MIC/MFC and conducting synergistic experiments with the marketed drug fluconazole. Following the screening protocol, we identified sesamin as a potential exo-1,3-ß-glucanase inhibitor, with relevant potency in inhibiting the growth of Candida species in a dose-dependent manner (MIC and MFC of 16 and 32 µg/mL, respectively). Furthermore, the combination of sesamin with fluconazole highlighted relevant synergistic effects. The described screening protocol revealed the natural product sesamin as a potential novel antifungal agent, showing an interesting predicted pharmacological profile, paving the way to the development of innovative therapeutics against fungal infections. Notably, our screening protocol can be helpful in antifungal drug discovery.

Loss to follow-up of HIV-exposed infants for confirmatory HIV test under Early Infant Diagnosis program in India: analysis of national-level data from reference laboratories.

BACKGROUND: Early Infant Diagnosis was launched in India in 2010 and its effect on the diagnosis of HIV-exposed infants needs to be assessed. The present study was done to find out the median age at DBS sample collection for early infant diagnosis and its trend over years, the median age at diagnosis of HIV among the HIV-exposed infants with DNA PCR tests, and the proportion of infants who completed testing cascades after detection of HIV-1 in a sample. METHODS: DNA PCR data (from 2013 to 2017) maintained at all regional reference laboratories in India was collated with each infant identified by a unique code. Cohort analysis of the infant data was used to find the median age at sample collection and diagnosis. The outcomes of testing in each cascade and the overall outcomes of testing for infants were prepared. RESULTS: The median age at sample collection for the four years combined at all India level was 60 days (48-110 days). The median age at diagnosis of HIV was 285 days (174-418 days). HIV-1 was detected in samples of 1897 (6.3%) infants out of 30,216 infants who had a DNA PCR test, out of whom 1070 (56.4%) completed the testing cascade and the rest were lost to follow-up. CONCLUSION: The data highlights delay in diagnosis; both due to delay in sample collection and turn-around-times. Loss to follow-up of HIV-exposed infants with virus detection is a significant concern to the Early Infant Diagnosis and tracking systems need to be strengthened.

Redox ticklers and beyond: Naphthoquinone repository in the spotlight against inflammation and associated maladies.

Cellular redox status has been considered as a focal point for the pathogenesis of multiple disorders. High and persistent levels of free radicals kick off inflammation and associated disorders. Though oxidative stress at high levels is harmful but at low levels it has been shown to exert cytoprotective effects. Therefore, cytoprotection by perturbation in cellular redox balance is a leading strategy for therapeutic interventions. Prooxidants are potent redox modifiers that generate mild oxidative stress leading to a spectrum of bioactivities. Naphthoquinones are a group of highly reactive organic chemical species that interact with biological systems owing to their prooxidants nature. Owing to the ability of naphthoquinones and its derivatives to perturb redox balance in a cell and modulate redox signaling, they have been in epicenter of drug development for plausible utilization in multiple clinical settings. The present review highlights the potential of 1,4-naphthoquinone and its natural derivatives (plumbagin, juglone, lawsone, menadione, lapachol and ß-lapachone) as redox modifiers with anti-inflammatory, anti-cancer, anti-diabetic and anti-microbial activities for implication in therapeutic settings.

Evaluation of benzothiophene carboxamides as analgesics and anti-inflammatory agents.

Nonsteroid anti-inflammatory drugs (NSAIDs) represent standard therapy for the alleviation of pain and inflammation. At present various classes of compounds have been reported as selective inhibitors of cyclooxygenase-2 (COX-2). However, they are associated with adverse side effects. To address these issues, we report here a new class of compounds that exhibit potent analgesic and anti-inflammatory response. Substituted bromo-benzothiophene carboxamides (4-11) were examined for their analgesic and anti-inflammatory properties. Our findings demonstrate that newly synthesized bromo-benzothiophene carboxamide derivatives 4, 6, and 8 attenuate nociception and inflammation at lower concentration than classical NSAIDs, such as ibuprofen. These compounds act by selectively inhibiting COX-2 and by disrupting the prostaglandin-E2-dependent positive feedback of COX-2 regulation, which was further substantiated by reduction in the levels of cytokines, chemokines, neutrophil accumulation, synthesis of prostaglandin-E2, expression of COX-2, and neutrophil activation at lower concentration than the classic NSAID ibuprofen. Toxicological study reveals that these compounds are well tolerated and metabolized to avoid any toxicity. Thus, these molecules represent a new class of analgesic and anti-inflammatory agents. © 2014 IUBMB Life, 66(3):201-211, 2014.

