Calodendrum Capense Research Articles

Southern African plants used as soap substitutes; phytochemical, antimicrobial, toxicity and formulation potential

A major proportion of the population in southern Africa relies on medicinal plants, commonly known as soapy plants, for bathing and washing; however, there is limited scientific evidence that validates the effectiveness of southern African soap plants. Therefore, this study aimed to investigate the phytochemistry, antimicrobial activity, and toxicity of plants used in southern Africa as soap substitutes. Thereafter, an effective antimicrobial herbal soap was formulated and assessed for antimicrobial efficacy. Plant selection was based on a comprehensive ethnobotanical literature review that was conducted to gather information on plants used as soap substitutes in southern Africa. A total of 29 plant extracts (26 plant species) were screened for antimicrobial activity against 16 relevant skin pathogens. The minimum inhibition concentration (MIC) assay was used to assess antimicrobial activity. The plant extracts were quantitatively screened for the presence of saponins. Furthermore, the plant extracts were also assessed for toxicity using the brine shrimp lethality assay (BSLA). Calodendrum capense (L.f.) Thunb., Pelargonium peltatum (L.) L'Hér. and Ptaeroxylon obliquum (Thunb.) Radlk. demonstrated notable broad-spectrum activity against most of the tested pathogens. Hermannia cuneifolia Jacq. displayed the highest saponin content (262.41 ± 1.90 mg/g), followed by Sideroxylon inerme L. subsp. inerme (71.34 ± 1.01 mg/ml), Acalypha glabrata Thunb. (70.48 ± 2.05 mg/g), and Noltea africana (L.) Endl. (68.53 ± 2.43 mg/g). Acalypha glabrata, Aloe maculata All., Bauhinia bowkeri Harv., Deinbollia oblongifolia (E. Mey. ex Arn.) Radlk., Ledebouria luteola Jessop., Pouzolzia mixta Sohm, and S. inerme subsp. inerme organic and aqueous extracts demonstrated the lowest toxic effects at 24 and 48 h. Calodendrum capense and Ptaeroxylon obliquum organic extracts were non-toxic at 500 μg/ml, and Pelargonium peltatum displayed low toxicity at a concentration of 125 μg/ml. Calodendrum capense, Pelargonium peltatum and Ptaeroxylon obliquum were selected as the three most favourable plants for soap formulation. Pelargonium peltatum and Calodendrum capense herbal soaps were categorized as first-grade soaps (84 and 80% total fatty matter, respectively). All the tested soaps having plant concentrations of 12.5 mg/ml inhibited all the tested micro-organisms except for Enterobacter cloacae. The findings (phytochemical, antimicrobial, toxicity) herein contribute to the knowledge gaps that exist in the ethnobotanical literature of some southern African soap plants and provide evidence for their potential to be incorporated into soap formulation.

Wood anatomy of the tribe Diosmeae, a large Cape lineage of Rutaceae

Summary The tribe Diosmeae (Rutaceae) encompasses circa 278 species classified in 11 genera: ten of them are shrubs endemic to the Cape Floristic Region (South Africa), while the only arborescent genus (two species) extends from South Africa to Tanzania. We examined the wood structure of 21 species representing nine genera of Diosmeae and analysed it with respect to their life form and climatic niches. Studied taxa share a suite of traits typical for the whole family: radial vessel multiples, simple perforation plates, minute alternate intervessel pits, distinctly bordered vessel-ray pits, non-septate libriform fibres, and — except for Empleurum — marginal axial parenchyma. However, unlike most Rutaceae, they also occasionally feature vessel-ray pits with reduced borders. Most of the studied species are very similar to each other in their wood structure and habit. The two exceptions are Calodendrum capense (the only canopy tree under study) and Empleurum unicapsulare (a large riparian shrub). The first differs from other species in having wider vessels, longer libriform fibres, prismatic crystals in ray cells and winged-aliform axial parenchyma (which may be plesiomorphic for the tribe); the latter is distinctive because it lacks growth rings and banded axial parenchyma. Analysing anatomy–climate relationship, we found that wood anatomy among shrubby Diosmeae relates to their size and environmental factors, rather than taxonomy. Particularly, the vessel grouping weakly increases with stricter water limitation along the gradient from a semi-arid winter-dry climate to a Mediterranean winter-wet climate.

