Predictive pharmacodynamic performance of the Eleveld pharmacokinetic-pharmacodynamic model for propofol: comparison of predicted and measured bispectral index.

BACKGROUND: The Eleveld pharmacokinetic-pharmacodynamic model for propofol predicts bispectral index (BIS) processed electroencephalogram values from estimated effect-site concentrations. We investigated agreement between measured and predicted BIS values during total intravenous anaesthesia (TIVA). METHODS: Forty participants undergoing lower limb surgery received TIVA using remifentanil target-controlled infusions and propofol by manually controlled, target-guided infusions based upon the Eleveld model and directed by two pharmacokinetic computer simulation applications: PKPD Tools and StelSim. We evaluated the predictive performance of the Eleveld model by calculating median prediction errors (BIS units) and by Bland-Altman analyses. We also performed |Bland-Altman analysis of supplementary data provided by the authors of the Eleveld model. RESULTS: Whereas median prediction errors were small (MDPE -1.9, MDAPE 10), the ranges were wide (-18.5 to 24.3 and 1.7 to 24.3). The proportion of MDAPE >10 BIS units was 47.8%. Bland-Altman analysis showed a small mean bias (-0.52 BIS units) with wide limits of agreement (-27.7 to 26.2). Each participant's limits of agreement did not meet the requirements for declaring interchangeability between the two measurements. The measurement differences depended on the BIS values, as indicated by the positive slopes of the differences vs BIS values. Bland-Altman analysis of the Eleveld model supplementary data revealed similar results. CONCLUSION: BIS predictions by the Eleveld model should be interpreted with caution. In spite of the acceptable MDPE and MDAPE, there are unacceptable degrees of both within-subject and between-subject variation during propofol target-controlled infusions. This limits the use of adjusting targeted concentrations to achieve desired simulated BIS values with confidence.

Effect of a carbohydrnate lollipop on the gastric volume of fasted pediatric patients.

BACKGROUND: Preoperative fasting is part of routine practice. Children subjected to prolonged preoperative fasting often suffer adverse effects. Consuming a preoperative lollipop may lessen their anxiety and have clinical benefits. AIMS: To assess the effect of consuming a lollipop on gastric volume and the feasibility of administering a lollipop to a child preoperatively. METHODS: In this prospective, repeated measures interventional study, we measured gastric antrum volume using ultrasound in children aged 2-18 years. We measured antrum volumes after participants had fasted for a minimum of 6 h for solids and 2 h for clear fluids. They then consumed a standard carbohydrate lollipop, and we repeated the antrum volume measurements after 1 h. RESULTS: Of the 38 patients enrolled, 32 completed the study; four had ingested additional food or liquid, and two were diagnosed with systemic disease the day after data collection. The gastric volume data were normally distributed. The mean volume change was 0.01 ml kg-1 (95% CI -0.02 to 0.05; p = .460). The mean postlollipop volume was 0.51 ml kg-1 (95% CI 0.43 to 0.58). CONCLUSIONS: Consuming a standard lollipop did not affect the gastric volume of fasted pediatric patients.

Comparison of Hemoglobin Measurements by 3 Point-of-Care Devices With Standard Laboratory Values and Reliability Regarding Decisions for Blood Transfusion.

BACKGROUND: We compared the accuracy of 3 point-of-care testing (POCT) devices with central laboratory measurements and the extent to which between-method disagreements could influence decisions to transfuse blood. METHODS: Hemoglobin concentrations [Hb] were measured in 58 adult patients undergoing cardiothoracic surgery using 2 Ilex GEM Premier 3500 blood gas analyzers (BG_A and BG_B) and a HemoCue Hb-201 device (HemoCue). Measurements were compared with our central laboratory's Siemens Advia 2120 flow cytometry system (laboratory [Hb] [Lab[Hb]]), regarded as the gold standard. We considered that between-method [Hb] differences exceeding 10% in the [Hb] range 6-10 g/dL would likely erroneously influence erythrocyte transfusion decisions. RESULTS: The 70 Lab[Hb] measurements ranged from 5.8 to 16.7 g/dL, of which 25 (36%) were <10.0 g/dL. Measurements by all 4 devices numbered 57. Mean POCT measurements did not differ significantly (P > .99). Results of the Bland-Altman analyses revealed statistically significant bias, with predominant underestimations by all 3 POCTs predominating. HemoCue upper and lower limits of agreement (LOA) were narrower, and the 95% confidence intervals (95% CIs) of the LOAs did not overlap with those of BG_A and BG_B. Similarly, a narrow mountain plot demonstrated greater precision for the HemoCue. Comparing BG_A with BG_B revealed no bias and narrow LOA. Error grid analysis within the [Hb] range 6-10 g/dL revealed that 5.3% of HemoCue measurements were beyond the permissible 10.0% error zone in contrast to 19.0% and 16.0% of the blood gas measurements. Possible inappropriate transfusion decisions based on POCT values generally erred toward unnecessary transfusions. Calculations of Cohen κ statistic indicated better chance-corrected agreement between HemoCue and Lab[Hb] regarding erythrocyte transfusions than the blood gas analyzers. CONCLUSIONS: All 3 POCT devices underestimated the Lab[Hb] and cannot be used interchangeably with standard laboratory measurements. BG_A and BG_B can be considered to be acceptably interchangeable with each other. Whereas the HemoCue had little bias and good precision, the blood gas analyzers revealed large bias and poor precision. We conclude that the tested HemoCue provides more reliable measurements, especially within the critical 6-10 g/dL range, with reduced potential for transfusion errors. Decisions regarding erythrocyte transfusions should also be considered in the light of clinical findings.

