Einfluß des Stoffwechsels auf die Pigmentzusammensetzung in alternden Kulturen von Euglena gracilis

Summary The qualitative and quantitative composition of the carotenoids of young cells of Euglena gracilis strain 1224-5/9 corresponded to that of the Z-strain.The frequently observed yellow-reddish discolouration of ageing cells was found to be caused by a heavy breakdown of the chlorophylls and not by an increased synthesis of the carotenoids.Furthermore there could be observed a remarkable decrease in the concentration of diadinoxanthin together with an increase in the amount of zeaxanthin in the course of the stationary growth phase. This phenomenon was attributed to a direct deepoxidation of diadinoxanthin on the basis of experiments with ¹⁴C-diadinoxanthin showing a transformation of the pigment into zeaxanthin and some other Euglena carotenoids, e.g. neoxanthin and -carotene.Because of their interconvertibility diadinoxanthin and neoxanthin are regarded as auxiliary pigments for the photosynthetic O₂-evolution.The transformation of diadinoxanthin into zeaxanthin in the ageing cells coincides in time with the switch from an aerobic to an anerobic cell metabolism. The latter is characterized by a decrease in the O₂-incorporation together with a simultaneous increase in the NADH-concentration and by a heavy excretion of glycolytic end products such as pyruvate and lactate after cell respiration has stopped completely. The transformation of diadinoxanthin into zeaxanthin is therefore attributed to a reduction of diadinoxanthin by the cytoplasmic NADH.As the same pigment transformation could be observed in cells kept in darkness and under conditions of artificially stopped respiration, it is likely that this transformation takes place independently of photosynthetic processes.The origin of the commutation of the cell metabolism and the cessation of respiration is still unknown. As the respiration of ageing cells can be revived in the darkness it is certainly linked to photosynthesis under light conditions.     

Heteroxanthin in Euglena gracilis

Summary 1. From a large scale preparation of Euglena gracilis, strain Z, besides the acetylenic pigments diatoxanthin and diadinoxanthin and the allene neoxanthin, an additional acetylenic xanthophyll has been isolated. 2. Mass and IR spectra and chemical reactions showed typical patterns of heteroxanthin from Vaucheria. 3. The pigment was transformed into diadinochrome-isomers with acidified acetone. 4. A partial synthesis of heteroxanthin from diadinoxanthin by LiAlH₄-reduction is described, confirming the structure proposed by Strain. 5. The identity of heteroxanthin with the trollein—like pigment described for Euglena is discussed.     

Chlorophylls and carotenoids of the marine alga Eutreptiella gymnastica

Monoalgal cultured Eutreptielia gymnastica contained chlorophyll a and b. The acetylenic carotenoids diatoxanthin and diadinoxanthin were among the main xanthophylls while their non-acetylenic analogues zeaxanthin and antheraxanthin were absent. The structurally most complex carotenoid was identical with neoxanthin. Three of the xanthophylls isolated could not be positively correlated with carotenoids previously reported from the Euglenophyceae. The ketocarotenoids astaxanthin, canthaxanthin and echinenone were absent.     

Stereochemistry of allene biosynthesis and the formation of the acetylenic carotenoid diadinoxanthin and peridinin (C37) from neoxanthin.

Intact cells of the alga Amphidinium carterae (Dinophyceae), and a cell-free system prepared from it, incorporated 14C, 3H-labelled mevalonate into lycopene, beta, beta-carotene, zeaxanthin, neoxanthin, diadinoxanthin and peridinin. The 14C/3H ratios of zeaxanthin, neoxanthin and diadinoxanthin formed from (2RS,3R)-[2-14C,2-3H2]mevalonate show that a hydrogen atom from C-2 of mevalonate is retained in the allene at C-8, and also at C-12 of peridinin. (3R,4R + 3S,4S)-[2-14C,4-3H1]Mevalonate gave 14C/3H ratios in peridinin which show that C-14 is lost. The three carbon atoms excised during the formation of the C37 carotenoid peridinin are C-13, C-14 and C-20 of neoxanthin.     

Neoxanthin from Helianthus,Taraxacum and Impatiens

Neoxanthin has been isolated from petals of Helianthus annuus, Taraxacum officinale and Impatiens nolitangere. It is identical with authentic neoxanthin from Euglena gracilis. MS and IR spectra were recorded, showing typical fragmentation patterns of neoxanthin, and an allene group. A pigment with the properties of deepoxineoxanthin and polar xanthophylls, which absorbed at very short wavelengths, were also isolated.     

