An active site-directed, irreversible inactivation of yeast hexokinase by (R,S)2,3-epoxypropyl beta-D-glucopyranoside

(1) Only (R,S)2′,3′-epoxypropyl β-d-glucopyranoside of the complete series of mono (R,S)2′.3′-epoxypropyl ethers and glycosides of d-glucopyranose significantly inactivated yeast hexokinase.(2) (R,S)2′,3′-Epoxypropyl β-d-glucopyranoside inactivates yeast hexokinase in the absence of MgATP^2?, The rate of inactivation is unaffected by MgATP^2?.(3) The rate of inactivation of hexokinase with (R,S)2′,3′-epoxypropyl β-d-ilucopyranoside was much greater when hexokinase was present in a monomeric form than when it was present in a dimeric form.(4) (R,S)2′,3′-Epoxypropyl β-d-glucopyranoside has a high K_t (0.38 M) and at a saturating concentrarion, the first order rate constant for the inactivation of monomeric hexokinase is 8.3 · 10^?4 sec.(5) d-Glucose protects against this inactivation and this was used to derive a dissocistion constant of 0.21 mM for d-glucose in the absence of MgATP^2?.(6) The alkylation of yeast hexokinase by (R,S)2′,3′-epoxypropyl β-d-gluco-pyranoside was not specific to the active site. When the concentration of (R,S)2′,3′-epoxypropyl β-d-glucopyranoside was 50 mM two thiol groups outside the active site were also alkylated.(7) The reaction between 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) and yeast hexokinase was examined in detail. Two thiol groups per monomer (mol. wt. 50000) reacted with a second order rate constant of 27 1 mole^?1 sec^?1. A third thiol group reacted more slowly with a second-order rate constant of 1.6 1 mole^?1 sec^?1 and a fourth thiol group reacted very slowly with inactivation of the enzyme. Tue second-order rate constant in this case was 0.1 1 mole^?1 sec^?1.     

Soybeans and radish leaves contain only one of the sulfonium diastereoisomers of S-adenosylmethionine

Using a liquid chromatography method that separates the two sulfonium diastereoisomers of adenosylmethionine, we have found that immature soybeans, soybean callus culture, radish leaves, yeast and rat liver contain only the (S)-sulfonium form of S-adenosylmethionine. Our findings contradict the suggestion by Stolowitz and Minch that 10–20% of naturally-occurring adenosylmethionine may have the (R)-configuration at the sulfonium pole. Absence of the (R)-sulfonium isomer of adenosylmethionine in biological materials indicates that the (R)-sulfonium form of adenosylmethionine present in commercial adenosylmethionine samples is an artifact of the isolation procedure. Our method of measuring the isomers of adenosylmethionine enabled us to readily determine the rate of racemization and hydrolysis of adenosylmethionine. Our rate constants for racemization (K_r) and hydrolysis (K_h) were 2.4 × 10^?6 sec^?1 and 12.3 × 10-^?6 sec^?1, respectively; values which are noticeably different from those of Wu and co-workers which were obtained with a more complicated method (K_r = 8 × 10^?1 sec^?1; K_h = 6 × 10^?6 sec^?1). We believe the absence of the (R)-isomer in vivo is best explained by stabilization of the (S)-isomer as suggested by Wu et al. Although the tissues we have analysed contained the (S)-sulfonium form of adenosylmethionine exclusively, when ethionine-resistant soybean cell lines were given ethionine, they accumulated both sulfonium diastereoisomers of adenosylethionine.     

In silico, NMR and pharmacological evaluation of an hydroxyoxindole cholinesterase inhibitor

From a screening study of various potential inhibitors for cholinesterases (ChEs), compound (rac)-1 (4-((3-hydroxy-2-oxo-3-phenylindolin-1-yl) methyl) piperidin-1-ium chloride) showed an IC₅₀ of 18?μM for butyrylcholinesterase (BuChE). Herein we present a toxicological and pharmacological evaluation of (rac)-1 to determine its potential for use as an alternative ChE inhibitor for the treatment of Alzheimer’s disease. The strategy adopted included in vivo and ex vivo studies with mouse models, Molecular Modelling and Saturation Transfer Difference (STD) NMR studies.Preliminary molecular docking studies were conducted with both (R) and (S)-1 with acetylcholinesterase (AChE) and BuChE, prior to advancing to the mouse model, and indeed favorable interactions were observed, with (R)-1 showing the best binding with AChE and (S)-1 with BuChE. STD-NMR studies were used to successfully validate these results. Toxicological studies were also conducted using the Artemia salina model, with donepezil as reference. It was found that in the in vivo mouse studies that (rac)-1 presented a slightly better inhibition of AChE (0.096?µmol.min^?1.mg^?1) than donepezil (0.112?µmol.min^?1.mg^?1) and the same level of inhibition for BuChE as donepezil (0.014?µmol.min^?1.mg^?1).     