In situ bioremediation of hexavalent chromium in presence of iron by dried sludge bacteria exposed to high chromium concentration.

Stability of chromium in the ferrochrome slag dumps and leachate are affected by pH, redox potential and the presence of other metallic species in the slag. It is desirable to keep chromium in slag dumps in the trivalent [Cr(III)] state because trivalent chromium is 1000 times less toxic to living organisms than the hexavalent form [Cr(VI)]. Due to the low toxicity and low mobility of Cr(III), it is recommended to convert Cr(VI) to Cr(III) wherever possible to protect the health of living organisms. In this study, the role of Cr(VI) reducing organisms for stabilising chromium in slag dumps was evaluated in the presence of iron [oxidation states Fe(II) and Fe(III)]. The study showed that stabilisation of chromium species in the trivalent state was most favourable under aerated conditions. Up to 100 mg/L Cr(VI) was reduced in less than 24 h by cultures grown under aerobic conditions in the presence of Fe(III). A much shorter time (6 h) was required to reduce the same amount of Cr(VI) in the presence of Fe(II). When oxygen was completely excluded, it was only possible to reduce 20 mg/L in about 48 h which was much slower than the removal of 100 mg/L in less than 24 h under aerated conditions. Fe(II) contributed directly to catalytic reduction of Cr(VI) reduction whereas Fe(III) was beneficial to Cr(VI) reduction up to an initial Cr(VI) concentration of 75 mg/L. Evaluation of Cr(VI) reduction kinetics showed that Cr(VI) reduction under aerobic conditions followed the non-competitively inhibited mixed-order reaction. Cr(VI) reduction in sealed reactor vessels, under anaerobic conditions, followed a modified non-competitive inhibition reaction model. The results indicate that chromium stabilisation in ferrochrome slag dumps would require maintenance of a fully aerated dump supplemented by a culture of Cr(VI) reducing organisms.

Burnout among rural hospital doctors in the Western Cape: Comparison with previous South African studies.

BACKGROUND: Burnout among doctors negatively affects health systems and, ultimately,patient care. AIM: To determine the prevalence of burnout among doctors working in the district health system in the Overberg and Cape Winelands districts of the Western Cape Province and to compare the findings with those of previous South African studies. SETTING: Rural district hospitals. METHODS: During 2013, a validated questionnaire (Maslach Burnout Inventory) was sent to 42 doctors working in the district health system within the referral area of the Worcester Hospital, consisting of the Overberg health district and the eastern half of the Cape Winelands. RESULTS: Response rate was 85.7%. Clinically significant burnout was found among 81% of respondents. High levels of burnout on all three subscales were present in 31% of participants.Burnout rates were similar to those of a previous study conducted among doctors working in the Cape Town Metropolitan Municipality primary health care facilities. Scores for emotional exhaustion (EE) and depersonalisation (DP) were greater than those of a national survey;however, the score for personal accomplishment (PA) was greater. EE and PA scores weresimilar to that of a study of junior doctors working in the Red Cross Children's Hospital;however, EE was smaller. CONCLUSION: This study demonstrates high burnout rates among doctors working at district level hospitals, similar to the prevalence thereof in the Cape Town Metropolitan primary health care facilities. Health services planning should include strategies to address and prevent burnout of which adequate staffing and improved work environment are of prime importance.