Chlorophyll-Protein Complexes from Euglena gracilis and Mutants Deficient in Chlorophyll b: I. Pigment Composition

The use of n-octyl-beta-d-glucopyranoside along with sodium dodecyl sulfate improves the retention of chlorophyll (Chl) by chlorophyll-protein complexes (CPs) prepared from thylakoids of Euglena gracilis Klebs var bacillaris Cori and yields several additional complexes. Thylakoids from wild-type (WT) cells, solubilized in these detergents and subjected to polyacrylamide gel electrophoresis at 0 degrees C, yield the following CPs, in order of relative molecular weight, containing the pigments shown in parentheses with their respective molar ratios where determined: CP Ia (Chl a, diadinoxanthin and beta-carotene; 100:12:5); CP I (Chl a and beta-carotene; 100:6-12); CPx (Chl and carotenoids); LHCP(2) (light-harvesting CP oligomer) (Chl a, Chl b, diadinoxanthin and neoxanthin; 12:4:3:1); CPy (Chl a, diadinoxanthin and beta-carotene; 100:14:8); CPa (Chl a and beta-carotene; 100:18-25) and LHCP (monomer) (Chl a, Chl b, diadinoxanthin and neoxanthin; 12:6:4:1). The LHCP complexes retain up to 40% of the total Chl and 80% of the Chl b in the thylakoids. CP Ia contains only a trace of Chl b (Chl a/b [mol/mol] = 62). The lower amount of Chl b in Euglena (about 10% of Chl a + b) compared to higher plants (about 30% of Chl a + b) is probably a consequence of the lower Chl b (relative to Chl a) in the LHCPs of Euglena rather than of fewer LHCPs being present. G(1)BU, Gr(1)BSL, and O(4)BSL, mutants of bacillaris low in Chl b (1-2% of Chl a + b), lack the CP Ia, LHCP, and LHCP(2) found in wildtype (WT); G(1) and O(4) also lack CPy. The mutants contain reduced amounts of Chl a (two-thirds of WT in Gr(1) and one-third in G(1) and O(4)) and neoxanthin (20-40% of WT) but retain levels of beta-carotene and diadinoxanthin close to those in cells of WT. The CPs remaining in the mutants have pigment compositions very similar to their counterparts from WT.     

The response of carotenoids and chlorophylls during virus infection of Emiliania huxleyi (Prymnesiophyceae)

We report the response of carotenoids and chlorophylls during 120 h time series virus infection experiments of the marine coccolithophorid Emiliania huxleyi (Lohm.) Hay et Mohler culture. The response of individual carotenoids to infection varied: Diatoxanthin (Dtx) increased rapidly relative to chlorophyll-a, whereas diadinoxanthin (Ddx) and β-carotene showed a rapid decrease and fucoxanthin and 19′hexanoyloxyfucoxanthin a slight increase. The response of the individual carotenoids reflects their role in epoxy/de-epoxidation cycling, antioxidant protection, biosynthetic conversion and vulnerability to photooxidative destruction. We observed for the first time the operation of the diadinoxanthin cycle occurring in response to viral infection in E. huxleyi with the de-epoxidation ratio (Dtx / (Dtx + Ddx)) increasing exponentially with time (R² = 0.92) and decreasing exponentially with F_V / F_M (R² = 0.97). Our findings contribute to our understanding of the conversion and fate of key biochemical cell constituents in algae and are important in understanding the physiological stress response to virus infection.     

Mimulaxanthin—a new allenic xanthophyll from the petals of Mimulus guttatus

Besides neoxanthin and deepoxineoxanthin, the main xanthophylls in the petals of Mimulus guttatus, an additional pigment, mimulaxanthin, has been obtained; it is 3,3′–5,5′-tetrahydroxy-6′-hydro-7-dehydro-β-carotene. Its neoxanthin-like spectrum is not changed by acids. Two hydroxyl groups are acetylatable. The diacetate can be silylated to a di(trimethylsilyl)-ether, and with acidic alcohols, yields a monoether. With CHCl₃ plus HCl 18 defined reaction-products are obtained, one of which is 3,3′-di-hydroxy-7,8-didehydro-α-carotene (monadoxanthin). One of the LiAlH₄-reduction products of neoxanthin is identical with mimulaxanthin, whereas mimulaxanthin with LiAlH₄ gives an acetylenic derivative. These results have been confirmed by IR spectrometry. Mimulaxanthin is not an artefact formed during extraction and purification.     

