Phytochemistry (v.69, #7)

Clarence A. “Bud” Ryan by Edward E. Ted Farmer; Gregg A. Howe; Greg Pearce; Andreas Schaller (1454-1456).

Cyanogenesis in plants and arthropods by Mika Zagrobelny; Søren Bak; Birger Lindberg Møller (1457-1468).
Cyanogenic glucosides are well known defense compounds produced in both arthropods and plants. This review summarizes the knowledge of cyanogenesis in arthropods and plants and outlines the emerging important functions of these compounds in both phylae.Cyanogenic glucosides are phytoanticipins known to be present in more than 2500 plant species. They are regarded as having an important role in plant defense against herbivores due to bitter taste and release of toxic hydrogen cyanide upon tissue disruption, but recent investigations demonstrate additional roles as storage compounds of reduced nitrogen and sugar that may be mobilized when demanded for use in primary metabolism. Some specialized herbivores, especially insects, preferentially feed on cyanogenic plants. Such herbivores have acquired the ability to metabolize cyanogenic glucosides or to sequester them for use in their own defense against predators. A few species of arthropods (within diplopods, chilopods and insects) are able to de novo biosynthesize cyanogenic glucosides and some are able to sequester cyanogenic glucosides from their food plant as well. This applies to larvae of Zygaena (Zygaenidae). The ratio and content of cyanogenic glucosides is tightly regulated in Zygaena filipendulae, and these compounds play several important roles in addition to defense in the life cycle of Zygaena. The transfer of a nuptial gift of cyanogenic glucosides during mating of Zygaena has been demonstrated as well as the involvement of hydrogen cyanide in male attraction and nitrogen metabolism. As more plant and arthropod species are examined, it is likely that cyanogenic glucosides are found to be more widespread than formerly thought and that cyanogenic glucosides are intricately involved in many key processes in the life cycle of plants and arthropods.
Keywords: Cyanogenic glucosides; Sorghum; Almond; Arthropods; Burnet moth; Zygaena; Cytochrome P450; UDPG-glucosyltransferase; β-glucosidase; β-cyanoalanine synthase; Nitrilase;

(a) The Yin and Yang symbol: The philosophical basis of some of the assumed properties and research on Cordyceps (see text)? (b) Cordyceps spp. parasitizing a dead Campanotus insect and (c) cordyheptapeptide A, a natural product from the fungus.Traditional Chinese medicines (TCM) are growing in popularity. However, are they effective? Cordyceps is not studied as systematically for bioactivity as another TCM, Ganoderma. Cordyceps is fascinating per se, especially because of the pathogenic lifestyle on Lepidopteron insects. The combination of the fungus and dead insect has been used as a TCM for centuries. However, the natural fungus has been harvested to the extent that it is an endangered species. The effectiveness has been attributed to the Chinese philosophical concept of Yin and Yang and can this be compatible with scientific philosophy? A vast literature exists, some of which is scientific, although others are popular myth, and even hype. Cordyceps sinensis is the most explored species followed by Cordyceps militaris. However, taxonomic concepts were confused until a recent revision, with undefined material being used that cannot be verified. Holomorphism is relevant and contamination might account for some of the activity. The role of the insect has been ignored. Some of the analytical methodologies are poor. Data on the “old” compound cordycepin are still being published: ergosterol and related compounds are reported despite being universal to fungi. There is too much work on crude extracts rather than pure compounds with water and methanol solvents being over-represented in this respect (although methanol is an effective solvent). Excessive speculation exists as to the curative properties. However, there are some excellent pharmacological data and relating to apoptosis. For example, some preparations are active against cancers or diabetes which should be fully investigated. Polysaccharides and secondary metabolites are of particular interest. The use of genuine anamorphic forms in bioreactors is encouraged.
Keywords: Fungus; Cordyceps sinensis; Cordyceps militaris; Lepidopteron; Traditional Chinese medicine; Cancer; Diabetes; Apoptosis;