4-Hydroxyisoleucine from seed of Trigonella foenum-graecum

The principal free amino acid present in seed of Trigonella foenum-graecum has been isolated and identified as (2S, 3R, 4R)-4-hydroxyisoleucine. This compound has not been reported previously as a constituent of higher plants, but it is a component of the toxic peptide, γ-amanitin, produced by Amanita phalloides. The (2S, 3R, 4R)-isomer lactonizes readily under acidic conditions, whilst strong acid causes partial epimerization. The (2R, 3R, 4R)-isomer forms a minor component of Trigonella seed. The 4-hydroxyisoleucine content of fenugreek increases during the growth of seedlings and plants, and ¹⁴C-isoIeucine was used effectively as a biosynthetic precursor.     

The synthesis of 4,7-disubstituted-2H-benzo[b][1,4]-oxazin-3(4H)-ones using Smiles rearrangement and their in vitro evaluation as platelet aggregation inhibitors

A series of novel benzo[b][1,4]oxazin-3(4H)-one derivatives were synthesized as platelet aggregation inhibitors for structure–activity relationships (SAR) analysis. The synthetic pattern, involved Smiles rearrangement for the preparation of benzoxazine, was proven to be more efficient than the conventional methods. Biological evaluation demonstrated that among all the synthesized compounds, compound 9u (IC₅₀ = 9.20 μM) exhibited the most potent inhibition activity compared with aspirin, the positive control (IC₅₀ = 7.07 μM). Molecular docking revealed that these set of compounds could be the GPIIb/IIIa antagonist for that they could be situated in the binding site of GPIIb/IIIa receptor quite well.     

Absolute configuration and stereochemical analysis of 3α,6β-dibenzoyloxytropane

Both enantiomers of 3α,6β-dibenzoyloxytropane (1) have been prepared from optical active 6β-hydroxyhyoscyamines establishing their absolute configurations as (?)-(3R,6R) and (+)-(3S,6S)-dibenzoyloxytropane. Independent stereochemical confirmation was obtained by vibrational circular dichroism measurements, since bands characteristic of (3R,6R) and (3S,6S) configurations of tropanediols derivatives were observed. In addition, a chiral HPLC method was developed for determining absolute configurations of tropane-related natural substances at the microgram (μg) level. The complete ¹H NMR characterization of the scaffold of 1 is also reported.     

Synthesis of (R,S)-isoproterenol,an inhibitor of tau aggregation,as an 11C-labeled PET tracer via reductive alkylation of (R,S)-norepinephrine with [2-11C]acetone

(R,S)-Isoproterenol inhibits the formation of toxic granular tau oligomers associated with neuronal loss and development of cognitive disorders, and is an attractive drug candidate for Alzheimer’s disease. To elucidate its behavior in the brain by positron emission tomography, we synthesize (R,S)-[¹¹C]isoproterenol by reductive alkylation of (R,S)-norepinephrine with [2-¹¹C]acetone, which was in turn synthesized in situ under improved conditions afforded a decay-corrected radiochemical yield of 54%. The reductive alkylation using NaBH(OAc)₃ as reducing agent in the presence of benzoic acid in DMSO/DMF (60:40 v/v) at 100 °C for 10 min gave (R,S)-[¹¹C]isoproterenol in an 87% radio-high performance liquid chromatography (HPLC) analytical yield. HPLC separation using a strong cation exchange column, followed by pharmaceutical formulation in the presence of d/l-tartaric acid, afforded (R,S)-[¹¹C]isoproterenol with a total radioactivity of 2.0 ± 0.2 GBq, a decay-corrected radiochemical yield of 19 ± 2%, chemical and radiochemical purities of 71% and >99%, respectively, and a molar activity of 100 ± 13 GBq/μmol (n = 3). The overall synthesis time from the end of the bombardment to pharmaceutical formulation was 48 min. A preliminary preclinical PET study in a rat demonstrated the potential of the radioligand for the evaluation of the penetration of (R,S)-isoproterenol in human brain.     