Southern African Soap Plants and Screening of Selected Phytochemicals and Quantitative Analysis of Saponin Content

In southern Africa, several plants are used ethnobotanically as soap substitutes, however, this information resides in different literature sources. The foaming and cleansing properties of such plants are attributed mainly to the presence of saponins, but other compounds such as alkaloids and terpenoids are also implicated. This study aimed to compile a comprehensive list of plants used traditionally as soap substitutes in southern Africa and to assess the chemical properties of selected species. Qualitative phytochemical analysis was done using five solvents (ethanol, methanol, water, chloroform, and acetone) to determine the presence of saponins, alkaloids, and terpenoids in selected soap plants. Quantitative analysis of the saponin content was done employing spectrophotometric tests of methanol extracts. There are thirty-seven (37) known southern African soap plants from twenty-four (24) different families, with the Fabaceae having the highest number of species (eight). Saponin concentrations of nine previously unstudied selected soap plants are reported for the first time in this study, whereby Calodendrum capense had the highest saponin concentrations are at 107.89 ± 4.89 mg/g, followed by Noltea africana (52.65 ± 6.81 mg/g), Crinum bulbispermum (35.43 ± 4.25 mg/g), and Merwilla plumbea (25.59 ± 0.83 mg/g). The knowledge of plant composition gives a better understanding of plant chemistry and possible use of plants medicinally, industrially and as soap substitutes. Furthermore, this allows the verification and the justification of traditional plant use. Soap plants have been used traditionally for many years, the potential to commercialise the use of these plants has been realised with the increase in the use of organic products by conscious consumers hence, the purpose of this investigation can have bearing on future projects and products.

Host suitability and feeding preference of the African citrus triozid Trioza erytreae Del Guercio (Hemiptera: Triozidae), natural vector of “Candidatus Liberibacter africanus”

AbstractAfrican citrus greening (ACGD) and huanglongbing (HLB) diseases are the most damaging diseases of citrus worldwide. Currently, the disease has no cure and has been attributed to the collapse of the citrus industry in several countries. In Africa, the causative agent “Candidatus” Liberibacter africanus is vectored by African citrus triozid (ACT) Trioza erytreae Del Guercio (Hemiptera: Triozidae). African citrus triozid is native to Africa but has been recently reported in Asia and Europe. Apart from citrus, Murraya koenigii (L.) and Clausena anisata (Willd) Hook. F. ex Benth. are also considered as preferred host plants. At present, there is scant information on host plant suitability and preference of T. erytreae. Also, there are contradictory reports on its reproduction and survival on rutaceous and non‐rutaceous host plants. In the present study, we tested the suitability and preference of rutaceous and non‐rutaceous trees and shrubs as potential ACT host plants in choice and no‐choice bioassays. The development from egg to the adult stage was longest on Calodendrum capense (Wright & Arn.) Engl. Host plants of superior quality accordingly to several ACT's biological parameters measured also revealed significantly higher morphometric characteristics. Our findings on the host status of the five rutaceous plants imply that these plants can greatly influence the population dynamics of ACT as well as the epidemiology of ACGD, and these can be a useful guide in the area‐wide management of the pest in Kenya.

English

A novel prenylfuroquinoline alkaloid capensenin (1), an alkaloid confusameline (2), two furanocoumarins psolaren (3) and bergapten (4), were isolated from hexane and dichloromethane crude extracts of stem bark, leaves and fruit pericarp of Calodendrum capense. Limonin (5) was also isolated from the stem bark, while limonin diosphenol (6) was isolated from the seeds. Capensenin (1) showed weak antimicrobial activity against Bacillus subtilis, while the leaves, stem bark and fruit pericarp crude extracts exhibited activity against Staphylococcus aureus, B. subtilis and P. citrinum. Hexane pericarp extract showed slight cytotoxicity to Vero cell E199 in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The structures of the compounds were elucidated by 1D and 2D nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and infra-red spectroscopy. Key words: Capensenin, 4-hydroxyfuroquinoline, furanocoumarin, Calodendrum capense, alkaloid, Rutaceae.

