Chemical constituents of Bulbophyllum wendlandianum (Kraenzl.) Dammer and their chemotaxonomic significance

Phytochemical investigation of Bulbophyllum wendlandianum (Kraenzl.) Dammer led to the isolation of twenty-three compounds 1–23 (flavanthrinin 1, coelonin 2, lusianthridin 3, densiflorol B 4, plicatol B 5, batatasin-lll 6, gigantol 7, 5-hydroxy-3,3′-dimethoxy-2-(p-hydroxybenzyl) bibenzyl 8, 2,2-dimethyl-5-hydroxy-6-carboxy-7-(2-phenylethyl) 9, tristin 10, p-hydroxybenzyl ethyl ether 11, p-hydroxybenzaldehyde 12, hydroquinone 13, coniferaldehyde 14, p-hydroxybenzyl alcohol 15, 3,4-dihydroxy benzaldehyde 16, stigmasterol 17, β-sitosterol 18, ergosterol peroxide 19, (+)pinoresinol 20, n-butyl sulfoxide 21, tridec-4E-en-l-yl acetate 22, ethyl linolate 23) including five phenanthrenes 1–5, five bibenzyls 6–10, six phenols 11–16, three sterols 17–19, one lignan 20, one n-butyl sulfoxide 21 and two fatty acids 22–23. The structures of these compounds were elucidated by spectroscopic analyses. This is the first report of isolation of compounds 1–23 from Bulbophyllum wendlandianum and compounds 8–9, 11, 13, 15–16 and 19–23 within genus Bulbophyllum. Compound 21 is a new natural product, isolated from a natural source for the first time. Furthermore, the chemotaxonomic significance of the isolates was also discussed.     

Secondary metabolites from Sterculia lychnophora Hance (Pangdahai)

From the ethanolic extracts of dried seeds of Sterculia lychnophora Hance Pierre (Malvaceae), a total of twenty-two (22) compounds were isolated. These included one lignan (1), three phenylpropanoids (5–6, 21), two flavonoid glycosides (8–9), two sesquiterpenoids (3, 17), two nucleosides (10, 12), three nitrogenous bases (4, 7, 14), three phenolic acids (2, 13, 20), two heterocyclic aromatic acids (11, 16) and two phytosteroids (18–19). For eighteen out of the 22 compounds, there is no report of their presence in S. lychnophora. There is no report of sixteen of them being present in the Sterculia genus, hence the first report. The isolated compounds showed a significant taxonomic relationship between S. lychnophora and other species of genus Sterculia. Compounds 13 and 20 might serve as important taxonomic markers for the Sterculia genus.     

Chemical constituents from the flower buds of Daphne genkwa (Thymelaeaceae)

Phytochemical investigation on the flower buds of Daphne genkwa led to the isolation of 22 compounds, including 17 daphne diterpenes (1–17), three tigliane types (18–20), and two diphenylpentanes (21–22). Compounds 19–21 were isolated from D. genkwa for the first time. These compounds were elucidated using spectroscopic methods and by comparing their data to those reported in the literature. On the basis of chemical research, the chemotaxonomic significance of the isolated compounds were discussed.     

Chemical constituents from Melodinus cochinchinensis (Lour.) Merr. and their chemotaxonomic significance

A phytochemical investigation on the twigs and leaves of Melodinus cochinchinensis (Lour.) Merr. resulted in the isolation and identification of 22 compounds, including seven sesamin-type lignans (1–7), three pentacyclic triterpenes (8–10), one anthraquinone (11), one flavanone (12), two phenolic compounds (13 and 14), five aspidosperma-type indole alkaloids (15–19), and three eburnan-type indole alkaloids (20–22). The structures of these compounds were elucidated by means of spectroscopic analysis, including HREIMS together with 1D and 2D NMR experiments, and comparison with reported data. Among them, compounds 1/4, 2/5, and 3/6 are three pairs epimers at C-7''. Compounds 1–6, 8 and 11 were firstly isolated from the family Apocynaceae, whereas 17 was isolated from Melodinus species for the first time. Compound 8 was only found in Juglans hopeiensis, while 11 was only found in roots of Rubia cordifolia. Compounds 1–6, 8, 11 and 15–22 could be considered as chemotaxonomic markers for M. cochinchinensis. Furthermore, the chemotaxonomic significance and distribution of these isolates in Melodinus genus are discussed in detail.     