Assessment of acceptability of black wheat flour products and factors affecting it among Anganwadi beneficiaries and workers: A mixed-method prospective observational study.

Introduction: Malnutrition is very common in India and black wheat might be an acceptable solution to this problem. The aim of the study was to assess acceptability of black wheat flour products and factors affecting it among Anganwadi beneficiaries and workers. Materials and Methods: This was a mixed-method prospective observational study. All the family members enrolled for supplementary nutrition and Anganwadi workers/helpers of three randomly selected Anganwadi centers were taken in the study. For qualitative data, in-depth interview was done, and for quantitative data, 9-point hedonic scale was administered. Braun and Clarke's six-phase data analysis framework was used for qualitative data. Results: A total of 16 pregnant females, 14 lactating females, 16 children, 2 Anganwadi workers, and 3 Anganwadi helpers participated in the study. Thematic analysis of the data revealed five significant themes. It included characteristics of black wheat flour, the process of making the product (experience of making the product), family acceptability, availability, and hygiene. Participants expressed that the black color appearance is one of the negative influencers in the acceptability of black wheat flour. Most of the participants liked the taste as well as the texture. However, kneading, rolling, and puffing were more challenging than traditional wheat flour. On the hedonic scale, the mean rank of acceptability is lowest for color (3.03), followed by puffing (3.49) and highest for texture (4.87) and taste (4.60). Conclusion: Our study results revealed that black wheat is acceptable to the Anganwadi beneficiaries and workers.

Unraveling the treasure trove of phytochemicals in mitigating the Salmonella enterica infection.

Foodborne diseases triggered by various infectious micro-organisms are contributing significantly to the global disease burden as well as to increasing mortality rates. Salmonella enterica belongs to the most prevalent form of bacteria accountable for significant burden of foodborne illness across the globe. The conventional therapeutic approach to cater to Salmonella enterica-based infections relies on antibiotic therapy, but the rapid emergence of the antibiotic resistance strains of Salmonella sp. necessitates the development of alternative treatment and prevention strategies. In light of this growing concern, the scientific community is rigorously exploring novel phytochemicals harnessed from medicinally important plants as a promising approach to curb Salmonella enterica infections. A variety of phytochemicals belonging to alkaloids, phenols, flavonoid, and terpene classes are reported to exhibit their inhibitory activity against bacterial cell communication, membrane proteins, efflux pumps, and biofilm formation among drug resistant Salmonella strains. The present review article delves to discuss the emergence of antibiotic resistance among Salmonella enterica strains, various plant sources, identification of phytochemicals, and the current state of research on the use of phytochemicals as antimicrobial agents against Salmonella enterica, shedding light on the promising potential of phytochemicals in the fight against this pathogen.

Artificial Intelligence in Drug Identification and Validation: A Scoping Review.

The end-to-end process in the discovery of drugs involves therapeutic candidate identification, validation of identified targets, identification of hit compound series, lead identification and optimization, characterization, and formulation and development. The process is lengthy, expensive, tedious, and inefficient, with a large attrition rate for novel drug discovery. Today, the pharmaceutical industry is focused on improving the drug discovery process. Finding and selecting acceptable drug candidates effectively can significantly impact the price and profitability of new medications. Aside from the cost, there is a need to reduce the end-to-end process time, limiting the number of experiments at various stages. To achieve this, artificial intelligence (AI) has been utilized at various stages of drug discovery. The present study aims to identify the recent work that has developed AI-based models at various stages of drug discovery, identify the stages that need more concern, present the taxonomy of AI methods in drug discovery, and provide research opportunities. From January 2016 to September 1, 2023, the study identified all publications that were cited in the electronic databases including Scopus, NCBI PubMed, MEDLINE, Anthropology Plus, Embase, APA PsycInfo, SOCIndex, and CINAHL. Utilising a standardized form, data were extracted, and presented possible research prospects based on the analysis of the extracted data.

