Longifoamide-A and B: Two new ceramides from Mentha longifolia (Lamiaceae)

Two new N-acylsphingosines (ceramides) named longifoamide A {6'-tetracosenamide, (6'-Z)-N-[2,3-dihydroxy-1-(hydroxymethyl)octadecyl]} and B {6'-tetracosenamide, (6'-Z)-N-[2,3,4-trihydroxy-1-(hydroxymethyl)octadecyl]} were isolated from a methanol extract of Mentha longifolia. Both ceramides were characterized with the aid of 1D and 2DNMR spectroscopic techniques and high resolution mass spectrometry.     

Mentha longifolia subsp. typhoides and subsp. schimperi: Antimicrobial and Antiquorum-Sensing Bioactivities

Chemistry of Natural Compounds -     

Free and Glycosidically Bound Volatiles of Mentha longifolia Growing in Croatia

The glycosides of volatile compounds and the essential oil were isolated from wild Mentha longifolia. After the enzymatic hydrolysis of glycosides, fourteen volatile aglycones were identified by GC/MS. The main aglycones were eugenol, 2-phenylethanol, benzyl alcohol, lavandulol, trans- and cis-carveol, 3-octanol, and 3-hexen-1-ol. The content of aglycones was 40.85 mg kg^-1 of dried plant material. The main components of the essential oil (yield 0.93 w/w) were carvone, piperitenone oxide, limonene, and -caryophyllene. Eugenol, carveol, 3-octanol, and -terpineol were identified in the aglycones and in the essential oil.     

Guaianolides from Salvia nubicola (Lamiaceae)

A new sesquiterpene-lactone (nubenolide) belonging to the guaianolide class along with its acetate (nubenolide acetate) and a dimer (bisnubenolide) have been isolated from Salvia nubicola collected from Quetta, Pakistan. Structures of all three new metabolites were elucidated with the aid of spectroscopic techniques including 2D-NMR. However, the structure of nubenolide was finally confirmed via single-crystal X-ray diffraction method.     

New Glycosides from Salvia moorcroftiana (Lamiaceae)

From the MeOH extract of Salvia moorcroftiana Wall. (Lamiaceae), four new compounds, the two flavonoid glycosides genkwanin 4′‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐galactopyranoside] ( 1 ) and genkwanin 4′‐[O‐α‐L ‐arabinopyranosyl‐(1→3)‐α‐L ‐rhamnopyranoside] ( 2 ), and the two benzene derivatives 4‐hydroxy‐2‐isopropyl‐5‐methylphenyl O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucopyranoside ( 3 ) and nonyl 4‐hydroxybenzoate ( 4 ), were isolated in addition to two known compounds. The structures of all new compounds were determined by 1D and 2D homonuclear and heteronuclear NMR spectroscopy and by comparison with published data.     

Two new xanthone diglycosides from Swertia longifolia Boiss

From aerial parts of Swertia longifolia Boiss., which grows in the north of Iran, five xanthones, two of which in diglycosidic form, were isolated. The structures were confirmed by means of their spectral data as isobellidifolin, bellidin, gentisein, 1,5-dihydroxy-3-methoxy-6-O-primeverosyl xanthone, and 8-hydroxy-3,5-dimethoxy-1-O-primeverosyl xanthone, the latter two of which were new derivatives in the plant kingdom.     

Glaucolide-A and -B,new germacranolide-type sesquiterpene lactones from Vernonia (compositae)

The structures of two new germacranolides, glaucolide-A (1a) and -B (1b), isolated from more than 25 species of Vernonia from the Western Hemisphere, have been established by a series of chemical transformations, and spectral and X-ray crystallographic studies.     

Eurycomaoside: a new quassinoid-type glycoside from the roots of Eurycoma longifolia

A new C(19)-quassinoid-type glycoside has been isolated from the roots of Eurycoma longifolia. The structure elucidation of the compound was achieved by a combination of one- and two-dimensional NMR techniques, including (1)H-(1)H-correlation spectroscopy (COSY), (1)H-(13)C-heteronuclear correlation spectroscopy (HMQC), and (1)H-(13)C-heteronuclear multiple-bond correlation spectroscopy (HMBC), as well as high resolution electrospray ionization Fourier transformation mass spectrometry (HR-ESI-FT-MS) data. The C(1)-glycosidation site in the quassinoid framework is encountered for the first time.     

