Velutinalide C,a New Polycyclic Phragmalin Limonoid from the Leaves of Chukrasia tabularis var. velutina

Velutinalide C ( 4 ), a new polycyclic phragmalin limonoid featuring a C(15)–C(21) linkage and a C₄ unit at C(15), together with two known related compounds, chukfuransins C and D ( 2 and 3 , resp.), was isolated from the leaves of Chukrasia tabularis var. velutina. The structure of the new compound 4 was elucidated on the basis of extensive spectroscopic analyses and comparison with literature data.     

New Phragmalin‐Type Limonoid Orthoesters from the Bark of Chukrasia tabularis var. velutina

Three new phragmalin‐type limonoid orthoesters, velutabularins K–M ( 1 – 3 ) and seven structurally related known compounds were isolated from the bark of Chukrasia tabularis var. velutina. The structures of these compounds were elucidated by spectroscopic analysis. The structure of 1 was confirmed by single crystal X‐ray diffraction. In addition, the brine shrimp lethality of compounds 1, 3 , and the known compounds was evaluated.     

Tabulvelutin A, the first 19-nor limonoid with unprecedented ring system from Chukrasia tabularis var. velutina

Tabulvelutin A (1), the first 19-nor limonoid incorporating a unique 7,10-γ-lactone, together with a biosynthetically related limonoid tabulvelutin B (2) was isolated from the stem bark of Chukrasia tabularis var. velutina. Their structures were elucidated by extensive spectroscopic analysis and chemical computation. The insecticidal activity of compounds 1 and 2 was also assessed.     

Chukvelutilides A-F, phragmalin limonoids from the stem barks of Chukrasia tabularis var. velutina

Chukvelutilides A-F (1-6), a new class of C-15-acyl phragmalin type limonoids, featuring a C-16/C-30 δ-lactone ring, were isolated from Chukrasia tabularis var. velutina. These compounds are suggested to possess a three- or four-carbon enolized acyl substituent at C-15 through a plausible biosynthetic origin. Their structures were elucidated by extensive spectroscopic means, and that of 1 was confirmed by single-crystal X-ray diffraction.     

Rastronole A,B, C,D, E,F, G und H; eine Gruppe multioxygenierter Diterpenbitterstoffe der ent-Kauran-Reihe aus Englerastrum scandens ALSTON

Rastronols A, B, C, D, E, F, G, and H, a group of multioxygenated bitter principles with ent-kaur-16-en-15-one structure from Englerastrum scandens ALSTON (Labiatae) We have isolated from the leaves of Englerastrum scandens from Kenya eight new, highly oxygenated ent-kaur-16-en-15-ones named rastronol A, B, C, D, E, F, G, and H, and determined their structures mainly by spectroscopic techniques as 1, 8, 14, 17, 20, 29, 39 , and 51 respectively.     

Five New Quassinoids from the Bark of Picrasma quassioides

Five new quassinoids, named picraqualides A–E ( 1 – 5 ), together with eleven known ones, nigakilactone E ( 6 ), nigakilactone F ( 7 ), kusulactone ( 8 ), javanicin U ( 9 ), 12‐norquassin ( 10 ), quassin ( 11 ), 2,3‐didehydropicrasin B ( 12 ), nigakilactone B ( 13 ), nigakilactone C ( 14 ), picrasin B ( 15 ), and simalikalacton C ( 16 ), were isolated from the EtOH extract of the bark of Picrasma quassioides (D. Don ) Benn . Their structures were determined mainly by spectroscopic methods, especially by 2D‐NMR techniques and circular dichroism (CD). Some empirical rules were summarized on the basis of ¹³C‐NMR spectral analysis to distinguish between OH (or Ac) groups attached at C(11) vs. C(13).     

New Diterpene Alkaloids from Aconitum sungpanense var. leucanthum

Five new C₁₉ diterpene alkaloids, leucanthumsines A ( 1 ), B ( 2 ), C ( 3 ), D ( 4 ), and E ( 5 ), were isolated from the Chinese medicinal herb Aconitum sungpanense var. leucanthum, together with the known C₁₉ diterpene alkaloids pseudaconine, neoline, 1‐O‐methyldelphisine, crassicaudine, chasmanine, talatisamine, indaconitine, ezochansmanine, and leueantine D. The structures of these new alkaloids were elucidated by HR‐MS and advanced NMR methods, including ¹H‐ and ¹³C‐NMR (DEPT), ¹H,¹H‐COSY, HMQC, and HMBC experiments.     

