Composition of the leaf, stem bark and root bark oils of Isolona cooperi investigated by GC (retention index), GC-MS and 13C-NMR spectroscopy

The leaf, stem bark and root bark oils of Isolona cooperi Hutchinson & Dalziel from the Ivory Coast have been analysed by GC (retention index), GC-MS and 13C-NMR spectroscopy. Two types of essential oil were produced by the plant. The leaf and stem bark oils were monoterpene-rich, containing principally (Z)-beta-ocimene and gamma-terpinene and three lactones, 5-[(E and Z)-hexylidene]-5H-furan-2-ones and massoia lactone, were present in appreciable amounts. Conversely, the root bark oil was dominated by 5-isopentenylindole and (E)-beta-caryophyllene. The strategy for the analysis of each oil was adapted according to the nature of the components.     

γ-Glutamylcysteinylserine — A New Homologue of Glutathione in Plants of the Family Poaceae*

In addition to glutathione (γ-GluCysGly), many species of the family Poaceae have another tripeptide which has the amino acid sequence γ-GluCysSer. This thiol was isolated from etiolated leaves of wheat (Triticum aestivum L. cv. Star). Its structure was elucidated by quantitative amino acid analysis after total hydrolysis and by partial hydrolysis with carboxypeptidase A and γ-glutamyltranspeptidase. The content of γ-GluCysSer in the leaves of T. aestivum is increased by incubation with sulfate and is severely diminished by incubation with buthionine sulfoximine, a specific inhibitor of γ-glutamylcysteine synthetase. Oxidized γ-GluCysSer is reduced by yeast glutathione reductase with a rate somewhat lower than for glutathione, but the new tripeptide is not a substrate of glutathione-S-transferase from equine liver. Besides homoglutathione (γ-GluCysßAla), a tripeptide found in plants of the order Fabales, the tripeptide γ-GluCysSer is the second homologue of glutathione detected in plants.     

Expressing an (E)-β-farnesene synthase in the chloroplast of tobacco affects the preference of green peach aphid and its parasitoid

(E)-β-Famesene(EβF) synthase catalyses the production of EβF,which for many aphids is the main or only component of the alarm pheromone causing the repellence of aphids and also functions as a kairomone for aphids' natural enemies.Many plants possess EβF synthase genes and can release EβF to repel aphids.In order to effectively recruit the plant-derived EβF synthase genes for aphid control,by using chloroplast transit peptide(CTP) of the small subunit of Rubisco(rbcS) from wheat(Triticum aestivum L.),we targeted AαβFS1,an EβF synthase gene from sweet wormwood(Artemisia annua L),to the chloroplast of tobacco to generate CTP + AαβFS1 transgenic lines.The CTP +AαβFS1 transgenic tobacco plants could emit EβF at a level up to 19.25 ng/day per g fresh tissues,4-12 fold higher than the AαβFS1 transgenic lines without chloroplast targeting.Furthermore,aphid/parasitoid behavioral bioassays demonstrated that the CTP + AαβFS1 transgenic tobacco showed enhanced repellence to green peach aphid(Myzus persicae) and attracted response of its parasitoid Diaeretiella rapae,thus affecting aphid infestation at two trophic levels.These data suggest that the chloroplast is an ideal subcellular compartment for metabolic engineering of plant-derived EβF synthase genes to generate a novel type of transgenic plant emitting an alarm pheromone for aphid control.     

Sex pheromone biosynthesis in the Asian corn borer Ostrinia furnacalis (II): Biosynthesis of (E)- and (Z)-12-tetradecenyl acetate involves Δ14 desaturation

Sex pheromone biosynthesis in the Asian corn borer Ostrinia furnacalis was studied by topical application of deuterium labelled fatty acids to the pheromone gland. The incorporation of the labelled acids into pheromone components and precursors was determined by gas chromatography with flame ionization detection and mass spectrometry in the selected ion monitoring mode. The labelling experiments suggest that the pheromone components (E)- and (Z)-12-tetradecenyl acetates are biosynthesized from palmitic acid by δ14 desaturation, followed by chain shortening (β-oxidation), reduction, and acetylation. This is the first confirmation of a Δ14 desaturase in an eukaryotic system.     