CRYPTIC HAPLOTYPES OF “CANDIDATUS LIBERIBACTER AFRICANUS”

“Candidatus Liberibacter africanus” (Laf) has long been recognised as a causal agent of the devastating citrus disease huanglongbing (HLB) or citrus greening. This species is currently restricted to Africa, the Arabian Peninsula and some Indian Ocean islands and is vectored by the African citrus psyllid, Trioza erytreae. Blotchy mottle on citrus leaves is characteristic of the disease. Somewhat similar symptoms in the rutaceous tree Calodendrum capensis (Cape chestnut) resulted in the discovery of Laf outside commercial citrus crops in South Africa. This was classed as a subspecies of Laf (capensis, hence LafC). In subsequent surveys of commercial citrus crops and Calodendrum, both natural and ornamental specimens, LafC was not found in citrus, nor has Laf been found in C. capensis. HLB was reported from Madagascar in 1968 but no sequences from this source have so far been published. Until fairly recently, only the reference 16S rRNA gene sequences of Laf (L22533) and LafC (AF137368) had been deposited in GenBank. Both of these reference sequences contain a number of unresolved nucleotides. When these nucleotide positions are invstigated by aligning against more recently available sequences, it becomes evident that these unresolved positions represent one percentage point difference in similarity between Laf and LafC. The originally reported 97.4% similarity is therefore incorrect based on this new information. Recalculating the similarity on the full length 16S rDNA sequence results in 99.54% similarity, a value too high to justify a subspecies status. LafC should therefore be downgraded as a haplotype of Laf. Further, the six 16S rRNA gene sequences currently available in GenBank identified as Laf as a species separate into two haplotype groups. The three haplotypes of Laf are therefore: (i) LafA, designated as the first accession sequenced (L22533); (ii) LafC, i.e the former subspecies “capensis”, to recognise the priority in the use of this term; (iii) LafB, the third previously unrecognised haplotype. Thus the cryptic presence of three haplotypes is revealed by this review of the Laf 16S rDNA sequences.

‘Candidatus Liberibacter’ in four indigenous Rutaceous species from South Africa

Author(s): Viljoen, R.; Steenkamp, E. T.; Pietersen, G. | Abstract: ‘Candidatus Liberibacter africanus’ (Laf), a phloem restricted, gram negative bacteria of the α-proteobacteria is the agent associated with Citrus greening disease in South Africa. A related bacterium ‘Candidatus Liberibacter africanus spp. capensis’ (LafC) was previously described from an indigenous Rutaceae tree, Calodendrum capense. This led to the hypothesis that other indigenous Rutaceous trees may also be infected with Liberibacters related to either Laf or LafC. Samples from 289 Vepris lanceolata, 231 Zanthoxylum capense, and 234 Clausena anisata were collected from within the natural distribution of these trees in South Africa. Total DNA was extracted and tested for the presence of a Liberibacter using a generic Liberibacter real-time PCR. ‘Candidatus Liberibacters’ present in positive samples were characterised by amplifying and sequencing the β-operon, 16S and omp gene regions. The percentage of Liberibacter positive samples differed per tree species with 6% V. lanceolata, 4% Z. capense and 11% C. anisata respectively, being infected. Phylogenetic analysis of the β-operon and omp gene regions, revealed unique phylogenetic clusters for Liberibacters associated with each tree species. Phylogenetic analysis from the 16S gene region however indicated that sequences obtained from V. lanceolata and C. anisata were similar to 16S sequences for LafC, whereas that obtained from Z. capense grouped on its own. Laf has not been identified from HLB-infected orchards from other Citrus producing countries other than Africa and the Mascarene Islands. The presence of related Liberibacters from indigenous Rutaceae species in South Africa may therefore suggest that Laf originated on the African continent.

Diesel Engine Emissions and Performance Characteristics under Cape Chestnut Biofuel

Cape Chestnut oil was processed to biodiesel through transesterification. Cape Chestnut kennels are reported to have oil content of 60% - 63% [1]. Properties of biodiesel were determined and compared with those of diesel and engine tests done at a constant speed of 1500 RPM on the biodiesel blends to evaluate their performance and emissions characteristics. Performance evaluation was in terms of Brake Specific Fuel Consumption (BSFC), Brake Horse Power (BHP) and Brake Thermal Efficiency (ETE). The engine was initially run on diesel to establish the reference characteristics before running on biodiesel blends. The biodiesel was blended with diesel volumetrically to 80% (B80), 50% (B50), 20% (B20) and 5% (B5) the percentage being the volume of biodiesel in the blended fuel. Diesel fuel had the lowest BSFC followed by B5 whose BSFC was 7.3% higher than that of diesel. BTE for B100 was lower than that of diesel by 20.3% while that of B5 was 7.6% lower. Concentration of SO2 in B100 was 92.7% lower than that of diesel fuel while that of B20 was 24.7% lower. NO and NO2 concentrations for B100 were around 15% higher than that of diesel. Particulate matter of less than 10 μm diameter (PM10) for diesel was found to be 72% of the total collected from all the test fuels as compared to that of biodiesel blends at 28%. The study concluded that Cape Chestnut biodiesel blends containing up to 20% biodiesel can be used in an unmodified diesel engine since their performance and emission characteristics were very similar to that of diesel but with reduced toxic gas emissions therefore friendly to the environment.