New Anthraquinone and Iridoid Glycosides from the Stems of Hedyotis hedyotidea

Five new anthraquinone glycosides, hedanthrosides A–E ( 1 – 5 , resp.) and two new iridoid glycosides, hediridosides A and B ( 6 and 7 , resp.), along with two known anthraquinones and four known iridoids, were isolated from the stems of Hedyotis hedyotidea (DC.) Merr . The structures of the new compounds were elucidated on the basis of 1D‐ and 2D‐NMR, and HR‐MS analysis and chemical methods.     

Five New C19‐Diterpenoid Alkaloids from Aconitum hemsleyanum

Five new C₁₉‐diterpenoid alkaloids, named hemsleyaconitines A–E ( 1 – 5 , resp.), were isolated from Aconitum hemsleyanum Pritz. By UV, IR, MS, 1D‐ and 2D‐NMR analyses, their structures were elucidated as 18‐dehydroxygeniculatine D ( 1 ), 6‐hydroxy‐14‐O‐veratroylneoline ( 2 ), 14‐O‐acetyl‐8‐ethoxysachaconitine ( 3 ), 18‐veratroylkaracoline ( 4 ) and 8‐O‐ethylaustroconitine B ( 5 ).     

New cyclopeptides from Trichoderma polysporum (Link ex Pers.) Rifai: cyclosporins B, D and E (author's transl)

New Cyclopeptides from Trichoderma polysporum (LINK EX PERS .) RIFAI : Cyclosporins B, D and E Cyclosporins represent a new group of biologically active metabolites produced by Trichoderma polysporum (LINK EX PERS .) RIFAI and other fungi imperfecti. The structures of the main components, cyclosporins A ( 1 ) and C( 3 ) have been determined as neutral cyclic oligopeptides composed of 11 amino acids, among them a new C₉-amino acid [2–4]. In addition, three minor metabolites, cyclosporins B, D and E, have now been isolated and characterized. Chemical investigation, spectroscopic evidence and X-ray analysis led to the structural formulae of cyclosporins B (2) and D (4) . Both compounds have the same sequence of amino acids as cyclosporin A (1) , with the exception of L -α-aminobutyric acid, replaced in cyclosporin B (2) by L -alanine and in cyclosporin D (4) by L -valine, respectively. Cyclosporins undergo a characteristic intramolecular N,O-acyl migration to furnish the corresponding basic isocompounds. The antifungal activities of cyclosporins are reported.     

Studies on Monoterpene Glucosides and Related Natural Products Part 51. Absolute Structures of Hydrangenosides A,B, C,D, E,F, and G. Novel Type Secoiridoid Glucosides from Two Hydrangea Plants

From Hydrangea macrophylla var. Macrophylla, four new secoiridoid glucosides, hydrangenosies A, B, C and D, were isolated, along with the known iridoid glucosides loganin, secologanin, secologanic acid and sweroside. Moreover, hydrangenosides E, F, and G, the glucosides of the same class, were isolated together with hydrangenosides C and D from Hydrangea Scandens. Based on spectroscopic and chemical methods, the novel structures of the new glucosides consisting of secologanin and a shikimate-malonate-derived unit which are joined by a C? C bond were elucidated. However, seven other Hydrangea plants were tested and found not to contain hydrangenoside-type glucosides.     

Triterpenoids from the Edible Leaves of Photinia serrulata

Five new triterpenoids, serrulatins A–E ( 1 – 5 ), including two new artifacts, together with ten known serrulatins, were isolated from the edible leaves of Photinia serrulata after extraction and purification. Their structures were identified on the basis of spectroscopic methods including 2D NMR experiments. Compounds 1 and 3 are unusual ursolic triterpenoids characterized by the occurrence of a C(13)?C(18) bond.     

