(+)-Piperitol from Paulownia tomentosa

The Mosquito Larvicidal Activity of Lignans from Branches of Cinnamomum camphora chvar. Borneol

The chemical investigation of branches of Cinnamomum camphora chvar. Borneol guided by mosquito larvicidal activity led to the isolation of fourteen known lignans (1-14). Their structures were elucidated unambiguously based on comprehensive spectroscopic analysis and comparison with the literature data. This is the first report of these compounds being isolated from branches of Cinnamomum camphora chvar. Borneol. Compounds 3-5 and 8-14 were isolated from this plant for the first time. All compounds isolated were subjected to anti-inflammatory, mosquito larvicidal activity and cytotoxic activity evaluation. Compounds (1-14) showed significant mosquito larvicidal activity against Culex pipiens quinquefasciatus with lethal mortality in 50% (LC₅₀), with values ranging from 0.009 to 0.24 μg/mL. Among them, furofuran lignans(1-8) exhibited potent mosquito larvicidal activity against Cx. p. quinquefasciatus, with LC₅₀ values of 0.009-0.021 μg/mL. From the perspective of a structure-activity relationship, compounds with a dioxolane group showed high mosquito larvicidal activity and have potential to be developed into a mosquitocide.

Paulownia Organs as Interesting New Sources of Bioactive Compounds

Paulownia spp. is a genus of trees in the Paulowniaceae family. It is native to southeastern Asia (especially China), where it has been cultivated for decorative, cultural, and medicinal purposes for over 2000 years. Depending on taxonomic classification, there are 6 to 17 species of Paulownia; P. tomentosa, P. elongata, P. fortunei, and P. catalpifolia are considered the most popular. Nowadays, Paulownia trees are planted in Asia, Europe, North America, and Australia for commercial, medical, and decorative purposes. Lately, growing interest in Paulownia has led to the development of various hybrids, the best-known being Clone in vitro 112, Shan Tong, Sundsu 11, and Cotevisa 2. Paulownia Clone in vitro 112 is an artificially created hybrid of two species of Paulownia: P. elongata and P. fortunei. The present review of selected papers from electronic databases including PubMed, ScienceDirect, and SCOPUS before 15 November 2022 describes the phytochemical characteristics, biological properties, and economic significance of various organs from different Paulownia species and hybrids, including P. tomentosa, P. elongata, P. fortunei, and Paulownia Clone in vitro 112. Many compounds from Paulownia demonstrate various biological activities and are promising candidates for natural preparations; for example, the leaves of Clone in vitro 112 have anti-radical and anticoagulant potential. However, further in vivo studies are needed to clarify the exact mechanism of action of the active substances and their long-term effects.

Phytochemical characteristics of Paulownia trees wastes and its use as unconventional feedstuff in animal feed

Due to the continuous increase in animal feed prices, and the presence of competition between humans and animals on food materials, it is imperative to identify other non-food plant resources to assist the animal feed industry and improve livestock productivity. Plant wastes may cause air, soil, and water pollution. However, if judiciously managed, they would be important resources. Plant wastes are used as feedstuffs and fertilizers. However, their use as animal feed is more useful than fertilizers. Because of the high content of fiber and non-protein N, these wastes are more valuable for feeding ruminants than poultry. The use of the plant wastes as feedstuffs could improve the environmental quality and profits for feed producers. Paulownias are fast-growing trees initially cultivated for wood production. However, due to their good nutritive value, their leaves have been used for ruminants, non-ruminants animals and poultry feeding. Furthermore, they are well-known for its medicinal and antibacterial properties. However, little is still known about its characteristics. This review aimed at providing detailed information about the nature, nutritional value, phytochemicals, and uses of Paulownia as a promising feedstuff in the fields of ruminants, non-ruminants, and poultry nutrition.

Geranylated flavanones from Paulownia coreana and their inhibitory effects on nitric oxide production

The activity-guided fractionation of the MeOH extract of the flower of Paulownia coreana led to the isolation of a new geranylated flavanone, 3'-O-methyl-5'-hydroxydiplacol (1), along with 10 known compounds (2-11). Their structures were determined using spectroscopic techniques, which included one and two dimensional (1- and 2D)-NMR. Among the isolates, compounds 1-6 showed potent inhibitory activities against lipopolysaccharide (LPS)-induced nitric oxide production with IC50 values ranging 1.48 to 16.66 µM.

New prenylated carbazole alkaloids from Zanthoxylum armatum

A phytochemical investigation on the ethyl acetate soluble fraction of Zanthoxylum armatum led in the isolation of two new prenylated alkaloids 2,6,7-trimethoxy-8-(3-methyl-2-butenyl)carbazole-3-carbaldehyde (1) and methyl-2,6,7-trimethoxy-8-(3-methyl-2-butenyl)carbazole-3-carboxylate (2), along with three known lignans cisamin (3), methyl pirpirtol (4), and fargesin (5) and one known alkaloid dictamine (6). Their structures were established on the basis of spectroscopic and crystallographic analysis and by comparison of the data with those in the literature. All the isolated compounds were screened for the DPPH free radical scavenging activity. Compounds 1, 2, and 6 showed profound activity while compounds 3-5 showed moderate activity.

