biological evaluation and studies of linear diarylheptanoids from Salisb. as urease inhibitors.

Plants of the family, specifically those belonging to the species, are commonly under consideration as potential therapeutic agents for the management of gastrointestinal diseases. In this study, we carried out a phytochemical study on Salisb. (or so-called "Nghe trang" in Vietnamese) grown in Vietnam, which yields three newly discovered 3,5-diacetoxy diarylheptanoids (1-3) and six known 3,5-dihydroxyl diarylheptanoids (4-9).

Four new species of (Sonerileae, Melastomataceae) from Vietnam.

is a genus currently treated in the polyphyletic . Recent phylogenomic analyses have identified a morphologically cohesive lineage referred to as the (raphides) clade, which should be excluded from and treated as a distinct genus under the name . Morphological and phylogenomic data have confirmed that four new species collected from Vietnam are part of the (raphides) clade.

Historical development of karst evergreen broadleaved forests in East Asia has shaped the evolution of a hemiparasitic genus (Orobanchaceae).

is a shrubby genus of about eight species distributed basically in East Asian evergreen broadleaved forests (EBLFs), with distribution centers in the karst regions of Yunnan, Guizhou, and Guangxi in southwestern China. Based on the hemiparasitic and more or less liana habits of this genus, we hypothesized that its evolution and distribution were shaped by the development of EBLFs there. To test our hypothesis, the most comprehensive phylogenies of hitherto were constructed based on plastome and nuclear loci (nrDNA, PHYA and PHYB); then divergence time and ancestral areas were inferred using the combined nuclear loci dataset.

Exceptionally well-preserved crocodilian coprolites from the Late Eocene of Northern Vietnam: Ichnology and paleoecological significance.

This study examines 55 coprolites from the Na Duong Basin to reconstruct the paleoenvironment. Coproecology sheds light on understanding the complex prey-predator relationships, trophic dynamics, and ecosystem evolution. Through quantitative and multidisciplinary analysis, the putative coprolites were attributed to crocodilian producers, leading to the establishment of a new ichnogenus and species, igen.

Three new species of (Sonerileae, Melastomataceae) from the Sino-Vietnamese border area.

, , and (Sonerileae, Melastomataceae), three species occurring in Sino-Vietnamese limestone karst regions, are described as new. Molecular phylogenetic analyses and morphological divergence indicate that these species are well separated from their close relatives in , justifying their recognition as distinct species. is unique in its interveinal areas prominently bullate each with an apical seta, a character otherwise never recorded in the genus.

 (Gesneriaceae), a new species from north-western Vietnam.

(Gesneriaceae), a new species from the limestone area in Son La Province, north-western Vietnam, is described here. The new species resembles , but it differs by the combination of corolla tube shape, stamens number and the length of pistil. Detailed morphological description, together with photographic plates, information on phenology, distribution, ecology and preliminary conservation status of the new species are presented.

A New abeo-Icetexane-Type Diterpenoid from the Stem Barks of Taxus wallichiana.

From a CH Cl -soluble fraction of the stem barks of Taxus wallichiana, one new abeo-icetexane-type diterpenoid, taxamairin I (1), was isolated. Its absolute configuration was elucidated based on spectroscopic interpretation and time-dependent density functional theory (TD-DFT) calculation of optical rotation. In addition, the plausible biosynthesis pathway for the formation of the new abeo-icetexane-type diterpenoid was proposed.

Paratrimerin Z, an undescribed chromene derivative from the roots of .

From an EtOAc-soluble fraction of the roots of , one undescribed chromene derivative, paratrimerin Z (), was isolated. Its structure was elucidated on the basis of NMR spectroscopic interpretation. The absolute configuration of was determined by the specific rotation analysis of its acid-catalyzed hydrolysis product.

Leaf fossils of (Arecaceae) from the Oligocene of northern Vietnam and their paleoclimatic implications.

Recent paleobotanical investigations in Vietnam provide a good opportunity to improve our understanding of the biodiversity and paleoclimatic conditions in the geological past of Southeast Asia. Palms (Arecaceae) are a diverse family of typical thermophilous plants with a relatively low tolerance for freezing. In this study, we describe well-preserved fossil palm leaves from the Oligocene Dong Ho Formation of Hoanh Bo Basin, northern Vietnam.

Out of chaos: Phylogenomics of Asian Sonerileae.

Sonerileae is a diverse Melastomataceae lineage comprising ca. 1000 species in 44 genera, with >70% of genera and species distributed in Asia. Asian Sonerileae are taxonomically intractable with obscure generic circumscriptions.

 (Gesneriaceae), a new species from central Vietnam.

, a new species of Gesneriaceae from central Vietnam, is described and illustrated here. The new species is most similar to by sharing peduncles up to 22 cm long, bracts 2, zygomorphic, yellow flowers with tubular corolla, stamens 4 with two pairs of coherent anthers and capsules up to 6 cm long. It mainly differs from the latter by the combination of some morphological characters of leaves (shape, base, apex and margin), size of calyx lobes, indumentum of corolla tube and inner surface of three lower corolla lobes.

-Tocopherol derivatives from the leaves of L.