Widespread occurrence of “Candidatus liberibacter africanus subspecies capensis” in Calodendrum capense in South Africa

Recent studies in citrus orchards confirmed that Citrus Greening, a heat sensitive citrus disease, similar to Huanglongbing (HLB), is associated with the presence of “Candidatus Liberibacter africanus” (Laf) in South Africa. Neither “Candidatus Liberibacter asiaticus” (Las), associated with HLB, “Candidatus Liberibacter americanus”, nor “Candidatus Liberibacter africanus ssp. capensis” (LafC), previously detected in the Western Cape, South Africa on an indigenous Rutaceous species, Calodendrum capense (L. f.) Thunb. (Cape Chestnut), were detected in citrus. The current study aims to determine the potential role of C. capense in the epidemiology of Citrus Greening in South Africa and whether LafC poses a risk to citriculture. A total of 278 C. capense samples were collected throughout South Africa and tested for Liberibacters using real-time PCR. While LafC was found in 100 samples, distributed from all areas where collected, no evidence of Laf infection in any sample was found . The identity of the LafC present was confirmed by sequencing the amplicon derived from conventional PCR of the ß-operon of the ribosomal protein gene region of the first 17 infected trees found and of a representative sample from each district. The Liberibacter status of 44 C. capense and 272 citrus (Midnight Valencia) trees growing in close proximity to each other for over 15 years was determined. Out of 44 C. capense specimens, 43 were infected with LafC, but none of the citrus trees were infected with LafC. Based on the results of this it appears that natural spread of LafC to citrus does not occur.

Essential Antioxidant Elements in Oils of the Cake and Shell of Calodendrum capense Nuts

Increasing deaths due to skin cancer have been attributed to the sun’s ultra-violet (UV)radiations which initiate free radical reactions. Synthetic sunscreens contain antioxidants that prevent the freeradical effects but risk skin exposure to harmful synthetic compounds of Cu, Mg, Mn and Zn. Calodendrumcapense nut oil (cape chestnut or yangu oil), popular for African skin care is destined for natural cosmetic.Literature is scarce on the antioxidant element composition of its oil. We report the levels of Cu, Mg, Mn andZn in oil from two parts of the nuts; cake and shells measured by AAS. Results show the potential supply of Cu,Mg, Mn and Zn from yangu oil of the two parts of the nuts that can serve as a physical sun-block. The use ofyangu oil for skin protection against UV radiations is encouraged.

Performance of a domestic cooking wick stove using fatty acid methyl esters (FAME) from oil plants in Kenya

With depletion of solid biomass fuels and their rising costs in recent years, there has been a shift towards using kerosene and liquefied petroleum gas (LPG) for domestic cooking in Kenya. However, the use of kerosene is associated with health and safety problems. Therefore, it is necessary to develop a clean, safe and sustainable liquid bio-fuel. Plant oil derivatives fatty acid methyl esters (FAME) present such a promising solution. This paper presents the performance of a wick stove using FAME fuels derived from oil plants: Jatropha curcus L. (Physic nut), Croton megalocarpus Hutch, Calodendrum capense (L.f.) Thunb., Cocos nucifera L. (coconut), soyabeans and sunflower. The FAME performance tests were based on the standard water-boiling tests (WBT) and compared with kerosene. Unlike kerosene all FAME fuels burned with odorless and non-pungent smell generating an average firepower of 1095 W with specific fuel consumption of 44.6 g L−1 (55% higher than kerosene). The flash points of the FAME fuels obtained were typically much higher (2.3–3.3 times) than kerosene implying that they are much safer to use than kerosene. From the results obtained, it was concluded that the FAME fuels have potential to provide safe and sustainable cooking liquid fuel in developing countries.