Adjusting the scent ratio: using genetically modified Vitis vinifera plants to manipulate European grapevine moth behaviour

Herbivorous insects use olfactory cues to locate their host plant within a complex olfactory landscape. One such example is the European grapevine moth Lobesia botrana, a key pest of the grape in the Palearctic region, which recently expanded both its geographical and host plant range. Previous studies have showed that a synthetic blend of the three terpenoids, (E)‐β‐caryophyllene, (E)‐β‐farnesene and (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT), was as attractive for the moth as the complete grape odour profile in laboratory conditions. The same studies also showed that the specific ratio of these compounds in the grape bouquet was crucial because a percentage variation in any of the three volatiles resulted in almost complete inhibition of the blend's attractiveness. Here, we report on the creation of stable grapevine transgenic lines, with modified (E)‐β‐caryophyllene and (E)‐β‐farnesene emission and thus with an altered ratio compared to the original plants. When headspace collections from these plants were tested in wind tunnel behavioural assays, they were less attractive than control extracts. This result was confirmed by testing synthetic blends imitating the ratio found on natural and transformed plants, as well as by testing the plants themselves. With this evidence, we suggest that a strategy based on volatile ratio modification may also interfere with the host‐finding behaviour of L. botrana in the field, creating avenues for new pest control methods.     

The role of volatile semiochemicals in mediating host location and selection by nuisance and disease-transmitting cattle flies

The role of volatile semiochemicals in mediating the location and selection within herds of Holstein-Friesian heifers by nuisance and disease-transmitting cattle flies was investigated using coupled gas chromatography-electrophysiology (GC-EAG), coupled gas chromatography-mass spectrometry (GC-MS), electrophysiology (EAG), laboratory behaviour and field studies. Using volatile extracts collected by air entrainment from heifers in the Netherlands, a number of active peaks were located by coupled GC-EAG for Musca autumnalis (de Geer) (Diptera: Muscidae) and Haematobia irritans (L.) (Diptera: Muscidae). Volatile samples were also collected from two heifers in Denmark shown in previous counting experiments to differ significantly in their fly loads. Coupled GC-EAG using Ha. irritans antennae revealed differences in the EAG response to the samples, with additional EAG activity in the sample collected from the heifer with the lower fly load. To identify more EAG active compounds, volatiles were also collected from 48-h-old urine by air entrainment. In total, 23 compounds were located and identified by coupled GC-EAG and GC-MS. Further electrophysiological testing of these compounds with five fly species [M. autumnalis, Ha. irritans, Hydrotaea irritans (L.) (Diptera: Muscidae), Stomoxys calcitrans (L.) (Diptera: Musicidae) and Wohlfahrtia magnifica (Schiner) (Diptera: Sarcophagidae)] showed that only some of the compounds were physiologically active across the range of flies tested. These included 1-octen-3-ol, 6-methyl-5-hepten-2-one, (Z)-3-hexen-1-ol, naphthalene, and all EAG active compounds identified from urine. Compounds showing significant EAG activity were tested for behavioural activity using a wind-tunnel designed for measuring upwind flight behaviour. At certain concentrations, 1-octen-3-ol, 6-methyl-5-hepten-2-one and 3-octanol increased upwind flight, whereas naphthalene, propyl butanoate and linalool reduced upwind flight. In field studies using small herds of heifers ranked according to their fly load, individual slow-release formulations of 1-octen-3-ol and 6-methyl-5-hepten-2-one, when applied to low and high fly loading heifers, reduced fly loads on these individuals. This study provides evidence for the hypothesis that the natural differential attractiveness within herds of Holstein-Freisian heifers, i.e. a single host species, for cattle flies is partly due to differences in volatile semiochemicals emitted from the host. It is suggested that this phenomenon applies to other vertebrate host species and their associated insect pests.     

Cytotoxic (9βH)‐Pimarane and (9βH)‐17‐Norpimarane Diterpenes from the Tuber of Icacina trichantha

Three (9βH)‐pimaranes, 1, 2 , and 3 , and two (9βH)‐17‐norpimaranes, 4 and 5 , belonging to a rare compound class in nature, were obtained from the tubers of Icacina trichantha for the first time. Compound 1 is a new natural product, and 2 – 5 have been previously reported. The structures were elucidated based on NMR and MS data, and optical rotation values. The absolute configurations of (9βH)‐pimaranes were unambiguously established based on X‐ray crystallographic analysis. Full NMR signal assignments for the known compounds 2, 4 , and 5 , which were not available in previous publications, are also reported. All five isolates displayed cytotoxic activities on MDA‐MB‐435 cells (IC₅₀ 0.66–6.44 μM ), while 2, 3 , and 4 also exhibited cytotoxicities on HT‐29 cells (IC₅₀ 3.00–4.94 μM ).     

