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Surgery for degenerative lumbar spondylolisthesis (DLS) has traditionally been indicated for patients with neurogenic claudication. Surgery improves patients' disability and lower extremity symptoms, but less is known about the impact on back pain.To evaluate changes in back pain after surgery and identify factors associated with these changes in surgically-treated DLS.Retrospective review of prospectively collected data.There were 486 consecutive patients with surgically-treated DLS who were enrolled in the Canadian Spine Outcomes Research Network prospective registry and identified for this study. Patients had demographic data, clinical information, disability (Oswestry Disability Index), and back pain rating scores collected prospectively at baseline, and 12 months follow-up RESULTS: Of the 486 DLS patients, 376 (77.3%) were successfully followed at 12 months. Mean age at baseline was 66.7 (standard deviation [SD] 9.2) years old, and 63% were female. Back pain improved significantly at 12 months, compared with baseline (p.001). Improvement in Numeric Rating Scale (NRS)-back pain ratings was on average 2.97 (SD 2.5) points at one year and clinically significant improvement in back pain was observed in 75% of patients (minimal clinically important difference (MCID) NRS-Pain 1.2 points). Multivariable logistic regression revealed five factors associated with meeting MCID NRS-back pain at 12 month follow up: higher baseline back pain, better baseline physical function (higher SF-12 Physical Component Score), symptoms duration less than 1 to 2 years, and having no intraoperative adverse events.Back pain improved significantly for patients treated surgically for DLS at 1-year follow-up.

Retrospective study.To identify prevalence of, reasons for, and predictors of emergency department (ED) utilization 6 months following elective thoracolumbar spine surgery.A retrospective review of a patient database was conducted (N = 577). Visits were divided by orthopedic spinal surgeons into (1) avoidable ED visit, (2) appropriate/no visit, and (3) unrelated visit.Demographics, pain scores, patient characteristics, and surgical factors.A total of 14.38% of patients made an ED visit the majority for avoidable reasons (11.43%). Avoidable ED visits were predominately attributed to pain (45.5%) and physiology-related issues (50.0%). Significant differences in the Numerical Rating Scale-leg pain (NRS-L);A large percentage of elective thoracolumbar surgery patients returned to the ED within 6 months for avoidable reasons. Patients likely to make avoidable visits could not be identified prior to surgery in a clinically meaningful way. Reasons for patients returning to the ED for avoidable reasons focused on pain management and minor physiological symptoms. Enhanced presurgical education may manage postsurgical expectations helping to prevent avoidable ED visits.

BACKGROUND CONTEXT Patient expectations have been demonstrated to influence recovery following spine surgery. Addressing patient expectations specifically in regards to pain and postsurgical healing is an important factor in improving recovery patterns. Presurgical education can potentially help manage patient expectations. Purpose The primary objective was to determine if participation in a single preoperative multidisciplinary educational session would result in reduced patient dissatisfaction with surgical expectations. A secondary objective was to determine if participation resulted in improvements in postsurgical pain, disability, and reductions in emergency room visits following surgery. Study Design A retrospective cohort study utilizing data from the Canadian Spine Outcomes and Research Network (CSORN) registry and hospital electronic medical records. Patient Sample Participants were patients receiving elective spinal fusion for 2–5 levels (N=206). Cohort 1 included patients who participated in preoperative multidisciplinary education (n=103). Cohort 2 included patients who opted out of the educational session (n=103). Outcome Measures Outcomes measured included the Oswestry Disability Index (ODI), NRS scales for back and leg pain (NRS-B/NRS-L), CSORN questions pertaining to patient satisfaction with surgery and whether or not the surgery met expectations. Electronic chart review quantified emergency room visits following surgery. Methods Spinal fusion patients are encouraged to attend a one time, two-hour education session 3–6 weeks prior to their surgery. The education session includes interactive discussions with nursing, physiotherapy, and occupational therapy staff concentrating on what patients should expect, how to best prepare for surgery and proper care postsurgery. A one-way ANOVA was conducted for continuous variables of interest (age, number of levels operated on, ASA score, and number of visits to the emergency room following surgery). Chi-squared analysis was conducted for categorical variables of interest (pathology, gender, patient satisfaction, and patient expectations). A two (Cohort; education: no education) × 2 (Time; baseline: follow-up) repeated measure ANOVA was conducted for NRS-B, NRS-L, and ODI. Significance was set at p Results Patients (n=103) who took part in the presurgical education sessions were significantly more satisfied with their surgery compared to the control cohort (p=.014). Patients (n=103) who did not participate in the education session failed to have their expectations met in terms of improvement in daily activities (p=.03), improvement in walking capacity (p=.03) and their expectation of back pain reduction (p=.001). There was a statistically significant effect of participation in the educational session reducing postoperative back pain (p=0.03), although this improvement did not reach a minimally clinically important difference. Number of visits to the emergency room in the 12 weeks following spine surgery was significantly lower (p=.04) for patients in the education cohort. Conclusions Reduced emergency room utilization, improved patient satisfaction, achievement of expected improvements and alleviation of back pain were documented with greater success following participation in a single 2-hour educational session prior to surgery. A single education session is a viable tool for improving patient outcomes due to its low administrative burden.