Essential oil composition, antimicrobial and cytotoxic activities of two endemic Stachys cretica subspecies (Lamiaceae) from Turkey

The chemical compositions of the water-distilled essential oil of Stachys cretica ssp. lesbiaca Rech. fil. and S. cretica ssp. trapezuntica Rech. fil. were determined by GC and GC-MS. Altogether 63 compounds were identified. The sesquiterpene hydrocarbon, germacrene D (20.3% and 12.9% respectively) was the main component identified in both oils. Furthermore, ethanol, light petroleum, dichloromethane, ethyl acetate and n-butanol extracts prepared from the aerial parts of the plants were tested for their antimicrobial activities against six bacterial strains and the yeast Candida albicans. The extracts exhibited no antibacterial activity, but the light petroleum and n-butanolic fractions showed low antifungal activities. Crude ethanolic extracts of the two subspecies were tested for their ability to inhibit the growth of HL-60 and Ishikawa human tumor cell lines. The IC50 values were 100 microg/mL for the HL-60 cell line and 200 microg/mL for the Ishikawa cell line.     

Iridoid and phenylethanoid glycosides from Phlomis longifolia var. longifolia

From the aerial parts of Phlomis longifolia var. longifolia four iridoid glucosides, shanzhiside methyl ester (1), 5-deoxypulchelloside I (2), lamalbide (3), phlomiol (4) and three phenylethanoid glycosides, verbascoside (5), forsythoside B (6), leucosceptoside A (7) along with the caffeic acid ester, chlorogenic acid (8) were isolated. The structures of the isolated compounds were established by spectroscopic (UV, IR, 1D- and 2D-NMR, FABMS) and chemical evidence. The structure elucidation of the iridoid compounds 2 and 3 are discussed in detail.     

A new preparative method for isolating cerebrosides and sphinogosine bases from cattle brain

Summary A new preparative method for the isolation of the cerebrosides and sphingosine bases from cattle brain is proposed.M. M. Shemyakin Institute of Bioorganic Chemistry, Academy of Sciences of the USSR, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 285–289, May–June, 1976.     

Determination of polyphenols in Mentha longifolia and M. piperita field-grown and in vitro plant samples using UPLC-TQ-MS

Nine polyphenols in the aerial parts of Mentha longifolia have been separated by chromatographic techniques. Their structures have been confirmed by HPLC/electrospray ionization-MS/MS. The compounds identified included rosmarinic acid, salvianolic acid L, dedihydro-salvianolic acid, luteolin-glucuronide, luteolin-diglucuronide, luteolin-glucopyranosyl-rhamnopyranoside, and eriodictyol-glucopyranosyl-rhamnopyranoside. The extracts of M. longifolia and M. piperita field plants, in vitro plants, callus tissues, and cell suspension cultures were profiled, and their polyphenol composition was compared in different tissues and quantified using ultra-performance column liquid chromatography (UPLC)/triple-quadrupole-MS in the selected-ion recording detection mode. Determination of desired compounds was based on calibration curves obtained for standards, which were previously isolated from M. longifolia aerial parts. The UPLC profiles revealed considerable differences in the synthesis of secondary metabolites among samples coming from field plants, in vitro plants, callus tissues, and cell suspension cultures. Plant tissues coming from field cultivation (for both M. piperita and M. longifolia) contained several phenolic compounds (flavonoids and phenolic acids), whereas plants from in vitro conditions, callus tissues, and suspension cultures contained only a few of them. Rosmarinic acid dominated in all of these samples. These results show that under in vitro conditions, the metabolism of phenolics undergoes a fundamental change.     

A new preparative method for isolating cerebrosides and sphinogosine bases from cattle brain

A new preparative method for the isolation of the cerebrosides and sphingosine bases from cattle brain is proposed.     

Isolation and total syntheses of two new alkaloids, dubiusamines-A, and -B, from Pandanus dubius

Chemical investigation of the crude base of Pandanus dubius led to the isolation of two new alkaloids, dubiusamine-A (1) and dubiusamine-B (2). The structures of the two alkaloids including their absolute configuration were unambiguously confirmed by 1D and 2D NMR analysis and asymmetric total synthesis.     

