The new agreement specifically addresses what authors can do with different versions of their manuscripte.g. use in theses and collections, teaching and training, conference presentations, sharing with colleagues, and posting on websites and repositories. The terms under which these uses can occur are clearly identified to prevent misunderstandings that could jeopardize final publication of a manuscript (Section II, Permitted Uses by Authors).

The monooxygenase enzyme CYP101B1, from Novosphingobium aromaticivorans DSM12444, binds norisoprenoids more tightly than monoterpenoids and oxidized these substrates with high regioselectivity. Ionols bound less tightly to CYP101B1 than ionones, but the levels of product formation remained high and the selectivity of oxidation was similar to that observed for the parent norisoprenoid. The structurally related sesquiterpene lactone (+)-sclareolide (9) was stereoselectively hydroxylated by CYP101B1 to (S)-(+)-3-hydroxysclareolide (9a). The turnover of monoterpenoid derivatives showed low levels of product formation and selectivity despite promising binding data. CYP101B1 catalyzed the selective oxidation of (1R)-(−)-nopol (14) and cis-jasmone (15), generating >90% (1R)-(−)-5-hydroxynopol (14a) and 4-hydroxy-cis-jasmone (15a), respectively. To develop strategies for the efficient and selective oxidation of monoterpenoid-based substrates using CYP101B1, we investigated the binding and catalytic properties of terpenoid acetates. The ester functional group of these substrates mimicked the carbonyl moiety of norisoprenoids and anchored the monoterpenoid acetates in the active site of CYP101B1 with high affinity for the monoterpenoid acetates. The oxidation of these substrates by CYP101B1 occurred with product formation rates in excess of 1000 min–1 and total turnover numbers of greater than 5000 being observed in all but one instance. Critically, the oxidations were regioselective, with several being stereoselective. (−)-Myrtenyl acetate (20) was oxidized regioselectively (>95%) to yield cis-4-hydroxy-myrtenyl acetate (20a), which was further oxidized to 4-oxomyrtenyl acetate (20b) using a whole-cell system, providing a biocatalytic route to generate intermediates used in the production of cannabinoid derivatives. The ester carbonyl moiety could also be used as a directing group also to enhance the activity and control the selectivity of P450-catalyzed reactions; for example, the turnover of l-(−)-bornyl acetate (18) and isobornyl acetate (19) by CYP101B1 generated 9-hydroxybornyl acetate (18a) and 5-exo-hydroxyisobornyl acetate (19a), respectively, as the sole products.

This study was aimed to boost up the dissolution rate of a sparingly aqueous soluble BCS Class II drug pitavastatin (PTV) by solid dispersion (SD) techniques using two hydrophilic polymers poloxamer 407 and hydroxypropylmethylcellulose (HPMC). Low aqueous solubility of PTV is associated with less oral bioavailability, and a real challenge in preparing appropriate dosage form. To enhance the aqueous solubility, physical mixing and SD formulations of PTV were developed by fusion and solvent evaporation methods using two hydrophilic polymers, poloxamer 407 and HPMC. Scanning electron microscopy (SEM) investigation indicated that PTV molecules were homogeneously dispersed in carrier prepared by different formulation methods at 1:2 and 1:3 ratios of PTV: polymer assuming amorphous SD state. The thermogravimetric profiles demonstrated that PTV was stable up to 198°C and began to decompose rapidly with significant weight loss as the temperature was raised over 190°C. Formulations prepared by SD techniques were stable at high temperature. In vitro studies illustrated that cumulative drug release of PTV: HPMC/poloxamer 407 formulations prepared by physical mixing, fusion and solvent evaporation techniques were better compared to pure PTV powder (61.42±0.91%). Among all the approaches, formulations prepared by solvent evaporation and fusion methods displayed higher cumulative releases of PTV than physical mixing formulations. The results of current study clearly indicated that PTV: HPMC/poloxamer 407 (1:2) formulations (S3, S1) developed by solvent evaporation method possess enhanced dissolution profile (96.06%; 95.62%) than the fusion SD formulations (F3; 94.62%, F1; 87.05%). Whereas PTV physical mixing formulations (P2; 82.32%, P4; 80.28%) containing high amount of carrier polymers (ratio 1:3) exhibited superior in vitro dissolution rates than formulations (P3; 68.70%, P1; 71.52%) having less quantity (ratio 1:2) of HPMC/poloxamer 407. It is apparent from the findings of this study that SD formulations (S3, S1, F3, F1) of PTV with HPMC/poloxamer 407 is a very promising approach for improving the in vitro dissolution profile of the sparingly aqueous soluble PTV. Moreover, 1:2 ratio formulations prepared by fusion and solvent evaporation SD approaches were found more effective to upgrade the release rate of PTV than the 1:3 formulations. Dhaka Univ. J. Pharm. Sci. 20(3): 325-336, 2022 (June) Centennial Special Issue

The monooxygenase, CYP101B1, selectively hydroxylates undistinct methylene C–H bonds in medium to large cycloalkyl rings and can generate oxabicycloundecanol derivatives.