Geographic variation in the field response of male European pine sawflies, Neodiprion sertifer, to different pheromone stereoisomers and esters

The European pine sawfly, Neodiprion sertifer (Geoffroy) (Hymenoptera: Diprionidae), is a widespread and economically important forest insect. The sex pheromone communication system of this species has been previously investigated in North America, Japan and Europe, with the acetate or propionate of the alcohol (2S,3S,7S)-3,7-dimethyl-2-pentadecanol (diprionol) shown to be the main pheromone component. In some locations, male attraction either increased or decreased by the addition of the (2S,3R,7R)-diprionyl acetate isomer. However, these studies were made with different batches of synthetic pheromones, with different types of traps and according to different procedures, so the observed differences might not reflect true geographic variation. Here we investigate the geographic pattern of male sawfly response by using identical chemicals, traps and experimental procedures at eight field sites ranging from Japan in the east to Canada in the west. We found an increased inhibitory effect of the (2S,3R,7R)-isomer from Japan and Siberia to Europe. At the eastern sites, increasing amounts of the (2S,3R,7R)-isomer up to and equal to the amount of the (2S,3S,7S )-isomer, did not influence the trap catch, whereas at sites in Europe, as little as 1% of the (2S,3R,7R)-isomer almost completely inhibited the attraction. The response of the North American population was intermediate. The only site in which the (2S,3R,7R)-isomer was essential for the attraction of males was in Siberia. A similar pattern was found for the (2S,3R,7S)-isomer. Both the acetate and the propionate form of the (2S,3S,7S)-isomer were attractive by themselves in Japan, Europe and North America, and neither the (2S,3R,7S)-isomer nor the (2S,3R,7R)-isomer alone were attractive, in the acetate or propionate form. We discuss the significance of our findings for the development of more efficient monitoring schemes and for the causes of population divergence and speciation in the European pine sawfly.     

Development of selective inhibitors for the treatment of rheumatoid arthritis: (R)-3-(3-(Methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)pyrrolidin-1-yl)-3-oxopropanenitrile as a JAK1-selective inhibitor

A series of 3(R)-aminopyrrolidine derivatives were designed and synthesized for JAK1-selective inhibitors through the modification of tofacitinib’s core structure, (3R,4R)-3-amino-4-methylpiperidine. From the new core structures, we selected (R)-N-methyl-N-(pyrrolidin-3-yl)-7H-pyrrolo[2,3-d]pyrimidin-4-amine as a scaffold for further SAR studies. From biochemical enzyme assays and liver microsomal stability tests, (R)-3-(3-(methyl(7H-pyrrolo[2,3-d]pyrimidin-4-yl)amino)pyrrolidin-1-yl)-3-oxopropanenitrile (6) was chosen for further in vivo test through oral administration. Compound 6 showed improved selectivity for JAK1 compared to that of tofacitinib (IC₅₀ 11, 2.4?×?10², 2.8?×?10³, and 1.1?×?10²?nM for JAK1, JAK2, JAK3, and TYK2, respectively). In CIA and AIA model tests, compound 6 exhibited similar efficacy to tofacitinib citrate.     

Chiral spin crossover iron(II) complex, fac-Λ-[Fe(HL)3](ClO4)2·EtOH (HL = 2-methylimidazol-4-yl-methylideneamino-R-(+)-1-methylphenyl)

A chiral spin crossover iron(II) complex, fac-Λ-[Fe^II(HL^R)₃](ClO₄)₂·EtOH was synthesized and its crystal structures in both the high-spin (HS) and low-spin (LS) states were determined, where HL^R denotes 2-methylimidazol-4-yl-methylideneamino-R-(+)-1-methylphenyl. The complex assumes octahedral coordination geometry of N₆ donor atoms by three bidentate ligands HL^R. The complex exists as the facial-Λ-isomer of fac-Λ-[Fe^II(HL^R)₃]²⁺ of the possible geometrical fac- and mer-isomers and the Δ- and Λ-enantiomorphs. The X-ray structural analyses revealed that the R-form of the ligand (HL^R) induces the fac-Λ-isomer of fac-Λ-[Fe^II(HL^R)₃]²⁺ and the S-form of the ligand (HL^S) induces the fac-Δ-isomer of fac-Δ-[Fe(HL^S)₃]²⁺. The complex fac-Λ-[Fe^II(HL^R)₃](ClO₄)₂·EtOH shows a complete steep spin crossover between the HS and the LS states at T_1/2 = 195 K.     