Purification and characterization of a stable oxygen-evolving Photosystem II complex from a marine centric diatom, Chaetoceros gracilis

Oxygen-evolving Photosystem II particles (crude PSII) retaining a high oxygen-evolving activity have been prepared from a marine centric diatom, Chaetoceros gracilis (Nagao et al., 2007). The crude PSII, however, contained a large amount of fucoxanthin chlorophyll a/c-binding proteins (FCP). In this study, a purified PSII complex which was deprived of major components of FCP was isolated by one step of anion exchange chromatography from the crude PSII treated with Triton X-100. The purified PSII was still associated with the five extrinsic proteins of PsbO, PsbQ', PsbV, Psb31 and PsbU, and showed a high oxygen-evolving activity of 2135 μmol O₂ (mg Chl a)^− 1 h^− 1 in the presence of phenyl-p-benzoquinone which was virtually independent of the addition of CaCl₂. This activity is more than 2.5-fold higher than the activity of the crude PSII. The activity was completely inhibited by 3-(3,4)-dichlorophenyl-(1,1)-dimethylurea (DCMU). The purified PSII contained 42 molecules of Chl a, 2 molecules of diadinoxanthin and 2 molecules of Chl c on the basis of two molecules of pheophytin a, and showed typical absorption and fluorescence spectra similar to those of purified PSIIs from the other organisms. In this study, we also found that the crude PSII was significantly labile, as a significant inactivation of oxygen evolution, chlorophyll bleaching and degradation of PSII subunits were observed during incubation at 25 °C in the dark. In contrast, these inactivation, bleaching and degradation were scarcely detected in the purified PSII. Thus, we succeeded for the first time in preparation of a stable PSII from diatom cells.     

Xanthophylls and abscisic Acid biosynthesis in water-stressed bean leaves

Experiments were designed to obtain evidence about the possible role of xanthophylls as abscisic acid (ABA) precursors in water-stressed leaves of Phaseolus vularis L. Leaves were exposed to ¹⁴CO₂ and the specific activities of several major leaf xanthophylls and stress-induced ABA were determined after a chase in ¹²CO₂ for varying periods of time. The ABA specific radioactivities were about 30 to 70% of that of lutein and violaxanthin regardless of the chase period. The specific activity of neoxanthin, however, was only about 15% of that of ABA. The effects of fluridone on xanthophyll and ABA levels and the extent of labeling of both from ¹⁴CO₂ were determined. Fluridone did not inhibit the accumulation of ABA when leaves were stressed once, although subsequent stresses in the presence of fluridone did lead to a reduced ABA accumulation. The incorporation of ¹⁴C from ¹⁴CO₂ into ABA and the xanthophylls was inhibited by fluridone and to about the same extent. The incorporation of ¹⁸O into ABA from violaxanthin which had been labeled in situ by means of the violaxanthin cycle was measured. The results indicated that a portion of the ABA accumulated during stress was formed from violaxanthin which had been labeled with ¹⁸O. The results of these experiments are consistent with a preformed xanthophyll(s) as the major ABA precursor in water-stressed bean leaves.     

Carotenoids of clam,coral and nudibranch zooxanthellae in aposymbiotic culture

The carotenoids of unialgal cultures originating from symbiotic zooxanthellae of two molluscan (Tridacna crocea, a giant clam, and Pteraeolidia ianthine a nudibranch) and one cnidian (Pseudopterogorgia bipinnata, a gorgonian coral) host have been analysed by HPLC or TLC procedures combined with several spectroscopic techniques including MS and NMR. A high total carotenoid content (0.45-0.63% of the dry wt) was obtained. The carotenoid pattern with C₃₇-norcarotenoids (peridinin and pyrrhoxanthin) comprising around 80% of total carotenoids, and β,β-carotene (2%), the ailenic dinoxanthin (3–4%) and the acetylenic diatoxanthin (1–3%) and diadinoxanthin (7–9%) representing minor C₄₀-carotenoids, corresponds to that of peridinin-producing free-living dinoflagellates. Supplementary ¹H NMR and ¹³C NMR data are reported for peridinin and pyrrhoxanthin. A polar, minor carotenoid, P447, was partly characterized as containing a disaccharide glycosidically bound to an allenic carotenoid aglycone. Re-evaluation of previous reports suggests the wide-spread occurrence of related carotenoid disaccharides in Dinophyceae for which they are considered a new chemosystematic marker.     