The role of calcium in apoptosis induced by 7β‐hydroxycholesterol and cholesterol‐5β,6β‐epoxide

Oxysterols, such as 7β‐hydroxy‐cholesterol (7β‐OH) and cholesterol‐5β,6β‐epoxide (β‐epoxide), may have a central role in promoting atherogenesis. This is thought to be predominantly due to their ability to induce apoptosis in cells of the vascular wall and in monocytes/macrophages. Although there has been extensive research regarding the mechanisms through which oxysterols induce apoptosis, much remains to be clarified. Given that experimental evidence has long associated alterations of calcium (Ca²⁺) homeostasis to apoptotic cell death, the aim of the present study was to determine the influence of intracellular Ca²⁺ changes on apoptosis induced by 7β‐OH and β‐epoxide. Ca²⁺ responses in differentiated U937 cells were assessed by epifluorescence video microscopy, using the ratiometric dye fura‐2. Over 15‐min exposure of differentiated U937 cells to 30 μM of 7β‐OH induced a slow but significant rise in fura‐2 ratio. The Ca²⁺ channel blocker nifedipine and the chelating agent EGTA blocked the increase in cytoplasmic Ca²⁺. Moreover, dihydropyridine (DHP) binding sites identified with BODIPY‐FLX‐DHP were blocked following pretreatment with nifedipine, indicating that the influx of Ca²⁺ occurred through L‐type channels. However, following long‐term incubation with 7β‐OH, elevated levels of cytoplasmic Ca²⁺ were not maintained and nifedipine did not provide protection against apoptotic cell death. Our results indicate that the increase in Ca²⁺ may be an initial trigger of 7β‐OH–induced apoptosis, but following chronic exposure to the oxysterol, the influence of Ca²⁺ on apoptotic cell death appears to be less significant. In contrast, Ca²⁺ did not appear to be involved in β‐epoxide–induced apoptosis. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:324–332, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/jbt.20295     

Racemization and hydrolysis of tropic acid alkaloids in the presence of cyclodextrins

Because of the constantly increasing demand for optically pure drugs it is of great importance to elucidate factors affecting stereochemistry, in order to provide a stable formulation with a high chiral quality of the desired isomer. Therefore, the effects of cyclodextrins (CyDs) and their alkylated and hydroxyalkylated derivatives on racemization and hydrolysis of (?)-(S)-hyoscyamine and (?)-(S)-scopolamine were examined kinetically and spectroscopically (NMR). Direct methods, based on a chiral and achiral chromatographic phase system, were used to determine their degradation products and enantiomer composition during stability tests. All different CyDs, except α-CyD, retarded racemization and hydrolysis. The inclusion of the drug substances in CyDs inhibits the attack of hydroxyl ions and/or water molecules and thus retards the racemization and hydrolysis. The racemization of the tropic acid alkaloids is dependent on the pH and temperature. NMR studies were used to evidence the formation of a soluble 1:1 complex in aqueous solution. © 1993 Wiley-Liss, Inc.     

Composition and Chemical Variability of Ivoirian Polyalthia oliveri Leaf Oil

The chemical composition of 45 essential oil samples isolated from the leaves of Polyalthia oliveri harvested in three Ivoirian forests was investigated by GC‐FID (retention indices measured on two columns of different polarities), and by ¹³C‐NMR, following a method developed in our laboratory. In total, 41 components were identified. The content of the main components varied drastically from sample to sample: (E)‐β‐caryophyllene (1.2 – 50.8%), α‐humulene (0.6 – 47.7%), isoguaiene (0 – 27.9%), alloaromadendrene (0 – 24.7%), germacrene B (0 – 18.3%), δ‐cadinene (0.4 – 19.3%), and β‐selinene (0.2 – 18.5%). The analysis of six oil samples selected in function of their chromatographic profiles is reported in detail. The 45 oil compositions were submitted to hierarchical cluster and principal components analysis, which allowed the distinction of three groups within the oil samples. The compositions of the oils from group I (15 samples) and II (12 samples) were dominated by (E)‐β‐caryophyllene and α‐humulene, respectively. Oil samples of group III (18 samples) needed to be partitioned into four subgroups III.1–III.4 whose compositions were dominated by alloaromadenrene, isoguaiene, germacrene B, and δ‐cadinene, respectively.     