Contributions of conserved serine and tyrosine residues to catalysis, ligand binding, and cofactor processing in the active site of tyrosine ammonia lyase by Amy C. Schroeder; Sangaralingam Kumaran; Leslie M. Hicks; Rebecca E. Cahoon; Coralie Halls; Oliver Yu; Joseph M. Jez (1496-1506).
Tyrosine ammonia lyase (TAL) catalyzes the conversion of l-tyrosine to p-coumaric acid using a 3,5-dihydro-5-methylidene-4H-imidazole-4-one (MIO) prosthetic group. Using a combination of site-directed mutagenesis, kinetic analysis, mass spectrometry, and fluorescence spectroscopy, the role of conserved active site residues are examined.Tyrosine ammonia lyase (TAL) catalyzes the conversion of l-tyrosine to p-coumaric acid using a 3,5-dihydro-5-methylidene-4H-imidazole-4-one (MIO) prosthetic group. In bacteria, TAL is used for production of the photoactive yellow protein chromophore and for caffeic acid biosynthesis in certain actinomycetes. Here we biochemically examine wild-type and mutant forms of TAL from Rhodobacter sphaeroides (RsTAL). Kinetic analysis of RsTAL shows that the enzyme displays a 90-fold preference for l-tyrosine versus l-phenylalanine as a substrate. The pH-dependence of TAL activity with l-tyrosine and l-phenylalanine demonstrates a common protonation state for catalysis, but indicates a difference in charge-state for binding of either amino acid. Site-directed mutagenesis demonstrates that Ser150, Tyr60, and Tyr300 are essential for catalysis. Mutation of Ser150 to an alanine abrogates formation of the MIO prosthetic group, as shown by mass spectrometry, and prevents catalysis. The Y60F and Y300F mutants were inactive with both amino acid substrates, but bound p-coumaric and cinnamic acids with less than 12-fold changes in affinity compared the wild-type enzyme. Analysis of MIO–dithiothreitol adduct formation shows that the reactivity of the prosthetic group is not significantly altered by mutation of either Tyr60 or Tyr300. The mechanistic roles of Ser150, Tyr60, and Tyr300 are discussed in relation to the three-dimensional structure of RsTAL and related MIO-containing enzymes.
Keywords: Enzyme mechanism; Prosthetic group; Mass spectrometry; Fluorescence spectroscopy; Tyrosine ammonia lyase;

Diversification of an ancient theme: Hydroxynitrile glucosides by Nanna Bjarnholt; Fred Rook; Mohammed Saddik Motawia; Claus Cornett; Charlotte Jørgensen; Carl Erik Olsen; Jerzy W. Jaroszewski; Søren Bak; Birger Lindberg Møller (1507-1516).
Three previously unknown β-hydroxynitrile glucosides were isolated from Ribes uva-crispa leaves: (2Z)-2-(β-d-glucopyranosyloxy)but-2-enenitrile, (2R,3R)- and (2R,3S)-2-methyl-3-(β-d-glucopyranosyloxy)butanenitrile. The data presented provide strong evidence that the biosynthetic pathways for β- and γ-hydroxynitrile glucosides represent a diversification of the pathway for cyanogenic glucoside biosynthesis.Many plants produce cyanogenic glucosides as part of their chemical defense. They are α-hydroxynitrile glucosides, which release toxic hydrogen cyanide (HCN) upon cleavage by endogenous plant β-glucosidases. In addition to cyanogenic glucosides, several plant species produce β- and γ-hydroxynitrile glucosides. These do not release HCN upon hydrolysis by β-glucosidases and little is known about their biosynthesis and biological significance. We have isolated three β-hydroxynitrile glucosides, namely (2Z)-2-(β-d-glucopyranosyloxy)but-2-enenitrile and (2R,3R)- and (2R,3S)-2-methyl-3-(β-d-glucopyranosyloxy)butanenitrile, from leaves of Ribes uva-crispa. These compounds have not been identified previously. We show that in several species of the genera Ribes, Rhodiola and Lotus, these β-hydroxynitrile glucosides co-occur with the l-isoleucine-derived hydroxynitrile glucosides, lotaustralin (α-hydroxynitrile glucoside), rhodiocyanosides A (γ-hydroxynitrile glucoside) and D (β-hydroxynitrile glucoside) and in some cases with sarmentosin (a hydroxylated rhodiocyanoside A). Radiolabelling experiments demonstrated that the hydroxynitrile glucosides in R. uva-crispa and Hordeum vulgare are derived from l-isoleucine and l-leucine, respectively. Metabolite profiling of the natural variation in the content of cyanogenic glucosides and β- and γ-hydroxynitrile glucosides in wild accessions of Lotus japonicus in combination with genetic crosses and analyses of the metabolite profile of the F2 population provided evidence that a single recessive genetic trait is most likely responsible for the presence or absence of β- and γ-hydroxynitrile glucosides in L. japonicus. Our findings strongly support the notion that the β- and γ-hydroxynitrile glucosides are produced by diversification of the cyanogenic glucoside biosynthetic pathway at the level of the nitrile intermediate.
Keywords: Ribes; Lotus; Rhodiola; Grossulariaceae; Crassulaceae; Fabaceae; Poaceae; Cyanogenic glucosides; Hydroxynitrile glucosides;