Characterization of ribosomes from the seed of Pinus lambertiana

Ribosomes isolated from seeds of the sugar pine, Pinus lambertiana, have been characterized: The ribosome has a sedimentation coefficient (s_20,w⁰) of 78·2 S and contains 41 % RNA and 58 % protein. On dialysis against buffer containing 0·5-1 mM MgCl₂, the ribosome was reversibly transformed into an intermediate form (60 S). Further removal of Mg²⁺ causes the intermediate ribosome to dissociate into subunits (30 S and 40 S). Treatment of the intermediate ribosome with p-chloromercuribenzoic acid caused the dissociation of the particle into subunits. Incubating the 80 S ribosome with the sulfhydryl reagent caused a rapid transformation of the particle into an intermediate type particle. These results suggest that sulfhydryl groups are involved not only in associating the subunits but also in maintaining the compact structure of the ribosomes. The ribosome contains three ribosomal RNA components of 28 S, 18 S and 5 S. The base compositions of the three ribosomal RNA components are different.     

Bradykinin-stimulated release of [3H]arachidonic acid from phospholipids of HSDM1C1 cells: Comparison of diacyl phospholipids and plasmalogens as sources of prostaglandin precursors

Ethanolamine plasmalogens (1-alk-1′-enyl-2-acyl-sn-glycero-3-phosphoethanolamines) of many tissues contain high levels of arachidonate at their 2-position, and in certain tissues have been implicated as possible donors of arachidonate required in the synthesis of prostaglandins and thromboxanes. In the present study, [³H]arachidonate-labeled phospholipids of HSDM₁C₁ cells, a cell line derived from a mouse fibrosarcoma, were examined to determine the donor of the arachidonic acid released upon bradykinin stimulation of the synthesis of PGE₂. HSDM₁C₁ cells labeled with [³H]arachidonic acid for 24 hr in serum-free medium were used in most of the experiments and had the following distribution of label among the cellular lipids; phosphatidylcholine (33%), phosphatidylinositol (20%), diacyl-sn-glycero-3-phosphoethanolamine (15%), ethanolamine plasmalogen (15%), and less polar lipids (16%). Bradykinin treatment stimulated a rapid hydrolysis of [³H]arachidonate from the cellular lipids and conversion of the released acid to PGE₂, which was secreted into the medium. The label was released predominantly from phosphatidylinositol and possibly from phosphatidylcholine with no detectable change in the labeling of diacyl- or 1-alk-1′-enyl-2-acyl-sn-glycero-3-phosphoethanolamine. The ethanolamine plasmalogens, therefore, do not appear to be involved in the stimulated release of arachidonate in the HSDM₁C₁ cells. Indomethacin blocked the bradykinin-stimulated synthesis of PGE₂ and to a lesser degree inhibited the release of [³H]-arachidonate from the cellular lipids into the medium.     

Violaxanthin de-epoxidase. Lipid composition and substrate specificity.

Violaxanthin de-epoxidase isolated from lettuce chloroplasts (Lactuca sativa var. Romaine) contained a single lipid component, monogalactosyldiglyceride (MG) at about 8 g per 100 g protein. The effects of MG on activation of solvent-extracted enzyme and on K_m suggest that MG has two roles, namely, as a functional component of the binding site and as a substrate-solubilizing agent whose structure satisfies binding site requirements. Substrate specificity examined with various naturally occurring and semisynthetic epoxy carotenoids with known chirality showed violaxanthin de-epoxidase to be stereospecific for 3-hydroxy, 5,6-epoxy carotenoids which are in a 3S, 5R, 6S configuration. Although monoepoxides with the above configuration were active, their rates varied, apparently due to the influence of structural differences in the nonepoxide end groups. Hence while all-trans neoxanthin showed low rates, the de-epoxidation rate of antheraxanthin was 5-fold higher than violaxanthin. Neoxanthin and violeoxanthin, both naturally occurring pigments with 9-cis configurations in the acyclic polyene chain, were inactive. These effects support the view that violaxanthin de-epoxidase is a mono de-epoxidase and that the stereospecific active center is situated in a narrow well-like cavity which favors an all-trans configuration of the polyene chain. The 3-hydroxy, 5,6-epoxy group of the naturally occurring pigments, diadinoxanthin, antheraxanthin, and β-cryptoxanthin epoxide are assumed to be the 3S, 5R, 6S configuration based on their reactivity with violaxanthin de-epoxidase.     