A New Long‐Chain Alkene and Antituberculosis Constituents from the Leaves of Pourthiaea lucida

A new long‐chain alkene, dotriacont‐1‐ene ( 1 ), was isolated from the leaves of Pourthiaea lucida, together with twelve known compounds. The structure of this new compound was determined by NMR and mass‐spectrometric analyses. Among the isolated compounds, α‐tocospiro A ( 2 ), α‐tocopheryl quinone ( 4 ), and (E)‐phytol ( 5 ) exhibited antituberculosis activities (MICs ≤30 μg/ml) against Mycobacterium tuberculosis H₃₇Rv in vitro.     

High‐fat diet induces cardiac remodelling and dysfunction: assessment of the role played by SIRT3 loss

Mitochondrial dysfunction plays an important role in obesity‐induced cardiac impairment. SIRT3 is a mitochondrial protein associated with increased human life span and metabolism. This study investigated the functional role of SIRT3 in obesity‐induced cardiac dysfunction. Wild‐type (WT) and SIRT3 knockout (KO) mice were fed a normal diet (ND) or high‐fat diet (HFD) for 16 weeks. Body weight, fasting glucose levels, reactive oxygen species (ROS) levels, myocardial capillary density, cardiac function and expression of hypoxia‐inducible factor (HIF)‐1α/‐2α were assessed. HFD resulted in a significant reduction in SIRT3 expression in the heart. Both HFD and SIRT3 KO mice showed increased ROS formation, impaired HIF signalling and reduced capillary density in the heart. HFD induced cardiac hypertrophy and impaired cardiac function. SIRT3 KO mice fed HFD showed greater ROS production and a further reduction in cardiac function compared to SIRT3 KO mice on ND. Thus, the adverse effects of HFD on cardiac function were not attributable to SIRT3 loss alone. However, HFD did not further reduce capillary density in SIRT3 KO hearts, implicating SIRT3 loss in HFD‐induced capillary rarefaction. Our study demonstrates the importance of SIRT3 in preserving heart function and capillary density in the setting of obesity. Thus, SIRT3 may be a potential therapeutic target for obesity‐induced heart failure.     

Epitope structure and binding affinity of single chain llama anti‐β‐amyloid antibodies revealed by proteolytic excision affinity‐mass spectrometry

ß‐Amyloid (Aß) immunotherapy has become a promising strategy for reducing the level of Aß in brain. New immunological approaches have been recently proposed for rapid, early diagnosis, and molecular treatment of neurodegenerative diseases related to Alzheimer's Disease (AD). The combination of proteolytic epitope excision and extraction and mass spectrometry using digestion with various proteases has been shown to be an efficient tool for the identification and molecular characterization of antigenic determinants. Here, we report the identification of the Aβ epitope recognized by the variable domain of single chain llama anti‐Aβ‐antibodies, termed Aβ‐nanobodies, that have been discovered in the blood of camelids and found to be promising candidates for immunotherapy of AD. The epitope recognized by two Aβ‐specific nanobodies was identified by proteolytic epitope extraction‐ and excision‐mass spectrometry using a series of proteases (trypsin, chymotrypsin, GluC‐protease, and LysC‐protease). Matrix‐assisted laser desorption ionization – mass spectrometric analysis of the affinity – elution fraction provided the epitope, Aβ(17–28), in the mid‐ to carboxy‐terminal domain of Aβ, which has been shown to exert an Aß‐fibril inhibiting effect. Affinity studies of the synthetic epitope confirmed that the Aβ(17–28) peptide is the minimal fragment that binds to the nanobodies. The interactions between the nanobodies and full length Aβ(1–40) or Aβ‐peptides containing or lacking the epitope sequence were further characterized by enzyme linked immunosorbent assay and bioaffinity analysis. Determinations of binding affinities between the Aβ‐nanobodies and Aβ(1–40) and the Aβ(17–28) epitope provided K_D values of approximately 150 and 700 nmol, respectively. Thus, the knowledge of the epitope may be highly useful for future studies of Aβ‐aggregation (oligomerization and fibril formation) and for designing new aggregation inhibitors. Copyright © 2012 John Wiley & Sons, Ltd.     