Antifungal efficacy of ten selected South African plant species against Cryptococcus neoformans

Fungal infections are a major threat to public health care. Cryptococcosis in humans and animals, caused by Cryptococcus neoformans, is a life-threatening disease. In a random antifungal screening of acetone leaf extracts of 400 tree species against Cryptococcus neoformans, the following plant species had good activity: Zanthoxylum capense (Thunb.) Harv. (Rutaceae), Morusmesozygia Stapf (Moraceae), Calodendrum capense (L.f.) Thunb. (Rutaceae), Catha transvaalensis Codd (Celastraceae), Cussonia zuluensis Strey (Araliaceae), Ochna natalitia (Meisn.) Walp. (Ochnaceae), Croton sylvaticus Hochst. ex C. Krauss (Euphorbiaceae), Maytenus undata (Thunb.) Blakelock (Celastraceae), Celtis africana Burm.f. (Ulmaceae), and Cassine aethiopica Thunb. (Celastraceae). Hexane, dichloromethane, acetone, and methanol extracts of these 10 plants were tested against Cryptococcus neoformans using bioautography and microdilution assays. Acetone extracted the highest quantity of plant material. Dichloromethane and hexane extracts of Maytenus undata showed clear bands in bioautography while the other species did not produce good results in bioautography. Maytenus undata extracts had promising antifungal activity against C. neoformans, with average minimum inhibitory concentration (MIC) of 0.09 mg/mL after 24 h and 0.18 mg/mL after 48 h incubation. Croton sylvaticus and Catha transvaalensis extracts also had good activity, with average MIC values of 0.07 mg/mL and 0.09 mg/mL, respectively. Because of the clear bands on bioautograms and low MIC values compared to the other plant species investigated, M. undata was identified as a good candidate for further studies.

A Survey for 'Candidatus Liberibacter' Species in South Africa Confirms the Presence of Only 'Ca. L. africanus' in Commercial Citrus.

Greening disease of citrus is a serious disease known in South Africa since the late 1920s. In South Africa, it is associated with infection by 'Candidatus Liberibacter africanus', a heat sensitive, phloem-limited, noncultured alpha-proteobacterium. Huanglongbing (HLB), a similar, but more devastating disease that was described initially from China but which now occurs in several citrus producing countries, is associated with a different Liberibacter species, 'Ca. L. asiaticus'. A 'Ca. L. africanus' subspecies, 'Ca. L. africanus subsp. capensis', has been found only in South Africa infecting an indigenous Rutaceous species, Calodendrum capense (Cape Chestnut), in the Western Cape in 1995. The discovery of a new Liberibacter species in Brazil, 'Ca. L. americanus', and the spread of 'Ca. L. asiaticus' to a number of additional countries over the last few years prompted us to assess whether only 'Ca. L. africanus' is present in commercial citrus orchards in South Africa. Samples displaying greening or similar symptoms were collected from 249 citrus trees from 57 orchards distributed throughout the greening affected citrus production areas of South Africa. Multiplex polymerase chain reaction (PCR) was performed on DNA extracts to detect the known citrus Liberibacters. Amplicons were obtained from 197 samples. None of the samples yielded a 1,027-bp amplicon indicative of 'Ca. L. americanus' infection. The amplicons of 84 samples were sequenced, and all were identical to the cognate 'Ca. L. africanus' Nelspruit sequence in GenBank. No instance of 'Ca. L. asiaticus' or 'Ca. L. africanus subsp. capensis' sequence was found. Geographically representative samples that tested negative for Liberibacter also tested negative for phytoplasmas based on real-time PCR results. Based on the results of this survey, it is concluded that to date only 'Ca. L. africanus' is associated with citrus greening in commercial citrus in South Africa.