BACKGROUND CONTEXT The importance of sagittal balance and spinopelvic parameters are recognized in the management and outcomes of adult spinal deformity and isthmic spondylolisthesis, but less is known regarding their role in degenerative lumbar spondylolisthesis (DLS). The purpose of this study is to determine the influence of baseline sagittal balance and spinopelvic parameters on pain, function, and health-related quality of life (HRQOL) of patients presenting with DLS. PURPOSE The purpose of this study is to determine the influence of baseline sagittal balance and spinopelvic parameters on pain, function, and health-related quality of life (HRQOL) of patients presenting with DLS. STUDY DESIGN/SETTING Prospective, multi-center study from the Canadian Spine Outcome and Research Network (CSORN). PATIENT SAMPLE Patients with DLS were enrolled in a prospective, multi-center study between 2015 and 2017. Inclusion into this study required DLS at 1 or 2 levels and symptoms of neurogenic claudication or radicular pain with our without back pain. Patients were excluded if they had previous lumbar spine surgery or the presence of another condition which significantly affected function OUTCOME MEASURES Patient-rated outcome measures included the Numeric Pain Rating Scale (NPRS) for back pain and leg pain, Oswestry Disability Index (ODI), SF-12 Physical Component Summary score (PCS) and Mental Component Summary score (MCS), EQ-5D. Pelvic parameter measurements included: sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), sagittal vertical axis (SVA), lumbar lurdosis (LL), thoracic kyphosis (TK), T1 spino-pelvic inclination (T1 SPI), and T9 spino-pelvic inclination (T9 SPI). METHODS Baseline patient demographics, radiographic spinopelvic parameters, and sagittal alignment were analyzed for possible correlation to HRQOL using Pearson correlations. RESULTS A total of 154 patients were analyzed (mean age: 65.8, BMI: 29.1) with grade I (72%) or II (28%) DLS, of which 95 were females. Primary symptoms were related to neurogenic claudication (80%), radiculopathy (15.3%) or back pain (4.7%). On average, symptom duration was greater than 2 years in 71% of patients. Patients had moderate to severe symptoms and disability (mean NRS back: 7.2, NRS leg: 7.3, ODI: 45.6, PCS-12: 33.2, MCS-12: 49.6, EQ-5D: 0.54). Baseline measurements of radiographic alignment included sacral slope (SS=34.9±16.7°), pelvic tilt (PT=24.8±9.5°), pelvic incidence (PI=57.4±13.8°), sagittal vertical axis (SVA=35.8±40.8mm), lumbar lordosis (LL=45.7±13.6°), thoracic kyphosis (TK=36.8±13.0°), T9-spinopelvic inclination (T9SPI=9.62±4.0°), and T1-spinopelvic inclination (T1SPI=4.43±10.4°). There were 54% of patients who had an insufficient lumbar lordosis based on the relationship between PI and LL (LL CONCLUSIONS Patients with DLS have global sagittal misalignment compared to published normative controls, highlighted by less lumbar lordosis, a PI to LL mismatch, and increased PT. Spinopelvic alignment was not associated with patient outcomes, although positive sagittal balance may also be influenced by spinal stenosis. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Deacetoxycephalosporin C (DAOC), a precursor of cephalosporins excreted by Cephalosporium and Streptomyces species, has been produced in Penicillium chrysogenum transformed with DNA containing a hybrid penicillin N expandase gene ( cef E h ) and a hybrid isopenicillin N epimerase gene ( cef D h ). DAOC from a P . chrysogenum transformant was identified by ultraviolet light (uv), high performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) and mass spectrum analyses. P. chrysogenum transformed with DNA containing cef E h without cef D h did not produce DAOC. Untransformed P. chrysogenum produced penicillin V (phenoxymethylpenicillin) but not DAOC. Transformants also produced penicillin V but, in general, less than untransformed P. chrysogenum . The cef E h and cef D h genes were constructed by replacing the open reading frame (ORF) of cloned P. chrysogenum pcb C and pen DE genes with the ORF of the Streptomyces clavuligerus expandase gene, cef E, and the ORF of the Streptomyces lipmanii epimerase gene, cef D, respectively. Analyses of representative transformants suggested that production of DAOC occurred via cef E h and cef D h genes stably integrated in the P. chrysogenum genome. DNA from untransformed P. chrysogenum did not hybridize to cef E or cef D gene probes.