Seasonal changes of fatty acid composition and thermotropic behavior of polar lipids from marine macrophytes by Nina M. Sanina; Svetlana N. Goncharova; Eduard Y. Kostetsky (1517-1527).
Fatty acid composition and thermotropic behavior of glyco-, phospho- and betaine lipids isolated from five species of marine macrophytes harvested in summer and winter were analyzed by GC, DSC and polarizing microscopy to clarify molecular mechanism of thermal adaptation of this plants to low and high environmental temperature.Major glyco- and phospholipids as well as betaine lipid 1,2-diacylglycero-O-4′-(N,N,N-tri-methyl)-homoserine (DGTS) were isolated from five species of marine macrophytes harvested in the Sea of Japan in summer and winter at seawater temperatures of 20–23 and 3 °C, respectively. GC and DSC analysis of lipids revealed a common increase of ratio between n−3 and n−6 polyunsaturated fatty acids (PUFAs) of polar lipids from summer to winter despite their chemotaxonomically different fatty acid (FA) composition. Especially, high level of different n−3 PUFAs was observed in galactolipids in winter. However, the rise in FA unsaturation did not result in the lowering of peak maximum temperature of phase transition of photosynthetic lipids (glycolipids and phosphatidylglycerol (PG)) in contrast to non-photosynthetic ones [phosphatidylcholine (PC) and phosphatidylethanolamine (PE)]. Different thermotropic behavior of these lipid groups was accompanied by higher content of n−6 PUFAs from the sum of n−6 and n−3 PUFAs in PC and PE compared with glycolipids and PG in both seasons. Seasonal changes of DSC transitions and FA composition of DGTS studied for the first time were similar to PC and PE. Thermograms of all polar lipids were characterized by complex profiles and located in a wide temperature range between −130 and 80 °C, while the most evident phase separation occurred in PGs in both seasons. Polarizing microscopy combined with DSC has shown that the liquid crystal – isotropic melt transitions of polar lipids from marine macrophytes began from 10 to 30 °C mostly, which can cause the thermal sensitivity of plants to superoptimal temperatures in their environment.
Keywords: Ahnfeltia tobuchiensis; Laminaria japonica; Sargassum pallidum; Ulva fenestrata; Zostera marina; Algae; Seagrass; Fatty acids; Thermotropic behavior; Glycolipids; Phospholipids; Betaine lipid DGTS;

Plant growth regulation activity of steviol and derivatives by Brás Heleno de Oliveira; Júlio César Stiirmer; José D. de Souza Filho; Ricardo Antonio Ayub (1528-1533).
Kaurenes 35 and beyeranes 610 were prepared and tested for plant growth regulation activity using lettuce hypocotyl and barley aleurone bioassays. Steviol (3) and isosteviol (9) were also tested in field-grown grapes.This work describes the preparation of tetracyclic diterpenoids and determination of their plant growth regulator properties. Stevioside (2) was used as starting material and the derivatives 13-hydroxy-ent-kaur-16-en-19-oic acid (steviol, 3), ent-7α,13-dihydroxy-kaur-16-en-19-oic acid (4), 13-hydroxy, ent-kaur-16,17-epoxi-19-oic acid (steviol epoxide, 5), 17-hydroxy-16-ketobayeran-19-oic acid (17-hydroxyisosteviol, 6), 17-hydroxy-16-hydroxyiminobayeran-19-oic acid (7), 16-ketobayeran-19-oic acid (isosteviol, 9), 16,17-dihydroxybeyeran-19-oic acid (8), and 16-hydroxyiminobayeran-19-oic acid (isosteviol oxime, 10) were obtained by simple chemical procedures. Another derivative, ent-7α,13-dihydroxycaur-15-en-19-oic acid (4), was obtained by biotransformation of steviol (3) by Penicillium citrinum. In order to determine the plant growth regulator activity the compounds were submitted to the lettuce hypocotyl and barley aleurone bioassays. All compounds showed significant activities in both bioassays. Steviol (3) and isosteviol (9) were also tested in field-grown grapes resulting in an increase in berry weight and size.
Keywords: Stevia rebaudiana; Asteraceae; Vitis vinifera; Familia; Vitaceae; Plant growth regulator; Diterpenoids; Stevioside; Steviol;

