Bio-Guided Isolation of New Compounds from Baccharis spp. as Antifungal against Botrytis cinerea.

Baccharis genus Asteraceae is widely used in traditional treatment against fever, headache, hepatobiliary disorders, skin ulcers, diabetes, and rheumatism, as well as an antispasmodic and diuretic. Its phytochemistry mainly shows the presence of flavonoids and terpenoids such as monoterpenes, sesquiterpenes, diterpenes, and triterpenes. Some of them have been evaluated for biological activities presenting allelopathic, antimicrobial, cytotoxic, and anti-inflammatory properties. In this paper, our research group reported the isolation, characterization, and antifungal evaluation of several molecules isolated from the dichloromethane extract from Baccharis prunifolia, Baccharis trinervis, and Baccharis zumbadorensis against the phytopathogen fungus Botrytis cinerea. The isolated compounds have not previously been tested against Botrytis, revealing an important source of antifungals in the genus Baccharis. Six known flavones were isolated from B. prunifolia. The dichloromethane extracts of B. trinervis and B. zumbadorensis were subjected to a bio-guided isolation, obtaining three known flavones, an α-hydroxidihydrochalcone mixture, one labdane, one triterpene, and two norbisabolenes from the most active fractions. The compounds 4'-methoxy-α-hydroxydihydrochalcone (7A), 3ß,15-dihydroxylabdan-7-en-17-al (8), and 13-nor-11,12-dihydroxybisabol-2-enone (11) are novel. The most active compounds were the Salvigenin (5) and 1,2-dihydrosenedigital-2-one (10) with an IC50 of 13.5 and 3.1 µg/mL, respectively.

Artificial Triterpenoid Fatty Acid Ester Isolated From the Leaves of Phytolacca icosandra L.

The methanol extract form the leaves of Phytolacca icosandra L., afforded the unprecedented artificial triterpenoid fatty acid ester 1 derived from the new natural triterpenoid phytolaccagenic acid 3-O-myristate (1a), along with the three known triterpenoids serjanic, acinosolic and phytolaccagenic acid (2 - 4). Their structures were stablished by HR-EI-MS, 1D and 2D NMR techniques. The possible mechanistic formation of 1 is proposed, and the in vitro toxicity of all compounds was assessed using the brine shrimp lethality assay (BSLA).

Icosandrin, a novel peltogynoid from the fruits of Phytolacca icosandra (Phytolaccaceae).

Besides the known compounds ( ± ) 3,3-bis-demethylpinoresinol (2), americanol A (3), spergulagenic acid (4), epi-acetylaleuritolic acid (5), 6'-palmityl-α-spinateryl-d-glucoside (6a) and 6'-palmityl-δ(7)-stigmastenyl-d-glucoside (6b), a novel peltogynoid (1) named icosandrin was obtained from the dried fruits of Phytolacca icosandra. This new compound was characterised by 1D-/2D-NMR, UV, IR and HR-MS techniques as 11ξ-methoxy-6,7-methylenedioxy-[2]benzopyrano-[4,3-b][1]-benzopyran-4-one. Toxicity of 1 was assessed through the Brine Shrimp Lethality Assay. Lignan 2 is reported for the first time in Phytolaccaceae family.

Acylated oleanane-type saponins from Ganophyllum giganteum.

Five oleanane-type saponins, 3-O-ß-D-glucuronopyranosylzanhic acid 28-O-ß-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-ß-D-fucopyranosyl ester (1), 3-O-ß-D-glucopyranosylzanhic acid 28-O-ß-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-ß-D-fucopyranosyl ester (2), zanhic acid 28-O-ß-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-ß-D-fucopyranosyl ester (3), zanhic acid 28-O-α-L-rhamnopyranosyl-(1→2)-4-O-[(3'-hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyroyloxy]-ß-D-fucopyranosyl ester (4), medicagenic acid 28-O-α-L-rhamnopyranosyl-(1→2)-4-O-[(3'-hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyroyloxy]-ß-D-fucopyranosyl ester (5), were isolated from the root barks of Ganophyllum giganteum. Compounds 4 and 5 possessed an unusual substitution of the C-4 position of the ß-D-fucopyranosyl moiety by a C10 ester group formed by two symmetrical C5 nilic acid. From a chemotaxonomic point of view, their structures are in accordance with the previous saponins isolated from the Doratoxyleae tribe of the Sapindaceae family. Their cytotoxicity and anti-inflammatory activity were also evaluated.

Vasorelaxant effects in aortic rings of eight diterpenoids isolated from three Venezuelan plants

Vasorelaxant activity Vasorelaxant effects of eight diterpenoids isolated from three Venezuelan plants [(+)-manool [(+)-labda-8(17),14-dien-13-ol], (+)-manoyl oxide, (+)-2-oxomanoyl oxide, sandaracopimara-8(14), 15-dien-3β, 19-diol, jhanidiol acetate (18-acetoxy-1βhydroxymanoyl oxide), jhanidiol (1β,18-dihydroxymanoyl oxide), ent-kaur-16-en-19ol and grandiflorenic acid (ent-kaur-9(11),16-dien-19-oic acid)] aortic rings were assessed in intact endothelium and endothelium-denuded isolated rat. Thw cumulative addition (10-6 to 10-4 M) of each product were carried out after contraction with phenylephrine (10-6 M). Jhanidiol acetate and ent-kaur-9,16-en-19-oic acid at 10-4 M dose concentration, exhibit the maximal vasorelaxant effect in endothelium-intact rings (51.61 ± 7.62% and 79.27 ± 7.41%, respectively). In endothelium-denuded aortic rings, the maximum vascular response exerted by both compounds was not abolished (64.14 ± 5.64% and 84.84 ± 3.62%, respectively). In denuded aortic rings, the half-maximal inhibitory concentration (IC50) Jhanidiol was obtained by the ethyl less than those obtained in rings endothelium (1.09 × 10-4 vs 7.29 × 10-5 M, respectively), although this difference was not significant. These results suggested that the mechanism behind the vasorelaxant effect of the two diterpene is mediated by endothelium-independent pathways.

Xanthones from aerial parts of Hypericum laricifolium Juss.

From the aerial parts of Hypericum laricifolium Juss., twelve compounds were isolated and identified. They were the xanthones: 1-hydroxy-7-methoxy-xanthone (1), 1,7-dihydroxy-xanthone (2), 2-hydroxy-xanthone (3), 6-deoxyisojacareubin (4), 1,3-dihydroxy-6-methoxy-xanthone (6), and 1,5,6-trihydroxy-7-methoxy-xanthone (7), together with beta-sitosterol, betulinic acid, vanillic acid, isoquercitrin and a mixture of quercetin and isorhamnetin. All the compounds were characterized by spectroscopic and mass spectrometric methods, and by comparison with literature data. Thisis the first report on the presence of xanthones in H.laricifolium. 1,3-Dihydroxy-6-methoxy-xanthone has been previously synthesized, but this is the first report of its isolation from a natural source.

Steroidal saponins from the fruits of Cestrum ruizteranianum.

Seven spirostane and furostane-type glycosides were isolated from the aqueous methanolic extract of the fruits of Cestrum ruizteranianum and characterized mainly by 2D NMR spectroscopy and mass spectrometry. These known saponins belong to the delta5-spirostene and delta5-furostene series and are reported in this species for the first time.

Triterpene saponins from the fruits of Phytolacca rugosa (Phytolaccaceae).

Four known serjanic acid glycosides were isolated from the fruits of Phytolacca rugosa and characterized mainly by 2D NMR spectroscopy and mass spectrometry. This aglycon has a chemotaxonomic significance for the genus Phytolacca.