The discovery, made in Oxford, that crude penicillin could cure systemic and life-threatening bacterial infections was followed by attempts to purify penicillin, to determine its structure and then to produce it by total chemical synthesis. The β-lactam structure of the molecule, first proposed in October 1943, was a source of controversy until 1945. However, no useful chemical synthesis was achieved and fermentation became the commercial source of the antibiotic. In 1953, one of the products of a Cephalosporium sp. from Sardinia was shown to be a new and hydrophilic penicillin (penicillin N). This was contaminated with a substance having the same side-chain but a characteristic absorption spectrum. The latter, cephalosporin C, showed antibacterial activity but was not inactivated by a penicillinase. The determination of its β-lactam structure and isolation of its nucleus enabled pharmaceutical companies to produce many semisynthetic cephalosporins. A new tripeptide was later found to be an intermediate in the biosynthesis of both penicillin N and cephalosporin C, and this was followed by the complete elucidation of the biosynthetic pathways leading to these compounds and to benzylpenicillin.

A study of the final stages of the biosynthesis of the penicillins in Penicillium chrysogenum has revealed two types of enzyme. One hydrolyses phenoxymethyl penicillin to 6-aminopenicillanic acid (6-APA). The other, also obtained from Aspergillus nidulans, transfers a phenylacetyl group from phenylacetyl CoA to 6-APA. The acyltransferase, purified to apparent homogeneity, had a molecular mass of 40 kDa. It also catalyses the conversion of isopenicillin N (IPN) to benzylpenicillin (Pen G) and hydrolyses IPN to 6-APA. In the presence of SDS it dissociates, with loss of activity, into fragments of ca 30 and 10.5 kDa, but activity is regained when these fragments recombine in the absence of SDS.

Miracle Cure. The Story of Antibiotics. By Milton Wainwright. Blackwell: 1990. Pp.196. £16.95.

A 7-alpha-methoxycephalosporin containing a carbamoyloxymethyl substituent at C-3 (cephamycin C) has been isolated from the extracellular fluid of an aqueous suspension of Streptomyces clavuligerus shaken in the presence of 18O2. The cephalosporin has been converted into its N-acetyl dimethyl ester and the distribution of 18O in the latter determined by chemical-ionization mass spectrometry. The results indicate that the oxygen atom of the methoxy group, as well as that linked to the exocyclic methylene group at C-3, is derived from molecular O2.

Isopenicillin N synthetase (IPS) cloned from Cephalosporium acremonium has been isolated from transformed Escherichia coli and purified to homogeneity. The resulting, abundant, recombinant protein, whilst undergoing slightly different N-terminal processing to that observed for the fungally-derived protein, has identical kinetics for the conversion of LLD-aminoadipoyl-cysteinyl-valine to isopenicillin N. Recombinant IPS converts analogue substrates into unusual beta-lactam antibiotics in exactly the same way as the fungal protein.