Waldenstrom macroglobulinemia presenting with pancreatic mass: a case report and review of literature.

CONTEXT: Waldenstrom macroglobulinemia is a rare lymphoplasmacytic lymphoma characterized by a wide range of clinical presentations related to direct tumor infiltration and the production of IgM. Most commonly it presents with cytopenia, hepatosplenomegaly, lymphadenopathy, constitutional symptoms, and hyperviscosity syndrome. CASE REPORT: We report a case of Waldenstrom macroglobulinemia in an 60-year-old female who initially presented with intermittent abdominal pain. The patient had no peripheral lymphadenopathy. On extensive investigation she was found to have pancreatic mass. The diagnosis of Waldenstrom macroglobulinemia was established after cytomorphology and immunohistochemical analysis of the patient's bone marrow revealed the presence of a lymphoid/lymphoplasmacytoid-like bone marrow infiltrate along with an elevated serum IgM level. The patient responded both clinically and serologically to chemotherapy. This case is unusual because the patient lacked all common clinical features of Waldenstrom macroglobulinemia with exception of anemia. CONCLUSION: To our knowledge this is the first report of a patient with Waldenstrom macroglobulinemia presenting with a pancreatic mass adding to the spectrum of clinical presentations seen in this disease. This adds to the wide variety of gastrointestinal related clinical presentations of Waldenstrom macroglobulinemia and points to the need for considering Waldenstrom macroglobulinemia along with other lymphoid neoplasms in the differential diagnosis of pancreatic lesions.

A protocol for feasibility of plasma based GeneXpert platform and Dried Blood Spot (DBS) based Abbott platform for HIV-1 viral load testing among the people living with HIV attending ART centers in India.

BACKGROUND: HIV-1 Viral load (VL) measures efficiency of the antiretroviral therapy (ART) after treatment initiation and helps to diagnose virological failures at an early stage. Current VL assays require sophisticated laboratory facilities. As well as there are other challenges pertaining to insufficient laboratory access, cold-chain management and sample transportation. Hence the number of HIV-1 VL testing laboratories is inadequate in the resource limited settings. The revised national tuberculosis elimination programme (NTEP) in India has developed a vast network of point of care (PoC) testing facilities for diagnosis of tuberculosis and several GeneXpert platforms are functional under this programme. Both the GeneXpert HIV-1 assay and HIV-1 Abbott real time assay are comparable and GeneXpert HIV-1 assay can be used as PoC for HIV-1 Viral load testing. Also, the dried blood spot (DBS) as a sample type has been considered as a good option for HIV-1 VL testing in hard to reach areas. This protocol is therefore developed to assess the feasibility of integrating HIV-1 VL testing among people living with HIV (PLHIV) attending ART centres using the two public health models under the current programme: 1. HIV-1 VL testing using GeneXpert platform and plasma as a sample type, and 2. HIV-1 VL testing using Abbott m2000 platform and DBS as a sample type. METHODS: This ethically approved feasibility study will be implemented at two moderate to high burden ART centres where VL testing facility is not available in the town. Under Model-1, arrangements will be made to carry out VL testing on the adjacent GeneXpert facility and under Model-2, DBS will be prepared on site and couriered to identified viral load testing laboratories. In order to assess the feasibility, data will be collected on pretested questionnaire pertaining to number of samples tested for VL testing, number of samples tested for tuberculosis (TB) diagnosis and the turnaround time (TAT). In-depth interviews will be conducted among the service providers at ART centre and different laboratories for addressing any issues regarding the model implementation. RESULTS: The proportion of PLHIV tested for VL at ART centres, total TAT for both models including TAT for sample transportation, sample testing and receipt of results as well as proportion of sample rejections and reasons for the same, correlation coefficient between DBS based and plasma based VL testing will be estimated using various statistical tools. CONCLUSION: If found promising, these public health approaches will be helpful for the policy makers and program implementation in scaling up HIV-1 viral load testing within India.