Phytochemical profile of Paulownia tomentosa (Thunb). Steud

Paulownia tomentosa, a member of the plant family Paulowniaceae and a rich source of biologically active secondary metabolites, is traditionally used in Chinese herbal medicine. Flavonoids, lignans, phenolic glycosides, quinones, terpenoids, glycerides, phenolic acids, and miscellaneous other compounds have been isolated from different parts of P. tomentosa plant. Recent interest in this species has focused on isolating and identifying of prenylated flavonoids, that exhibit potent antioxidant, antibacterial, and antiphlogistic activities and inhibit severe acute respiratory syndrome coronavirus papain-like protease. They show cytotoxic activity against various human cancer cell lines and inhibit the effects of human cholinesterase, butyrylcholinesterase, and bacterial neuraminidases. Most of the compounds considered here have never been isolated from any other species of plant. This review summarizes the information about the isolated compounds that are active, their bioactivities, and the structure-activity relationships that have been worked out for them.

Bioactive compounds from the roots of Asiasarum heterotropoides

A new tetrahydrofuran lignan, (7S,8R,7'S,8'S)-3-methoxy-3',4'-methylenedioxy-7,9'-epoxylignane-4,7',9-triol (1), and 21 known compounds 2–22 were isolated from the roots of Asiasarum heterotropoides by chromatographic separation methods. The structures of all compounds 1–22 were elucidated by spectroscopic analysis including 1D- and 2D-NMR. Fourteen of these compounds (1–3, 7, 10, 12–17, 19, 21, and 22) were isolated from this species in this study for the first time. All of the isolates were evaluated for their anticancer activities using in vitro assays. Among the 22 tested compounds, two (compounds 5 and 7) induced the downregulation of NO production, FOXP3 expression, and HIF-1α transcriptional activity.

Geranylated flavanones from the secretion on the surface of the immature fruits of Paulownia tomentosa

Chemical investigation of the methanol extract of the viscous secretion on the surface of immature fruits of Paulownia tomentosa furnished nine geranylated flavanones, 6-geranyl-5,7-dihydroxy-3',4'-dimethoxyflavanone (1), 6-geranyl-3',5,7-trihydroxy-4'-methoxyflavanone (2), 6-geranyl-4',5,7-trihydroxy-3',5'-dimethoxyflavanone (3), 6-geranyl-4',5,5',7-tetrahydroxy-3'-methoxyflavanone (4), 6-geranyl-3,3',5,7-tetrahydroxy-4'-methoxyflavanone (5), 4',5,5',7-tetrahydroxy-6-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]-3'-methoxyflavanone (6), 3,3',4',5,7-pentahydroxy-6-[6-hydroxy-3,7-dimethyl-2(E),7-octadienyl]flavanone (7), 3,3',4',5,7-pentahydroxy-6-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]flavanone (8), and 3,4',5,5',7-pentahydroxy-3'-methoxy-6-(3-methyl-2-butenyl)flavanone (9), along with six known geranylated flavanones. Among these, compounds 4, 6-9 and the known 6-geranyl-3',4',5,7-tetraahydroxyflavanone (diplacone), 6-geranyl-3,3',4',5,7-pentahydroxyflavanone (diplacol) and 3',4',5,7-pentahydroxy-6-[7-hydroxy-3,7-dimethyl-2(E)-octenyl]flavanone showed potent radical scavenging effects towards DPPH radicals.

An antiviral furanoquinone from Paulownia tomentosa Steud

A methanol extract of the stem bark of Paulownia tomentosa showed antiviral activity against poliovirus types 1 and 3. Sequential liquid-liquid extraction with n-hexane, chloroform and water, and a silicagel column chromatography resulted in the purification of a compound. The compound was identified as methyl-5-hydroxy-dinaphthol[1,2-2',3']furan-7,12-dione-6-carbox yla te on the basis of spectroscopic data. The component caused a significant reduction of viral cytopathic effect when it was subjected to a standard antiviral assay by using HeLa cells. The EC(50) of the compound against poliovirus type 1 strain Brunhilde, and type 3 strain Leon were 0.3 microg/mL and 0.6 microg/mL, respectively.

Antibacterial phenylpropanoid glycosides from Paulownia tomentosa Steud

The butanol extract of Paulownia tomentosa stem showed antibacterial activity against Staphylococcus aureus (SG511, 285 and 503), Streptococcus pyogenes (A308 and A77) and Streptococcus faecium MD8b etc. The most active compound of the extract was identified to be campneoside I, which had a minimal inhibitory concentration (MIC) of 150 micrograms/ml against Streptococcus and Staphylococcus species. From such antibacterial activity, the methoxy group of campneoside I was postulated to be the essential element for the antibacterial activity.