1. The stereoisomers of delta-(alpha-aminoadipyl)-L-cysteinylvaline (LLD, LLL and DLD) were synthesized from valine labelled with 3H in its methyl groups or in the alpha position. L-Cysteinyl-D-[4,4′-3H]valine was also synthesized. 2. 3H was incorporated into a compound that behaved like penicillin N when the LLD tripeptide containing either a methyl- or an alpha-labelled valine residue was incubated with a cell-free system prepared by lysis of protoplasts of Cephalosporium acremonium. 3. Incorporation was not observed under these conditions from the labelled all-L- or DLD-tripeptide, from L-cysteinyl-D-[4,4′-3H]valine, or of Penicillium chrysogenum appeared to be the LLD isomer, like that from C. acremonium. 5. These findings are discussed in relation to penicillin biosynthesis.

1. The apoenzyme obtained on removal of Zn(2+) from beta-lactamase II from Bacillus cereus 569/H/9 showed less than 0.001% of the activity of the Zn(2+)-containing enzyme. 2. Removal of Zn(2+) led to a conformational change in the enzyme and partial unmasking of a thiol group. 3. Replacement of Zn(2+) by Co(2+), Cd(2+), Mn(2+) or Hg(2+) gave enzymes with significant, but lower, beta-lactamase activity. No activity was detected in the presence of Cu(2+), Ni(2+), Mg(2+) or Ca(2+). 4. Equilibrium dialysis indicated that the enzyme had at least two Zn(2+) binding sites. With benzylpenicillin as substrate the variation in activity with concentration of Zn(2+) indicated that activity paralleled binding of Zn(2+) to the site of highest affinity. 5. Replacement of Zn(2+) by Co(2+) and Cd(2+) gave enzymes with absorption bands at 340 and 245nm respectively, and raised the question of whether the thiol group in the enzyme is a metal-ion ligand. 6. Reduction of the product obtained by reaction of denatured beta-lactamase II with Ellman's reagent [5,5'-dithiobis-(2-nitrobenzoic acid)] gave a protein which could refold to produce beta-lactamase II activity in high yield.

Isopenicillin N synthetase was extracted from Cephalosporium acremonium and purified about 200-fold. The product showed one major protein band, coinciding with synthetase activity, when subjected to electrophoresis in polyacrylamide gel. An isopenicillin N synthetase from Penicillium chrysogenum was purified about 70-fold by similar procedures. The two enzymes resemble each other closely in their Mr, in their mobility on electrophoresis in polyacrylamide gel and in their requirement for Fe2+ and ascorbate for maximum activity. Preliminary experiments have shown that a similar isopenicillin N synthetase can be extracted from Streptomyces clavuligerus.

δ -(L-α-Amino[1,1,6- 17O/18O-adipyl]-L-cysteinyl-D-valine was converted into isopenicillin N in cell-free extracts of Cepholosporium acremonium with no loss of 17O/18O label as shown by 17O NMR spectroscopy and mass spectrometry. Incubation of unlabelled tripeptide in a cell-free system containing17O/18O enriched water produced isopenicillin N with no incorporation of 17O/18O.

Presence of pulsus paradoxus, PCO2, sternocleidomastoid retraction, and flow rates have been used at the bedside to assess the severity of acute asthma. In our study of 49 adult patients, pulse rate, respiratory rate and pulsus paradoxus were shown to be significantly higher in patients assuming the upright position on admission to the emergency center; arterial pH, PO2, and peak expiratory flow rate were significantly lower in the upright patients. All upright patients had sternocleidomastoid retraction. Peak expiratory flow rate was 73.3 +/- 5 liters per minute in diaphoretic patients, 134 +/- 21 liters per minute in non-diaphoretic, upright patients, and 225 +/- 7.5 liters per minute in recumbent patients (p less than 0.02). No recumbent patient had a peak expiratory flow rate of less than 150 liters per minute or a PCO2 of greater than 44 mm Hg. The index of Fischl, signifying a need for admission to the hospital if greater than 4, was 4 or higher in 70 percent of upright patients and in 88 percent of diaphoretic patients. Only 7 percent of recumbent patients had Fischi indexes of greater than 4.