Safety, efficacy and anti-inflammatory activity of rho iso-alpha-acids from hops by Amy J. Hall; John G. Babish; Gary K. Darland; Brian J. Carroll; Veera Reedy Konda; Robert H. Lerman; Jeffery S. Bland; Matthew L. Tripp (1534-1547).
Rho iso-alpha-acids (RIAA) is a modified extract from the flower cone of hops (Humulus lupulus L.). The safety profile and anti-inflammatory activity of RIAA was assessed using in vitro models and clinical biomarkers. This study suggests that RIAA is an alternative to NSAIDs with an expected reduction in adverse events.A defined mixture of rho iso-alpha-acids (RIAA), a modified hop extract, was evaluated for anti-inflammatory efficacy and safety. RIAA inhibited LPS-stimulated PGE2 formation with >200-fold selectivity of COX-2 (IC50  = 1.3 μg/ml) over COX-1 (IC50  > 289 μg/ml). This occurred only when RIAA was added prior to, but not post, LPS stimulation. Consistent with this observation, RIAA produced no physiologically relevant, direct inhibition of COX-1 or COX-2 peroxidase activity. This suggests that RIAA inhibits inducible but not constitutive COX-2. In support, we found RIAA showed minimal PGE2 inhibition (IC50  = 21 μg/ml) relative to celecoxib (IC50  = 0.024 μg/ml), aspirin (IC50  = 0.52 μg/ml) or ibuprofen (IC50  = 0.57 μg/ml) in the AGS gastric mucosal model, where COX-1 and -2 are expressed constitutively. Taken together these results predict RIAA may have lower potential for gastrointestinal and cardiovascular toxicity observed with COX enzyme inhibitors. Following confirmation of bioavailable RIAA administered orally, gastrointestinal safety was assessed using the fecal calprotectin biomarker in a 14-day human clinical study; RIAA (900 mg/day) produced no change compared to naproxen (1000 mg/day), which increased fecal calprotectin 200%. Cardiovascular safety was addressed by PGI-M measurements where RIAA (1000 mg) did not reduce PGI-M or affect the urinary PGI-M/TXB2 ratio. Drug interaction potential was evaluated against six major CYPs; of relevance, RIAA inhibited CYP2C9. Toxicity was assessed in a 21-day oral, mouse subchronic toxicity study where no dose dependent histopathological effects were noted. Clinically, RIAA (1000 mg/day) produced a 54% reduction in WOMAC Global scores in a 6-week, open-label trial of human subjects exhibiting knee osteoarthritis.
Keywords: Humulus lupulus L.; Cannabidaceae; Hops; Rho iso-alpha-acids; NSAID; Anti-inflammatory; Cyclooxygenase; PGE2; Prostaglandin; Knee osteoarthritis; Calprotectin;

Muscarinic receptor binding activity of polyoxygenated flavones from Melicope subunifoliolata by L.Y. Chung; K.F. Yap; S.H. Goh; M.R. Mustafa; Z. Imiyabir (1548-1554).
Six polymethoxyflavones [melibentin (1); melisimplexin (3); 3,3′,4′,5,7-pentamethoxyflavone (4); meliternatin (5); 3,5,8-trimethoxy-3′,4′,6,7-bismethylenedioxyflavone (6); and isokanugin (7)] and one furanocoumarin [5-methoxy-8-geranyloxypsoralen (2)] were isolated. Compounds 2 and 6 were isolated for the first time from Melicope subunifoliolata. The muscarinic receptor binding activities of these compounds were investigated.The bark extract of Melicope subunifoliolata (Stapf) T.G. Hartley showed competitive muscarinic receptor binding activity. Six polymethoxyflavones [melibentin (1); melisimplexin (3); 3,3′,4′,5,7-pentamethoxyflavone (4); meliternatin (5); 3,5,8-trimethoxy-3′,4′,6,7-bismethylenedioxyflavone (6); and isokanugin (7)] and one furanocoumarin [5-methoxy-8-geranyloxypsoralen (2)] were isolated from the bark extract. Compounds 2 and 6 were isolated for the first time from M. subunifoliolata. The methoxyflavones (compounds 1, 3, 4, 5, 6, and 7) show moderate inhibition in a muscarinic receptor binding assay, while the furanocoumarin (compound 2) is inactive. The potency of the methoxyflavones to inhibit [3H]NMS-muscarinic receptor binding is influenced by the position and number of methoxy substitution. The results suggest these compounds are probably muscarinic modulators, agonists or partial agonists/antagonists.
Keywords: Melicope subunifoliolata; Rutaceae; Flavonoid; Muscarinic receptor;