Steroid sapogenins from Tristagma uniflorum

From bulbs of Tristagma uniflorum the known sapogenins tigogenin, neotigogenin and (20S,22R,25S)-5α-spirostan-3β,25-diol, as well as the new (20S,22R,25R)-5α-spirostan-3β,25-diol, (20S,22S,25S)-5α-furostan-22,25-epoxy-3β,26-diol and (20S,22S,25R) -5α-furostan-22,25-epoxy-3β,26-diol, were isolated and characterized by spectroscopic (IR, ¹H NMR, ¹³C NMR, MS) methods.     

Configurational studies on red algae carotenoids

The configurations of (6′R)-β,ε-carotene, (3′R,6′R)-β,ε-caroten-3′-ol (α-cryptoxanthin), (3R,3′R,6′R)-β,ε-carotene-3,3′-diol (lutein), (3R)-β,β-caroten-3-ol (β-cryptoxanthin), (3R,3′R)-β,β-carotene-3,3′-diol (zeaxanthin) and all-trans (3S,5R,6S,3′R)-5,6-epoxy-5,6-dihydro-β,β-carotene-3,3′-diol (antheraxanthin) were established by CD and ¹H NMR studies. The red algal carotenoids consequently possessed chiralities at each chiral center (C-3, C-5, C-6, C-3′, C-6′), corresponding to the chiralities established for the same carotenoids in higher plants. Two post mortem artifacts from Erythrotrichia carnea were assigned the chiral structures (3S,5R,8R,3′R)-5,8-epoxy-5,8-dihydro-β,β-carotene-3,3′-diol [(8R)-mutatoxanthin] and (3S,5R,8S,3′R)-5,8-epoxy-5,8-dihydro-β,β-carotene-3,3′-diol [(8S)-mutatoxanthin]. This is the first well documented report of a naturally occurring β,ε-caroten-3′-ol (¹H NMR, CD, chemical derivatization).     

22,23-Epoxides of Sitosterol and Related 7-Oxygenated Δ5-Sterols

(22S,23S)-22,23-Epoxysitosterol, (22R,23R)-22,23-epoxysitosterol, (22S, 23S)-22,23-epoxy-7-ketositosterol, (22R,23R)-22,23-epoxy-7-ketositosterol, (22S, 23S)-22,23-epoxy-7α-hydroxysitosterol, (22S,23S)-22,23-epoxy-7β-hydroxysitosterol, and (22R, 23R)-22,23-epoxy-7β-hydroxysitosterol were synthesized. Their ¹H and ¹³C NMR and the mass spectra of their trimethylsilyl derivatives were studied.     

An efficient lipase-catalyzed enantioselective hydrolysis of (R,S)-azolides derived from N-protected proline, pipecolic acid, and nipecotic acid

In the Candida antarctica lipase B-catalyzed hydrolysis of (R,S)-azolides derived from (R,S)-N-protected proline in water-saturated methyl tert-butyl ether (MTBE), high enzyme activity with excellent enantioselectivity (V _S V _R ^?1 ?>?100) for (R,S)-N-Cbz-proline 1,2,4-triazolide (1) and (R,S)-N-Cbz-proline 4-bromopyrazolide (2) was exploited in comparison with their corresponding methyl ester analog (3). Changing of the substrate structure, water content, solvent, and temperature was found to have profound influences on the lipase performance. On the basis of enzyme activity and enantioselectivity and solvent boiling point, the best reaction condition of using 1 as the substrate in water-saturated MTBE at 45 °C was selected and further employed for the successful resolution of (R,S)-N-Cbz-pipecolic 1,2,4-triazolide (5) and (R,S)-N-Boc-nipecotic 1,2,4-triazolide (9). Moreover, more than 89.1 % recovery of remained (R)-1 is obtainable in five cycles of enzyme reusage, when pH 7 phosphate buffers were employed as the extract at 4 °C.     