Comparison of Minimally and More Invasive Methods of Determining Mixed Venous Oxygen Saturation.

OBJECTIVE: To investigate the accuracy of a minimally invasive, 2-step, lookup method for determining mixed venous oxygen saturation compared with conventional techniques. DESIGN: Single-center, prospective, nonrandomized, pilot study. SETTING: Tertiary care hospital, university setting. PARTICIPANTS: Thirteen elective cardiac and vascular surgery patients. INTERVENTIONS: All participants received intra-arterial and pulmonary artery catheters. Minimally invasive oxygen consumption and cardiac output were measured using a metabolic module and lithium-calibrated arterial waveform analysis (LiDCO; LiDCO, London), respectively. For the minimally invasive method, Step 1 involved these minimally invasive measurements, and arterial oxygen content was entered into the Fick equation to calculate mixed venous oxygen content. Step 2 used an oxyhemoglobin curve spreadsheet to look up mixed venous oxygen saturation from the calculated mixed venous oxygen content. The conventional "invasive" technique used pulmonary artery intermittent thermodilution cardiac output, direct sampling of mixed venous and arterial blood, and the "reverse-Fick" method of calculating oxygen consumption. MEASUREMENTS AND MAIN RESULTS: LiDCO overestimated thermodilution cardiac output by 26%. Pulmonary artery catheter-derived oxygen consumption underestimated metabolic module measurements by 27%. Mixed venous oxygen saturation differed between techniques; the calculated values underestimated the direct measurements by between 12% to 26.3%, this difference being statistically significant. CONCLUSION: The magnitude of the differences between the minimally invasive and invasive techniques was too great for the former to act as a surrogate of the latter and could adversely affect clinical decision making.

What keeps health professionals working in rural district hospitals in South Africa?

BACKGROUND: The theme of the 2014 Southern African Rural Health Conference was 'Building resilience in facing rural realities'. Retaining health professionals in South Africa is critical for sustainable health services. Only 12% of doctors and 19% of nurses have been retained in the rural areas. The aim of the workshop was to understand from health practitioners why they continued working in their rural settings. CONFERENCE WORKSHOP: The workshop consisted of 29 doctors, managers, academic family physicians, nurses and clinical associates from Southern Africa, with work experience from three weeks to 13 years, often in deep rural districts. Using the nominal group technique, the following question was explored, 'What is it that keeps you going to work every day?' Participants reflected on their work situation and listed and rated the important reasons for continuing to work. RESULTS: Five main themes emerged. A shared purpose, emanating from a deep sense of meaning, was the strongest reason for staying and working in a rural setting. Working in a team was second most important, with teamwork being related to attitudes and relationships, support from visiting specialists and opportunities to implement individual clinical skills. A culture of support was third, followed by opportunities for growth and continuing professional development, including teaching by outreaching specialists. The fifth theme was a healthy work-life balance. CONCLUSION: Health practitioners continue to work in rural settings for often deeper reasons relating to a sense of meaning, being part of a team that closely relate to each other and feeling supported.

Heparinase thromboelastography compared with activated coagulation time for protamine titration after cardiopulmonary bypass.

OBJECTIVE: The present study is a comparison of two point-of-care (POC) tests as endpoints of protamine titration after CPB. The authors hypothesized that using the heparinase-kaolin thromboelastography (TEG-HK) R-time difference would more readily identify residual heparin necessitating additional protamine than when using activated coagulation time (ACT). The primary endpoint was the between-group difference in protamine dose. Whether this approach would lessen postoperative bleeding and sequelae also was investigated. DESIGN: Single center, blinded, prospective, randomized study. SETTING: University teaching hospital. PARTICIPANTS: Eighty-two adult patients for on-pump coronary artery bypass and/or valve surgery. INTERVENTIONS: Patients were randomized. In the ACT group, protamine was titrated until ACT did not exceed baseline by more than 10%. In the TEG group, a TEG-HK R-time difference less than 20% was targeted. Protamine was repeated to achieve the endpoints. Clinicians in the ACT group were blinded to TEG data and vice versa. MEASUREMENTS AND MAIN RESULTS: There was no between-group difference in total protamine dose (3.9 ± 0.6 and 4.2 ± 0.7; 95% CI of the difference between means: -0.544 to 0.008 mg/kg; p = 0.057) or protamine:heparin ratios (1.3:1 and 1.4:1; 95% CI of the difference between means: -0.05 to 0.03 mg/mg; p = 0.653). In the ACT group, 17% of patients required a second protamine dose, and in the TEG group, 24% of patients required a second protamine dose. No between-group differences in the postoperative transfusion requirements or intensive care unit length of stay were demonstrated. CONCLUSION: No difference was identified in protamine dosing using either ACT or TEG-HK R-time difference as endpoints. Heparinase TEG may be useful for monitoring heparin reversal.