The disulphide corresponding to the above thiol has been synthesised, but all attempts to reduce this substance to the thiol were unsuccessful, although an alternative procedure via a thiomercury intermediate, enabled the thiol to be generated in situ , the properties of this thiol, however, are not in accord with those previously described for a putative free intermediate in penicillin biosynthesis. 1

L-Alanyl-L-tyrosine and glycyl-L-phenylalanine labelled with 14C competed with each other and with the dipeptide antibiotic bacilysin for transport into Staphylococcus aureus NCTC 6571 in a medium which did not support growth. They also competed with other dipeptides and several tripeptides. The fast initial transport ofthe two labelled peptides appeared to show Michaelis-Menten kinetics. Neither was transported into a bacilysin-resistant mutant of S. aureus NCTC 6571, although tyrosine was taken up by the mutant as readily as it was by the parent strain. Uptake of alanyltyrosine or glycylphenylalanine was followed by rapid hydrolysis of the peptide and the excretion of tyrosine or phenylalanine. Glycine liberated from glycylphenylalanine was partly degraded and partly incorporated into the bacterial wall. The behaviour of these dipeptides paralleled the inactivation of bacilysin by suspensions of S. aureus and the appearance of its C-terminal amino acid, anticapsin, in the extracellular fluid.

The title peptide ( 1 ) has been synthesized and incubated with an active cell-free extract of Cephalosporium acremonium , no conversion to active antibiotics was observed; however on co-incubation with the Arnstein tripeptide (ACV) ( 2 ), strong inhibition of the conversion of ACV to isopenicillin N was observed.

1. Phenoxymethylpenicillin sulphoxide 4-methoxybenzyl ester was labelled with 3H in its 2-β-methyl group. Its specific radioactivity was 362 mCi/mmol. 2. Removal of the side chain of this compound yielded the corresponding ester of 6-aminopenicillanic acid sulphoxide and coupling of the latter with the appropriate protected α-aminoadipic acid gave 4-methoxybenzyloxycarbonylisopenicillin N sulphoxide di-4-methoxybenzyl ester or the corresponding derivative of penicillin N. 3. Removal of the protective groups by hydrogenolysis and reduction of the sulphoxide group yielded 3H-labelled isopenicillin N or penicillin N. 4. 3H-labelled phenoxymethylpenicillin sulphoxide was obtained by hydrogenolysis from its 4-methoxybenzyl ester. Reduction of its sulphoxide group and subsequent removal of the side chain gave 3H-labelled 6-aminopenicillanic acid.

Ernst Boris Chain was one of the highly gifted scientists who found refuge in Britain from Hitler’s regime in Germany. His great contribution to science and medicine lay in his role in the initiation of the work in Oxford which led to the demonstration of the therapeutic power of penicillin. For this he shared a Nobel Prize with Howard Florey and Alexander Fleming. He was a cosmopolitan and controversial figure.

SUMMARY: Osmotically fragile protoplasts have been prepared by the action of lytic enzymes on the mycelium of Penicillium chrysogenum and Cephalosporium acremonium. The yield of protoplasts, based on DNA content, was up to 18 %. Pretreatment of the mycelium with a thiol compound was necessary with Cephalosporium but not with Penicillium. Electron micrographs indicated that the protoplasts contained all the intracellular organelles of the mycelium and were bounded only by a cytoplasmic membrane. The metabolic activity of the protoplasts, as measured by their respiration, ability to maintain intracellular amino-acid pools, and antibiotic production, was similar to that of control mycelium. l-Valine and l-α-aminoadipic acid, which are precursors of penicillin N and cephalosporin C, were taken up and concentrated by the protoplasts of C. acremonium, although the latter transported l-valine less rapidly than did the corresponding mycelium. Protoplasts of P. chrysogenum took up l-valine but not l-α-aminoadipic acid or its δ-ester. There was little or no transport of the corresponding d-amino acids by protoplasts of either organism.