人面果树皮中口 山 酮 化合物及其DPPH自由基的清除活性

从人面果乙酸乙酯提取物中分离出5个新的口 山 酮 化合物garcinenone A (1), B (3), C (4), D (7) and E (8)和7个已知化合物,其结构经过波谱技术,特别是2D-NMR技术来鉴定。Jacareubin (2), 1,4,6-trihydroxy-5-methoxy-7-(3-methyl-2-buteny1)xanthone (6), subeliptenone B (11) 和symphoxanthone (12)为首次从该植物中分离出来。在DPPH自由基的清除活性实验中,所有的化合物都显示抗氧化活性,其IC50的值在 6.0-23.2 mM。结果表明人面果是潜在的有前景的天然抗氧化剂。     

4-dehydroxyepisarcovagine A,a new steroidal alkaloid from Sarcococca pruniformis Lindl.

A new steroidal alkaloid, 4-dehydroxyepisarcovagine A (1), along with seven known alkaloids, sarcovagine D (2), sarcovagenine C (3), epoxysarcovagenine D (4), Pachysamine L (5), Pachysamine E (6), sarcovagine A (7) and sarcovagine B (8), was isolated from the roots and stems of Sarcococca pruniformis Lindl. The structure of compound 1 was elucidated by means of spectroscopic analysis.     

Steroidal Saponins from the Rhizomes of Smilacina henryi

Five steroidal saponins, namely henryiosides A–E ( 1 – 5 ), were isolated from the EtOH extract of the rhizomes of Smilacina henryi. Their structures were elucidated by the extensive use of 1D‐ and 2D‐NMR experiments, along with HR‐MALDI‐MS analysis and the results of acid hydrolysis. The aglycones of henryiosides A–E possess a C(7)?C(8) or C(9)?C(11) bond and were not previously found in saponins.     

Furanone Derivatives from Aspergillus sp. XW‐12, an Endophytic Fungus in Huperzia serrata

Two new 5‐methoxyfuran‐3(2H)‐one derivatives, huaspenone A ( 1 ) and B ( 2 ), together with four known ones, i.e., aspertetronin A ( 3 ), aspertetronin B ( 4 ), gregatin E ( 5 ), and penicilliol A ( 6 ), were isolated from the cultures of an endophytic fungus Aspergillus sp. XW‐12, derived from the stems of Huperzia serrata. The structures of the new isolates were established by detailed interpretation of the 1D‐ and 2D‐NMR and HR‐ESI‐MS data.     

Pseurotin B,C, D,and E. Further New Metabolites of Pseudeurotium ovalis STOLK

The structures 2–5 are assigned to the pseurotin B, C, D and E, which are new metabolites of Pseudeutorium ovalis STOLK , based on spectroscopic data and chemical transformations.     

Velutabularins A-J, phragmalin-type limonoids with novel cyclic moiety from Chukrasia tabularis var. velutina

Velutabularins A-J, ten novel phragmalin-type limonoids, were isolated from the stem bark of Chukrasia tabularis var. velutina. In structures of 1-6, the tetrahydrofuran ring from dehydration of OH-15 and OH-17, ring C and 13/14/18-cyclopropanyl moiety formed an unprecedented 8-oxatricyclo[4,3,1^1,6]decane. Compounds 7-10 are derivates of 1-6 opening the tetrahydrofuran ring. All of these compounds possess a novel C-16/C-30 δ-lactone ring, which were reported in phragmalins rarely. The structures of these novel compounds were elucidated based on extensive 1D and 2D spectroscopic analysis. The absolute configuration of 5 and 9 were determined by the calculated electronic circular dichroism (ECD) method. The anti-inflammatory activities of major compounds (2, 4, 5, 9) were evaluated for inhibitory activity against lipopolysaccharide (LPS) induced nitric oxide (NO) production in macrophage (RAW264.7) cell line.     

Five New Steroidal Glycosides from Caralluma dalzielii

Five new pregnane glycosides, caradalzielosides A–E ( 1 – 5 ), were isolated from the aerial parts of Caralluma dalzielii. Their structures were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic analysis as well as by HR‐FAB‐MS experiments.     

Tabularisins A-D, phragmalin ortho esters with new skeleton isolated from the seeds of Chukrasia tabularis

Tabularisins A-D (1-4), a new class of phragmalins incorporating a cyclopropanyl ring, were isolated from Chukrasia tabularis. Compounds 1 and 2 are also the first examples of phragmalins with an 8,9,11-ortho ester. The structures of 1 and 3 were confirmed by single crystal X-ray studies. The absolute configuration of 2 was determined by CD exciton chirality method on its benzoate (2a), and those of 1, 3, and 4 were proposed by correlating with 2 chemically and biogenetically.