Allometric or lean body mass scaling of propofol pharmacokinetics: towards simplifying parameter sets for target-controlled infusions.

Uncertainty exists as to the most suitable pharmacokinetic parameter sets for propofol target-controlled infusions (TCI). The pharmacokinetic parameter sets currently employed are clearly not universally applicable, particularly when patient attributes differ from those of the subjects who participated in the original research from which the models were derived. Increasing evidence indicates that the pharmacokinetic parameters of propofol can be scaled allometrically as well as in direct proportion to lean body mass (LBM). Appraisal of hitherto published studies suggests that an allometrically scaled pharmacokinetic parameter set may be applicable to a wide range of patients ranging from children to obese adults. On the other hand, there is evidence that propofol pharmacokinetic parameters, scaled linearly to LBM, provide improved dosing in normal and obese adults. The 'Schnider' pharmacokinetic parameter set that has been programmed into commercially available TCI pumps cannot be employed at present for morbidly obese patients (body mass index >40 kg/m2), because of anomalous behaviour of the equation used to calculate LBM, resulting in administration of excessive amounts of propofol. Simulations of TCI using improved equations to calculate LBM indicate that the Schnider model delivers similar amounts of propofol to morbidly obese patients as do the allometrically scaled pharmacokinetic parameter sets. These hypotheses deserve further investigation. To facilitate further investigation, researchers are encouraged to make their data freely available to the WorldSIVA Open TCI Initiative (http://opentci.org).

Comparative MIC evaluation of a generic ceftriaxone by broth microdilution on clinically relevant isolates from an academic hospital complex in South Africa.

We evaluated the in vitro microbiological efficacy of a generic ceftriaxone product against several clinically significant organisms collected from sterile sites. The minimum inhibitory concentration (MIC) of each was determined simultaneously with the reference and the generic ceftriaxone product. Comparative analysis of MICs between the two products for each isolate was performed using both categorical (interpretive) agreement and essential (actual MIC value) agreement. A total of 260 isolates were tested. Overall, there was categorical agreement of 98.9% and essential agreement of 95.8%. The categorical agreement for all isolates (96.7 - 100%) accorded with international standards, as no very major errors were seen and the major error rate was less than 3%. Of the 90 isolates of E. coli (40), Klebsiella spp. (40) and Salmonella spp. (10), 87.6% had an MIC less than or equal to 0.12mg/l. The generic ceftriaxone product showed equivalent efficacy by MIC determination to the reference formulation. Ceftriaxone remains a viable and useful antimicrobial agent against a variety of clinically relevant organisms in our setting.

The performance of compartmental and physiologically based recirculatory pharmacokinetic models for propofol: a comparison using bolus, continuous, and target-controlled infusion data.

BACKGROUND: With the growing use of pharmacokinetic (PK)-driven drug delivery and/or drug advisory displays, identifying the PK model that best characterizes propofol plasma concentration (Cp) across a variety of dosing conditions would be useful. We tested the accuracy of 3 compartmental models and 1 physiologically based recirculatory PK model for propofol to predict the time course of propofol Cp using concentration-time data originated from studies that used different infusion schemes. METHODS: Three compartmental PK models for propofol, called the "Marsh," the "Schnider," and the "Schüttler" models, and 1 physiologically based recirculatory model called the "Upton" model, were used to simulate the time course of propofol Cp. To test the accuracy of the models, we used published measured plasma concentration data that originated from studies of manual (bolus and short infusion) and computer-controlled (target-controlled infusion [TCI] and long infusion) propofol dosing schemes. Measured/predicted (M/P) propofol Cp plots were constructed for each dataset. Bias and inaccuracy of each model were assessed by median prediction error (MDPE) and median absolute prediction error (MDAPE), respectively. RESULTS: The M/P propofol Cp in the 4 PK models revealed bias in all 3 compartmental models during the bolus and short infusion regimens. In the long infusion, a worse M/P propofol Cp at higher concentration was seen for the Marsh and the Schüttler models than for the 2 other models. Less biased M/P propofol Cp was found for all models during TCI. In the bolus group, after 1 min, a clear overprediction was seen for all 3 compartmental models for the entire 5 min; however, this initial error resolved after 4 min in the Schnider model. The Upton model did not predict propofol Cp accurately (major overprediction) during the first minute. During the bolus and short infusion, the Marsh model demonstrated worse MDPE and MDAPE compared with the 3 other models. During short infusion, MDAPE for the Schnider and Schüttler models was better than the Upton and the Marsh models. All models showed similar MDPE and MDAPE during TCI simulations. During long infusion, the Marsh and the Schüttler models underestimated the higher plasma concentrations. CONCLUSION: When combining the performance during various infusion regimens, it seems that the Schnider model, although still not perfect, is the recommended model to be used for TCI and advisory displays.