New withanolides from a cross of a South African chemotype by chemotype II (Israel) in Withania somnifera

Three new withanolides have been isolated from hybrids obtained by crossing a chemotype of Withania somnifera received from South Africa and chemotype II originating in Israel. The compounds have been characterized as 4β,20α-dihydroxy-1-oxo-5β,6β-epoxy-20R,22R-witha-24-enolide, 20α-hydroxy-1,4-dioxo-5β,6β-epoxy-20R,22R-witha-2,24-dienolide, and 20α-hydroxy-1,4-dioxo-5β,6β-epoxy-20R,22R-witha-2-enolide. The major steroid of the plant is withanolide D, while the other known withanolides present are 4β,20α-dihydroxy-1-oxo-5β,6β-epoxy-20R,22R,24S,25R-witha-2-enolide and withaferin A. The structures assigned to the new compounds are based on spectral evidence, analysis of their fragmentation under electron impact, and on chemical correlation with known compounds. The formation of these withanolides in this new hybrid is discussed briefly.     

Chemical constituents from the roots of Fallopia convolvulus (L.) A. Löve

Twenty compounds, including three sterols (1–3), three phenols (4, 14 and 15), four anthraquinones (5, 7, 8 and 16), one chromone (6), two stilbenes (9 and 10), three amides (11–13), three flavonoids (17–19) and one organic acid (20), were obtained by modern phytochemical isolation methods. Their structures were identified by spectroscopic methods and in comparison with the published data in the references. Among them, compound 2, 3, 11 and 13 were firstly discovered from genus Fallopia, and compounds 1, 5–8, 10, 14, 15, 17, 19 and 20 were obtained from F. convolvulus for the first time. The chemotaxonomic significance of these compounds was also discussed, which revealed the relationships between F. convolvulus and some other species of Polygonaceae family.     

Chemical constituents from Piper boehmeriifolium (Miq.) Wall. ex C. DC

The chemical investigation of whole plants Piper boehmeriifolium (Miq.) Wall. ex C. DC. led to the isolation of 22 compounds, including two lignans (1–2), sixteen amide alkaloids (3–18), one diterpene (19), two monoterpenes (20–21), and one phenylpropanoid (22). Their structures were elucidated by extensive spectroscopic analyses including NMR, MS, and by comparison with the literature. Compounds 1–2, 6–7, 11–12, 14, and 17–22 were firstly isolated from P. boehmeriifolium, while compounds 2, and 19–20 were isolated from Piper genus for the first time. The chemotaxonomic significance of these isolated compounds is discussed.     

Chemical constituents of Melodinus hemsleyanus diels

Phytochemical investigation on the aerial parts of Melodinus hemsleyanus diels (Jahrb, Syst, 1995) led to the isolation and identification of 27 compounds, including fifteen aspidosperma-type alkaloids (1–15), four quinoline-type alkaloids (16–19), three quebrachamine-type alkaloids (20–22), and five eburna-type alkaloids (23–27). The structure of compound 1 was elucidated by means of spectroscopic analysis, including HRESIMS, and 1D and 2D NMR experiments. Compounds 1–2, 6, 10, 12, 13, 15, 16 and 20–27 are herein reported for the first time from the studied plant, while the compounds 1–2 and 21 have not previously been recorded in the genus Melodinus. The aspidosperma-type monoterpenoid indole alkaloids in M. hemsleyanus could serve as chemotaxonomic markers.     

Phytochemical and chemotaxonomic studies on Dioscorea collettii

A chemical investigation of Dioscorea collettii led to the isolation of twenty-nine compounds, including six steroid saponins (1–6), thirteen monocyclic phenols (7–19), two flavonoids (20–21), three sterols (22–24), and five cyclodipeptides (25–29). The chemical structures of these compounds were elucidated using spectroscopic methods and by comparing their data to that reported in the literature. This study is the first report of compounds 2–4, 7, 14–17, 21, and 23–24 in D. collettii, while compounds 8–13, 18–20, and 25–29 were first isolated from the genus Dioscorea and the family Dioscoreaceae. The chemotaxonomic significance of the isolated compounds is discussed.     