Improvement of carbonyl reductase activity for the bioproduction of tert-butyl (3R,5S)-6-chloro-3,5-dihydroxyhexanoate

tert-Butyl (3R,5S)-6-chloro-3,5-dihydroxyhexanoate ((3R,5S)-CDHH) is a key chiral intermediate for the side chain synthesis of rosuvastatin. In this study, random mutagenesis, site-saturation mutagenesis and combinatorial mutagenesis methods were applied to improve the activity of a synthesized stereoselective short chain carbonyl reductase (SCR) to prepare (3R,5S)-CDHH. After screened by high-throughput screening method and high-performance liquid chromatography, mut-Phe145Met/Thr152Ser and mut-Phe145Tyr/Thr152Ser, were obtained, and the enzyme activities of mutants were improved by 1.60- and 1.91-fold compared with parent enzyme, respectively. The catalytically efficiencies (kcat/Km) of mut-Phe145Met/Thr152Ser and mut-Phe145Tyr/Thr152Ser exhibited 5.11- and 8.07-fold improvements in initial activity toward (S)-6-chloro-5-hydroxy-3-oxohexanoate ((S)-CHOH), respectively. In the asymmetric reduction, mut-Phe145Tyr/Thr152Ser catalyzed 500 g L⁻¹ of (S)-CHOH to produce (3R,5S)-CDHH with >99% yield and >99% e.e., and the highest space-time yield achieved at 752.76 mmol L⁻¹ h⁻¹ g⁻¹ wet cell weight within 8 h bioconversion. This study provides a foundation for the preparation of (3R,5S)-CDHH by carbonyl reductase.     

Influence of temperature, light and nutrients on the growth rates of the macroalga Gracilaria domingensis in synthetic seawater using experimental design

In the present study, the daily relative growth rates (DRGR, in percent per day) of the red macroalga Gracilaria domingensis in synthetic seawater was investigated for the combined influence of five factors, i.e., light (L), temperature (T), nitrate (N), phosphate (P), and molybdate (M), using a statistical design method. The ranges of the experimental cultivation conditions were T, 18–26°C; L, 74–162?μmol photons m^?2?s^?1; N, 40–80?μmol?L^?1; P, 8–16?μmol?L^?1; and M, 1–5?nmol?L^?1. The optimal conditions, which resulted in a maximum growth rate of ≥6.4% d^?1 from 7 to 10?days of cultivation, were determined by analysis of variance (ANOVA) multivariate factorial analysis (with a 2⁵ full factorial design) to be L, 74?μmol photons m^?2?s^?1; T, 26°C; N, 80?μmol?L^?1; P, 8?μmol?L^?1; and M, 1?nmol?L^?1. In additional, these growth rate values are close to the growth rate values in natural medium (von Stosch medium), i.e., 6.5–7.0% d^?1. The results analyzed by the ANOVA indicate that the factors N and T are highly significant linear terms, X _L, (α?=?0.05). On the other hand, the only significant quadratic term (X _Q) was that for L. Statistically significant interactions between two different factors were found between T vs. L and N vs. T. Finally, a two-way (linear/quadratic interaction) model provided a quite reasonable correlation between the experimental and predicted DRGR values (R _adjusted ² ?=?0.9540).     

Anti-hepatitis B virus lignans from the root of Streblus asper

Four new lignans, strebluslignanol F (1), (7′R,8′S,7″R,8″S)-erythro-strebluslignanol G (2), isomagnaldehyde (3) and isostrebluslignanaldehyde (4), along with 12 known lignans (5–16) were isolated from the ethyl acetate-soluble part of MeOH extract of the root of Streblus asper. Their structures were elucidated through various spectroscopic methods, including 1D NMR (¹H NMR, ¹³C NMR), 2D NMR (HMQC, HMBC and NOESY) and HRMS. The stereochemistry at the chiral centers was determined using CD spectra, as well as analyses of coupling constants and optical rotation data. The isolated lignans were evaluated for their anti-HBV activities in vitro using the HBV transfected HepG2.2.15 cell line. The most active lignans, (7′R,8′S,7″R,8″S)-erythro-strebluslignanol G, magnolol, isomagnolol and isolariciresinol, exhibited significant anti-HBV activities with IC₅₀ values of 1.58, 2.03, 10.34 and 3.67 μM, respectively, for HBsAg with no cytotoxicity, and of 3.24, 3.76, 8.83 and 14.67 μM, respectively, for HBeAg with no cytotoxicity. (7′R,8′S,7″R,8″S)-erythro-Strebluslignanol G and magnolol showed significant anti-HBV activities to inhibit the replication of HBV DNA with the IC₅₀ values of 9.02 and 8.67 μM, respectively.     