From an ethyl acetate-soluble fraction of the leaves of , one new trimeric -tocopherol derivative named as tocomuntin A (), together with three known -tocopherol derivatives (-) were isolated. Their structures were elucidated based on the interpretation of NMR and MS spectroscopic data. In this work, -tocopherol () was found to have -glucosidase inhibitory activity for the first time (IC, 47.

When tropical and subtropical congeners met: Multiple ancient hybridization events within Eriobotrya in the Yunnan-Guizhou Plateau, a tropical-subtropical transition area in China.

Global climate changes during the Miocene may have created ample opportunities for hybridization between members of tropical and subtropical biomes at the boundary between these zones. Yet, very few studies have explored this possibility. The Yunnan-Guizhou Plateau (YGP) in Southwest China is a biodiversity hotspot for vascular plants, located in a transitional area between the floristic regions of tropical Southeast Asia and subtropical East Asia.

A new diphenylheptanoid from the rhizomes of .

A phytochemical investigation of the rhizomes of  was carried out, leading to the isolation of a new diphenylheptanoid, zedoaroxane A (), together with four known compounds (-). Their structures were elucidated based on NMR spectroscopic data. All isolated compounds possessed -glucosidase inhibitory activity, with the IC values ranging from 35.

(Gesneriaceae), a new species from Son La Province, northern Vietnam.

, a new species from Son La Province, northern Vietnam, is described and illustrated. The phylogenetic study revealed that the new species is most closely related to and . The morphological comparison suggests it as the third new species of and distinguished from and by a combination of morphological characters of leaf blades, bracts, calyx and corolla, especially its peltate leaf blades.

Decumbic anhydride from the stem barks of (Anacardiaceae).

From an EtOAc-soluble fraction of the stem barks of (Anacardiaceae), decumbic anhydride () and four known compounds - were isolated. Their chemical structures were elucidated based on the spectroscopic data interpretation. The GIAO-DFT calculation of C NMR chemical shifts was carried out to clarify the structure of .

Paratrimerin I, cytotoxic acridone alkaloid from the roots of .

Bioactivity-guided fractionation of the CHCl-soluble extract of the roots of was carried out to obtain a new acridone alkaloid, paratrimerin I. Its structure was elucidated based on NMR spectroscopic data interpretation. Paratrimerin I showed noteworthy cytotoxicity against the HepG2 human hepatocellular and MCF-7 human breast carcinoma cell lines, with the submicromolar IC values of 0.

(Gesneriaceae), a new lithophilous dwelling genus and species with zigzag corolla tube from southern Vietnam.

, a new genus from southern Vietnam is described with a single species, . The new genus is morphologically most similar to and but it differs from the latter two by having four fertile stamens. Nuclear ribosomal internal transcribed spacer (ITS) region and plastid intron spacer () DNA sequence data from the new genus and eighty-seven species representing 42 genera within tribe Didymocarpeae are used to resolve its generic placement.

A new phenylheptanoid from the leaves of L.

Phytochemical study on the EtOAC-soluble extract of the leaves of furnished the isolation of a new phenylheptanoid, gnetumal (), along with five known compounds (-). Their isolation was carried out by using the column chromatography and their structures were elucidated based on the basis of the spectral interpretation. Bioactivity assay of these compounds indicated that gnetumal () and -coumaric acid () possessed more potent tyrosinase inhibitory activity, with IC values of 31.

Three new fossil records of (Equisetaceae) from the Neogene of south-western China and northern Vietnam.

Three fossil species of (Equisetaceae) were reported from the Neogene of south-western China and northern Vietnam, based on well-preserved rhizomes with tubers. Equisetum cf. pratense Ehrhart from the middle Miocene of Zhenyuan County, Yunnan Province, China is characterised by a bunch of three ovate tubers with longitudinal ridges on the surface.

A new phenolic acid from the wood of .

From the methanol extract of the wood of (Anacardiaceae), we had isolated a new secondary metabolite named gedebic acid () and six known compounds (). Their chemical structures were determined by spectroscopic methods as well as comparing with data in the literature. All compounds were tested for -glucosidase inhibitory activity.

(Gesneriaceae), a new species from East Guangxi, China.

A new species, F.Wen, B.Pan & T.

Checklist to the (Urticaceae) of Vietnam including 19 new records, ten new combinations, two new names and four new synonyms.

(Urticaceae) comprises several hundred herbaceous species distributed in tropical and subtropical Africa, Asia, Australia and Oceania. The greatest species richness occurs on limestone karst in Southeast Asia. Taxonomic revisions of are largely out of date and contradict each other with respect to the delimitation of and Most herbaria in SE Asia and worldwide contain significant amounts of unidentified material.

(Gesneriaceae), a new species from Vietnam.

, a new species from Vietnam is described and illustrated with photographs. The new species is morphologically similar to and , but can be easily distinguished by a combination of characters. So far, five species have been recorded in the genus from Vietnam.

Tyrosinase inhibitory activity of flavonoids from Artocarpus heterophyllous.

Background: Tyrosinase is an oxidoreductase that is very important in medicine and cosmetics because the excessive production of melanin causes hyperpigmentation. The development of novel, effective tyrosinase inhibitors has long been pursued. In preliminary tests, we found that an extract of the wood of Artocarpus heterophyllous (AH) potently inhibited tyrosinase activity.