1. A procedure was devised which is suitable for the isolation of beta-lactamase I and beta-lactamase II from Bacillus cereus 569/H/9 on a large scale. After adsorption on to Celite both enzymes were eluted in good yield and separated by chromatography on Sephadex CM-50. 2. beta-Lactamase I was separated into three main components by isoelectric focusing and into two components by chromatography. 3. The Zn(2+)-requiring beta-lactamase II obtained by this procedure had a lower molecular weight (22000) than beta-lactamase I (28000) and also differed from the latter in containing one cysteine residue. 4. The beta-lactamase II contained no carbohydrate, but showed the thermostability of the enzyme isolated earlier as a protein-carbohydrate complex. 5. Amino acid analyses and tryptic-digest ;maps' indicate that some degree of homology between beta-lactamase I and beta-lactamase II is possible, but that beta-lactamase I is not composed of the entire sequence of beta-lactamase II together with an additional peptide fragment. 6. A 6-methylpenicillin and a 7-methylcephalosporin showed much lower affinities for both enzymes than did penicillins and cephalosporins themselves.

S INCE THE chemistry of antibiotics of clinical importance was reviewed by Regna [ I] ten years ago, many more substances in this category have been assigned definitive structures. Since this article is concerned mainly with antibiotics which have become of interest to medicine, directly or indirectly, within the last ten years, important substances such as streptomycin and chloramphenicol are not included. However, most of the new substances belong to groups or families of which the first members had been discovered before 1955. The classification of antibiotics may be based on the nature of the microorganisms by which they are produced, on chemical structures which reflect their biogenesis, or on biological activity. The third procedure has been used here in that a division has been made between substances which are of particular interest because of their antibacterial activity, antifungal activity and wider cytotoxic properties, respectively. Within these broad groups, antibiotics which are structurally related have been brought together.

1. Crystalline beta-lactamase I from Bacillus cereus 569/H yielded only amino acids on acid hydrolysis, but crystalline beta-lactamase II from the same organism yielded also substantial quantities of neutral sugars and amino sugars. 2. Analysis with an amino acid analyser indicated that the two enzymes were similar though not identical in overall amino acid composition. Analysis of neutral and amino sugars as their silyl derivatives by gas-liquid chromatography showed that the carbohydrate moiety of beta-lactamase II contained residues of glucose, galactose, mannose, fucose, glucosamine and galactosamine. 3. After oxidation and hydrolysis both beta-lactamases gave small amounts of cysteic acid. After treatment of inactive Zn(2+)-free beta-lactamase II with N-ethylmaleimide or iodoacetate enzymic activity was not restored by the addition of Zn(2+).

1. The production of penicillin N and cephalosporin C by two mutants of a Cephalosporium sp. has been studied with cultures grown in a chemically defined medium and with suspensions of washed mycelium in water or a buffered salt solution. 2. Antibiotic synthesis began at an early stage of growth and its rate per unit weight of mycelium appeared to pass its maximum as morphological changes were occurring in young hyphae. This rate subsequently declined, but rapid production could continue after net growth had ceased. 3. In a series of shake-flask fermentations in the growth medium, increases in the yield of penicillin N above the mean were correlated with much smaller increases in the yield of cephalosporin C and vice versa. 4. In suspensions of washed mycelium, moderate decreases in the efficiency of aeration increased the yield of penicillin N and decreased that of cephalosporin C. A similar result normally followed the addition of methionine to the suspension fluid, and in both cases there was usually an increase in the yield of the two antibiotics combined. 5. The apparent intracellular concentrations of the antibiotics were much lower than those attained extracellularly and also much lower than those of most of the amino acids in the intracellular pool. No detectable amount of [(14)C]penicillin N added to the extracellular fluid was found to enter the mycelium. 6. Very small amounts of peptide material whose behaviour was similar to that of the sulphonic acid of delta-(alpha-amino-adipoyl)cysteinylvaline on paper electrophoresis at pH1.8 were found in extracts of the mycelium that had been oxidized with performic acid. 6-Aminopenicillanic acid and 7-aminocephalosporanic acid were not detected. 7. Ultrasonic treatment of the mycelium resulted in rapid fragmentation of mycelial chains, rupture of many individual cells, and the liberation of amino acids and other substances into the medium. 8. Ultrasonically treated preparations synthesized penicillin N and cephalosporin C rapidly after a lag of 12hr. Antibiotic synthesis was accompanied by the growth of hyphae from swollen mycelial fragments and by the re-establishment of permeability barriers resulting in the uptake of amino acids from the medium.