Uptake of exogenous metabolites by virus-transformed cells: changes induced by temperature and pH.

Bestatin, [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl]-(S)-leucine, inhibited aminopeptidase B and leucine aminopeptidase in a competitive manner and their K_i values were calculated to be 6 × 10^?8 and 2 × 10^?8M, respectively. Among all stereoisomers of bestatin synthesized, those which have a (2S)-configuration in the 3-amino-2-hydroxy-4-phenylbutanoyl moiety showed marked inhibition against aminopeptidase B and leucine aminopeptidase compared with the other isomers which have (2R)-configuration. One of the isomers, [(2S,3S)-3-amino-2-hydroxy-4-phenylbutanoyl]-(R)-leucine, showed somewhat stronger activity against aminopeptidase B than bestatin. Aminopeptidase B appears to be a metallo-exopeptidase. It is proposed that bestatin and its active isomers are effective due to a mechanism other than a chelating action at the active center.     

Variations in leaf respiration across different seasons for Mediterranean evergreen species

Leaf respiration (R _L) of evergreen species co-occurring in the Mediterranean maquis developing along the Latium coast was analyzed. The results on the whole showed that the considered evergreen species had the same R _L trend during the year, with the lowest rates [0.83 ± 0.43 μmol(CO₂) m^?2 s^?1, mean value of the considered species] in winter, in response to low air temperatures. Higher R _L were reached in spring [2.44 ± 1.00 μmol(CO₂) m^?2 s^?1, mean value] during the favorable period, and in summer [3.17 ± 0.89 μmol(CO₂) m^?2 s^?1] during drought. The results of the regression analysis showed that 42% of R _L variations depended on mean air temperature and 13% on total monthly rainfall. Among the considered species, C. incanus, was characterized by the highest R _L in drought [4.93 ± 0.27 μmol(CO₂) m^?2 s^?1], low leaf water potential at predawn (Ψ_pd= ?1.08 ± 0.18 MPa) and midday (Ψ_md = ?2.75 ± 0.11 MPa) and low relative water content at predawn (RWC_pd = 80.5 ± 3.4%) and midday (RWC_md = 67.1 ± 4.6%). Compared to C. incanus, the sclerophyllous species (Q. ilex, P. latifolia, P. lentiscus, A. unedo) and the liana (S. aspera), had lower R _L [2.72 ± 0.66 μmol(CO₂) m^?2 s^?1, mean value of the considered species], higher RWC_pd (91.8 ± 1.8%), RWC_md (82.4 ± 3.2%), Ψ_pd (?0.65 ± 0.28 MPa) and Ψ_md (?2.85 ± 1.20 MPa) in drought. The narrow-leaved species (E. multiflora, R. officinalis, and E. arborea) were in the middle. The coefficients, proportional to the respiration increase for each 10°C rise (Q₁₀), ranging from 1.49 (E. arborea) to 1.98 (A. unedo) were indicative of the different sensitivities of the considered species to air temperature variation.     

Yield and kinetic constants estimation in the production of hydroxy fatty acids from oleic acid in a bioreactor by Pseudomonas aeruginosa 42A2

We modelled the production of hydroxy fatty acids from oleic acid by Pseudomonas aeruginosa 42A2 in a bioreactor with a non-dispersive aeration system. First, we designed an adapted wetted-wall gas-absorption column, offering a k _La value of 39.9 h^?1, to enhance oxygen absorption in the culture media and prevent foam formation. Then, we analysed different kinetic models to simulate the yield coefficients and the kinetic constants in this bacterial transformation. Monod model fitting (μ _max1?=?0.51 h^?1, K _S1?=?1.60 C-mol l^?1, μ _max2?=?0.12 h^?1, K _S2?=?0.035 C-mol l^?1, and k ₂?=?0.033 h^?1) showed a good accuracy with the experimental data sets and was chosen for its simplicity. Lastly, mass balances were carried out to establish the stoichiometry of this biotransformation with the following yield coefficients, Υ _X/OA, Υ _{X/(10S)-HPOME} and Υ _{(10S)-HPOME/(7S10S)-HPOME} of 0.172, 0.347 and 2.388 C-mol C-mol^?1, respectively.