Access, timeliness and retention for HIV testing under early infant diagnosis (EID) program, India.

Early Infant Diagnosis of HIV infection services are crucial for managing the perinatally acquired HIV infection. Assessing the performance of the EID services and its underlying determinants is important for the National AIDS Control Program, India. The objectives of this study were to find out access to HIV testing, the timeliness of the testing cascade, and the proportion of HIV exposed infants who are followed up to 18 months for a definitive diagnosis of HIV. The study design was a mixed method. A total of 11 states accounting for 80% of HIV-positive pregnant women were selected. Program records from a total of 62 Integrated counselling and testing centres (ICTCs) served as the source of information. The qualitative component included interviews of program managers at the state and district level, service providers at the ICTC level, and caregivers of HIV exposed infants. In the sampled 62 ICTCs, 78% of the HIV exposed infants had at least one HIV test. Of the infants who had HIV tests, 50% had at first sample collected by 8 weeks of age. The median turnaround time from sample collection to DNA PCR testing was 36 (IQR 19-70) days and that to next sample collection in case of detection of virus in the first sample was 66 (IQR 55-116) days. At 18 months of age, 544 (62%) HIV exposed infants were retained in the EID testing cascade. A total of 30 infants were diagnosed with HIV at a median age of 421 (IQR 149-650) days. More than three fourth of the HIV exposed infants had access to early infant diagnosis (EID) services. Both demand and supply-side factors contribute to access, timeliness and retention and there is a need to address these factors.

Pyrene-fluorene hybrids containing acetylene linkage as color-tunable emitting materials for organic light-emitting diodes.

New blue- to yellow-emitting materials have been developed by incorporating fluorene-based chromophores on pyrene core with acetylene linkage and using multifold palladium-catalyzed cross-coupling reactions. Both mono- and tetrasubstituted derivatives have been synthesized and characterized. The tetrasubstituted derivatives displayed red-shifted emission when compared to the monosubstituted derivative indicative of an extended conjugation in the former. End-capping with a diphenylamine unit further red-shifted the absorption and emission profiles and imparted a weak dipolar character to the molecules. Amine-containing derivatives displayed positive solvatochromism in the fluorescence spectra indicating a more polar excited state due to an efficient charge migration from the diphenylamine donor to the pyrene π-acceptor. All of the derivatives were tested as emitting dopants with host material 4,4'-bis(9H-carbazol-9-yl)biphenyl (CBP) in a multilayered OLED and found to exhibit bright blue or yellow electroluminescence. The device utilizing 1,3,6,8-tetrasubstituted pyrene derivative as a dopant emitter displayed highest maximum luminescence 4630 cd/m(2) with power efficiency 3.8 lm/W and current efficiency 7.1 cd/A at 100 cd/m(2) attributable to the proper alignment of energy levels that led to the efficient harvesting of excitons. All of the devices exhibited color purity over a wide range of operating voltages.

Reappraisal of SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1/INI-1 deficient tumor: Report of two cases.

SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 is a tumor suppressor gene located at chromosome 22q11.2. In the past decade, a major stride has been taken for decoding the molecular genesis of various tumors which has resulted in the addition of newer tumors harboring loss of this gene.

Nano to rescue: repository of nanocarriers for targeted drug delivery to curb breast cancer.

Breast cancer is a heterogeneous disease with different intrinsic subtypes. The conventional treatment of surgical resection, chemotherapy, immunotherapy and radiotherapy has not shown significant improvement in the survival rate of breast cancer patients. The therapeutics used cause bystander toxicities deteriorating healthy tissues. The breakthroughs of nanotechnology have been a promising feat in selective targeting of tumor site thus increasing the therapeutic gain. By the application of nanoenabled carriers, nanomedicines ensure targeted delivery, stability, enhanced cellular uptake, biocompatibility and higher apoptotic efficacy. The present review focuses on breakthrough of nanoscale intervention in targeted drug delivery as novel class of therapeutics. Nanoenabled carriers like polymeric and metallic nanoparticles, dendrimers, quantum dots, liposomes, solid lipid nanoparticles, carbon nanotubes, drug-antibody conjugates and exosomes revolutionized the targeted therapeutic delivery approach. These nanoassemblies have shown additional effect of improving the solubility of drugs such as paclitaxel, reducing the dose and toxicity. The present review provides an insight on the different drug conjugates employed/investigated to curb breast cancer using nanocarrier mediated targeted drug delivery. However, identification of appropriate biomarkers to target, clearer insight of the biological processes, batch uniformity, reproducibility, nanomaterial toxicity and stabilities are the hurdles faced by nanodrugs. The potential of nano-therapeutics delivery necessitates the agglomerated efforts of research community to bridge the route of nanodrugs for scale-up, commercialization and clinical applications.