PPAR‐β facilitating maturation of hepatic‐like tissue derived from mouse embryonic stem cells accompanied by mitochondriogenesis and membrane potential retention

Relatively little is known about mitochondria metabolism in differentiating embryonic stem (ES) cells. Present research focused on several elements of cellular energy metabolism in hepatic‐like tissue derived from mouse ES cells. We demonstrated that mitochondrial location patterns and mitochondrial membrane potential (ΔΨ_m) existed in subsequent differentiation of the tissue. Mitochondriogenesis appeared at the early stage and kept a normal ΔΨ_m in differentiated mature hepatocytes. Peroxisome proliferator‐activated receptor‐α (PPAR‐α) expression was transitorily increased at the beginning, and kept a relatively low level later, which accompanied by expression of PPAR‐γ coactivator (PGC)‐1α, a master regulator of mitochondrial biogenesis. PPAR‐β expression showed robust up‐regulation in the late differentiation course. Enhanced co‐expressions of PPAR‐β and albumin with catalysis of UDP‐glucuronosyltransferases (UGTs) were observed at mature stage. While PPAR‐γ expression changed little before and after differentiation. Mitochondriogenesis could be accelerated by PPAR‐α specific agonist WY14643 and abolished by its antagonist GW6471 at the early stage. Neither of them affected mitochondrial ΔΨ_m and albumin generation in the differentiated hepatocytes. Furthermore, maturation of hepatic‐like tissue and mitochondriogenesis in hepatocyte could be efficiently stimulated by PPAR‐β specific agonist L165041 and abolished by PPAR‐β specific antagonist GSK0660, but not affected by PPAR‐γ specific agonist GW1929. In conclusion, the derived hepatic tissue morphologically possessed cellular energy metabolism features. PPAR‐α seemed only necessary for early mitochondriogenesis, while less important for ΔΨ_m retention in the mature tissue derived. The stimulation of PPAR‐β but not ‐γ enhanced hepatogenesis, hepatocytes maturation, and mitochondriogenesis. PPAR‐β took an important role in cellular energy metabolism of hepatogenesis. J. Cell. Biochem. 109: 498–508, 2010. © 2009 Wiley‐Liss, Inc.     

Regulation of long-term oviposition in the house cricket,Acheta domesticus: Roles of prostaglandin and factors associated with sperm

The transfer of spermatophore contents derived from testes during mating greatly stimulates ovipositional activity for long periods of time in the house cricket, Acheta domesticus (L.). Since prostaglandins appear to play a role in reproduction in several insect species, and since prostaglandin synthesis enzymes occur in cricket testes and spermatophores, we investigated the role of prostaglandins in the regulation of long-term oviposition. Inactivation of prostaglandin synthesis enzymes in males or females using specific inhibitors failed to block mating-induced increases in egg laying. However, males lacking sperm because of X-irradiation were unable to induce oviposition even though they mated, transferred spermatophores, and had high levels of prostaglandins in both testes and spermatophores. X-irradiation was also used to generate males with nonfunctional sperm. Females mated to these animals readily laid eggs, which failed to develop. It appeared that sperm or a factor associated with sperm induced long-term oviposition in female house crickets. Prostaglandin synthesis enzymes transferred from the male to females may have other roles in the female, for example, in sperm maintenance in the spermatheca. Previous observations strongly suggest that prostaglandins induce egg laying behavior and activity; they may be synthesized by female enzymes that are regulated by male-derived factors.     

Genetically engineered maize plants reveal distinct costs and benefits of constitutive volatile emissions in the field