Fingerprint profile of Ginkgo biloba nutritional supplements by LC/ESI-MS/MS by S. Ding; E. Dudley; S. Plummer; J. Tang; R.P. Newton; A.G. Brenton (1555-1564).
The effectiveness of fingerprint in quality control of plant extract is a very important issue. In this paper we describe a fingerprint profile method using a capillary HPLC/MS method which can identify more than 70 components from the Ginkgo biloba product. The fingerprint profiles of five commercial G. biloba nutritional supplements were obtained and compared. Ginkgo biloba is one of the most popular herb nutrition supplements, with terpene lactones and flavonoids being the two major active components. A fingerprint profile method was developed using a capillary HPLC/MS method which can identify more than 70 components from the G. biloba product. The method allows the flavonoids and terpene lactones to be detected simultaneously and information of both the parent ion and its fragmentation can be obtained in just one HPLC/MS run. Targeted post-acquisition analysis allows mass spectrometric information regarding the identification of flavonoid components to be easily distinguished from other data, however the same approach for terpene lactones was less successful due to dimer formation and requires further development. The fingerprint profiles of five commercial G. biloba nutritional supplements were obtained and compared; variation of some components among the samples was observed and fortification could be detected. In the quality control analysis of the G. biloba product this method could be viewed as complementary to specific quantitative analysis of some bioactive components of the herb.
Keywords: Fingerprint; Ginkgo biloba; Flavonoids; Terpene lactones;

Steroidal saponins and pseudoalkaloid oligoglycoside from Brazilian natural medicine, “fruta do lobo” (fruit of Solanum lycocarpum) by Seikou Nakamura; Masako Hongo; Sachiko Sugimoto; Hisashi Matsuda; Masayuki Yoshikawa (1565-1572).
Steroidal saponins, lyconosides Ia, Ib, II, III, and IV and a steroidal pseudoalkaloid oligoglycoside, lobofrutoside, were isolated from a Brazilian natural medicine, “fruta do lobo” (the fruit of Solanum lycocarpum St. Hil.). The structures of the constituents were elucidated on the basis of chemical and physicochemical evidence.Steroidal saponins, lyconosides Ia, Ib, II, III, and IV and a steroidal pseudoalkaloid oligoglycoside, lobofrutoside, were isolated from a Brazilian natural medicine, “fruta do lobo” (the fruit of Solanum lycocarpum St. Hil.). The chemical structures of these compounds were elucidated on the basis of analysis of chemical and physicochemical evidence.
Keywords: Solanum lycocarpum; Solanaceae; Brazilian natural medicine; Steroidal saponin; Steroidal pseudoalkaloid oligoglycoside; Wolf-fruit; Lyconoside; Lobofrutoside;

Rhamnoarabinosyl and rhamnoarabinoarabinosyl side chains as structural features of coffee arabinogalactans by Fernando M. Nunes; Ana Reis; Artur M.S. Silva; M. Rosário M. Domingues; Manuel A. Coimbra (1573-1585).
Coffee beans contain 7% of a water soluble highly branched type II arabinogalactan-protein (AGP) having rhamnoarabinosyl and rhamnoarabinoarabinosyl side chains. These side chains are reported for the first time as structural features of plant AGPs.The hot water soluble green coffee arabinogalactans, representing nearly 7% of total coffee bean arabinogalactans, were characterized by 1H and 13C NMR and, after partial acid hydrolysis, by ESI-MS/MS. Data obtained showed that these are highly branched type II arabinogalactans covalently linked to proteins (AGP), with a protein moiety containing 10% of 4-hydroxyproline residues. They possess a β-(1 → 3)-Galp/β-(1 → 3,6)-Galp ratio of 0.80, with a sugars composition of Rha:Ara:Gal of 0.25:1.0:1.5, and containing 2 mol% of glucuronic acid residues. Beyond the occurrence of single α-l-Araf residues and [α-l-Araf-(1 → 5)-α-l-Araf-(1→] disaccharide residues as side chains, these AGPs contain unusual side chains at O-3 position of the β-(1 → 6)-linked galactopyranosyl residues composed by [α-l-Rhap-(1 → 5)-α-l-Araf-(1→] and [α-l-Rhap-(1 → 5)-α-l-Araf-(1 → 5)-α-l-Araf-(1→] oligosaccharides. Rhamnoarabinosyl and rhamnoarabinoarabinosyl side chains are reported for the first time as structural features of plant arabinogalactan-proteins.
Keywords: Coffee; Polysaccharides; Oligosaccharides; AGP; NMR; Mass spectrometry;

