## 1 Introduction  
Fungal endophytes colonize plant species living throughout the Earth and form a balanced correlation with the host plants [1]. These fungi inter- or intracellularly reside in healthy plant tissues for a part or all of their life cycle without causing any disease sign to the host. Fungal endophytes are able to synthesize numerous metabolites classified into various groups such as alkaloids, coumarins, flavonoids, lignans, saponins, terpenes, quinones, and xanthones, which serve as prolific sources of antibiotic, anticancer, and antioxidant agents [1,2]. Brasilamide J from the ethyl acetate extracts of _Penicillium janthinellum_ isolated from _Panax notoginseng_ showed significant inhibition of the Gram-positive _B. subtilis_ and _S. aureus_ but not Gram-negative bacteria [3]. Two macrolides named myrotheines H and I were isolated from the crude extract of _Paramynothecium__rudium_, both of which displayed cytotoxicity against SF-268 (human glioblastoma), NCI-H460 (human non-small cell lung cancer), and HepG-2 (human liver cancer) cell lines [4]. The trend of finding bioactive compounds from endophytic fungi is becoming expansive, as the demand for using new and cheaper drugs is rapidly increasing.  
Xylariales is regarded as one of the most diverse groups of Ascomycota, with the abundant distribution expressed in robust growth in dead wood, plants, and nests of termites and ants [5]. Among them, the genus _Xylaria_ offers a potential framework of bioactive compounds indicated by the discovery of 445 compounds since 1994. _Xylaria_ cf. _curta_, isolated as an endophyte from potato stem tissue, produced xylarichalasin A that showed strong cytotoxicity against human breast adenocarcinoma (MCF-7) and human hepatocellular carcinoma (SMMC-7721) cancer cell lines, with IC\({}_{50}\) values of 6.3 uM and 8.6 uM, respectively [5]. Xylareremophil produced by the endophytic fungus _Xylaria_ sp. GDG-102 had antibacterial activity against _Microoccus luteus_ and _Proteus vulgaris_[6]. Notably, xylarglycosides A and B isolated from the _Illigera celebica_-derived fungus _Xylaria_ sp. KYJ-15 exhibited not only antibacterial activities against _S. aureus_ but also DPPH radical scavenging activity [7]. _Xylaria_ spp. have been considered for their antimicrobial activity as beneficial interactions between medicinal plants and endophytes in response to pathogens and stress conditions.  
_Keteleeria__evolyniana_ is one of the three currently existing _Keteleeria_ species in the world and classified as Vulnerable (VU) in the IUCN Red List [8]. Importantly, it is distributed in southwestern China, Laos, and Vietnam only and partly used for traditional medicine. In folk medicine, the bark or leaves of _K. evelyniana_ can be used as decoctions or ointments for pain relief and anti-inflammation. Essential oils isolated from Vietnamese _Keteleeria__evolyniana_ Mast are rich in \(\alpha\)-pinene and \(\beta\)-pinene, (E)-\(\beta\)-caryophyllene, limonene, and (E)-\(\beta\)-caryophyllene [9]. A previous study isolated 12 compounds that belonged to benzoic acid allopynosides and lignan glycosides from the twigs of _K. evelyniana_; however, no antibacterial and anticancer activities were detected [10]. In addition, bacteria associated with decaying sapwood and heartwood of _K. evelyniana_ were identified using 16S rRNA gene sequencing [11]. Therefore, the present study focused on isolation, screening, and characterization of bioactive compounds produced by endophytic fungi isolated from _K. evelyniana_. This study can be novel as fungal endophytes from _K. evelyniana_ have not been investigated yet.