A survey of wound care knowledge in South Africa

Chronic wounds afflict millions worldwide; incurring significant health care costs and chronic suffering. Clinicians are often unsure about treatment; resulting in poor outcomes. Objective. To determine the scope of knowledge possessed by fifth-year medical students; general practitioners (GPs) and surgical registrars; concerning chronic wound management. Design. Cross-sectional study.Methods. Deans of eight South African medical schools received letters requesting information regarding time devoted to wound-care training. Knowledge-based questionnaires were distributed to final-year students at two universities; surgical registrars at four universities and GPs attending refresher courses. Results. Four medical schools replied; of whom only two offered formal teaching. 162 medical students; 45 GPs and 47 surgical registrars completed questionnaires. The overall median (25th - 75th percentiles) knowledge scores for registrars; GPs and students were 65(55 - 70); 55(45 - 65) and 45(35 - 50) respectively. Whereas the scores of registrars and GPs did not differ; the student scores were significantly less. Only 32of registrars and 18of GPs attained scores of 70or more. 96considered training to be inadequate. Interest in wound care was only mild to moderate; with more GPs than registrars requesting literature. Conclusions. Very little; if any; training on chronic wounds is offered in South Africa. The levels of knowledge cannot be considered adequate for successful treatment; nor for teaching to undergraduates. This preliminary study cannot reflect the attitudes and knowledge throughout the country. However; it is clear that there is a need for improved education about these conditions that have huge clinical and economic consequences

A Survey of Wound Care Knowledge in South Africa

Chronic wounds afflict millions worldwide; incurring significant health care costs and chronic suffering. Clinicians are often unsure about treatment; resulting in poor outcomes. Objective. To determine the scope of knowledge possessed by fifth-year medical students; general practitioners (GPs) and surgical registrars; concerning chronic wound management. Design. Cross-sectional study.Methods. Deans of eight South African medical schools received letters requesting information regarding time devoted to wound-care training. Knowledge-based questionnaires were distributed to final-year students at two universities; surgical registrars at four universities and GPs attending refresher courses. Results. Four medical schools replied; of whom only two offered formal teaching. 162 medical students; 45 GPs and 47 surgical registrars completed questionnaires. The overall median (25th - 75th percentiles) knowledge scores for registrars; GPs and students were 65(55 - 70); 55(45 - 65) and 45(35 - 50) respectively. Whereas the scores of registrars and GPs did not differ; the student scores were significantly less. Only 32of registrars and 18of GPs attained scores of 70or more. 96considered training to be inadequate. Interest in wound care was only mild to moderate; with more GPs than registrars requesting literature. Conclusions. Very little; if any; training on chronic wounds is offered in South Africa. The levels of knowledge cannot be considered adequate for successful treatment; nor for teaching to undergraduates. This preliminary study cannot reflect the attitudes and knowledge throughout the country. However; it is clear that there is a need for improved education about these conditions that have huge clinical and economic consequences

Arterial oxygenation and one-lung anesthesia.

PURPOSE OF REVIEW: In the presence of the obligatory shunt during one-lung ventilation, arterial oxygenation is determined by the magnitude of the shunt in addition to the oxygen content of the mixed venous blood coursing through that shunt. The present discussion aims to heighten awareness of factors determining arterial oxygenation during one-lung anesthesia, other than the magnitude of the shunt and dependent lung low-ventilation perfusion units. RECENT FINDINGS: A convenient way to increase mixed venous and thereby arterial oxygenation is to raise cardiac output. While this approach has achieved some success when increasing cardiac output from low levels, other studies have highlighted limitations of this approach when cardiac output attains very high levels. The effect of anesthesia techniques on the relationship between oxygen consumption and cardiac output could also explain unanswered questions regarding the pathophysiology of arterial oxygenation during one-lung anesthesia. SUMMARY: The effects of anesthesia techniques on oxygen consumption, cardiac output and therefore mixed venous oxygenation can significantly affect arterial oxygenation during one-lung anesthesia. While pursuing increases in cardiac output may, under limited circumstances, benefit arterial oxygenation during one-lung ventilation, this approach is not a panacea and does not obviate the necessity to optimize dependent lung volume.