Dengue, a mosquito transmitted febrile viral disease, is a serious public health concern in Bangladesh. Despite significant number of incidences and reported deaths each year, there are inadequate number of studies relating the temporal trends of the clinical parameters as well as socio-demographic factors with the clinical course of the disease. Therefore, this study aims to associate the clinical parameters, demographic and behavioral factors of the dengue patients admitted in a tertiary care hospital in Dhaka, Bangladesh during the 2019 outbreak of dengue with the clinical course of the disease. Data were collected from the 336 confirmed dengue in-patients and analyzed using SPSS 26.0 software. Majority of the patients were male (2.2 times higher than female) who required longer time to recover compared to females (p < 0.01), urban resident (54.35%) and belonged to the age group of 18–40 years (73.33%). Dengue fever (90.77%) and dengue hemorrhagic fever (5.95%) were reported in most of the dengue patients while fever (98%) was the most frequently observed symptom. A significantly positive association was found between patient’s age and number of manifested symptoms (p = 0.013). Average duration of stay in the hospital was 4.9 days (SD = 1.652) and patient’s recovery time was positively correlated with delayed hospitalization (p < 0.01). Additionally, recovery time was negatively correlated with initial blood pressure (both systolic (p = 0.001, and diastolic (p = 0.023)) and platelet count (p = 0.003) of the patients recorded on the first day of hospitalization. Finally, a statistical model was developed which predicted that, hospital stay could be positively associated with an increasing trend of temperature, systolic blood pressure and reduced platelets count. Findings of this study may be beneficial to better understand the clinical course of the disease, identify the potential risk factors and ensure improved patient management during future dengue outbreaks.

Adamantane, 1‐ and 2‐adamantanol and 2‐adamantanone, were poor substrates for the cytochrome P450 enzyme CYP101B1. The CYP101B1 catalysed oxidation of 1‐adamantyl methyl ketone, and methyl 2‐(1‐adamantyl acetate), were more active generating a majority of the 4‐hydroxy metabolite. Substrate engineering using acetate and isobutyrate ester directing groups significantly increased the affinity, activity and coupling efficiency of CYP101B1 for the esters compared to the parent adamantanols, resulting in enhanced product formation rates (720 to 1350 nmol.(nmol‐P450)−1.min−1). The majority of the turnovers were selective for C−H bond hydroxylation with 4‐hydroxy‐1‐adamantyl isobutyrate and the 5‐hydroxy‐2‐adamantyl esters being generated as the sole majority product, 97 %, with high total turnover numbers, ranging from 4130 to 16500. In addition N‐(1‐adamantyl)acetamide, was oxidised by CYP101B1 whereas 1‐adamantylamine, was not. Whole‐cell biocatalytic reactions were used to generate the products in good yield. Overall the use of ester protecting groups and the modification of the amine to an amide enabled the more efficient and selective biocatalytic oxidation of adamantane frameworks.

Oxidation of polyaromatic hydrocarbons by P450s can be lowered by redox cycling but CYP101B1 regioselectively hydroxylated substituted naphthalenes and biphenyls.

Rosuvastatin (RVT) is a BCS class II antilipidemic crystalline drug, which exhibits low bioavailability due to its very poor aqueous solubility; therefore, it is challenging to develop a proper formulation of RVT. To enhance solubility and bioavailability of this API, an attempt has been made by implementing solid dispersion technique. Solid dispersion (SD) technique is a solubility enhancing technique where one or more active entities are dispersed in an inert medium (matrix or carrier) at solid state. In this study, different ratios of Kollicoat® IR (KIR) and Kollidon® 90F (KF90) polymers were used with API to prepare various formulations by physical mixing (PM) and SD approaches; here solvent evaporation technique was used whereas methanol was used as solvent which was completely evaporated from the homogenously dispersed system by placing in a water-bath at 60-65°C and then in oven for 30 minutes at 50 °C. Among the formulations, RVT-KF90 SD formulations showed the most promising result in in-vitro study in terms of drug release profile (78.04 – 99.21%) in comparison to pure RVT (63.1%) and physical mixing of RVT with those polymers. USP dissolution apparatus type II was used at 37°C ± 0.5°C with 50 rpm to conduct the in-vitro experiment. The experiment also unraveled that the dissolution of RVT improved with increasing the amounts of polymers. Subsequently, stability of the developed formulations was conducted by Fourier transforms infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) as well as scanning electron microscopy (SEM). The results obtained from FTIR ensured no involvement of any significant drug-excipient interaction. Moreover, the DSC study signified thermal stability at high temperature. Besides, the SEM micrograph illustrated homogenous distribution of RVT in the polymer and transformation of crystal-like RVT into amorphous formulations. Dhaka Univ. J. Pharm. Sci. 20(2): 199-211, 2021 (December)