Bioactive Abietane-Type Diterpenoid Glycosides from Leaves of Clerodendrum infortunatum (Lamiaceae)

In this study, two previously undescribed diterpenoids, (5R,10S,16R)-11,16,19-trihydroxy-12-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-17(15→16),18(4→3)-diabeo-3,8,11,13-abietatetraene-7-one (1) and (5R,10S,16R)-11,16-dihydroxy-12-O-β-d-glucopyranosyl-(1→2)-β-d-glucopyranosyl-17(15→16),18(4→3)-diabeo-4-carboxy-3,8,11,13-abietatetraene-7-one (2), and one known compound, the C₁₃-nor-isoprenoid glycoside byzantionoside B (3), were isolated from the leaves of Clerodendrum infortunatum L. (Lamiaceae). Structures were established based on spectroscopic and spectrometric data and by comparison with literature data. The three terpenoids, along with five phenylpropanoids: 6′-O-caffeoyl-12-glucopyranosyloxyjasmonic acid (4), jionoside C (5), jionoside D (6), brachynoside (7), and incanoside C (8), previously isolated from the same source, were tested for their in vitro antidiabetic (α-amylase and α-glucosidase), anticancer (Hs578T and MDA-MB-231), and anticholinesterase activities. In an in vitro test against carbohydrate digestion enzymes, compound 6 showed the most potent effect against mammalian α-amylase (IC₅₀ 3.4 ± 0.2 μM) compared to the reference standard acarbose (IC₅₀ 5.9 ± 0.1 μM). As yeast α-glucosidase inhibitors, compounds 1, 2, 5, and 6 displayed moderate inhibitory activities, ranging from 24.6 to 96.0 μM, compared to acarbose (IC₅₀ 665 ± 42 μM). All of the tested compounds demonstrated negligible anticholinesterase effects. In an anticancer test, compounds 3 and 5 exhibited moderate antiproliferative properties with IC₅₀ of 94.7 ± 1.3 and 85.3 ± 2.4 μM, respectively, against Hs578T cell, while the rest of the compounds did not show significant activity (IC₅₀ > 100 μM).     

Abietanes and a Novel 20‐Norabietanoid from Plectranthus cyaneus (Lamiaceae)

Antioxidative‐activity‐guided fractionation of extracts of the aerial parts of the title plant yielded the two novel abietanoid diterpenoids 11,20‐dihydroxysugiol (=11,12,20‐trihydroxyabieta‐8,11,13‐trien‐7‐one; 3 ) and 1,11‐epoxy‐6,12‐dihydroxy‐20‐norabieta‐1(10),5,8,11,13‐pentaen‐7‐one ( 4 ) in addition to 11‐hydroxysugiol (=12‐O‐demethylcryptojaponol=11,12‐dihydroxyabieta‐8,11,13‐trien‐7‐one; 2 ) and the main constituent carnosolon (=6,20‐epoxy‐6,11,12‐trihydroxyabieta‐8,11,13‐trien‐7‐one; 1 ). The structures were established on the basis of spectroscopic, chiroptic, and X‐ray crystallographic evidence.     

Paeonilactone-A, -B,and -C,new monoterpenoids from paeony root

Three new monoterpenoids named paeonilactone-A, -B, and -C were isolated from Paeony root (roots of Paeonia albiflora PALLAS var. trichocarpa BUNGE) and their structures were determined to be $\text{2}$, $\text{3}$, and $\text{4}$, respectively, by means of chemical and spectroscopic studies.     

Clerodendrumol,A New Triterpenoid from Clerodendrum yaundense Gürke (Lamiaceae)

A new lupane‐type triterpene named clerodendrumol ( 1 ), i.e., (16α)‐lupa‐12,20(29)‐dien‐16‐ol, together with five known compounds, octacosa‐(5Z,9Z)‐dienoic acid ( 3 ), tetracosanoic acid ( 4 ), genkwanin ( 5 ), (12S)‐hydroxyoctadeca‐(9Z,13E,15E)‐trienoic acid ( 6 ), and (9S)‐hydroxyoctadeca‐(10E,12E)‐dienoic acid ( 7 ), were isolated from the twigs of Clerodendrum yaundense. O‐Acetylclerodendrumol ( 2 ), a derivative of 1 , was prepared by a standard acetylation procedure applied to compound 1 . The structure of the new compound was elucidated using spectroscopic analysis (NMR and MS) data, and chemical conversions (acetylation and deacetylation). The human breast cancer cell line (MDA‐MB‐231) was sensitive to all test samples, and clerodendrumol ( 1 ) as well as its derivative 2 had good activity (IC₅₀ values 7.5 and 13.2 μM ). Genkwanin ( 5 ) exhibited strong activity on HeLa cell line with IC₅₀ 7.8 μM .