Indigenous oil crops as a source for production of biodiesel in Kenya

In this study, oils extracted from four crops, Jatropha curcas L., Croton megalocarpus Hutch, Calodendrum capense (L.f.) Thunb. (cape chestnut) and Cocos nucifera L. (coconut) were transesterified in methanol using sodium hydroxide as a catalyst. Methyl esters obtained were characterized by GC-MS and further tested for fuel properties relative to convectional diesel fuels (automotive and kerosene). Methyl esters of commercial oils: sunflower and soybean were also tested for fuel properties for comparison. Some of parameters tested included kinematic viscosity, flash point, distillation temperatures, copper corrosion, cetane number, ash content, and gross heating value. The results showed hexadecanoate and octadecanoate were common fatty acids esters identified in the four analyzed methyl esters. Total unsaturation was highest for Croton ester with 86.6 %, Jatropha and C. capense esters had unsaturation of 65.2 % and 61.2 %, respectively, while coconut ester recorded only 2.8 %. The ester viscosities at 40 °C were with range of 4.16-4.63 mm2/s except coconut ester with viscosity 2.71 mm2/s, which is close to that of kerosene 2.35 mm2/s. The esters were found to be less volatile that diesel fuels with coconut esters registering as most volatile among the esters. Esters of sunflower and soybean have their volatility very close to that of Jatropha ester. The flash points of the esters were typically much higher (> 100 °C) than petroleum diesels, automotives and kerosene (74 and 45.5 °C, respectively). Jatropha, sunflower and soybean esters passed the ASTM standard D6751 for flash point; 130 °C minimum, all the esters however were within the European standard EN-14214 for biodiesel of above 101 °C. The density of the esters was found to be 2-4 % higher than that of petroleum automotive diesel and 10-12 % more than that of kerosene. The heating values of the esters were however 12 % lower than diesel fuels on average. In general, coconut esters were found to compare well with kerosene while the rest of the esters showed properties very close to that of automotive diesel and can thus be used as neat or blended fuels in diesel engines without any modifications.

Colonial logging and recent subsistence harvesting affect the composition and physiognomy of a podocarp dominated Afrotemperate forest

Indigenous forests are declining throughout southern Africa, partly because of exogenous disturbances such as harvesting of forest resources. We evaluate the influence of colonial logging and present-day harvesting of pole-size trees (2–15 cm dbh), used for construction and fuelwood, on the structure and composition of iGxalingenwa forest in KwaZulu-Natal, South Africa. This forest has a distinctive physiognomy, with a thicket-like understorey and an emergent layer of primarily coniferous Podocarpus spp. These emergent trees represent individuals that were too small to be harvested during the colonial period. We argue that the dense angiosperm-dominated understorey arose in gaps created by logging, which allowed greater light levels at the forest floor. The understorey has since been intensively harvested (36% of available stems) for pole-sized stems, including canopy species, effectively suppressing the advanced regeneration as well as the replacement of the senescing canopy and emergent tree populations. The harvesting intensity of pole-sized stems is related to the species, size, and availability of trees. Few straight pole-sized stems are available among the understorey species and typically straight-stemmed canopy species are opportunistically harvested. Examination of community composition further suggests that, without management intervention, this forest will have a reduced stature, a thicket-like physiognomy, and be less diverse and less dominated by conifers. To rescue iGxalingenwa forest from this successional path requires a reduction in harvesting pressure on seedlings and saplings of species that normally dominate the canopy layer, many of which ( Podocarpus falcatus, Ptaeroxylon obliquum and Calodendrum capense) appear to have declining populations. The effects of commercial logging a century ago still persist and are being compounded by subsistence harvesting with significant changes to forest physiognomy and composition and the possibility of arrested succession.

ISOLATION AND CHARACTERIZATION OF LARVICIDAL COMPONENTS AGAINST MOSQUITO LARVAE ( AEDES AEGYPTI LINN.) FROM CALODENDRUM CAPENSE THUNB

Chromatographic analysis of air-dried root barks and seeds of Calodendrum capense Thunb led to the isolation of calodendrolide ( 1 ), limonin ( 2 ) and limonin diosphenol ( 3 ) whose structures were elucidated using physical and spectroscopic techniques. The compounds and the crude extract were then tested against mosquito 2 nd instar larvae of the species Aedes aegypti Linn senso stricto , a yellow fever vector at concentrations of 25, 50, 75, and 100 ppm. Calodendrolide ( 1 ) was the most toxic as it killed all the larvae even at the lower concentration of 25 ppm. In addition, concentrations of 15, 10, 5 and 1 ppm of this compound retained moderate efficacy. Calodendrolide ( 1 ), C. capense root bark crude, limonin ( 2 ), and limonin diosphenol ( 3 ) had LC 50 values of 13.1, 29.2, 71.6 and 217.1 ppm, respectively. KEY WORDS : Aedes aegypti , Limonoids, Calodendrum capense , 2 nd instar larvae, Limonin, Limonin diosphenol Bull. Chem. Soc. Ethiop. 2005, 19(1), 145-148.