The withanolides of Withania somnifera chemotypes I and II

Seven steroidal lactones of the withanolide series have been isolated as minor constituents of the leaves of Withania somnifera Dun. (Solanaceae) chemotype I, along with the major component withaferin A. Structures have been assigned to the new compounds: withanolide N (17α,27-dihydroxy-1-oxo-20R,22R-witha-2,5,14,24-tetraenolide) (6a) and withanolide O (4β,17α-dihydroxy-1-oxo-20R,22R-witha-2,5,8(14),24-tetraenolide) (7a). Similarly the leaves of W. somnifera chemotype II afforded three new withanolides along with the major component withanolide D (9a) and trace amounts of withanolide G (10). The new compounds are: 27-hydroxywithanolide D(4β,20α,27-trihydroxy-1-oxo-5β,6β-epoxy-20R,22R-witha-2,24-dienolide) (11a), 14α-hydroxywithanolide D (4β,14α,20α-trihydroxy-1-oxo-5β,6β-epoxy-20R,22R-witha-2,24-dienolide) (12a) and 17α-hydroxywithanolide D (4β,17β,20α-trihydroxy-1-oxo-5β,6β-epoxy-20S,22R-witha-2,24-dienolide) (13a). Whereas all the withanolides of chemotype I are unsubstituted at C-20 (20α-H), those of chemotype II possess an OH at this position (20α-OH).     

Chemical constituents from Hovenia dulcis Thunb. And their chemotaxonomic significance

Phytochemical investigations on the fruit stalks and seeds of the plant Hovenia dulcis Thunb. led to the isolation of twenty-one compounds, including three triterpenes (1–3), two sterols (4–5), five flavonoids (6–10), two sesquiterpenes (11–12), one lignan (13), two phenylpropanoids (14–15), four benzoic acid derivatives (16–19), one acid amide (20) and one cerebroside (21). The structures of these compounds were elucidated on the basis of spectroscopic analysis and comparison with previous literatures. Among them, ten compounds (4, 11–12, 14–20) were isolated from familiy Rhamnaceae, two (13, 21) from the genus Hovenia, and three (5, 8, 10) from the species Hovenia dulcis Thunb. for the first time, respectively. The chemotaxonomic significance of these isolates was also discussed.     

First Coffea arabica karyogram showing that this species is a true allotetraploid

Evolutive studies have verified that Coffea arabica (2n = 44) is a natural segmental allopolyploid originated from a cross between two diploid (2n = 22) Coffea species. Data obtained by classical cytogenetic analyses showed that C. arabica chromosomes are small and morphologically similar, which hampers the karyogram assembly with well-identified homologue pairs. In the present study, the C. arabica complement was reanalysed using an improved cytogenetic protocol that allowed the obtention of high-quality prometaphasic and metaphasic chromosomes. The results showed that chromosomes are cytogenetically distinct (1, 2, 19, 20, 21 and 22) and identical (3–4, 5–6, 7–8, 9–10, 11–12, 13–14, 15–16 and 17–18), with regard to their total length, short and long arm sizes or chromosome classes. Our work suggests that C. arabica is a true non-segmental allotetraploid but originated from different species exhibiting similar and distinct chromosomes.     

Chemical constituents of Chimaphila japonica Miq

A phytochemical study of the whole plants of Chimaphila japonica Miq. led to the isolation of 23 compounds, including ten triterpenoids (1–10), six flavonoids (11–16), two sterols (17 and 18), two quinonoids (19 and 20), one saccharide derivative (21), one phenolic glycoside (22), and one megastigmane glycoside (23). The structures of these isolated compounds were identified using NMR spectroscopy (¹H and ¹³C) by comparison with previously reported data. All compounds, except 19 and 22, were reported from C. japonica for the first time. Among them, 16 compounds (1–4, 6–9, 12, 13, 15, 16, 18, 20, 21, and 23) were reported from genus Chimaphila for the first time, while compounds 12, 16, and 23 were isolated from the Ericaceae family for the first time. The chemotaxonomic significance of the isolates was also discussed.     

Steroids and anthraquinones from the deep-sea-derived fungus Aspergillus nidulans MCCC 3A00050

Aspergillus nidulans MCCC 3A00050 was isolated from a deep-sea sediment sample of the western Pacific Ocean. A systematic investigation on its chemical constituents led to the isolation of 19 compounds, including 13 steroids (1–13), four anthraquinones (14–17), one phenolics (18), and one chromanone (19). For the first time, three diosgenins (1–3) were isolated from fungi, three ergosterols (4–6) from the genus of Aspergillus, while other 11 miscellaneous compounds (7–11 and 14–19) from the species of Aspergillus nidulans. The isolation of diosgenins (1–3) and ergosterols (4–6) might be used as chemotaxonomic markers for the genus of Aspergillus and the species of Aspergillus nidulans, respectively.     