Euodionosides A–G: Megastigmane glucosides from leaves of Euodia meliaefolia by Miwako Yamamoto; Takeyuki Akita; Yuka Koyama; Etsuko Sueyoshi; Katsuyoshi Matsunami; Hideaki Otsuka; Takakazu Shinzato; Atsushi Takashima; Mitsunori Aramoto; Yoshio Takeda (1586-1596).
From leaves of Euodia meliaefolia, seven megastigmane glucosides (1–7) were isolated. The structures of euodionosides A–G (1–7) were established by the spectroscopic method and chemical evidence.From a 1-BuOH-soluble fraction of the MeOH extract of leaves of Euodia meliaefolia, collected in Okinawa, seven megastigmane glucosides, named euodionosides A–G, were isolated together with three known megastgmane glucosides, and two aliphatic and three phenolic compounds. Their structures were elucidated through a combination of spectroscopic analyses and application of the modified Mosher’s method.
Keywords: Euodia meliaefolia; Rutaceae; Euodionoside; Megastigmane glucoside; Modified Mosher’s method;

Triterpenoidal saponins from Hydrocotyle sibthorpioides by Hui-Chi Huang; Chia-Ching Liaw; Li-Jie Zhang; Hsi-Uo Ho; Li-Ming Yang Kuo; Ya-Ching Shen; Yao-Haur Kuo (1597-1603).
Oleanane-type triterpenoid saponins, hydrocosisaponins A–F (16), were isolated from Hydrocotyle sibthorpioides along with a known saponin, hydrocotyloside VII (7). Their structures were established by spectroscopic and chemical methods. The cytotoxic activity of saponins were evaluated several human tumor cell lines.Oleanane-type triterpenoidal saponins, hydrocosisaponins A–F (16), along with a known saponin, hydrocotyloside VII (7), were isolated from Hydrocotyle sibthorpioides. Their structures were established on the basis of spectroscopic analyses including NMR spectroscopic techniques (13C, 1H, COSY, HMQC, HMBC, TOCSY and NOESY). Biological evaluation established that saponins possessing four sugar units (three d-glucoses and one l-arabinose) (47) exhibited moderate cytotoxicity against KB, Daoy and WiDr human tumor cell lines.
Keywords: Hydrocotyle sibthorpioides; Umbelliferae; Oleanane-type triterpenoidal saponin; Cytotoxicity; Chemotaxonomy;

Chemistry and weak antimicrobial activities of phomopsins produced by mangrove endophytic fungus Phomopsis sp. ZSU-H76 by Zhongjing Huang; Xiaoling Cai; Changlun Shao; Zhigang She; Xuekui Xia; Yiguang Chen; Jianxiang Yang; Shining Zhou; Yongcheng Lin (1604-1608).
Three metabolites named phomopsin A (1), B (2) and C (3), together with two known compounds cytosporone B and C, were isolated from the mangrove endophytic fungus, Phomopsis sp. ZSU-H76. Their antimicrobial activities were tested.Three metabolites named phomopsin A (1), B (2) and C (3), together with two known compounds cytosporone B (4) and C (5), were isolated from the mangrove endophytic fungus, Phomopsis sp. ZSU-H76 obtained from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly by 1D and 2D NMR spectroscopic techniques. The medium-sized cyclic phenol ether based on 1 or 2 is rare in natural products. In bioassays, compounds 1, 2, and 3 had no significant antibiotic activities, but compounds 4 and 5 inhibited two fungi Candida albicans and Fusarium oxysporum with an MIC ranging from 32 to 64 μg/ml.
Keywords: Mangrove; Excoecaria agallocha; Euphorbiaceae; Endophytic fungus; Metabolites; Phomopsis sp.; Antimicrobial activity;