Butein as a potential binder of human ACE2 receptor for interfering with SARS-CoV-2 entry: a computer-aided analysis.

Natural products have been included in our dietary supplements and have been shown to have numerous therapeutic properties. With the looming danger of many zoonotic agents and novel emerging pathogens mainly of viral origin, many researchers are launching various clinical trials, testing these compounds for their antiviral activity. The present work deals with some of the available natural compounds from the literature that have demonstrated activity in counteracting pathogen infections. Accordingly, we screened, using in silico methods, this subset of natural compounds for searching potential drug candidates able to interfere in the recognition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and its target human angiotensin-converting enzyme 2 (hACE2) receptor, leading to the viral entry. Disrupting that recognition is crucial for slowing down the entrance of viral particles into host cells. The selected group of natural products was examined, and their interaction profiles against the host cell target protein ACE2 were studied at the atomic level. Based on different computer-based procedures including molecular docking, physicochemical property evaluation, and molecular dynamics, butein was identified as a potential hit molecule able to bind the hACE2 receptor. The results indicate that herbal compounds can be effective for providing possible therapeutics for treating and managing coronavirus disease 2019 (COVID-19) infection.

Structural basis for the functional and inhibitory mechanisms of ß-hydroxyacyl-acyl carrier protein dehydratase (FabZ) of Plasmodium falciparum.

The ß-hydroxyacyl-acyl carrier protein dehydratase of Plasmodium falciparum (PfFabZ) catalyzes the third and important reaction of the fatty acid elongation cycle. The crystal structure of PfFabZ is available in hexameric (active) and dimeric (inactive) forms. However, PfFabZ has not been crystallized with any bound inhibitors until now. We have designed a new condition to crystallize PfFabZ with its inhibitors bound in the active site, and determined the crystal structures of four of these complexes. This is the first report on any FabZ enzyme with active site inhibitors that interact directly with the catalytic residues. Inhibitor binding not only stabilized the substrate binding loop but also revealed that the substrate binding tunnel has an overall shape of "U". In the crystal structures, residue Phe169 located in the middle of the tunnel was found to be in two different conformations, open and closed. Thus, Phe169, merely by changing its side chain conformation, appears to be controlling the length of the tunnel to make it suitable for accommodating longer substrates. The volume of the substrate binding tunnel is determined by the sequence as well as by the conformation of the substrate binding loop region and varies between organisms for accommodating fatty acids of different chain lengths. This report on the crystal structures of the complexes of PfFabZ provides the structural basis of the inhibitory mechanism of the enzyme that could be used to improve the potency of inhibitors against an important component of fatty acid synthesis common to many infectious organisms.

Benzothiophene carboxamide derivatives as novel antimalarials.

Bromo-benzothiophene carboxamide derivatives have been shown in the preceding article to inhibit Plasmodium falciparum Enoyl-ACP reductase. Here, we report bromo-benzothiophene carboxamide derivatives as potent inhibitors of Plasmodium asexual blood-stages in vitro as well as in vivo in the mouse model. These compounds specifically impair the development of metabolically active trophozoite stage of intraerythrocytic cycle and the intravenous administration of 3-bromo-N-(4-fluorobenzyl)-benzo[b]thiophene-2-carboxamide (compound 6) enhances the longevity of P. berghei infected mice by 2 weeks compared to disease control animals thereby preventing the onset of ataxia and convulsions in treated mice. These compounds thus hold promise for the development of potent antimalarials.