Genetic manipulation of plant volatile emissions is a promising tool to enhance plant defences against herbivores. However, the potential costs associated with the manipulation of specific volatile synthase genes are unknown. Therefore, we investigated the physiological and ecological effects of transforming a maize line with a terpene synthase gene in field and laboratory assays, both above‐ and below ground. The transformation, which resulted in the constitutive emission of (E)‐β‐caryophyllene and α‐humulene, was found to compromise seed germination, plant growth and yield. These physiological costs provide a possible explanation for the inducibility of an (E)‐β‐caryophyllene‐synthase gene in wild and cultivated maize. The overexpression of the terpene synthase gene did not impair plant resistance nor volatile emission. However, constitutive terpenoid emission increased plant apparency to herbivores, including adults and larvae of the above ground pest Spodoptera frugiperda, resulting in an increase in leaf damage. Although terpenoid overproducing lines were also attractive to the specialist root herbivore Diabrotica virgifera virgifera below ground, they did not suffer more root damage in the field, possibly because of the enhanced attraction of entomopathogenic nematodes. Furthermore, fewer adults of the root herbivore Diabrotica undecimpunctata howardii were found to emerge near plants that emitted (E)‐β‐caryophyllene and α‐humulene. Yet, overall, under the given field conditions, the costs of constitutive volatile production overshadowed its benefits. This study highlights the need for a thorough assessment of the physiological and ecological consequences of genetically engineering plant signals in the field to determine the potential of this approach for sustainable pest management strategies.     

Preparative isolation and purification of four flavonoids from the petals of nelumbo nucifera by high‐speed counter‐current chromatography

Introduction – Flavonoids, the primary constituents of the petals of Nelumbo nucifera, are known to have antioxidant properties and antibacterial bioactivities. However, efficient methods for the preparative isolation and purification of flavonoids from this plant are not currently available. Objective – To develop an efficient method for the preparative isolation and purification of flavonoids from the petals of N. nucifera by high‐speed counter‐current chromatography (HSCCC). Methodology – Following an initial clean‐up step on a polyamide column, HSCCC was utilised to separate and purify flavonoids. Purities and identities of the isolated compounds were established by HPLC‐PAD, ESI‐MS, ¹H‐NMR and ¹³C‐NMR. Results – The separation was performed using a two‐phase solvent system composed of ethyl acetate–methanol–water–acetic acid (4 : 1 : 5 : 0.1, by volume), in which the upper phase was used as the stationary phase and the lower phase was used as the mobile phase at a flow‐rate of 1.0 mL/min in the head‐to‐tail elution mode. Ultimately, 5.0 mg syringetin‐3‐O‐β‐d‐glucoside, 6.5 mg quercetin‐3‐O‐β‐d‐glucoside, 12.8 mg isorhamnetin‐3‐O‐β‐d‐glucoside and 32.5 mg kaempferol‐3‐O‐β‐d‐glucoside were obtained from 125 mg crude sample. Conclusion – The combination of HSCCC with a polyamide column is an efficient method for the preparative separation and purification of flavonoids from the petals of N. nucifera. Copyright © 2009 John Wiley & Sons, Ltd.     

Geographic and Phenotypic Variation in Heartwood and Essential‐Oil Characters in Natural Populations of Santalum austrocaledonicum in Vanuatu

Phenotypic variation in heartwood and essential‐oil characters of Santalum austrocaledonicum was assessed across eleven populations on seven islands of Vanuatu. Trees differed significantly in their percentage heartwood cross‐sectional area and this varied independently of stem diameter. The concentrations of the four major essential‐oil constituents (α‐santalol, β‐santalol, (Z)‐β‐curcumen‐12‐ol, and cis‐nuciferol) of alcohol‐extracted heartwood exhibited at least tenfold and continuous tree‐to‐tree variation. Commercially important components α‐ and β‐santalol found in individual trees ranged from 0.8–47% and 0–24.1%, respectively, across all populations, and significant (P<0.05) differences for each were found between individual populations. The Erromango population was unique in that the mean concentrations of its monocyclic ((Z)‐β‐curcumen‐12‐ol and cis‐nuciferol) sesquiterpenes exceeded those of its bi‐ and tricyclic (α‐ and β‐santalol) sesquiterpenes. Heartwood colour varied between trees and spanned 65 colour categories, but no identifiable relationships were found between heartwood colour and α‐ and β‐santalol, although a weak relationship was evident between colour saturation and total oil concentration. These results indicate that the heartwood colour is not a reliable predictive trait for oil quality. The results of this study highlight the knowledge gaps in fundamental understanding of heartwood biology in Santalum genus. The intraspecific variation in heartwood cross‐sectional area, oil concentration, and oil quality traits is of considerable importance to the domestication of sandalwood and present opportunities for the development of highly superior S. austrocaledonicum cultivars that conform to the industry's International Standards used for S. album.