Triterpenoid saponins from the fruits and galls of Sapindus mukorossi by Hui-Chi Huang; Ming-Der Wu; Wei-Jern Tsai; Sin-Chung Liao; Chia-Ching Liaw; Li-Chuan Hsu; Yang-Chang Wu; Yao-Haur Kuo (1609-1616).
Four new oleanane-type saponins (1-4) and two new dammarane-type saponins (5 and 6), along with seven known saponins (7-13) were isolated from Sapindus mukorossi. Biological evaluation exhibited that oleanane-type saponins showed moderate cytotoxicity.Six saponins, sapinmusaponin K (1) [hederagenin-3-O-(3-O-acetyl-α-l-arabinopyranosyl)-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)-α-l-arabinopyranoside], sapinmusaponin L (2) [hederagenin-3-O-(4-O-acetyl-α-l-arabinopyranosyl)-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)-α-l-arabino-pyranoside], sapinmusaponin M (3) [hederagenin-3-O-(2,3-O-diacetyl-β-d-xylopyranosyl)-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)-α-l-arabinopyranoside], sapinmusaponin N (4) [hederagenin-3-O-(2,4-O-diacetyl-β-d-xylopyranosyl)-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)-α-l-arabinopyranoside], sapinmusaponin O (5) [3,7,20(S)-trihydroxydammar-24-ene-3-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside], and sapinmusaponin P (6) [3,7,20(R)-trihydroxydammar-24-ene-3-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranoside], along with seven known saponins (713), were isolated from fruits and the galls of Sapindus mukorossi. Their structures were elucidated by 1D and 2D NMR spectroscopic techniques and acid hydrolysis. Biological evaluation indicated that saponins 14 and 713 showed moderate cytotoxicity against several human tumor cell lines.
Keywords: Sapindus mukorossi; Sapindaceae; Oleanane-type saponins; Dammarane-type saponins; Cytotoxic activity;

Oligosaccharide polyester and triterpenoid saponins from the roots of Polygala japonica by Jing Fu; Li Zuo; Jingzhi Yang; Ruoyun Chen; Dongming Zhang (1617-1624).
An oligosaccharide polyester (1) and four triterpenoid saponins (25) along with five known compounds were isolated from the roots of Polygala japonica. Their structures were determined by 1D and 2D NMR spectroscopy, chemical methods and by comparison with data reported in the literature.An oligosaccharide polyester, 1-O-(E)-p-coumaroyl-(3-O-benzoyl)-β-d-fructofuranosyl-(2 → 1)-[6-O-(E)-feruloyl-β-d-glucopyranosyl-(1 → 2)]-[6-O-acetyl-β-d-glucopyranosyl-(1 → 3)-(4-O-acetyl)-β-d-glucopyranosyl-(1 → 3)]-4-O-[4-O-α-l-rhamnopyranosyl-(E)-p-coumaroyl]-α-d-glucopyranoside (polygalajaponicose I), and four triterpenoid saponins, 3β, 23, 27-trihydroxy-29-O-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranosyl-olean-12-en-28-oic acid (polygalasaponin XLVII), 3-O-β-d-glucopyranosyl presenegenin 28-O-α-l-rhamnopyranosyl-(1 → 2)-β-d-fucopyranosyl ester (polygalasaponin XLVIII), 3-O-β-d-glucopyranosyl presenegenin 28-O-β-d-galactopyranosyl-(1 → 5)-β-d-apiofuranosyl-(1 → 4)-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-β-d-glucopyranosyl ester (polygalasaponin XLIX) and 2β, 27-dihydroxy-3-O-β-d-glucopyranosyl 11-oxo-olean-12-en-23, 28-dioic acid 28-O-β-d-galactopyranosyl-(1 → 5)-β-d-apiofuranosyl-(1 → 4)-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-β-d-fucopyranosyl ester (polygalasaponin L), in addition to five known compounds have been isolated from the roots of Polygala japonica.
Keywords: Polygala japonica; Polygalaceae; Oligosaccharide polyester; Triterpenoid saponins; Polygalajaponicose; Polygalasaponin;