Phytochemical and chemotaxonomic studies on Pteris wallichiana J. Agardh

A systematic phytochemical investigation of Pteris wallichiana J. Agardh resulted in the isolation of twenty compounds, including five sesquiterpenes (1–5), six flavonoids (6–11), seven phenolic acids (12–18) and two fatty acids (19 and 20). Their structures were deduced from MS, NMR and ORD data. This is the first report of compounds dehydropterosin B (2), (2R,3S)-pterosin C (4), (2R,3R)-pterosin L (5), apigenin (6), luteolin (7), luteolin-7-O-glucoside (10), caffeic acid (13), vanillin (14), 3,4-dihydroxybenzaldehyde (15), chlorogenic acid (17), 3,5-dicaffeoylquinic acid (18), suberic acid (19) and azelaic acid (20) from P. wallichiana and of compounds 15, 19 and 20 from the family Pteridaceae. Furthermore, a chemotaxonomic study of the isolates was performed.     

Biotransformation of ent-pimaradienoic acid by cell cultures of Aspergillus niger

Microbial transformation stands out among the many possible semi-synthetic strategies employed to increase the variety of chemical structures that can be applied in the search for novel bioactive compounds. In this paper we obtained ent-pimaradienoic acid (1, PA, ent-pimara-8(14),15-dien-19-oic acid) derivatives by fungal biotransformation using Aspergillus niger strains. To assess the ability of such compounds to inhibit vascular smooth muscle contraction, we also investigated their spasmolytic effect, along with another five PA derivatives previously obtained in our laboratory, on aortic rings isolated from male Wistar rats. The microbial transformation experiments were conducted at 30 °C using submerged shaken liquid culture (120 rpm) for 10 days. One known compound, 7α-hydroxy ent-pimara-8(14),15-dien-19-oic acid (2), and three new derivatives, 1β-hydroxy ent-pimara-6,8(14),15-trien-19-oic acid (3), 1α,6β,14β-trihydroxy ent-pimara-7,15-dien-19-oic acid (4), and 1α,6β,7α,11α-tetrahydroxy ent-pimara-8(14),15-dien-19-oic acid (5), were isolated and identified on the basis of spectroscopic analyses and computational studies. The compounds obtained through biotransformation (2–5) did not display a significant antispasmodic activity (values ranging from 0% to 16.8% of inhibition); however the previously obtained diterpene, methyl 7α-hydroxy ent-pimara-8(14),15-dien-19-oate (8), showed to be very effective (82.5% of inhibition). In addition, our biological results highlight the importance to study the antispasmodic potential of a large number of novel diterpenes, to conduct further structure–activity relationship investigations.     

Chemical constituents from Valeriana officinalis L. var. Iatifolia Miq. and their chemotaxonomic significance

Twenty-one compounds, including four monoterpenoids (1–4) (two new natural products, 1 and 2), four sesquiterpenes (5–8), two iridoids (9 and 10), four steroids (11–14), five phenolic compounds (15–19), and two alkaloids (20 and 21), were isolated from the roots of Valeriana officinalis L. var. Iatifolia Miq. Their chemical structures were established by spectroscopic methods and further confirmed by comparison with published data in the literature. Among them, eight compounds (1, 2, 6–8, 13, 18, and 21) are being reported from the family Valerianaceae for the first time, and compounds 9–12 were obtained from V. officinalis for the first time. The chemotaxonomic significance of the isolated compounds is discussed.     

Chemical constituents from the roots of Pteroxygonum giraldii Damme et Diels

Twenty-four compounds were obtained from Pteroxygonum giraldii and were classified as five triterpenes (1–5), two sterols (6 and 7), two quinones (8 and 11), three stilbenes (9, 10 and 18) and twelve flavonoids (12–17, 19–24). Seventeen of these compounds were obtained from the genus Pteroxygonum for the first time. The chemotaxonomic significance of this plant was also discussed. Compounds 10, 12 and 23 can serve as the fingerprints for P. giraldii, and compounds 12, 13, 17 and 22–24 are recognized as typical metabolites of P. giraldii. Both Pteroxygonum and Polygonum might have the same origin and could be classified into the same tribe among Polygonaceae. Furthermore, due to the presence of stilbenes, Pteroxygonum may have some taxonomic relationships with Fallopia, Rumex and Reynoutria.     

Chemical constituents isolated from Valeriana officinalis L

Phytochemical investigations on the leaves of Valeriana officinalis L. led to the isolation of 18 compounds, including eight lignans (1–8), three sesquiterpenoids (9–11), five iridoids (12–16), and two aldehydes (17–18) The structure elucidation of isolated compounds was achieved on the basis of NMR and mass spectral data. Among them, three compounds (9–16, 18) are reported from V. officinalis for the first time and one compound (5) was isolated from the genus Valeriana for the first time. In addition, six compounds (2, 4, 6–8, 17) are isolated for the first time from Valerianaceae family. The chemotaxonomic significance of these isolated compounds has also been discussed.