Lockhart & Abraham (1956) found that two compounds which appeared to be aspartyl-lysine and aspartyl(isoleucyl)-lysine respectively were formed when bacitracin A was hydrolysed with 11 Nhydrochloric acid at 800. The aspartic acid residue in these compounds had the L-configuration and was linked to the e-amino group of L-lysine. However, both compounds carried a net positive charge at pH 7 and this raised the question whether they were simple peptides. The synthesis of peptides in which aspartic acid is joined through its mand f,carboxyl group respectively to the e-amino group of lysine has therefore been undertaken. For purposes of comparison the aand f,-i8ohexylamides of aspartic acid have also been synthesized. L-Aspartic acid and L-lysine have been used in this work but no attempt has been made to discover whether significant racemization occurs in the course of any of the reactions. It seemed possible that the reaction of N-benzyloxycarbonyl-L-aspartic anhydride (I) with the copper complex of L-lysine or with x-toluene-psulphonyl-L-lysine ester (a-tosyl-L-lysine ester) would provide a simple route to both e-N-(a-Laspartyl)-L-lysine (II) and e-N-(fi-L-aspartyl)-Llysine (III). The anhydride (I) was used by Bergmann & Zervas (1932) in peptide synthesis and was later shown to yield a mixture of oaand f-aspartyl derivatives on reaction with several amino acid esters (LeQuesne & Young, 1952; John & Young, 1954). C065-CH2-0-CO-NH-CH-CO >0 CH2-CO (I)

1. delta-(l-alpha-Aminoadipyl)-l-cysteine, the corresponding d- and dl-alpha-aminoadipyl isomers, delta-(dl-alpha-amino[6-(14)C]adipyl)-l-cysteine and gamma- and alpha-l-glutamyl-l-cysteine were synthesized. 2. The behaviour of delta-(l-aminoadipyl)-l-cysteine and the corresponding d- and dl-alpha-aminoadipyl isomers was studied in the presence of suspensions of intact mycelium of a Cephalosporium sp., suspensions treated ultrasonically and extracts obtained by grinding with alumina. 3. With intact mycelium the l-alpha-aminoadipyl isomer was removed more rapidly from the extracellular fluid than the corresponding d-isomer. 4. Addition of delta-(dl-alpha-amino[6-(14)C]adipyl)-l-cysteine to suspensions of intact mycelium led to the labelling of extracellular and intracellular penicillin N and cephalosporin C, but also to extensive hydrolysis of the dipeptide. 5. Broken-cell systems hydrolysed delta-(l-alpha-aminoadipyl)-l-cysteine and the corresponding d-alpha-aminoadipyl isomer, but the former was hydrolysed more readily than the latter. 6. gamma- and alpha-l-Glutamyl-l-cysteine were also hydrolysed but delta-(l-alpha-aminoadipyl)-l-cysteinyl-l-valine was not. 7. Only part of the enzyme activity in broken-cell systems responsible for the hydrolysis of delta-(alpha-aminoadipyl)-l-cysteine was present in the supernatant obtained on centrifugation at 20000g. 8. Possible implications of these findings are discussed.

1. Three peptides containing alpha-aminoadipic acid and cysteine have been obtained in small amounts from the mycelium of a Cephalosporium sp. 2. The peptides were precipitated as cuprous mercaptides together with glutathione and resolved from the latter and from each other by preparative paper electrophoresis and chromatography either in the sulphonic acid form or as S-sulphonyl derivatives. From the S-sulphonyl derivatives they were obtained in the thiol form. 3. One peptide (P3) was shown by amino acid analysis and the mass spectrum of the NS-ethoxycarbonyl derivative of its methyl ester to be delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine. A second peptide (P2) contained alpha-aminoadipic acid, cysteine, valine and glycine, and the third peptide (P1) contained alpha-aminoadipic acid, cysteine, beta-hydroxyvaline and glycine.