Trimeric proteracacinidins and a (6-->6)-bis-leucoteracacinidin from Acacia galpinii and Acacia caffra.

The rare series of trimeric proteracacinidins is extended by identification of the first analogs with exclusive C-C interflavanyl bonds, i.e. epioritin-(4beta-->6)-oritin-(4alpha-->6)-epioritin-4alpha-ol,oritin-(4beta-->6)-oritin-(4alpha-->6)-epioritin-4alpha-ol, and epioritin-(4beta-->6)-epioritin-(4beta-->6)-epioritin-4alpha-ol. These compounds are accompanied by the bis-leucoteracacinidin, epioritin-4alpha-ol-(6-->6)-epioritin-4beta-ol, the first naturally occurring bis-flavan-3,4-diol.

Propofol in paediatric anaesthesia.

PURPOSE OF REVIEW: In this review we intend to ascertain trends in propofol administration for paediatric anaesthesia and sedation. RECENT FINDINGS: Propofol is being 'discovered' by non-anaesthesiologist practitioners of paediatric sedation. However it appears that the drug is not infrequently administered alone for painful procedures, necessitating large doses that result in uncontrolled general anaesthesia with a high potential for adverse events. An elegant technique comprises small doses of short-acting opioid (e.g. fentanyl 1 mug/kg) with low-dose propofol infusion. This does not result in worsening of pre-existing right-to-left intracardiac shunts. The dilemma is to educate non-anaesthesiologists about propofol pharmacokinetics and pharmacodynamics and in particular about the advantages of combined drug therapy. A paediatric target-controlled system for propofol has undergone preliminary clinical evaluation and it is hoped that administration according to pharmacokinetic principles will refine administration to infants and children. Sporadic cases of the propofol infusion syndrome in patients receiving prolonged sedation in intensive care units continue to be reported (characterized by metabolic acidosis, rhabdomyolysis and myocardial failure). It appears that one mechanism may be a deficiency of mitochondrial oxidative processes possibly induced by a dialyzable substance, perhaps a propofol metabolite. Propofol has been used with some success in treating postoperative laryngospasm and for tracheal intubation without muscle relaxants. SUMMARY: Propofol should be used with extreme caution for prolonged sedation in intensive care unit patients, at dose rates of below 5 mg/kg per h, while maintaining extreme vigilance for signs of developing propofol infusion syndrome. If used correctly propofol is a suitable drug for sedation outside the operating room.

(4-->6)-Coupled proteracacinidins and promelacacinidins from Acacia galpinii and Acacia caffra.

The series of naturally occurring proanthocyanidins with 7,8-dihydroxylated A-rings is extended by identification of the proteracacinidins epioritin-(4beta-->6)-oritin-4alpha-ol, epioritin-(4beta-->6)-ent-oritin-4alpha-ol, ent-oritin-(4beta-->6)-epioritin-4alpha-ol, ent-oritin-(4beta-->6)-oritin-4alpha-ol, ent-oritin-(4alpha-->6)-epioritin-4alpha-ol, ent-oritin-(4alpha-->6)-oritin-4alpha-ol, ent-oritin-(4alpha-->6)-epioritin-4beta-ol, the 'mixed' pro-teracacinidins/-melacacinidins epioritin-(4beta-->6)-epimesquitol-4alpha-ol, epioritin-(4beta-->6)-epimesquitol-4beta-ol and epimesquitol-(4beta-->6)- epioritin-4alpha-ol, and the promelacacinidin epimesquitol-(4beta-->6)-epimesquitol-4beta-ol.

Structure and stereochemistry of dimeric proteracacinidins possessing the rare C-4(C) --> C-5(D) interflavanyl linkage.

The rare series of (4-->5)-linked proteracacinidins is extended by identification of oritin-(4alpha-->5)-epioritin-4beta-ol, ent-epioritin-(4alpha-->5)-epioritin-4beta-ol, epioritin-(4beta-->5)-epioritin-4alpha-ol and ent-oritin-(4beta-->5)-epioritin-4alpha-ol from the heartwoods of Acacia galpinii and Acacia caffra.