Somatic variations on a yellow mutant in Nicotiana tabacum L. (a1+/a1a2+/a2) I. Non-reciprocal genetic events occurring in leaf cells

A greenish-yellow mutant was obtained after treatment of seeds of Nicotiana tabacum L. var. Xanthi n.c. with ethyl methanesulfonate (EMS). Two genetically independent mutations (a₁ and a₂) were isolated. The first mutation (a₁) antagonizes the function of its partially dominant a₁⁺ allele. The second mutation (a₂) is amorphous but strongly interacts with a₁.Among the nine possible genotypes at the two loci, five varied in somatic cells. The heterozygous state a₁⁺/a₁ strongly increased the frequency of both spontaneous and induced variations. However, two homozygotes also showed variations.Variants were isolated from induced and spontaneous non-reciprocal and reciprocal variations within paliside tissues by bud induction in vitro. They were genetically tested. In this first paper, only non-reciprocal variations are reported.Green variants from the greenish-yellow (J¹) dihybrid a₁⁺/a₁a₂⁺/a₂ clone had two genotypes: the first was due to true reversions of a₁ to a₁⁺, whereas the second was due to amorphous a₁⁰ mutations from a₁. These a₁⁰ mutations may well be deletions.The lightest yellow variants from J¹ were due to mutations either from a₁⁺ into a₁ or from a₂⁺ into a₂.Deletions at the a₁⁺?a₁ locus led to either yellow variations when a₁⁺ was lost, or to false reversions when the antagonistic allele a₁ was lost.Amorphous alleles at the a₁⁺?a₁ locus were also isolated from tissues other than J⁺. They gave zygotic lethality (s) that probably varied with the size of the deletions. Thus, true reversions and deletions at the a₁⁺?a₁ locus could be distinguished from one another by progeny tests.Other variants showed higher frequencies of spontaneous variations (instability). Somatic changes observed in these unstable systems were due to modifications at the marker loci. The genetic nature of this instability is not yet known.There is strong evidence that the genetic events involved in these non-reciprocal variations were deletions, conversions and point mutations. True reversions from a₁ into a₁⁺ and new mutations from a₁⁺ into a₁ were obtained only from a₁⁺/a₁. It was therefore supposed that the changes observed took place only in heterozygotes, and the conversion hypothesis was made. Attempts are being made to prove that conversions do exist in higher plants, and to find out if this process, as deletions, is induced by radiation.     

Interconversion of trans, trans and cis, trans farnesol by enzymes from Andrographis

When trans, trans-farnesol [4,8,12-¹⁴C₃,1-³H₂] is isomerized to cis, trans-farnesol by soluble enzymes from Andrographis paniculata tissue cultures, 50% of the tritium label is lost. The same loss is observed when isomerization occurs in the opposite direction. This is in accordance with the proposed mechanism for isomerization via aldehydes.     

Four new species of Chryseobacterium from the rhizosphere of coastal sand dune plants, Chryseobacterium elymi sp. nov., Chryseobacterium hagamense sp. nov., Chryseobacterium lathyri sp. nov. and Chryseobacterium rhizosphaerae sp. nov.

The taxonomic positions of five Gram-negative, non-spore-forming and non-motile bacterial strains isolated from the rhizosphere of sand dune plants were examined using a polyphasic approach. The analysis of the 16S rRNA gene sequence indicated that all of the isolates fell into four distinct phylogenetic clusters belonging to the genus Chryseobacterium of the family Flavobacteriaceae. The 16S rRNA gene sequence similarities of isolates to mostly related type strains of Chryseobacterium ranged from 97.5% to 98.5%. All strains contained MK-6 as the predominant menaquinone, and iso-C_15:0, iso-C_17:0 3-OH and a summed feature of iso-C_15:0 2-OH and/or C_16:1 ω7c as the dominant fatty acids. Combined phenotypic, genotypic and chemotaxonomic data supported that they represented four novel species in the genus Chryseobacterium, for which the names Chryseobacterium hagamense sp. nov. (type strain RHA2-9^T=KCTC 22545^T=NBRC 105253^T), Chryseobacterium elymi sp. nov. (type strain RHA3-1^T=KCTC 22547^T=NBRC 105251^T), Chryseobacterium lathyri sp. nov. (type strain RBA2-6^T=KCTC 22544^T=NBRC 105250^T), and Chryseobacterium rhizosphaerae sp. nov. (type strain RSB3-1^T=KCTC 22548^T=NBRC 105248^T) are proposed.     