Physical Properties of Crude Oil from Cape Chestnut (<i>Calendrum capense</i>)

Physical properties of crude oil from cape chestnut (Calendendrum capense) were determined. The effects of temperature and methods of extraction on some of the properties were analysed. The density of the oil decreased linearly with increase in temperature from 9316 kg/m3 at 1000C. Methods of extraction had no significant effect on the density of the oil. The viscosity of the oil decreased exponentially with increase in temperature from 134.7 mm2/s at 100C to 7.5 mm2/s at 1000C and was not significantly affected by the methods of extraction. The calorific values of the oil was about 404MJ/kg and its specific heat capacity was less than 2.2 kJ/kg 0K whereas thermal conductivity was greater than 1.3 kJ/hr 0Km. The ash content of the oils ranged from 0.008% for mechanically extracted oil to 0.106% for chemically extracted oil. The chemically extracted oil had low flash point of 670C compared to the mechanically extracted oil of 2150C. The chemically extracted oil had a high pH of 6.0 where as the mechanically extracted oil had a lower pH of 6.0 where as the mechanically extracted oil had a lower pH of 3.7. The oil showed a high potential for use as lubricant and as fuel in diesel engine. Journal of Agriculture, Science and Technology Vol.3(1) 2001: 43-52

Genomic characterization of a liberibacter present in an ornamental rutaceous tree, Calodendrum capense, in the Western Cape Province of South Africa. Proposal of 'Candidatus Liberibacter africanus subsp. capensis'.

In 1994, the uncultured phloem-restricted bacteria of citrus huanglongbing (ex-greening) disease in Asia and Africa were characterized as 'Candidatus Liberobacter asiaticum' and 'Candidatus Liberobacter africanum', respectively. Following the rules of the International Code of Nomenclature of Bacteria, the two bacterial species have now been renamed 'Candidatus Liberibacter asiaticus' and 'Candidatus Liberibacter africanus'. A third liberibacter was detected by PCR in an ornamental rutaceous tree, Cape chestnut (Calodendrum capense), in South Africa. The new liberibacter was characterized by serology and from the sequences of its 16S rDNA, intergenic 16S/23S rDNA and ribosomal protein genes of the beta operon. Phylogenetic analysis showed that the liberibacter present in C. capense differed from the two previously described liberibacter species from citrus and that it was more closely related to 'Candidatus Liberibacter africanus' than to 'Candidatus Liberibacter asiaticus'. It is proposed that the liberibacter from C capense be assigned a subspecies status, 'Candidatus Liberibacter africanus subsp. capensis'.

Presence of “Candidatus Liberibacter africanus” in the Western Cape province of South Africa

For many years, in South Africa, Huanglongbing (HLB) was restricted to the Eastern part of the country (Rustenburg, Mpumalanga, KwaZulu-Natal) and absent from the Eastern (EC) and Western Cape (WC) provinces. In November 1994, suspicious symptoms were observed on clementine trees in the Stellenbosch area (WC). In 1996 and 1997, leaf samples from WC orchards were sent to Bordeaux for analysis and found to be infected by Candidatus Liberib- acter africanus. To confirm these results, 82 samples were collected by some of us in April 1998, and tested by PCR. The presence of Candidatus L. africanus in Stellenbosch/Paarl areas of WC was confirmed in clementine, grapefruit, and lemon. Mottled leaves of Cape chestnut ( Caloden- drum capense ), a wild rutaceous tree also gave positive PCR tests. Symptoms of Huanglongbing (HLB) were first reported in South Africa in the Rustenburg region in the late 1920s. The disease was known to be present in the citrus-growing regions of the North West Province, Mpumalanga and KwaZulu-Natal.

Fatty acid composition of seed kernel oil of calodendrum capense (l.f.) thunb.

AbstractSeed kernels ofCalodendrum capense (L.f.) Thunb. yielded 60% of a light yellow oil which had the following fatty acid composition: 23.8% palmitic, 4.5% stearic, 33.7% oleic, 35.6% linoleic, 1.4% linolenic and 1.0% arachidic. Myristic and behenic acids were present in trace amounts, and the kernel cake contained 37.6% crude protein.