Solubilization of active (H+ + K+)-ATPase from gastric membrane

(H⁺ + K⁺)-ATPase-enriched membranes were prepared from hog gastric mucosa by sucrose gradient centrifugation. These membranes contained Mg²⁺-ATPase and p-nitrophenylphosphatase activities (68 ± 9 μmol P_i and 2.9 ± 0.6 μmol p-nitrophenol/mg protein per h) which were insensitive to ouabain and markedly stimulated by 20 mM KCl (respectively, 2.2- and 14.8-fold). Furthermore, the membranes autophosphorylated in the absence of K⁺ (up to 0.69 ± 0.09 nmol P_i incorporated/mg protein) and dephosphorylated by 85% in the presence of this ion. Membrane proteins were extracted by 1–2% (w/v) n-octylglucoside into a soluble form, i.e., which did not sediment in a 100 000 × g × 1 h centrifugation. This soluble form precipitated upon further dilution in detergent-free buffer. Extracted ATPase represented 32% (soluble form) and 68% (precipitated) of native enzyme and it displayed the same characteristic properties in terms of K⁺-stimulated ATPase and p-nitrophenylphosphatase activities and K⁺-sensitive phosphorylation: Mg²⁺-ATPase (μmol P_i/mg protein per h) 32 ± 9 (basal) and 86 ± 20 (K⁺-stimulated); Mg²⁺-p-nitrophenylphosphatase (μmol p-nitrophenol/mg protein per h) 2.6 ± 0.5 (basal) and 22.2 ± 3.2 (K⁺-stimulated); Mg²⁺-phosphorylation (nmol P_i/mg protein) 0.214 ± 0.041 (basal) and 0.057 ± 0.004 (in the presence of K⁺). In glycerol gradient centrifugation, extracted enzyme equilibrated as a single peak corresponding to an apparent 390 000 molecular weight. These findings provide the first evidence for the solubilization of (H⁺ + K⁺)-ATPase in a still active structure.     

高寒矮嵩草草甸冬季CO2释放特征

冬季碳排放在高寒草地年内碳平衡中占有重要位置。为探讨高寒草地冬季碳排放特征及温度敏感性,于2003-2005年在中国科学院海北高寒草甸生态系统研究站,利用密闭箱-气相色谱法连续观测了高寒矮嵩草草甸2个冬季的生态系统、土壤呼吸通量特征。结果表明:1)高寒矮嵩草草甸冬季生态系统呼吸、土壤呼吸均具有明显的日变化和季节变化规律,温度是其主要的控制因子,能够解释44%以上的呼吸速率变异。2)冬季生态系统呼吸与土壤呼吸速率在统计上没有显著差异,土壤呼吸占生态系统呼吸的比例高达85%以上。3)2003-2004年冬季生态系统呼吸、土壤呼吸的Q₁₀值分别为1.53,1.38;2004-2005年冬季生态系统呼吸与土壤呼吸的Q₁₀值为1.86,1.68,2个冬季生态系统呼吸的Q₁₀值均高于土壤呼吸。4)未发现高寒矮嵩草草甸冷冬年份的Q₁₀值高于暖冬年份以及冬季的Q₁₀值高于生长季。     

Carotenoids of Eriobotrya japonica

The carotenoids of the loquat fruit Eriobotrya japonica Golden Nugget variety, were investigated. They were identified according to their chromatographic, spectrophotometric and chemical properties and compared with standard pigments. For some of the carotenoids, MS were determined. Pulp and peels were investigated separately. The main pattern of the pulp carotenoids was β-carotene (33%), γ-carotene (6%), cryptoxanthin (22%), lutein, violaxanthin and neoxanthin, each about 3–4%. The peel, with a carotenoid content 5 times as high, had a similar pattern, but the ratio between the main pigments differed: β-carotene (50%); γ-carotene (5%); cryptoxanthin (5%); lutein (13%); violaxanthin, neoxanthin, 3–4%. The carotenoids of the loquat (subfamily Maloideae) were very similar to those of the apricot (Prunus armeniaca-subfamily Prunoideae) both of the family of Rosaceae. The intergeneric differences are more pronounced, which is of possible taxonomic significance. The lower concentration of cryptoxanthin and the high concentration of lutein in the peels is noteworthy and of biosynthetic interest.